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Efficacy of visual rehabilitation of patients with pellucid marginal degeneration fitted with SPOT® scleral contact lenses
Journal français d’ophtalmologie (2020) 43, e1—e5
Disponible en ligne sur
ScienceDirect www.sciencedirect.com
ORIGINAL ARTICLE
Efficacy of visual rehabilitation of patients with pellucid marginal degeneration fitted with SPOT® scleral contact lenses S. Bézé a,∗, C. Benoist D’azy a, C. Lambert b, F. Chiambaretta a a
Ophthalmology service, centre hospitalier régional universitaire Gabriel-Montpied, place Henri-Dunant, 63000 Clermont-Ferrand, France b Délégation à la recherche clinique et informatique, centre hospitalier régional universitaire Gabriel-Montpied, place Henri-Dunant, 63000 Clermont-Ferrand, France Received 9 September 2019; accepted 17 November 2019 Available online 10 December 2019
KEYWORDS Corneal degeneration; Cornea; Contact lens fitting; Scleral lenses; Pellucid marginal degeneration
∗
Summary Purpose. — To assess visual improvement in patients with pellucid marginal degeneration (PMD) after fitting with SPOT® scleral contact lenses (Scleral Protection & Ocular Treatment, Laboratoires d’Appareillage Oculaire, Amphion-Les-Bains, France). Methods. — We report a case series of 5 patients with PMD and unsatisfactory refractive correction managed at Clermont-Ferrand university hospital from January to December 2018 fitted with customized SPOT scleral lenses. We assessed the best-corrected visual acuity (BCVA) before and after fitting with SPOT, keratometric data and tolerability of the scleral lenses. Results. — Nine eyes of 5 patients aged 51.8 ± 8.47 years were fitted. The BCVA was significantly improved from 0.51 logMAR (± 0.39) to 0.04 logMAR (± 0.07) (P < 0.001). Sixty-six percent of the patients recovered optimal BCVA. No serious adverse event was reported. The presence of whitish deposits and an inordinate amount of manipulation required were the main disadvantages of the lenses. Nevertheless, all the patients considered them to be comfortable. Conclusion. — Fitting PMD patients who have failed conventional optical devices with SPOT scleral lenses significantly improves BCVA, without serious adverse events, allowing surgery to be deferred even when it appears to be unavoidable. © 2019 Elsevier Masson SAS. All rights reserved.
Corresponding author. E-mail addresses: [email protected], [email protected] (S. Bézé).
https://doi.org/10.1016/j.jfo.2019.11.004 0181-5512/© 2019 Elsevier Masson SAS. All rights reserved.
e2
S. Bézé et al.
1. Introduction Pellucid marginal degeneration (PMD) is a rare, bilateral, asymmetric corneal ectasia of unknown origin [1]. No biostatistical studies have evaluated the incidence or prevalence of this disorder [2], characterized by a progressive non-inflammatory inferior peripheral thinning of the cornea, forming a band of thinning which can be seen on biomicroscopy between the 4:00 and 8:00 meridians, separated from the limbus by a 1—2-mm crescent of healthy cornea [3]. The characteristic (but non-specific) topographic appearance on axial mapping includes a flattening of the upper two thirds of the vertical meridians and a step-off in the inferior oblique hemi-meridians, producing a so-called ‘‘walrus mustache,’’ ‘‘windmill’’ or ‘‘crab claw’’ appearance and inducing irregular against the rule astigmatism [2]. PMD can be differentiated from other corneal ectasias, since, as opposed to keratoconus, neither scarring (except after hydrops) nor Fleischer rings are seen, and as opposed to Terrien’s marginal degeneration, neither lipid deposits nor neovascularization are seen [1,2]. Despite the healthy epithelium and transparency of the diseased cornea, the best corrected visual acuity of PMD patients decreases in proportion to the increase in irregular astigmatism, rendering the functional prognosis very severe. Although early cases of PMD can be fit in glasses [4] or soft, rigid or even hybrid contact lenses [5], fitting soon becomes difficult, requiring various surgical techniques: lamellar [6] or penetrating [7] keratoplasty intracorneal ring segments [8], wedge resections [9], relaxing incisions, tuck-in lamellar keratoplasty (TILK) [10], etc. However, these techniques are difficult and their complications numerous [7—10]. Scleral contact lenses are an interesting non-surgical option in these situations [11,12]. These large diameter scleral contact lenses form a tear meniscus between themselves and the cornea, thus correcting high refractive aberrations. We report the management of 5 PMD patients fir in SPOT (Scleral Protection & Ocular Treatment, Laboratoires d’Appareillage Oculaire, Amphion-Les-Bains, France) scleral contact lenses in 2018 at the Clermont-Ferrand university medical center, for whom we studied the best corrected visual acuity before and after SPOT fitting, as well as the contact lens tolerability.
