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Characteristics of Peripapillary Choroidal Cavitation Detected by Optical Coherence Tomography
Characteristics of Peripapillary Choroidal Cavitation Detected by Optical Coherence Tomography Shu-I Yeh, MD,1,3 Wei-Chun Chang, MD,1,2 Chien-Hsiu Wu, MD,1,2 Yu-Wen Lan, MD,1,2 Jui-Wen Hsieh, MD,1,2 Shawn Tsai, MD,1,2 Lee-Jen Chen, MD1,2 Purpose: To evaluate the clinical features of peripapillary choroidal cavitation (PCC) detected by optical coherence tomography (OCT). Design: Retrospective, observational case series. Participants: One hundred twenty-two eyes from 83 patients diagnosed with PCC by OCT database review were included in this study. Methods: Stereoscopic color fundus photographs from eyes with PCC were reviewed by 2 independent ophthalmologists. They were masked to the refractive error, axial length, and OCT findings. Main Outcome Measures: Chart review and data analysis included gender, age, best-corrected visual acuity (BCVA), refractive error, axial length, clinical appearance of the peripapillary area, and associated funduscopic abnormalities. Results: One hundred twenty-two eyes with PCC from 83 patients were analyzed. Among the patients, 41.8% were men and 58.2% were women. The mean age was 48.2⫾12.6 years and mean BCVA in logarithm of the minimum angle of resolution units was 0.23⫾0.43. The mean refractive error in spherical equivalent was ⫺9.03⫾5.11 diopters (D) and mean axial length (AL) was 27.36⫾2.09 mm. With respect to refractive error, 90 eyes (73.8%) were highly myopic (ⱖ– 6.00 D), 24 eyes (19.7%) had low myopia (⬍⫺6.00 D), 5 eyes (4.1%) were emmetropic (1.00 to ⫺1.00 D), and 3 eyes (2.6%) were hyperopic (⬎1.00 D). Forty eyes (32.8%) with PCC had AL of less than 26.50 mm (mean, 25.11⫾1.07 mm; range, 22.51–26.42 mm). Patients with eyes with PCC that had low myopia, were emmetropic, and were hyperopic also were significantly older than patients with highly myopic eyes (P⬍0.05). Stereoscopic fundus photographs demonstrated a yellow-orange, localized, well-circumscribed peripapillary lesion in 57 (46.7%) eyes with PCC. A PCC with opening was observed in 14 (26.4%) of 53 eyes with excavated myopic conus and in 5 (7.2%) of 69 eyes without excavated myopic conus (P⬍0.05). Conclusions: This study demonstrated that peripapillary choroidal cavitation is common and not exclusive to highly myopic eyes. The funduscopic finding of a yellow-orange peripapillary abnormality may not be evident in all eyes with demonstrable PCC by OCT. Although its pathogenesis and pathologic significance require further investigation, PCC may be a degenerative change in aging eyes. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Ophthalmology 2013;120:544 –552 © 2013 by the American Academy of Ophthalmology.
Eye imaging has grown in importance for the diagnosis of ocular diseases. Optical coherence tomography (OCT) has emerged at the forefront of tissue imaging by providing high-resolution, cross-sectional, and complex 3-dimensional imaging of biological tissues.1 The advent of OCT in ophthalmology not only allowed the diagnosis of previously unrecognized diseases such as macular degeneration, macular choroidal neovascularization, foveal retinal detachment without macular hole, or macular retinoschisis in highly myopic eyes,2,3 but also made possible a noninvasive microstructural analysis of the retina, optic disc, and surrounding tissues. Freund et al4 first described the presence of an asymptomatic, well-circumscribed, yellow-orange, peripapillary lesion at the inferior border of the myopic conus in eyes with high myopia. The OCT images of these peripapillary lesions were interpreted as demonstrating localized retinal
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© 2013 by the American Academy of Ophthalmology Published by Elsevier Inc.
pigment epithelium (RPE) detachment. Consequently, the new entity was named inaccurately as peripapillary detachment in pathologic myopia. Successive case series reported by Shimada et al5,6 confirmed similar findings and added that peripapillary detachments in pathologic myopia were localized detachments of the RPE from the choroid adjacent to the optic nerve and may surround the entire optic disc. Although OCT findings of an intrachoroidal hyporeflective space with normal overlying retina and RPE were consistent among the investigators, Toranzo et al7 and Tateno et al,8 using newer-generation OCT imaging, affirmed that peripapillary detachment in pathologic myopia would be described more accurately as intrachoroidal cavitation or choroidal schisis. Recently, Freund et al9 re-evaluated this entity using enhanced depth imaging spectral-domain OCT and showed that the characteristic peripapillary lesions may be associated with choroidal thickening with or without ISSN 0161-6420/13/$–see front matter http://dx.doi.org/10.1016/j.ophtha.2012.08.028
Yeh et al 䡠 Peripapillary Choroidal Cavitation Detected by OCT hyporeflective areas of cavitation and proposed the term peripapillary choroidal thickening and cavitation to describe more accurately the spectrum of OCT findings associated with this lesion. The exact pathogenesis and clinical significance of this abnormality remains unknown. The purpose of this study was to evaluate the clinical characteristics of peripapillary choroidal cavitation (PCC) detected by OCT in a large series of patients to elucidate the pathogenesis and clinical significance of this peripapillary abnormality.
using a commercially available ultrasound machine (Sonomed AB 5500, Grove City, Ohio). The definition of high myopia was a refractive error of ⫺6.00 D or more or an AL of more than 26.5 mm. A few patients were recalled to complete missing data such as the axial length measurement and visual field examination. Statistical analyses were performed using the Fisher exact test, chi-square test, Welch corrected t test, and 1-way analysis of variance test. A P value of less than 0.05 was considered significant.
Results Patients and Methods This was a retrospective data analysis study approved by the Ethics Committee of the Mackay Memorial Hospital. Informed consent was obtained from all subjects, and the study adhered to the guidelines of the Declaration of Helsinki. The OCT imaging database from patients examined at the Ophthalmology Department of the Mackay Memorial Hospital from January 2006 through February 2009 were analyzed. All eyes with demonstrable PCC by OCT were included in this study. The diagnosis criteria for PCC were based on the OCT finding of an intrachoroidal hyporeflective space located below the normal plane of the RPE adjacent to the optic nerve. Two authors (L.J.C. and S.I.Y.) performed the OCT image readings and 2 authors (Y.W.L. and C.H.W.) performed the stereoscopic fundus photograph readings. They were masked to the refractive error and ophthalmologic findings. Eyes with history of ocular injuries or ocular surgery other than cataract extraction were excluded from this study. Also, patients with any systemic disorder other than controlled diabetes mellitus and systemic hypertension were excluded from this study. Routine stereoscopic color fundus photographs were obtained at the time of the patient’s first appointed OCT scanning examination and included eyes with a variety of chorioretinal disorders and glaucoma. The OCT (Stratus 3000 OCT; Humphrey-Zeiss, Dublin, CA) examination involved cross-sectional imaging of the macular, peripapillary, and optic nerve head regions that were registered as baseline data and were obtained by a single operator. Two or more horizontal, vertical, or oblique OCT linear scans (approximately 6 mm in length) were recorded around the optic disc and also at the fovea in each eye. Peripapillary circular scans and optic nerve head linear scans for retinal nerve fiber layer thickness profiles were performed in patients with glaucoma or suspected glaucoma. Follow-up OCT scans were obtained by direct linear scanning of the known pathologic area. Retrospective chart review of 122 eyes of 83 patients with PCC detected by OCT was performed. Medical records from these patients were reviewed for the following data: age at initial examination, gender, number of eyes involved, refractive error, bestcorrected visual acuity (BCVA), axial length, past refractive or cataract surgery, and associated chorioretinal diseases. Stereoscopic color fundus photographs were re-evaluated for peripapillary abnormalities and other associated myopic fundus changes, such as tilted disc, myopic conus, lacquer cracks, isolated subretinal hemorrhages, posterior staphyloma, macular atrophy of the RPE and choroid (myopic macular degeneration), Fuchs’ spots, and choroidal neovascularization. Visual field examinations also were reviewed for glaucomatous abnormalities. Refractive errors of ⫺1.00 ⬍ spherical equivalent ⬍ ⫺6.00 diopters (D) were considered low myopia. For emmetropia and hyperopia, the definition was refractive errors from 1.00 to ⫺1.00 D and more than 1.00 D, respectively. The refractive errors were expressed as a mean value in the spherical equivalent. A-scan axial length measurements in millimeters were obtained from all eyes by
In 122 eyes of 83 patients (32 men and 51 women; mean age⫾standard deviation [SD], 48.2⫾12.6 years; range, 19 –74 years), PCC was demonstrated by OCT with 100% agreement between the 2 observers. The mean refractive error⫾SD in eyes with PCC was ⫺9.03⫾5.11 D (range, 1.5 to ⫺26.0 D), and the mean axial length⫾SD was 27.36⫾2.09 mm (range, 22.51–33.26 mm). The mean BCVA⫾SD in logarithm of the minimum angle of resolution units at initial examination was 0.23⫾0.43 (range, ⫺0.08 to ⫺2.00). In 17 eyes, vision loss was caused by macular changes associated with high myopia: myopic macular degeneration, foveoschisis, isolated macular subretinal hemorrhage, and macular choroidal neovascularization. Seventy-seven eyes (63.1%) were diagnosed with glaucoma or suspected glaucoma. Forty-six eyes (37.7%) received antiglaucomatous eye drop treatment for glaucomatous visual field defect or nerve fiber layer abnormalities (Table 1).