2. Materials and methods 2.1. Study population Nine eyes of 5 PMD patients underwent SPOT contact lens fitting (Fig. 1) at the Clermont-Ferrand university medical center between January and December 2018. The patients met all the criteria of PMD, with clinically apparent non-inflammatory inferior peripheral corneal thinning separated from the limbus by a crescent of healthy cornea, and the typical topographic ‘‘walrus mustache’’ appearance (Wavelight Oculyzer II, Pentacam, Germany) (Fig. 2). In cases of possible coexisting keratoconus, these patients were excluded. All patients had failed conventional refractive options (glasses, soft or rigid contact lenses).
Figure 1. SPOT contact lens on a left eye with inferior pellucid marginal degeneration, with verification of the fit by fluorescein instillation.
2.2. Data collection The following data were collected: clinical and demographic characteristics of the patients, type of optical correction prior to fitting, corneal topographic data, best corrected visual acuity before and after fitting (verified on followup after 1 month of wear), characteristics of SPOT lenses chosen, complications of fitting, and comfort in SPOT lenses.
2.3. Customized fitting procedure During the first visit, the diameter of SPOT lens was chosen according to the size of the globe, the depth of the cul-desacs and comfort. The vault (elevation of the lens relative to a horizontal plane) had to create a fluid space between the cornea and the contact lens of approximately one-half corneal thickness. The material chosen, which depends on the pathology and desired oxygen permeability, was ‘‘XO2 ’’ (Boston® XO2 Labo. Bausch &Lomb, United States, Dk = 161) in all cases in our series. The lens was filled with nonpreserved normal saline and placed with the patient tilting his or her head face-down. After 3 hours of wear, flow of tears under the lens was verified by fluorescein staining of the space created by the vault. Scleral touch was adjusted by flattening or steepening the radius, adding back surface toricity, or creating notches or truncations. The refractive power was adjusted by over-refraction. A customized lens was prescribed, handled and worn during the second visit. If comfortable, the lens was worn for 1 month, and a follow-up visit evaluated the comfort and visual acuity.
2.4. Statistical analysis Statistical analyses were performed with Stata software (version 13; StataCorp, College Station, Texas, USA), using
Visual rehabilitation of patients with PMD fitted with SPOT®
Figure 2.
e3
Keratometry data consistent with pellucid marginal degeneration.
a bilateral type 1 error risk of 5%. The population was described in terms of numbers and associated percentages for categorical variables and mean ± standard deviation or median [interquartile interval] for quantitative variables, depending on their statistical distribution. Since both eyes of the same patient could be studied, change in visual acuity (logMAR) before/after fitting was measured by a mixed linear model, defining the patient as a random effect and time (before/after) as a fixed effect.
3.1. Keratometric data The mean flattest meridian K1 was 38.0 ± 10.9 D, the steepest meridian K2 was 52.3 ± 3.8 D, and the maximum keratometry Kmax was 59.4 ± 10.1 D. The minimum pachymetry was 392 ± 86.7 m. The mean corneal astigmatism was 14.4 ± 10.2 D, with a mean axis of 94.4◦ ± 18.9. This keratometric data is reported in Table 2 and is consistent with the against the rule irregular astigmatism induced by PMD ectasia.
3.2. Visual acuity results
3. Results Between January and December 2018 at the ClermontFerrand university medical center, we collected data on 9 eyes (4 right, 5 left) of 5 patients (2 women, 3 men), age 51.8 ± 8.47 years (range 42—65 years), fitted in SPOT contact lenses for PMD. The condition was bilateral in 4 patients out of 5; 2 patients (40%) had previously received glasses due to contact lens intolerance, and 3 (60%) had been fitted in rigid contact lenses. The clinical and demographic characteristics of the patients are reported in Table 1.