Distribution for Age, Refractive Error, and Axial Length There were 90 (73.8%) eyes in the high myopia group: the mean age⫾SD was 45.8⫾11.1 years (range, 24 –74 years), the mean refractive error⫾SD was ⫺11.14⫾4.04 D (range, ⫺6.00 to ⫺26.0 D), and the mean axial length⫾SD was 28.13⫾1.69 mm (range, 25.19 –33.36 mm). Low myopia accounted for 24 (19.7%) eyes: the mean age⫾SD was 51.6⫾13.9 years (range, 19 –70 years), the mean refractive error⫾SD was ⫺4.23⫾1.42 D (range, ⫺1.50 to Table 1. Clinical Characteristics of Patients and Eyes with Peripapillary Choroidal Cavitation Characteristic No patients (no. eyes) Gender No. men (no. eyes) No. women (no. eyes) Mean age⫾SD (yrs) Mean BCVA⫾SD (logMAR) Mean refractive error⫾SD in SE (D) Mean axial length⫾SD (mm) Presence of yellow-orange peripapillary abnormality Tilted discs, no. (%) Peripapillary crescent, no. (%) Posterior staphyloma, no. (%) Maculopathy, no. (%) Glaucomatous VF or NFL thinning, no. (%)
Value 83 (122) 32 (51) 51 (71) 47.9⫾12.32 0.23⫾0.43 ⫺9.03⫾5.11 27.36⫾2.09 109/122 (89.3%) 85/122 (69.7%) 120/122 (98.4%) 49/122 (40.2%) 17/122 (13.9%) 46/122 (37.7%)
BCVA ⫽ best-corrected visual acuity; D ⫽ diopters; logMAR ⫽ logarithm of the minimum angle of resolution; NFL ⫽ nerve fiber layer; SD ⫽ standard deviation; SE ⫽ spherical equivalent; VF ⫽ visual field.
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Ophthalmology Volume 120, Number 3, March 2013 Table 2. Clinical Characteristics of Eyes with Peripapillary Choroidal Cavitation According to Refractive Error
Refractive Error
Eye, No. (%)
Age (yrs), MeanⴞStandard Deviation (Range)
Spherical Equivalent (Diopters), MeanⴞStandard Deviation (Range)
Axial Length (mm), MeanⴞStandard Deviation (Range)
High myopia (SEⱕ⫺6.0 D) Low myopia (⫺1.0 D⬍SE⬍⫺6.0 D) Emmetropia (⫹1.0 DⱕSEⱕ⫺1.0 D) Hyperopia (SE⬎⫹1.0 D) Total
90 (73.8) 24 (19.7) 5 (4.1) 3 (2.5) 122 (100)
45.8⫾11.09 (24–74) 51.6⫾13.91 (19–70) 59.2⫾12.24 (42–72) 65.0⫾8.00 (57–73) 47.9⫾12.32 (19–74)
⫺11.14⫾4.04 (⫺6.00 to ⫺26.00) ⫺4.23⫾1.42 (⫺1.50 to ⫺5.75) ⫺0.30⫾0.84 (⫺1.00 to 1.00) 1.58⫾0.38 (1.25–2.00) ⫺9.03⫾5.11 (1.50 to ⫺26.00)
28.13⫾1.69 (25.19–33.26) 25.69⫾1.30 (24.03–26.46) 24.10⫾1.12 (23.00–25.63) 23.12⫾1.08 (22.50–24.37) 27.36⫾2.09 (22.50–33.26)
D ⫽ diopter; SE ⫽ spherical equivalent.
⫺5.75 D), and the mean axial length⫾SD was 25.69⫾1.30 mm (range, 24.03–26.46 mm). In the emmetropia group (5 eyes of 5 patients), the mean age⫾SD was 59.2⫾12.2 years (range, 42–72 years), the mean refractive error was ⫺0.30⫾0.84 D (range, ⫺1.00 to 1.00 D), and the mean axial length⫾SD was 24.10⫾1.12 mm (range, 23.0 –25.63 mm). There were only 3 hyperopic eyes from 3 patients; the mean age⫾SD was 65.0⫾8.0 years (range, 57–73 years), the mean refractive error⫾SD was 1.58⫾0.38 D (range, 1.25–2.00 D), and the mean axial length⫾SD was 23.12⫾1.08 mm (range, 22.5–24.37 mm; Table 2). The age distribution of patients with PCC is shown in Figure 1. There were 3 patients (4 eyes) younger than 30 years, one of whom was younger than 20 years. Patients whose eyes had low myopia, emmetropia, or hyperopia and who had PCC were significantly older than patients whose eyes had high myopia (P⬍0.05, Mann– Whitney U test). The distribution of the refractive error and axial length in eyes with PCC are shown in Figure 2 and Figure 3, respectively. In eyes with high myopia (73.8%), PCC was more frequent, although it could be shown in eyes with low myopia (19.7%), emmetropia (4.1%), and even hyperopia (2.5%; Fig 2). Eighty-two (67.2%) of 122 eyes with PCC had an axial length of 26.5 mm or more. Eyes with low myopia, emmetropia, or hyperopia and PCC had a mean axial length that was significantly shorter than that of eyes with high myopia (P⬍0.05). The difference in the mean axial length was not statistically significant among PCC eyes with low myopia and emmetropia (P⬎0.05). A similar finding also was observed among PCC eyes with emmetropia and hyperopia (P⬎0.05; Fig 3).
Nearly all eyes with PCC had peripapillary crescent (or myopic conus), except for 2 eyes from 1 patient (98.4%). Tilted optic disc
and posterior staphyloma were observed in 85 (69.7%) and 49 (40.2%) eyes, respectively (Table 1). Associated ocular fundus abnormalities were observed in 18 eyes (14.8%): 7 (5.7%) with myopic macular degeneration, 5 (4.1%) with foveoschisis, 2 (1.6%) with isolated macular subretinal hemorrhage, 1 (0.8%) with lacquer crack, 1 (0.8%) with macular puckering, 1 (0.8%) with macular choroidal neovascularization, and 1 (0.8%) with peripheral retinal break. Identifiable peripapillary abnormality around the optic disc, myopic conus, or both occurred in 109 (89.3%) of 122 eyes with PCC. Clinically unrecognized PCC occurred in 13 eyes with total agreement between the observers (Fig 4A, B). The characteristic yellow-orange, localized, well-circumscribed, peripapillary lesion, as described by Freund et al4 (Fig 4C, D), was demonstrated in only 57 eyes. Other peripapillary abnormalities that may suggest the presence of PCC included yellowish focal flat blurring (Fig 4E, F) or pigmentary change around the margin of the optic disc, the myopic conus, or both (Fig 4G, H). The agreement between the 2 independent ophthalmologists who read the stereoscopic color fundus photographs was 100% for the presence of a yellow-orange peripapillary lesion and 86% for other peripapillary abnormalities. Although the presence of the characteristic yellow-orange peripapillary lesion was seen more commonly in highly myopic eyes (39 eyes; 68.4%), it also occurred in eyes with low myopia (16 eyes) and emmetropia (1 eye). None of the hyperopic eyes with PCC demonstrated any peripapillary abnormalities (Fig 5). The clinical evidence of a yellow-orange peripapillary lesion was not correlated with patient age, axial length, or refractive error (P⬎0.05). Excavations or posterior extensions in the area of the myopic conus were found in 53 (43.4%) of the 122 eyes with PCC. In these eyes, the inferotemporal retinal vein markedly bent at the transition from the PCC to the myopic conus. In 13 eyes, the extreme excavated myopic conus resulted in a posterior bowing of the sclera at its transition with the optic disc. The inferotemporal
Figure 1. Bar graph showing the age distribution in patients with peripapillary choroidal cavitation detected by optical coherence tomography.