Visual acuity prior to fitting was 0.51 logMAR (± 0.39), and a net gain in mean visual acuity at the 1-month follow-up after fitting was seen, with a mean visual acuity of 0.04 logMAR (± 0.07) (P < 0.001). It should be noted that 66% of the patients returned to optimal 0 logMAR visual acuity. Only one eye, initially 0.1 logMAR, did not improve after SPOT contact lens fitting.
3.3. Tolerability and complications The lenses were worn for a mean of 8.7 hours ± 1.9 per day. On systematic questioning, all patients considered SPOT
e4 Table 1
S. Bézé et al. Demographic and clinical characteristics of patients.
n=5
(mean ± SD) (min—max)
Age (mean ± SD) (min—max) Sex Male, n (%) Female, n (%) Eyes (9) Right, n (%) Left, n (%) Indication Glasses failure, n (%) Rigid contact lens failure, n (%) Visual acuity prior to fitting (logMAR)(mean ± SD) (min—max)
51.8 ± 8.5 (42—65)
Table 2
3 (60) 2 (40) 4 (44.4) 5 (55.6) 2 (40) 3 (60) 0.5 ± 0.39 (0.1—1.1)
Keratometric characteristics of fitted eyes.
n=9
(mean ± SD) (min—max)
Flattest meridian (K1 ) (diopters) Steepest meridian (K2 ) (diopters) Maximum keratometry (Kmax ) (diopters) Minimum pachymetry (m) Corneal astigmatism Power (diopters) Axis (degrees)
38.0 ± 10.9 (16.3—52.5) 52.3 ± 3.8 (45.7—58) 59.3 ± 10.1 (46.8—75.2) 392 ± 86.7 (195—478)
contact lens wear ‘‘comfortable,’’ and three patients (60%) described putting scleral lenses in as ‘‘time-consuming.’’ No severe adverse effects (infectious, hypoxic or immuneallergic) occurred. One patient described binocular diplopia on putting the lenses in, which regressed spontaneously in 1 month and was no longer reported at the follow-up visit. All patients described deposits in the lenses upon taking them out, but these deposits did not result in early cessation of lens wear in any of the patients, and they required only a simple once or twice a day rinse with non-preserved normal saline.
4. Discussion In our series, fitting with SPOT scleral contact lenses significantly improved visual acuity in patients with PMD, going from 0.51 logMAR (± 0.39) to 0.04 logMAR (± 0.07) (P < 0.001), consistent with previous observations in the literature. Although few studies specifically addressed this rare corneal pathology, Rathi et al. [11] had shown a significant improvement in visual acuity in 20 eyes of 12 PMD patients fitted with PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem, Boston Foundation for Sightight, United States) scleral lenses, and Asena et al. [12] had similar results with 24 eyes with PMD fitted with MISA (Microlens Contactlens Technolgy, Arnhem, Holland) scleral lenses. The study population is representative of the disease, with a mean age of 51.8 years and a slight male predominance [1]. The small number of cases is also expected,
14.4 ± 10.2 (4.9—34.4) 94.4 ± 18.9 (66—121)
given the rarity of this pathology, often confused with keratoconus. We deliberately excluded patients for whom we might have diagnosed concurrent keratoconus and PMD. Although scleral contact lenses were historically poorly tolerated, oxygen permeability has enabled them to become an effective and comfortable tool for visual rehabilitation in patients with significant irregular astigmatism poorly corrected with glasses or classic contact lenses (soft, rigid or hybrid). The indication for SPOT lenses in PMD is validated, similarly to a number of other pathologies that cause astigmatism, in cases of failure of classic optical correction: keratoconus [13], clear but irregularly shaped corneal transplant [14], high and/or irregular astigmatism, and corneal scar [15]. The absence of major adverse effects makes SPOT contact lenses a safe device. The formation of corneal deposits during wear constitutes the main adverse effect reported, but this is easily addressed by simple rinsing [16], and negligible compared to the increase in visual acuity provided by wearing scleral lenses. One patient, greatly improved by scleral lens fitting (her best corrected visual acuity going from 1/10 in the right eye and 5/10 in the left eye with glasses to 10/10 in both eyes with SPOT lenses), described transient binocular diplopia on initial wear, which spontaneously resolved in 1 month. This might be explained by a loss of binocular fusion under low-vision conditions, which became apparent upon improvement of the visual acuity and spontaneously and progressively returned to normal in 1 month [17]. Given these observations and the rarity of the disease, a multicenter, masked, controlled study would allow for
Visual rehabilitation of patients with PMD fitted with SPOT®
e5
confirmation of the efficacy of SPOT lenses in the visual rehabilitation of patients with PMD, and a longer follow-up would verify safety.