Figure 2. Bar graph showing the distribution of refractive errors in patients with peripapillary choroidal cavitation detected by optical coherence tomography. D ⫽ diopters; SE ⫽ spherical equivalent.
Funduscopic Characteristics of the Peripapillary Choroidal Cavitation
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Figure 3. Bar graph showing the distribution of axial length measurements in patients with peripapillary choroidal cavitation detected by optical coherence tomography.
retinal vein seemed to acquire a bayonet course by disappearing into the PCC space and resurging at the border of the myopic conus and PCC (Fig 6A).
Optical Coherence Tomography Features of the Peripapillary Choroidal Cavitation The OCT scans of the optic disc and adjacent area showed an intrachoroidal hyporeflective space located below the normal plane of the RPE in all eyes included in this study (Fig 4). The PCC invariably involved the area inferior to the optic disc regardless of the clinical features of the peripapillary lesion. In 48 (39%) of 122 eyes, OCT evidenced images of intrachoroidal splitting or schisis characterized by intracavitary cleavage bands and hyperreflective fluid-like images (Figs 5A and 6B). The presence of a yelloworange peripapillary lesion was not indicative of the OCT findings of intrachoroidal schisis or cavitation (P⬎0.05). In 19 (16%) eyes, OCT evidenced an apparent communication between the choroidal cavity and the vitreous cavity at the junction of the PCC and the myopic conus (Figs 4H and 6B, D). A PCC with opening was observed in 14 (26.4%) of 53 eyes with excavated myopic conus, and in 5 (7.2%) of 69 eyes without excavated myopic conus. This difference in the incidence was significant (P⬍0.05, Fisher exact probability test).
Discussion This retrospective study analyzed a large series of 122 eyes with PCCs detected by OCT. Freund et al4 were the first to describe PCC in eyes with high myopia. Since then, PCC has been pictured clinically as a yellow-orange peripapillary lesion at the inferior border of the myopic conus in highly myopic eyes. In the current study, only 57 of 122 eyes with PCC showed the characteristic yellow-orange peripapillary lesion. Although other identifiable peripapillary abnormalities such as yellowish focal flat blurring or pigmentary changes around the margin of the optic disc or myopic conus were reported in 52 eyes, the agreement between the color fundus photograph readers was only 86%. Considering the fact that the color fundus readings may be biased by the retrospective design of this study, the actual prevalence of clinically unrecognized PCC should be higher than the 10.7% (13 eyes) reported in this study. Shimada et al5 described 2 cases of PCC detected by OCT in eyes without peripapillary abnormalities around the myopic conus. In the present study, most of the clinically unrecognized PCCs were incidental findings from OCT scans of glaucomatous
eyes. Similar data also were reported by Park et al10 when assessing the usefulness of enhanced depth imaging OCT for evaluating deep structures of the optic nerve complex (optic nerve head and peripapillary structures) in glaucoma. These observations suggested that PCCs may be present more frequently than may be expected by the ophthalmoscopic observations alone. The real prevalence of PCC remains unknown. In 2 consecutive studies conducted by Shimada et al,5,6 the prevalence of PCC in eyes with high myopia was as high as 4.9% and 9.4%. In contrast, PCCs were not observed in any eyes in the emmetropia and low myopia control groups. Both Tateno et al8 and Wei et al11 reported, exceptionally, 1 isolated case of PCC in an eye with low myopia. In the present study, high myopia was the most common refractive error among eyes with PCC (73.8%). However, PCC occurred in 24 (19.7%) eyes with low myopia, 5 (4.1%) eyes with emmetropia, and 3 (2.6%) eyes with hyperopia. Because the mean refractive error may be influenced by both corneal and lens power, the axial length of these eyes with PCC was analyzed. Surprisingly, this study demonstrated that 40 (32.8%) of 122 eyes with PCC had an axial length of less than 26.5 mm. As expected, eyes with low myopia, emmetropia, or hyperopia and PCC had a mean axial length significantly shorter than that of eyes with high myopia (P⬍0.05); however, the difference in the mean axial length was not statistically significant among PCC eyes with low myopia and emmetropia (P⬎0.05). Additionally, the clinical features of PCC were not correlated with patient age, axial length, or refractive error (P⬎0.05, Mann–Whitney U test), although 98.4% of PCCs occurred at the margin of a peripapillary crescent (or myopic conus). These findings indicated that PCC seemed to be overrepresented in high myopia and was associated strongly with a peripapillary crescent. Shimada et al5 reported that PCC was rare among young patients. They described only 1 case of PCC in a patient younger than 30 years in a series of 31 cases. This study confirmed their findings by demonstrating that only 3 of 83 patients were younger than 30 years. Moreover, this study found that eyes with low myopia, emmetropia, or hyperopia and PCC were of patients who were significantly older than patients whose eyes had high myopia (P⬍0.05, Mann– Whitney U test; Table 2). These data suggested that pathologic changes in eyes with high myopia may not be the only factor involved in the formation of PCC, and ocular changes in an aging eye may play a role in the pathogenesis of this abnormality. Many of the findings of the present study were similar to those reported by Shimada et al.6 In all eyes, PCC consistently involved the area inferior to the optic disc, although it was not limited to this area and sometimes surrounded almost the entire optic disc. This study also demonstrated that the inferotemporal retinal vein markedly bent at the border edge between the myopic conus and PCC in 53 eyes (43.4%). This rate was lower than reported previously by Shimada et al6 in eyes with high myopia (83.9% of eyes with PCC); however, it was compatible with the current study population, which included eyes with a wider range of refractive error. In eyes with extreme excavation of the
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Figure 4. Funduscopic features of highly myopic eyes with peripapillary choroidal cavitation (PCC). A, Fundus photograph showing the absence of yellow-orange peripapillary abnormality. B, Optical coherence tomography section across the optic disc clearly evidencing a PCC (asterisk). C, Characteristic yellow-orange peripapillary lesion (black arrow): well-circumscribed, elevated, patchy lesion around optic disc and myopic conus (black arrow). D, Optical coherence tomography section across the peripapillary lesion demonstrating a hyporeflective space inferior to the retinal pigment epithelium, corresponding to the PCC (asterisk). E, Peripapillary abnormality that may suggest the presence of PCC presenting as a focal flat blurring inferior to the optic disc and myopic conus (black arrow). F, Optical coherence tomography section across the peripapillary abnormality showing a hyporeflective image corresponding to PCC (asterisk). G, Peripapillary abnormality that may suggest the presence of PCC presenting as pigmentary change around optic disc and myopic conus (black arrow). H, Optical coherence tomography section across the peripapillary abnormality showing a hyporeflective image corresponding to PCC (asterisk) with opening into the vitreous space. White arrows in A, C, E, and G indicate the orientation of the corresponding OCT scans shown in B, D, F, and H.
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Figure 5. Peripapillary choroidal cavitation (PCC; asterisks) in eyes with low myopia, emmetropia, and hyperopia. A, Left hyperopic eye of a 65-year-old woman with ⫹1.25 diopters (D) spherical equivalent (SE) and axial length of 22.5 mm. Peripapillary choroidal cavitation was detected by optical coherence tomography (OCT) despite the absence of a yellow-orange peripapillary lesion at funduscopic examination. B, Left emmetropic eye of a 72-year-old man with ⫺0.75 D SE and axial length of 25.6 mm. Characteristic yellow-orange peripapillary lesion was evidenced on funduscopic examination, and OCT showed a hyporeflective image corresponding to PCC. C, Left low myopic eye of a 59-year-old man with ⫺5.5 D SE and axial length of 25.4 mm. Characteristic yellow-orange peripapillary lesion was evidenced on funduscopic examination, and OCT showed a hyporeflective image corresponding to PCC. White arrows in A, B, and C indicate the orientation of the corresponding OCT scans.