[6] Al-Torbak AA. Deep anterior lamellar keratoplasty for pellucid marginal degeneration. Saudi J Ophthalmol 2013;27:11—4. [7] Speaker MG, Arentsen JJ, Laibson PR. Long-term survival of large diameter penetrating keratoplasties for keratoconus and pellucid marginal degeneration. Acta Ophthalmol Suppl 1989;192:17—9. [8] Akaishi L, Tzelikis PF, Raber IM. Ferrara intracorneal ring implantation and cataract surgery for the correction of pellucid marginal corneal degeneration. J Cataract Refract Surg 2004;30:2427—30. [9] Cameron JA. Results of lamellar crescentic resection for pellucid marginal corneal degeneration. Am J Ophthalmol 1992;113:296—302. [10] Kaushal S, Jhanji V, Sharma N, Tandon R, Titiyal JS, Vajpayee RB. ‘‘Tuck In’’ Lamellar Keratoplasty (TILK) for corneal ectasias involving corneal periphery. Br J Ophthalmol 2008;92: 286—90. [11] Rathi VM, Dumpati S, Mandathara PS, Taneja MM, Sangwan VS. Scleral contact lenses in the management of pellucid marginal degeneration. Cont Lens Anterior Eye 2016;39: 217—20. [12] Asena L, Altınörs DD. Clinical outcomes of scleral Misa lenses for visual rehabilitation in patients with pellucid marginal degeneration. Cont Lens Anterior Eye 2016;39:420—4. [13] Galvis V, Tello A, Carre˜ no NI, Ni˜ no CA, Berrospi RD. Scleral lenses reduce the need for corneal transplants in severe keratoconus. Am J Ophthalmol 2018;190:202—3. [14] Barnett M, Lien V, Li JY, Durbin-Johnson B, Mannis MJ. Use of scleral lenses and miniscleral lenses after penetrating keratoplasty. Eye Contact Lens 2016;42:185—9. [15] Cressey A, Jacobs DS, Remington C, Carrasquillo KG. Improvement of chronic corneal opacity in ocular surface disease with prosthetic replacement of the ocular surface ecosystem (PROSE) treatment. Am J Ophthalmol Case Rep 2018;10:108—13. [16] Ortenberg I, Behrman S, Geraisy W, Barequet IS. Wearing time as a measure of success of scleral lenses for patients with irregular astigmatism. Eye Contact Lens 2013;39:381—4. [17] Sherafat H, White JE, Pullum KW, Adams GG, Sloper JJ. Anomalies of binocular function in patients with longstanding asymmetric keratoconus. Br J Ophthalmol 2001;85:1057—60.
5. Conclusion Oxygen permeable SPOT scleral contact lenses appear to be an interesting alternative for the optical, non-surgical management of patients with PMD, when classic devices (glasses or other contact lenses) have ceased to work or become poorly tolerated. Essentially, they provide almost perfect visual rehabilitation, with a mean visual acuity after fitting of 0.04 logMAR, and only minor side effects. The mild complexity of manipulation in no way constitutes a barrier to their effective use.
Disclosure of interest The authors declare that they have no competing interest. F.C.: Consultant for Alcon, Théa, Horus, Santen.