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Figure 6. Peripapillary choroidal cavitation (PCC) with opening in highly myopic eyes with and without excavated myopic conus. A, Fundus photograph of a highly myopia eye with a yellow-orange peripapillary lesion and extreme excavated myopic conus. The inferotemporal retinal vein bending (bayonet) could be evidenced as the vein disappeared into the PCC and resurged at the border of the myopic conus and PCC (black arrow). B, Communication between the PCC and the vitreous space at the junction of the lesion and the myopic conus was detected (asterisk). Hyperreflective intracavitary images suggestive of choroidal splitting (arrowhead) and intracavitary septum (arrows) also were visualized by optical coherence tomography (OCT). C, Fundus photograph of a highly myopic eye with yellow-orange peripapillary lesion and large, not-excavated myopic conus. D, Opening of the intrachoroidal cavity into the vitreous cavity also was evidenced by OCT inferiorly, at the junction of the PCC, and at the myopic conus (asterisk). White arrows in A and C indicate the orientation of the corresponding OCT scans shown in B and D.
myopic conus, the inferotemporal retinal vein demonstrated a bayonet course: it appeared to enter the PCC space and to disappear after bending at the border between the myopic conus and the PCC (Fig 6A). As suggested by Shimada et al,6 the bent retinal vein at the border between the myopic conus and PCC was not an uncommon phenomenon among patients with high myopia and PCC. Although it is uncertain whether the marked bending of the retinal vein in excavated myopic conus eventually may impair the retinal venous flow, this study demonstrated that excavated myopic conus significantly increased the incidence of open PCC detected by OCT (P⬍0.05, Fisher exact probability test; Fig 6). First-generation OCT imaging of the yellow-orange peripapillary lesions in highly myopic eyes revealed images that were interpreted as localized peripapillary detachment of RPE and retina.5,6,9 By using newer-generation OCT imaging, Toranzo et al7 first demonstrated that these peripapillary lesions constitute areas of intrachoroidal cavitation with normal overlying RPE and retina. This study confirmed comparable OCT findings for all eyes included in the data analysis. Both Shimada et al5,6 and Freund et al9 observed that, in some cases, OCT revealed an apparent communication of PCC between the choroidal cavity and the vitreous cavity at the junction of the PCC and the myopic conus. Wei et al11 confirmed similar findings in 6 of 13 analyzed eyes and added that intrachoroidal tissue splitting without optical
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empty cavity was found in several cases. Because of the retrospective design of this study, the prevalence of PCC with opening was only 16% (19 of 122). Similar to Tateno et al8 and Wei et al,11 this study evidenced OCT images of intrachoroidal splitting or schisis characterized by intracavitary cleavage bands and hyperreflective fluid-like images in 48 (39%) eyes of PCC. The authors agree with Freund et al9 in their review that the coexistence of these intrachoroidal findings adjacent to PCCs was relatively common, reinforcing the idea that they may be different stages of 1 disease spectrum.7–9 In the current series, 17 eyes with PCC had some evidence of maculopathy secondary to pathologic myopia that included myopic macular degeneration, foveoschisis, isolated macular subretinal hemorrhage, lacquer crack, and macular choroidal neovascularization. Shimada et al12 suggested that eyes with a PCC may be at risk of a macular retinal detachment developing. They reported a case of macular retinal detachment associated with PCC. Optical coherence tomography detected a communication of the PCC to the vitreous cavity and continuity to the subretinal space. However, 2 retinal hole-like lesions were found at the border of the myopic conus. The present study did not find any case of macular detachment. There were 19 eyes with open PCCs into the vitreous cavity, 3 of which had associated foveoschisis. The area of macular schisis was well
Yeh et al 䡠 Peripapillary Choroidal Cavitation Detected by OCT delimited nasally at the border of the myopic conus. The authors agree with Wei et al11 that the adherence of the retina and RPE at the conus margin may prevent the break from opening into the subretinal space. Eventually, PCC with opening and foveoschisis may coexist as pathologic changes in highly myopic eyes. Vitreous tractional forces resulting in retinal breaks may still be the main cause for the development of macular retinal detachment in eyes with PCC. The pathologic changes specific to PCC and its pathogenesis are still being discussed. Because PCC occurred more frequently in eyes with high myopia, many proposed hypotheses have connected PCC with fundus changes in pathologic myopia. Toranzo et al7 assumed that the progression of the staphyloma breaks the collagenous limiting tissue of Elschnig that connects the choroid to the optic nerve, resulting in separation of the sclera from the RPE by creating a traction cavitation inside the choroid. Shimada et al5 suggested that the posterior excavation of the myopic conus leads to a mechanical stretch of the structurally weaker conus area and the surrounding peripapillary tissue, resulting in splitting of the intrachoroidal structures and formation of cystoid spaces. These cystoid spaces may enlarge and coalesce to form a large cystic area seen as a hyporeflective space on OCT. Wei et al11 agree that the progression of peripapillary staphyloma may stretch and disrupt the tissue at the edge of the myopic conus; however, they believe that the choroidal schisis or a fluid pocket derived from the vitreous fluid gains access into the peripapillary choroidal tissue. The adherence of the retina and RPE at the conus margin prevents the break from opening into the subretinal space. This study demonstrated that PCCs did not occur exclusively in eyes with high myopia. They also were found in eyes with low myopia, emmetropia, and hyperopia. Moreover, these patients were significantly older than those with PCC and high myopia. Aging may play an important role in the pathogenesis of PCC. The conus area and the surrounding peripapillary tissue may be a structurally weaker area per se because of its transitional tissue characteristics. With aging, there may be a decrease in the ability of the tissue to absorb fluids originating from the subretinal space, suprachoroidal space, optic canal, or vitreous cavity. Gravitation of these fluids, even if it is minimal and asymptomatic, results in the formation of fluid pockets at the inferior margin of the conus area. These observations explain the consistent inferior location of the PCC in relationship to the optic nerve, and the fact that it occurs rarely in eyes of young patients. In the authors’ view, the ectatic changes in high myopia eyes are contributory factors to the weakening of the conus area and its surrounding tissue.5,7,11 The retrospective design and the unknown clinical significance of PCCs remain the main limitations of this study. Previous reports by Freund et al4,9 and Wei et al11 noted that PCCs remained stable during several years of follow-up and did not seem to affect visual function. The present data were similar to those of Shimada et al5,6 that demonstrated that PCC had glaucoma-like visual field defects more frequently than eyes without PCC. Seventy-seven eyes (63.1%) had a diagnosis of glaucoma or suspected glaucoma. Forty-six of
them (37.7%) received antiglaucomatous eye drops because of a glaucomatous visual field defect or nerve fiber layer abnormalities. The clinical significance of these glaucomalike visual field defects in eyes with PCC is unclear because glaucoma is at times difficult to be diagnosed in highly myopic eyes because of an atypical optic disc and visual field changes. Another limitation to the current study is the use of conventional time-domain OCT rather than Fourier or spectral-domain OCT to assess deep structures of the posterior segment. Conventional time-domain OCT has a limited capacity to image deep posterior segment tissues such as vascular structures, peripapillary choroid, sclera, and the optic nerve because of a depth-dependent decrease in sensitivity and scattering of light by pigment and blood. Spectral-domain OCT offers higher scan speeds and improved axial image resolution compared with time-domain OCT.10,13,14 Therefore, it is expected that spectral-domain OCT should reduce errors from eye motion and should improve reproducibility, sensitivity, and specificity of image detection of PCCs. In summary, this study showed that PCC was not exclusively found in eyes with high myopia because it also was demonstrated in eyes with low myopia emmetropia, and hyperopia. The characteristic yellow-orange peripapillary lesion may not always be evidenced in the funduscopic examination for all eyes with demonstrable PCC by OCT. Although ectatic changes in eyes with pathologic myopia have been attributed to causing weakening of the conus area and its surrounding tissue, physiologic changes resulting from aging may play a role in the pathogenesis of PCC. Further prospective studies with a more representative study population would be needed to investigate the clinical significance of this entity.
References 1. Huang D, Swanson EA, Lin CP, et al. Optical coherence tomography. Science 1991;254:1178 – 81. 2. Baba T, Ohno-Matsui K, Futagami S, et al. Prevalence and characteristics of foveal retinal detachment without macular hole in high myopia. Am J Ophthalmol 2003;135:338 – 42. 3. Takano M, Kishi S. Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma. Am J Ophthalmol 1999;128:472– 6. 4. Freund KB, Ciardella AP, Yannuzzi LA, et al. Peripapillary detachment in pathologic myopia. Arch Ophthalmol 2003; 121:197–204. 5. Shimada N, Ohno-Matsui K, Nishimuta A, et al. Peripapillary changes detected by optical coherence tomography in eyes with high myopia. Ophthalmology 2007;114:2070 – 6. 6. Shimada N, Ohno-Matsui K, Yoshida T, et al. Characteristics of peripapillary detachment in pathologic myopia. Arch Ophthalmol 2006;124:46 –52. 7. Toranzo J, Cohen SY, Erginay A, Gaudric A. Peripapillary intrachoroidal cavitation in myopia. Am J Ophthalmol 2005; 140:731–2. 8. Tateno H, Takahashi K, Fukuchi T, et al. Choroidal schisis around the optic nerve in myopic eyes evaluated by optical coherence tomography [in Japanese]. Rinsho Ganka 2005;59: 327–31.