References [1] Ambrósio JR, Klyce SD, Smolek MK, Wilson SE. Pellucid marginal corneal degeneration. J Refract Surg 2002;18:86—8. [2] Jinabhai A, Radhakrishnan H, O’Donnell C. Pellucid corneal marginal degeneration: a review. Cont Lens Anterior Eye 2011;34:56—63. [3] Martínez-Abad A, Pi˜ nero DP. Pellucid marginal degeneration: detection, discrimination from other corneal ectatic disorders and progression. Contact Lens Anterior Eye 2018;42:341—9. [4] Tzelikis PF, Cohen EJ, Rapuano CJ, Hammersmith KM, Laibson PR. Management of pellucid marginal corneal degeneration. Cornea 2005;24:555—60. [5] Fernandez-Velazquez FJ, Kerasoft IC. compared to Rose-K in the management of corneal ectasias. Cont Lens Anterior Eye 2012;35:175—9.
Disponible en ligne sur
ScienceDirect www.sciencedirect.com
ORIGINAL ARTICLE
Efficacy of visual rehabilitation of patients with pellucid marginal degeneration fitted with SPOT® scleral contact lenses S. Bézé a,∗, C. Benoist D’azy a, C. Lambert b, F. Chiambaretta a a
Ophthalmology service, centre hospitalier régional universitaire Gabriel-Montpied, place Henri-Dunant, 63000 Clermont-Ferrand, France b Délégation à la recherche clinique et informatique, centre hospitalier régional universitaire Gabriel-Montpied, place Henri-Dunant, 63000 Clermont-Ferrand, France Received 9 September 2019; accepted 17 November 2019 Available online 10 December 2019
KEYWORDS Corneal degeneration; Cornea; Contact lens fitting; Scleral lenses; Pellucid marginal degeneration
∗
Summary Purpose. — To assess visual improvement in patients with pellucid marginal degeneration (PMD) after fitting with SPOT® scleral contact lenses (Scleral Protection & Ocular Treatment, Laboratoires d’Appareillage Oculaire, Amphion-Les-Bains, France). Methods. — We report a case series of 5 patients with PMD and unsatisfactory refractive correction managed at Clermont-Ferrand university hospital from January to December 2018 fitted with customized SPOT scleral lenses. We assessed the best-corrected visual acuity (BCVA) before and after fitting with SPOT, keratometric data and tolerability of the scleral lenses. Results. — Nine eyes of 5 patients aged 51.8 ± 8.47 years were fitted. The BCVA was significantly improved from 0.51 logMAR (± 0.39) to 0.04 logMAR (± 0.07) (P < 0.001). Sixty-six percent of the patients recovered optimal BCVA. No serious adverse event was reported. The presence of whitish deposits and an inordinate amount of manipulation required were the main disadvantages of the lenses. Nevertheless, all the patients considered them to be comfortable. Conclusion. — Fitting PMD patients who have failed conventional optical devices with SPOT scleral lenses significantly improves BCVA, without serious adverse events, allowing surgery to be deferred even when it appears to be unavoidable. © 2019 Elsevier Masson SAS. All rights reserved.
Corresponding author. E-mail addresses: [email protected], [email protected] (S. Bézé).
https://doi.org/10.1016/j.jfo.2019.11.004 0181-5512/© 2019 Elsevier Masson SAS. All rights reserved.
e2
S. Bézé et al.
1. Introduction Pellucid marginal degeneration (PMD) is a rare, bilateral, asymmetric corneal ectasia of unknown origin [1]. No biostatistical studies have evaluated the incidence or prevalence of this disorder [2], characterized by a progressive non-inflammatory inferior peripheral thinning of the cornea, forming a band of thinning which can be seen on biomicroscopy between the 4:00 and 8:00 meridians, separated from the limbus by a 1—2-mm crescent of healthy cornea [3]. The characteristic (but non-specific) topographic appearance on axial mapping includes a flattening of the upper two thirds of the vertical meridians and a step-off in the inferior oblique hemi-meridians, producing a so-called ‘‘walrus mustache,’’ ‘‘windmill’’ or ‘‘crab claw’’ appearance and inducing irregular against the rule astigmatism [2]. PMD can be differentiated from other corneal ectasias, since, as opposed to keratoconus, neither scarring (except after hydrops) nor Fleischer rings are seen, and as opposed to Terrien’s marginal degeneration, neither lipid deposits nor neovascularization are seen [1,2]. Despite the healthy epithelium and transparency of the diseased cornea, the best corrected visual acuity of PMD patients decreases in proportion to the increase in irregular astigmatism, rendering the functional prognosis very severe. Although early cases of PMD can be fit in glasses [4] or soft, rigid or even hybrid contact lenses [5], fitting soon becomes difficult, requiring various surgical techniques: lamellar [6] or penetrating [7] keratoplasty intracorneal ring segments [8], wedge resections [9], relaxing incisions, tuck-in lamellar keratoplasty (TILK) [10], etc. However, these techniques are difficult and their complications numerous [7—10]. Scleral contact lenses are an interesting non-surgical option in these situations [11,12]. These large diameter scleral contact lenses form a tear meniscus between themselves and the cornea, thus correcting high refractive aberrations. We report the management of 5 PMD patients fir in SPOT (Scleral Protection & Ocular Treatment, Laboratoires d’Appareillage Oculaire, Amphion-Les-Bains, France) scleral contact lenses in 2018 at the Clermont-Ferrand university medical center, for whom we studied the best corrected visual acuity before and after SPOT fitting, as well as the contact lens tolerability.
2. Materials and methods 2.1. Study population Nine eyes of 5 PMD patients underwent SPOT contact lens fitting (Fig. 1) at the Clermont-Ferrand university medical center between January and December 2018. The patients met all the criteria of PMD, with clinically apparent non-inflammatory inferior peripheral corneal thinning separated from the limbus by a crescent of healthy cornea, and the typical topographic ‘‘walrus mustache’’ appearance (Wavelight Oculyzer II, Pentacam, Germany) (Fig. 2). In cases of possible coexisting keratoconus, these patients were excluded. All patients had failed conventional refractive options (glasses, soft or rigid contact lenses).
Figure 1. SPOT contact lens on a left eye with inferior pellucid marginal degeneration, with verification of the fit by fluorescein instillation.
2.2. Data collection The following data were collected: clinical and demographic characteristics of the patients, type of optical correction prior to fitting, corneal topographic data, best corrected visual acuity before and after fitting (verified on followup after 1 month of wear), characteristics of SPOT lenses chosen, complications of fitting, and comfort in SPOT lenses.
2.3. Customized fitting procedure During the first visit, the diameter of SPOT lens was chosen according to the size of the globe, the depth of the cul-desacs and comfort. The vault (elevation of the lens relative to a horizontal plane) had to create a fluid space between the cornea and the contact lens of approximately one-half corneal thickness. The material chosen, which depends on the pathology and desired oxygen permeability, was ‘‘XO2 ’’ (Boston® XO2 Labo. Bausch &Lomb, United States, Dk = 161) in all cases in our series. The lens was filled with nonpreserved normal saline and placed with the patient tilting his or her head face-down. After 3 hours of wear, flow of tears under the lens was verified by fluorescein staining of the space created by the vault. Scleral touch was adjusted by flattening or steepening the radius, adding back surface toricity, or creating notches or truncations. The refractive power was adjusted by over-refraction. A customized lens was prescribed, handled and worn during the second visit. If comfortable, the lens was worn for 1 month, and a follow-up visit evaluated the comfort and visual acuity.
2.4. Statistical analysis Statistical analyses were performed with Stata software (version 13; StataCorp, College Station, Texas, USA), using
Visual rehabilitation of patients with PMD fitted with SPOT®
Figure 2.
e3
Keratometry data consistent with pellucid marginal degeneration.
a bilateral type 1 error risk of 5%. The population was described in terms of numbers and associated percentages for categorical variables and mean ± standard deviation or median [interquartile interval] for quantitative variables, depending on their statistical distribution. Since both eyes of the same patient could be studied, change in visual acuity (logMAR) before/after fitting was measured by a mixed linear model, defining the patient as a random effect and time (before/after) as a fixed effect.
3.1. Keratometric data The mean flattest meridian K1 was 38.0 ± 10.9 D, the steepest meridian K2 was 52.3 ± 3.8 D, and the maximum keratometry Kmax was 59.4 ± 10.1 D. The minimum pachymetry was 392 ± 86.7 m. The mean corneal astigmatism was 14.4 ± 10.2 D, with a mean axis of 94.4◦ ± 18.9. This keratometric data is reported in Table 2 and is consistent with the against the rule irregular astigmatism induced by PMD ectasia.