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12. Shimada N, Ohno-Matsui K, Iwanaga Y, et al. Macular retinal detachment associated with peripapillary detachment in pathologic myopia. Int Ophthalmol 2009;29:99 –102. 13. Sull AC, Vuong LN, Price LL, et al. Comparison of spectral/ Fourier domain optical coherence tomography instruments for assessment of normal macular thickness. Retina 2010; 30:235– 45. 14. Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain optical coherence tomography. Am J Ophthalmol 2008;146:496 –500.
Footnotes and Financial Disclosures Originally received: January 30, 2012. Final revision: August 2, 2012. Accepted: August 14, 2012. Available online: December 1, 2012.
Presented as a poster at: 23rd Asia Pacific Academy of Ophthalmology (APAO) Congress, June 28-July 2, 2008, Hong Kong. Manuscript no. 2012-138.
1
Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan.
2
Department of Medicine, Nursing and Management College, Mackay Memorial Hospital, Taipei, Taiwan.
3
Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
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Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Correspondence: Lee-Jen Chen, MD, Department of Ophthalmology, Mackay Memorial Hospital, No. 92, Section 2, Chun-Shan North Road, Taipei 104, Taiwan. E-mail:[email protected].
Eye imaging has grown in importance for the diagnosis of ocular diseases. Optical coherence tomography (OCT) has emerged at the forefront of tissue imaging by providing high-resolution, cross-sectional, and complex 3-dimensional imaging of biological tissues.1 The advent of OCT in ophthalmology not only allowed the diagnosis of previously unrecognized diseases such as macular degeneration, macular choroidal neovascularization, foveal retinal detachment without macular hole, or macular retinoschisis in highly myopic eyes,2,3 but also made possible a noninvasive microstructural analysis of the retina, optic disc, and surrounding tissues. Freund et al4 first described the presence of an asymptomatic, well-circumscribed, yellow-orange, peripapillary lesion at the inferior border of the myopic conus in eyes with high myopia. The OCT images of these peripapillary lesions were interpreted as demonstrating localized retinal
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pigment epithelium (RPE) detachment. Consequently, the new entity was named inaccurately as peripapillary detachment in pathologic myopia. Successive case series reported by Shimada et al5,6 confirmed similar findings and added that peripapillary detachments in pathologic myopia were localized detachments of the RPE from the choroid adjacent to the optic nerve and may surround the entire optic disc. Although OCT findings of an intrachoroidal hyporeflective space with normal overlying retina and RPE were consistent among the investigators, Toranzo et al7 and Tateno et al,8 using newer-generation OCT imaging, affirmed that peripapillary detachment in pathologic myopia would be described more accurately as intrachoroidal cavitation or choroidal schisis. Recently, Freund et al9 re-evaluated this entity using enhanced depth imaging spectral-domain OCT and showed that the characteristic peripapillary lesions may be associated with choroidal thickening with or without ISSN 0161-6420/13/$–see front matter http://dx.doi.org/10.1016/j.ophtha.2012.08.028
Yeh et al 䡠 Peripapillary Choroidal Cavitation Detected by OCT hyporeflective areas of cavitation and proposed the term peripapillary choroidal thickening and cavitation to describe more accurately the spectrum of OCT findings associated with this lesion. The exact pathogenesis and clinical significance of this abnormality remains unknown. The purpose of this study was to evaluate the clinical characteristics of peripapillary choroidal cavitation (PCC) detected by OCT in a large series of patients to elucidate the pathogenesis and clinical significance of this peripapillary abnormality.
using a commercially available ultrasound machine (Sonomed AB 5500, Grove City, Ohio). The definition of high myopia was a refractive error of ⫺6.00 D or more or an AL of more than 26.5 mm. A few patients were recalled to complete missing data such as the axial length measurement and visual field examination. Statistical analyses were performed using the Fisher exact test, chi-square test, Welch corrected t test, and 1-way analysis of variance test. A P value of less than 0.05 was considered significant.
Results Patients and Methods This was a retrospective data analysis study approved by the Ethics Committee of the Mackay Memorial Hospital. Informed consent was obtained from all subjects, and the study adhered to the guidelines of the Declaration of Helsinki. The OCT imaging database from patients examined at the Ophthalmology Department of the Mackay Memorial Hospital from January 2006 through February 2009 were analyzed. All eyes with demonstrable PCC by OCT were included in this study. The diagnosis criteria for PCC were based on the OCT finding of an intrachoroidal hyporeflective space located below the normal plane of the RPE adjacent to the optic nerve. Two authors (L.J.C. and S.I.Y.) performed the OCT image readings and 2 authors (Y.W.L. and C.H.W.) performed the stereoscopic fundus photograph readings. They were masked to the refractive error and ophthalmologic findings. Eyes with history of ocular injuries or ocular surgery other than cataract extraction were excluded from this study. Also, patients with any systemic disorder other than controlled diabetes mellitus and systemic hypertension were excluded from this study. Routine stereoscopic color fundus photographs were obtained at the time of the patient’s first appointed OCT scanning examination and included eyes with a variety of chorioretinal disorders and glaucoma. The OCT (Stratus 3000 OCT; Humphrey-Zeiss, Dublin, CA) examination involved cross-sectional imaging of the macular, peripapillary, and optic nerve head regions that were registered as baseline data and were obtained by a single operator. Two or more horizontal, vertical, or oblique OCT linear scans (approximately 6 mm in length) were recorded around the optic disc and also at the fovea in each eye. Peripapillary circular scans and optic nerve head linear scans for retinal nerve fiber layer thickness profiles were performed in patients with glaucoma or suspected glaucoma. Follow-up OCT scans were obtained by direct linear scanning of the known pathologic area. Retrospective chart review of 122 eyes of 83 patients with PCC detected by OCT was performed. Medical records from these patients were reviewed for the following data: age at initial examination, gender, number of eyes involved, refractive error, bestcorrected visual acuity (BCVA), axial length, past refractive or cataract surgery, and associated chorioretinal diseases. Stereoscopic color fundus photographs were re-evaluated for peripapillary abnormalities and other associated myopic fundus changes, such as tilted disc, myopic conus, lacquer cracks, isolated subretinal hemorrhages, posterior staphyloma, macular atrophy of the RPE and choroid (myopic macular degeneration), Fuchs’ spots, and choroidal neovascularization. Visual field examinations also were reviewed for glaucomatous abnormalities. Refractive errors of ⫺1.00 ⬍ spherical equivalent ⬍ ⫺6.00 diopters (D) were considered low myopia. For emmetropia and hyperopia, the definition was refractive errors from 1.00 to ⫺1.00 D and more than 1.00 D, respectively. The refractive errors were expressed as a mean value in the spherical equivalent. A-scan axial length measurements in millimeters were obtained from all eyes by
In 122 eyes of 83 patients (32 men and 51 women; mean age⫾standard deviation [SD], 48.2⫾12.6 years; range, 19 –74 years), PCC was demonstrated by OCT with 100% agreement between the 2 observers. The mean refractive error⫾SD in eyes with PCC was ⫺9.03⫾5.11 D (range, 1.5 to ⫺26.0 D), and the mean axial length⫾SD was 27.36⫾2.09 mm (range, 22.51–33.26 mm). The mean BCVA⫾SD in logarithm of the minimum angle of resolution units at initial examination was 0.23⫾0.43 (range, ⫺0.08 to ⫺2.00). In 17 eyes, vision loss was caused by macular changes associated with high myopia: myopic macular degeneration, foveoschisis, isolated macular subretinal hemorrhage, and macular choroidal neovascularization. Seventy-seven eyes (63.1%) were diagnosed with glaucoma or suspected glaucoma. Forty-six eyes (37.7%) received antiglaucomatous eye drop treatment for glaucomatous visual field defect or nerve fiber layer abnormalities (Table 1).