3.2. Visual acuity results
3. Results Between January and December 2018 at the ClermontFerrand university medical center, we collected data on 9 eyes (4 right, 5 left) of 5 patients (2 women, 3 men), age 51.8 ± 8.47 years (range 42—65 years), fitted in SPOT contact lenses for PMD. The condition was bilateral in 4 patients out of 5; 2 patients (40%) had previously received glasses due to contact lens intolerance, and 3 (60%) had been fitted in rigid contact lenses. The clinical and demographic characteristics of the patients are reported in Table 1.
Visual acuity prior to fitting was 0.51 logMAR (± 0.39), and a net gain in mean visual acuity at the 1-month follow-up after fitting was seen, with a mean visual acuity of 0.04 logMAR (± 0.07) (P < 0.001). It should be noted that 66% of the patients returned to optimal 0 logMAR visual acuity. Only one eye, initially 0.1 logMAR, did not improve after SPOT contact lens fitting.
3.3. Tolerability and complications The lenses were worn for a mean of 8.7 hours ± 1.9 per day. On systematic questioning, all patients considered SPOT
e4 Table 1
S. Bézé et al. Demographic and clinical characteristics of patients.
n=5
(mean ± SD) (min—max)
Age (mean ± SD) (min—max) Sex Male, n (%) Female, n (%) Eyes (9) Right, n (%) Left, n (%) Indication Glasses failure, n (%) Rigid contact lens failure, n (%) Visual acuity prior to fitting (logMAR)(mean ± SD) (min—max)
51.8 ± 8.5 (42—65)
Table 2
3 (60) 2 (40) 4 (44.4) 5 (55.6) 2 (40) 3 (60) 0.5 ± 0.39 (0.1—1.1)
Keratometric characteristics of fitted eyes.
n=9
(mean ± SD) (min—max)
Flattest meridian (K1 ) (diopters) Steepest meridian (K2 ) (diopters) Maximum keratometry (Kmax ) (diopters) Minimum pachymetry (m) Corneal astigmatism Power (diopters) Axis (degrees)
38.0 ± 10.9 (16.3—52.5) 52.3 ± 3.8 (45.7—58) 59.3 ± 10.1 (46.8—75.2) 392 ± 86.7 (195—478)
contact lens wear ‘‘comfortable,’’ and three patients (60%) described putting scleral lenses in as ‘‘time-consuming.’’ No severe adverse effects (infectious, hypoxic or immuneallergic) occurred. One patient described binocular diplopia on putting the lenses in, which regressed spontaneously in 1 month and was no longer reported at the follow-up visit. All patients described deposits in the lenses upon taking them out, but these deposits did not result in early cessation of lens wear in any of the patients, and they required only a simple once or twice a day rinse with non-preserved normal saline.
4. Discussion In our series, fitting with SPOT scleral contact lenses significantly improved visual acuity in patients with PMD, going from 0.51 logMAR (± 0.39) to 0.04 logMAR (± 0.07) (P < 0.001), consistent with previous observations in the literature. Although few studies specifically addressed this rare corneal pathology, Rathi et al. [11] had shown a significant improvement in visual acuity in 20 eyes of 12 PMD patients fitted with PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem, Boston Foundation for Sightight, United States) scleral lenses, and Asena et al. [12] had similar results with 24 eyes with PMD fitted with MISA (Microlens Contactlens Technolgy, Arnhem, Holland) scleral lenses. The study population is representative of the disease, with a mean age of 51.8 years and a slight male predominance [1]. The small number of cases is also expected,
14.4 ± 10.2 (4.9—34.4) 94.4 ± 18.9 (66—121)
given the rarity of this pathology, often confused with keratoconus. We deliberately excluded patients for whom we might have diagnosed concurrent keratoconus and PMD. Although scleral contact lenses were historically poorly tolerated, oxygen permeability has enabled them to become an effective and comfortable tool for visual rehabilitation in patients with significant irregular astigmatism poorly corrected with glasses or classic contact lenses (soft, rigid or hybrid). The indication for SPOT lenses in PMD is validated, similarly to a number of other pathologies that cause astigmatism, in cases of failure of classic optical correction: keratoconus [13], clear but irregularly shaped corneal transplant [14], high and/or irregular astigmatism, and corneal scar [15]. The absence of major adverse effects makes SPOT contact lenses a safe device. The formation of corneal deposits during wear constitutes the main adverse effect reported, but this is easily addressed by simple rinsing [16], and negligible compared to the increase in visual acuity provided by wearing scleral lenses. One patient, greatly improved by scleral lens fitting (her best corrected visual acuity going from 1/10 in the right eye and 5/10 in the left eye with glasses to 10/10 in both eyes with SPOT lenses), described transient binocular diplopia on initial wear, which spontaneously resolved in 1 month. This might be explained by a loss of binocular fusion under low-vision conditions, which became apparent upon improvement of the visual acuity and spontaneously and progressively returned to normal in 1 month [17]. Given these observations and the rarity of the disease, a multicenter, masked, controlled study would allow for
Visual rehabilitation of patients with PMD fitted with SPOT®
e5
confirmation of the efficacy of SPOT lenses in the visual rehabilitation of patients with PMD, and a longer follow-up would verify safety.