Distribution for Age, Refractive Error, and Axial Length There were 90 (73.8%) eyes in the high myopia group: the mean age⫾SD was 45.8⫾11.1 years (range, 24 –74 years), the mean refractive error⫾SD was ⫺11.14⫾4.04 D (range, ⫺6.00 to ⫺26.0 D), and the mean axial length⫾SD was 28.13⫾1.69 mm (range, 25.19 –33.36 mm). Low myopia accounted for 24 (19.7%) eyes: the mean age⫾SD was 51.6⫾13.9 years (range, 19 –70 years), the mean refractive error⫾SD was ⫺4.23⫾1.42 D (range, ⫺1.50 to Table 1. Clinical Characteristics of Patients and Eyes with Peripapillary Choroidal Cavitation Characteristic No patients (no. eyes) Gender No. men (no. eyes) No. women (no. eyes) Mean age⫾SD (yrs) Mean BCVA⫾SD (logMAR) Mean refractive error⫾SD in SE (D) Mean axial length⫾SD (mm) Presence of yellow-orange peripapillary abnormality Tilted discs, no. (%) Peripapillary crescent, no. (%) Posterior staphyloma, no. (%) Maculopathy, no. (%) Glaucomatous VF or NFL thinning, no. (%)
Value 83 (122) 32 (51) 51 (71) 47.9⫾12.32 0.23⫾0.43 ⫺9.03⫾5.11 27.36⫾2.09 109/122 (89.3%) 85/122 (69.7%) 120/122 (98.4%) 49/122 (40.2%) 17/122 (13.9%) 46/122 (37.7%)
BCVA ⫽ best-corrected visual acuity; D ⫽ diopters; logMAR ⫽ logarithm of the minimum angle of resolution; NFL ⫽ nerve fiber layer; SD ⫽ standard deviation; SE ⫽ spherical equivalent; VF ⫽ visual field.
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Ophthalmology Volume 120, Number 3, March 2013 Table 2. Clinical Characteristics of Eyes with Peripapillary Choroidal Cavitation According to Refractive Error
Refractive Error
Eye, No. (%)
Age (yrs), MeanⴞStandard Deviation (Range)
Spherical Equivalent (Diopters), MeanⴞStandard Deviation (Range)
Axial Length (mm), MeanⴞStandard Deviation (Range)
High myopia (SEⱕ⫺6.0 D) Low myopia (⫺1.0 D⬍SE⬍⫺6.0 D) Emmetropia (⫹1.0 DⱕSEⱕ⫺1.0 D) Hyperopia (SE⬎⫹1.0 D) Total
90 (73.8) 24 (19.7) 5 (4.1) 3 (2.5) 122 (100)
45.8⫾11.09 (24–74) 51.6⫾13.91 (19–70) 59.2⫾12.24 (42–72) 65.0⫾8.00 (57–73) 47.9⫾12.32 (19–74)
⫺11.14⫾4.04 (⫺6.00 to ⫺26.00) ⫺4.23⫾1.42 (⫺1.50 to ⫺5.75) ⫺0.30⫾0.84 (⫺1.00 to 1.00) 1.58⫾0.38 (1.25–2.00) ⫺9.03⫾5.11 (1.50 to ⫺26.00)
28.13⫾1.69 (25.19–33.26) 25.69⫾1.30 (24.03–26.46) 24.10⫾1.12 (23.00–25.63) 23.12⫾1.08 (22.50–24.37) 27.36⫾2.09 (22.50–33.26)
D ⫽ diopter; SE ⫽ spherical equivalent.
⫺5.75 D), and the mean axial length⫾SD was 25.69⫾1.30 mm (range, 24.03–26.46 mm). In the emmetropia group (5 eyes of 5 patients), the mean age⫾SD was 59.2⫾12.2 years (range, 42–72 years), the mean refractive error was ⫺0.30⫾0.84 D (range, ⫺1.00 to 1.00 D), and the mean axial length⫾SD was 24.10⫾1.12 mm (range, 23.0 –25.63 mm). There were only 3 hyperopic eyes from 3 patients; the mean age⫾SD was 65.0⫾8.0 years (range, 57–73 years), the mean refractive error⫾SD was 1.58⫾0.38 D (range, 1.25–2.00 D), and the mean axial length⫾SD was 23.12⫾1.08 mm (range, 22.5–24.37 mm; Table 2). The age distribution of patients with PCC is shown in Figure 1. There were 3 patients (4 eyes) younger than 30 years, one of whom was younger than 20 years. Patients whose eyes had low myopia, emmetropia, or hyperopia and who had PCC were significantly older than patients whose eyes had high myopia (P⬍0.05, Mann– Whitney U test). The distribution of the refractive error and axial length in eyes with PCC are shown in Figure 2 and Figure 3, respectively. In eyes with high myopia (73.8%), PCC was more frequent, although it could be shown in eyes with low myopia (19.7%), emmetropia (4.1%), and even hyperopia (2.5%; Fig 2). Eighty-two (67.2%) of 122 eyes with PCC had an axial length of 26.5 mm or more. Eyes with low myopia, emmetropia, or hyperopia and PCC had a mean axial length that was significantly shorter than that of eyes with high myopia (P⬍0.05). The difference in the mean axial length was not statistically significant among PCC eyes with low myopia and emmetropia (P⬎0.05). A similar finding also was observed among PCC eyes with emmetropia and hyperopia (P⬎0.05; Fig 3).
Nearly all eyes with PCC had peripapillary crescent (or myopic conus), except for 2 eyes from 1 patient (98.4%). Tilted optic disc
and posterior staphyloma were observed in 85 (69.7%) and 49 (40.2%) eyes, respectively (Table 1). Associated ocular fundus abnormalities were observed in 18 eyes (14.8%): 7 (5.7%) with myopic macular degeneration, 5 (4.1%) with foveoschisis, 2 (1.6%) with isolated macular subretinal hemorrhage, 1 (0.8%) with lacquer crack, 1 (0.8%) with macular puckering, 1 (0.8%) with macular choroidal neovascularization, and 1 (0.8%) with peripheral retinal break. Identifiable peripapillary abnormality around the optic disc, myopic conus, or both occurred in 109 (89.3%) of 122 eyes with PCC. Clinically unrecognized PCC occurred in 13 eyes with total agreement between the observers (Fig 4A, B). The characteristic yellow-orange, localized, well-circumscribed, peripapillary lesion, as described by Freund et al4 (Fig 4C, D), was demonstrated in only 57 eyes. Other peripapillary abnormalities that may suggest the presence of PCC included yellowish focal flat blurring (Fig 4E, F) or pigmentary change around the margin of the optic disc, the myopic conus, or both (Fig 4G, H). The agreement between the 2 independent ophthalmologists who read the stereoscopic color fundus photographs was 100% for the presence of a yellow-orange peripapillary lesion and 86% for other peripapillary abnormalities. Although the presence of the characteristic yellow-orange peripapillary lesion was seen more commonly in highly myopic eyes (39 eyes; 68.4%), it also occurred in eyes with low myopia (16 eyes) and emmetropia (1 eye). None of the hyperopic eyes with PCC demonstrated any peripapillary abnormalities (Fig 5). The clinical evidence of a yellow-orange peripapillary lesion was not correlated with patient age, axial length, or refractive error (P⬎0.05). Excavations or posterior extensions in the area of the myopic conus were found in 53 (43.4%) of the 122 eyes with PCC. In these eyes, the inferotemporal retinal vein markedly bent at the transition from the PCC to the myopic conus. In 13 eyes, the extreme excavated myopic conus resulted in a posterior bowing of the sclera at its transition with the optic disc. The inferotemporal
Figure 1. Bar graph showing the age distribution in patients with peripapillary choroidal cavitation detected by optical coherence tomography.
Figure 2. Bar graph showing the distribution of refractive errors in patients with peripapillary choroidal cavitation detected by optical coherence tomography. D ⫽ diopters; SE ⫽ spherical equivalent.
Funduscopic Characteristics of the Peripapillary Choroidal Cavitation
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Figure 3. Bar graph showing the distribution of axial length measurements in patients with peripapillary choroidal cavitation detected by optical coherence tomography.
retinal vein seemed to acquire a bayonet course by disappearing into the PCC space and resurging at the border of the myopic conus and PCC (Fig 6A).
Optical Coherence Tomography Features of the Peripapillary Choroidal Cavitation The OCT scans of the optic disc and adjacent area showed an intrachoroidal hyporeflective space located below the normal plane of the RPE in all eyes included in this study (Fig 4). The PCC invariably involved the area inferior to the optic disc regardless of the clinical features of the peripapillary lesion. In 48 (39%) of 122 eyes, OCT evidenced images of intrachoroidal splitting or schisis characterized by intracavitary cleavage bands and hyperreflective fluid-like images (Figs 5A and 6B). The presence of a yelloworange peripapillary lesion was not indicative of the OCT findings of intrachoroidal schisis or cavitation (P⬎0.05). In 19 (16%) eyes, OCT evidenced an apparent communication between the choroidal cavity and the vitreous cavity at the junction of the PCC and the myopic conus (Figs 4H and 6B, D). A PCC with opening was observed in 14 (26.4%) of 53 eyes with excavated myopic conus, and in 5 (7.2%) of 69 eyes without excavated myopic conus. This difference in the incidence was significant (P⬍0.05, Fisher exact probability test).
Discussion This retrospective study analyzed a large series of 122 eyes with PCCs detected by OCT. Freund et al4 were the first to describe PCC in eyes with high myopia. Since then, PCC has been pictured clinically as a yellow-orange peripapillary lesion at the inferior border of the myopic conus in highly myopic eyes. In the current study, only 57 of 122 eyes with PCC showed the characteristic yellow-orange peripapillary lesion. Although other identifiable peripapillary abnormalities such as yellowish focal flat blurring or pigmentary changes around the margin of the optic disc or myopic conus were reported in 52 eyes, the agreement between the color fundus photograph readers was only 86%. Considering the fact that the color fundus readings may be biased by the retrospective design of this study, the actual prevalence of clinically unrecognized PCC should be higher than the 10.7% (13 eyes) reported in this study. Shimada et al5 described 2 cases of PCC detected by OCT in eyes without peripapillary abnormalities around the myopic conus. In the present study, most of the clinically unrecognized PCCs were incidental findings from OCT scans of glaucomatous
eyes. Similar data also were reported by Park et al10 when assessing the usefulness of enhanced depth imaging OCT for evaluating deep structures of the optic nerve complex (optic nerve head and peripapillary structures) in glaucoma. These observations suggested that PCCs may be present more frequently than may be expected by the ophthalmoscopic observations alone. The real prevalence of PCC remains unknown. In 2 consecutive studies conducted by Shimada et al,5,6 the prevalence of PCC in eyes with high myopia was as high as 4.9% and 9.4%. In contrast, PCCs were not observed in any eyes in the emmetropia and low myopia control groups. Both Tateno et al8 and Wei et al11 reported, exceptionally, 1 isolated case of PCC in an eye with low myopia. In the present study, high myopia was the most common refractive error among eyes with PCC (73.8%). However, PCC occurred in 24 (19.7%) eyes with low myopia, 5 (4.1%) eyes with emmetropia, and 3 (2.6%) eyes with hyperopia. Because the mean refractive error may be influenced by both corneal and lens power, the axial length of these eyes with PCC was analyzed. Surprisingly, this study demonstrated that 40 (32.8%) of 122 eyes with PCC had an axial length of less than 26.5 mm. As expected, eyes with low myopia, emmetropia, or hyperopia and PCC had a mean axial length significantly shorter than that of eyes with high myopia (P⬍0.05); however, the difference in the mean axial length was not statistically significant among PCC eyes with low myopia and emmetropia (P⬎0.05). Additionally, the clinical features of PCC were not correlated with patient age, axial length, or refractive error (P⬎0.05, Mann–Whitney U test), although 98.4% of PCCs occurred at the margin of a peripapillary crescent (or myopic conus). These findings indicated that PCC seemed to be overrepresented in high myopia and was associated strongly with a peripapillary crescent. Shimada et al5 reported that PCC was rare among young patients. They described only 1 case of PCC in a patient younger than 30 years in a series of 31 cases. This study confirmed their findings by demonstrating that only 3 of 83 patients were younger than 30 years. Moreover, this study found that eyes with low myopia, emmetropia, or hyperopia and PCC were of patients who were significantly older than patients whose eyes had high myopia (P⬍0.05, Mann– Whitney U test; Table 2). These data suggested that pathologic changes in eyes with high myopia may not be the only factor involved in the formation of PCC, and ocular changes in an aging eye may play a role in the pathogenesis of this abnormality. Many of the findings of the present study were similar to those reported by Shimada et al.6 In all eyes, PCC consistently involved the area inferior to the optic disc, although it was not limited to this area and sometimes surrounded almost the entire optic disc. This study also demonstrated that the inferotemporal retinal vein markedly bent at the border edge between the myopic conus and PCC in 53 eyes (43.4%). This rate was lower than reported previously by Shimada et al6 in eyes with high myopia (83.9% of eyes with PCC); however, it was compatible with the current study population, which included eyes with a wider range of refractive error. In eyes with extreme excavation of the
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Figure 4. Funduscopic features of highly myopic eyes with peripapillary choroidal cavitation (PCC). A, Fundus photograph showing the absence of yellow-orange peripapillary abnormality. B, Optical coherence tomography section across the optic disc clearly evidencing a PCC (asterisk). C, Characteristic yellow-orange peripapillary lesion (black arrow): well-circumscribed, elevated, patchy lesion around optic disc and myopic conus (black arrow). D, Optical coherence tomography section across the peripapillary lesion demonstrating a hyporeflective space inferior to the retinal pigment epithelium, corresponding to the PCC (asterisk). E, Peripapillary abnormality that may suggest the presence of PCC presenting as a focal flat blurring inferior to the optic disc and myopic conus (black arrow). F, Optical coherence tomography section across the peripapillary abnormality showing a hyporeflective image corresponding to PCC (asterisk). G, Peripapillary abnormality that may suggest the presence of PCC presenting as pigmentary change around optic disc and myopic conus (black arrow). H, Optical coherence tomography section across the peripapillary abnormality showing a hyporeflective image corresponding to PCC (asterisk) with opening into the vitreous space. White arrows in A, C, E, and G indicate the orientation of the corresponding OCT scans shown in B, D, F, and H.
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Figure 5. Peripapillary choroidal cavitation (PCC; asterisks) in eyes with low myopia, emmetropia, and hyperopia. A, Left hyperopic eye of a 65-year-old woman with ⫹1.25 diopters (D) spherical equivalent (SE) and axial length of 22.5 mm. Peripapillary choroidal cavitation was detected by optical coherence tomography (OCT) despite the absence of a yellow-orange peripapillary lesion at funduscopic examination. B, Left emmetropic eye of a 72-year-old man with ⫺0.75 D SE and axial length of 25.6 mm. Characteristic yellow-orange peripapillary lesion was evidenced on funduscopic examination, and OCT showed a hyporeflective image corresponding to PCC. C, Left low myopic eye of a 59-year-old man with ⫺5.5 D SE and axial length of 25.4 mm. Characteristic yellow-orange peripapillary lesion was evidenced on funduscopic examination, and OCT showed a hyporeflective image corresponding to PCC. White arrows in A, B, and C indicate the orientation of the corresponding OCT scans.
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Figure 6. Peripapillary choroidal cavitation (PCC) with opening in highly myopic eyes with and without excavated myopic conus. A, Fundus photograph of a highly myopia eye with a yellow-orange peripapillary lesion and extreme excavated myopic conus. The inferotemporal retinal vein bending (bayonet) could be evidenced as the vein disappeared into the PCC and resurged at the border of the myopic conus and PCC (black arrow). B, Communication between the PCC and the vitreous space at the junction of the lesion and the myopic conus was detected (asterisk). Hyperreflective intracavitary images suggestive of choroidal splitting (arrowhead) and intracavitary septum (arrows) also were visualized by optical coherence tomography (OCT). C, Fundus photograph of a highly myopic eye with yellow-orange peripapillary lesion and large, not-excavated myopic conus. D, Opening of the intrachoroidal cavity into the vitreous cavity also was evidenced by OCT inferiorly, at the junction of the PCC, and at the myopic conus (asterisk). White arrows in A and C indicate the orientation of the corresponding OCT scans shown in B and D.