[6] Al-Torbak AA. Deep anterior lamellar keratoplasty for pellucid marginal degeneration. Saudi J Ophthalmol 2013;27:11—4. [7] Speaker MG, Arentsen JJ, Laibson PR. Long-term survival of large diameter penetrating keratoplasties for keratoconus and pellucid marginal degeneration. Acta Ophthalmol Suppl 1989;192:17—9. [8] Akaishi L, Tzelikis PF, Raber IM. Ferrara intracorneal ring implantation and cataract surgery for the correction of pellucid marginal corneal degeneration. J Cataract Refract Surg 2004;30:2427—30. [9] Cameron JA. Results of lamellar crescentic resection for pellucid marginal corneal degeneration. Am J Ophthalmol 1992;113:296—302. [10] Kaushal S, Jhanji V, Sharma N, Tandon R, Titiyal JS, Vajpayee RB. ‘‘Tuck In’’ Lamellar Keratoplasty (TILK) for corneal ectasias involving corneal periphery. Br J Ophthalmol 2008;92: 286—90. [11] Rathi VM, Dumpati S, Mandathara PS, Taneja MM, Sangwan VS. Scleral contact lenses in the management of pellucid marginal degeneration. Cont Lens Anterior Eye 2016;39: 217—20. [12] Asena L, Altınörs DD. Clinical outcomes of scleral Misa lenses for visual rehabilitation in patients with pellucid marginal degeneration. Cont Lens Anterior Eye 2016;39:420—4. [13] Galvis V, Tello A, Carre˜ no NI, Ni˜ no CA, Berrospi RD. Scleral lenses reduce the need for corneal transplants in severe keratoconus. Am J Ophthalmol 2018;190:202—3. [14] Barnett M, Lien V, Li JY, Durbin-Johnson B, Mannis MJ. Use of scleral lenses and miniscleral lenses after penetrating keratoplasty. Eye Contact Lens 2016;42:185—9. [15] Cressey A, Jacobs DS, Remington C, Carrasquillo KG. Improvement of chronic corneal opacity in ocular surface disease with prosthetic replacement of the ocular surface ecosystem (PROSE) treatment. Am J Ophthalmol Case Rep 2018;10:108—13. [16] Ortenberg I, Behrman S, Geraisy W, Barequet IS. Wearing time as a measure of success of scleral lenses for patients with irregular astigmatism. Eye Contact Lens 2013;39:381—4. [17] Sherafat H, White JE, Pullum KW, Adams GG, Sloper JJ. Anomalies of binocular function in patients with longstanding asymmetric keratoconus. Br J Ophthalmol 2001;85:1057—60.
5. Conclusion Oxygen permeable SPOT scleral contact lenses appear to be an interesting alternative for the optical, non-surgical management of patients with PMD, when classic devices (glasses or other contact lenses) have ceased to work or become poorly tolerated. Essentially, they provide almost perfect visual rehabilitation, with a mean visual acuity after fitting of 0.04 logMAR, and only minor side effects. The mild complexity of manipulation in no way constitutes a barrier to their effective use.
Disclosure of interest The authors declare that they have no competing interest. F.C.: Consultant for Alcon, Théa, Horus, Santen.
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