myopic conus, the inferotemporal retinal vein demonstrated a bayonet course: it appeared to enter the PCC space and to disappear after bending at the border between the myopic conus and the PCC (Fig 6A). As suggested by Shimada et al,6 the bent retinal vein at the border between the myopic conus and PCC was not an uncommon phenomenon among patients with high myopia and PCC. Although it is uncertain whether the marked bending of the retinal vein in excavated myopic conus eventually may impair the retinal venous flow, this study demonstrated that excavated myopic conus significantly increased the incidence of open PCC detected by OCT (P⬍0.05, Fisher exact probability test; Fig 6). First-generation OCT imaging of the yellow-orange peripapillary lesions in highly myopic eyes revealed images that were interpreted as localized peripapillary detachment of RPE and retina.5,6,9 By using newer-generation OCT imaging, Toranzo et al7 first demonstrated that these peripapillary lesions constitute areas of intrachoroidal cavitation with normal overlying RPE and retina. This study confirmed comparable OCT findings for all eyes included in the data analysis. Both Shimada et al5,6 and Freund et al9 observed that, in some cases, OCT revealed an apparent communication of PCC between the choroidal cavity and the vitreous cavity at the junction of the PCC and the myopic conus. Wei et al11 confirmed similar findings in 6 of 13 analyzed eyes and added that intrachoroidal tissue splitting without optical
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empty cavity was found in several cases. Because of the retrospective design of this study, the prevalence of PCC with opening was only 16% (19 of 122). Similar to Tateno et al8 and Wei et al,11 this study evidenced OCT images of intrachoroidal splitting or schisis characterized by intracavitary cleavage bands and hyperreflective fluid-like images in 48 (39%) eyes of PCC. The authors agree with Freund et al9 in their review that the coexistence of these intrachoroidal findings adjacent to PCCs was relatively common, reinforcing the idea that they may be different stages of 1 disease spectrum.7–9 In the current series, 17 eyes with PCC had some evidence of maculopathy secondary to pathologic myopia that included myopic macular degeneration, foveoschisis, isolated macular subretinal hemorrhage, lacquer crack, and macular choroidal neovascularization. Shimada et al12 suggested that eyes with a PCC may be at risk of a macular retinal detachment developing. They reported a case of macular retinal detachment associated with PCC. Optical coherence tomography detected a communication of the PCC to the vitreous cavity and continuity to the subretinal space. However, 2 retinal hole-like lesions were found at the border of the myopic conus. The present study did not find any case of macular detachment. There were 19 eyes with open PCCs into the vitreous cavity, 3 of which had associated foveoschisis. The area of macular schisis was well
Yeh et al 䡠 Peripapillary Choroidal Cavitation Detected by OCT delimited nasally at the border of the myopic conus. The authors agree with Wei et al11 that the adherence of the retina and RPE at the conus margin may prevent the break from opening into the subretinal space. Eventually, PCC with opening and foveoschisis may coexist as pathologic changes in highly myopic eyes. Vitreous tractional forces resulting in retinal breaks may still be the main cause for the development of macular retinal detachment in eyes with PCC. The pathologic changes specific to PCC and its pathogenesis are still being discussed. Because PCC occurred more frequently in eyes with high myopia, many proposed hypotheses have connected PCC with fundus changes in pathologic myopia. Toranzo et al7 assumed that the progression of the staphyloma breaks the collagenous limiting tissue of Elschnig that connects the choroid to the optic nerve, resulting in separation of the sclera from the RPE by creating a traction cavitation inside the choroid. Shimada et al5 suggested that the posterior excavation of the myopic conus leads to a mechanical stretch of the structurally weaker conus area and the surrounding peripapillary tissue, resulting in splitting of the intrachoroidal structures and formation of cystoid spaces. These cystoid spaces may enlarge and coalesce to form a large cystic area seen as a hyporeflective space on OCT. Wei et al11 agree that the progression of peripapillary staphyloma may stretch and disrupt the tissue at the edge of the myopic conus; however, they believe that the choroidal schisis or a fluid pocket derived from the vitreous fluid gains access into the peripapillary choroidal tissue. The adherence of the retina and RPE at the conus margin prevents the break from opening into the subretinal space. This study demonstrated that PCCs did not occur exclusively in eyes with high myopia. They also were found in eyes with low myopia, emmetropia, and hyperopia. Moreover, these patients were significantly older than those with PCC and high myopia. Aging may play an important role in the pathogenesis of PCC. The conus area and the surrounding peripapillary tissue may be a structurally weaker area per se because of its transitional tissue characteristics. With aging, there may be a decrease in the ability of the tissue to absorb fluids originating from the subretinal space, suprachoroidal space, optic canal, or vitreous cavity. Gravitation of these fluids, even if it is minimal and asymptomatic, results in the formation of fluid pockets at the inferior margin of the conus area. These observations explain the consistent inferior location of the PCC in relationship to the optic nerve, and the fact that it occurs rarely in eyes of young patients. In the authors’ view, the ectatic changes in high myopia eyes are contributory factors to the weakening of the conus area and its surrounding tissue.5,7,11 The retrospective design and the unknown clinical significance of PCCs remain the main limitations of this study. Previous reports by Freund et al4,9 and Wei et al11 noted that PCCs remained stable during several years of follow-up and did not seem to affect visual function. The present data were similar to those of Shimada et al5,6 that demonstrated that PCC had glaucoma-like visual field defects more frequently than eyes without PCC. Seventy-seven eyes (63.1%) had a diagnosis of glaucoma or suspected glaucoma. Forty-six of
them (37.7%) received antiglaucomatous eye drops because of a glaucomatous visual field defect or nerve fiber layer abnormalities. The clinical significance of these glaucomalike visual field defects in eyes with PCC is unclear because glaucoma is at times difficult to be diagnosed in highly myopic eyes because of an atypical optic disc and visual field changes. Another limitation to the current study is the use of conventional time-domain OCT rather than Fourier or spectral-domain OCT to assess deep structures of the posterior segment. Conventional time-domain OCT has a limited capacity to image deep posterior segment tissues such as vascular structures, peripapillary choroid, sclera, and the optic nerve because of a depth-dependent decrease in sensitivity and scattering of light by pigment and blood. Spectral-domain OCT offers higher scan speeds and improved axial image resolution compared with time-domain OCT.10,13,14 Therefore, it is expected that spectral-domain OCT should reduce errors from eye motion and should improve reproducibility, sensitivity, and specificity of image detection of PCCs. In summary, this study showed that PCC was not exclusively found in eyes with high myopia because it also was demonstrated in eyes with low myopia emmetropia, and hyperopia. The characteristic yellow-orange peripapillary lesion may not always be evidenced in the funduscopic examination for all eyes with demonstrable PCC by OCT. Although ectatic changes in eyes with pathologic myopia have been attributed to causing weakening of the conus area and its surrounding tissue, physiologic changes resulting from aging may play a role in the pathogenesis of PCC. Further prospective studies with a more representative study population would be needed to investigate the clinical significance of this entity.
References 1. Huang D, Swanson EA, Lin CP, et al. Optical coherence tomography. Science 1991;254:1178 – 81. 2. Baba T, Ohno-Matsui K, Futagami S, et al. Prevalence and characteristics of foveal retinal detachment without macular hole in high myopia. Am J Ophthalmol 2003;135:338 – 42. 3. Takano M, Kishi S. Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma. Am J Ophthalmol 1999;128:472– 6. 4. Freund KB, Ciardella AP, Yannuzzi LA, et al. Peripapillary detachment in pathologic myopia. Arch Ophthalmol 2003; 121:197–204. 5. Shimada N, Ohno-Matsui K, Nishimuta A, et al. Peripapillary changes detected by optical coherence tomography in eyes with high myopia. Ophthalmology 2007;114:2070 – 6. 6. Shimada N, Ohno-Matsui K, Yoshida T, et al. Characteristics of peripapillary detachment in pathologic myopia. Arch Ophthalmol 2006;124:46 –52. 7. Toranzo J, Cohen SY, Erginay A, Gaudric A. Peripapillary intrachoroidal cavitation in myopia. Am J Ophthalmol 2005; 140:731–2. 8. Tateno H, Takahashi K, Fukuchi T, et al. Choroidal schisis around the optic nerve in myopic eyes evaluated by optical coherence tomography [in Japanese]. Rinsho Ganka 2005;59: 327–31.
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Ophthalmology Volume 120, Number 3, March 2013 9. Freund KB, Mukkamala SK, Cooney MJ. Peripapillary choroidal thickening and cavitation. Arch Ophthalmol 2011;129: 1096 –7. 10. Park SC, De Moraes CG, Teng CC, et al. Enhanced depth imaging optical coherence tomography of deep optic nerve complex structures in glaucoma. Ophthalmology 2012;119: 3–9. 11. Wei YH, Yang CM, Chen MS, et al. Peripapillary intrachoroidal cavitation in high myopia: reappraisal. Eye (Lond) 2009;23:141– 4.
12. Shimada N, Ohno-Matsui K, Iwanaga Y, et al. Macular retinal detachment associated with peripapillary detachment in pathologic myopia. Int Ophthalmol 2009;29:99 –102. 13. Sull AC, Vuong LN, Price LL, et al. Comparison of spectral/ Fourier domain optical coherence tomography instruments for assessment of normal macular thickness. Retina 2010; 30:235– 45. 14. Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain optical coherence tomography. Am J Ophthalmol 2008;146:496 –500.
Footnotes and Financial Disclosures Originally received: January 30, 2012. Final revision: August 2, 2012. Accepted: August 14, 2012. Available online: December 1, 2012.
Presented as a poster at: 23rd Asia Pacific Academy of Ophthalmology (APAO) Congress, June 28-July 2, 2008, Hong Kong. Manuscript no. 2012-138.
1
Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan.
2
Department of Medicine, Nursing and Management College, Mackay Memorial Hospital, Taipei, Taiwan.
3
Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
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Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Correspondence: Lee-Jen Chen, MD, Department of Ophthalmology, Mackay Memorial Hospital, No. 92, Section 2, Chun-Shan North Road, Taipei 104, Taiwan. E-mail:[email protected].