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Meesmann epithelial corneal dystrophy: recurrence following photorefractive keratectomy
CASE REPORT Meesmann epithelial corneal dystrophy: recurrence following photorefractive keratectomy Meesmann epithelial corneal dystrophy (MECD) is a rare, bilateral, autosomal-dominant trait having genetic heterogeneity such that mutations in either of 2 different genes responsible for keratin production (KRT3 and KRT12) cause a single dystrophic phenotype.1 MECD is characterized by myriad, small intraepithelial vesicles appearing in whorled and wedge-shaped patterns.1 These greyish opacity patterns can be viewed by biomicroscopy using direct illumination. Upon retroillumination, distinct, solitary, round, transparent microcysts are visible. Additionally, the epithelial basement membrane may be irregular,2–4 abnormally thick, and multilaminar.5,6 Occurring as early as 6 months of age, more typically it is delayed until late childhood or early adulthood, and slowly progresses. Although usually asymptomatic, lacrimation, photophobia, irritation, glare, and mild visual acuity reduction may develop.7 Although no treatment is usually necessary, if discomfort or visual impairment develops, then treatment options include soft contact lenses,8 superficial keratectomy without or with mitomycin C,9 phototherapeutic keratectomy (PTK),10 lamellar keratoplasty,11 or penetrating keratoplasty.12
Although dystrophy frequently recurs after any of these treatments, in some cases recurrence may be delayed or less severe,6,13 or may not occur.10,14 As de-epithelialization of the central cornea occurs in the course of photorefractive keratectomy, we questioned whether the healing epithelium would demonstrate dystrophic characteristics. Although photorefractive keratectomy (PRK), PTK, and laser-assisted in situ keratomileusis (LASIK) have been studied for more common anterior corneal dystrophies, their application in MECD has yet to be reported.15
CASE REPORT A 32-year-old white male desiring refractive surgery for correction of a myopic refractive error ( 2.25 to 0.75 168 OD and 2.00 to 1.00 15 OS) correctable to 20/20 in each eye was evaluated for surgery. By slit lamp, the corneal epithelium demonstrated myriad minute, discrete, graywhite punctate opacities, clear upon retro-illumination, and diffusely distributed over the corneal surface, particularly in the central 6 mm diameter of the interpalpebral zone (Fig. 1A). The corneas otherwise appeared normal, and corneal sensation was intact. Given the patient’s visual potential and otherwise normal eyes, excimer PRK was judged appropriately, and
Fig. 1 — (A) Preoperative slit-lamp retroillumination of the iris discloses myriad intraepithelial vesicles or microcysts, predominantly in the interpalpebral zone (most readily visible adjacent to pupillary margin). (B) At 6 weeks after PRK, the healed corneal epithelium is free of vesicles within the area of operative epithelial debridement. (C) At 5 months post-PRK, epithelial vesicle density has returned to approximately 30%–40% of preoperative level in the central treatment zone. (D) At 12 months post-PRK, epithelial vesicle density has returned essentially to preoperative levels. PRK, photorefractive keratectomy. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Case Report accordingly this procedure was conducted without difficulty in the left and subsequently right eyes utilizing 20% ethanol-assisted mechanical de-epithelialization of the central cornea and standard PRK ablation with a VISX STAR S2™ (AMO; Abbott Laboratories Inc, Abbott Park, IL) excimer laser. An Acuvue bandage contact lens (Johnson & Johnson, New Brunswick, NJ) was applied, followed by tobramycin 0.3% and dexamethasone 0.1% ophthalmic suspension (Tobradexs; Alcon Laboratories Inc, Fort Worth, TX) and ketorolac tromethamine (0.4%) ophthalmic solution (Acular LSs; Allergan Inc, Irvine, CA), all 4 times daily. The bandage soft contact lens and medications were continued for approximately 1 week postoperatively, during which time the corneal epithelial defects had healed uneventfully in both eyes. At each visit, specifically preoperative and postoperative day 1; week 1, 2, 3, 4, and 6; and month 2, 5, 6, and 12 and utilizing the slit-lamp biomicroscope aided by a magnifying reticule, vesicular counts and size measurements within the central 6-mm-diameter ablation zone were performed by the same observer (J.V.G.). (Given the semiquantitative limits of such observations, vesicular counts were compared as an approximate percentage relative to pretreatment population density.)
RESULTS The healed corneal epithelium demonstrated no abnormality until 6 weeks in the right eye (Fig. 1B) and 3 weeks in the left eye, at which time typical intraepithelial microvesicles again became occasionally apparent. By 2 months, vesicular population density was found to be at 10%–15% of preoperative levels, increasing to 30%–40% between 2 and 5 months (Fig. 1C) and further to 75%– 90% by 6 months. At 12 months (Fig. 1D), vesicular density was equivalent to the preoperative measurement. By 2 months, vesicle diameters measured up to 20 microns and increased up to 30 microns at 5 months. By 6 months, vesicle diameter measured up to 40 microns and by 12 months measured as large as 50 microns. Importantly, no problems of initial epithelial healing or recurrent erosion were encountered, and corneal sensation remained intact. After 1 year, uncorrected visual acuity was 20/20 OD and 20/20 OS with a refractive error of 0.25 OD and plano OS.
DISCUSSION MECD, a disorder of the corneal epithelium and basement membrane, has been traditionally treated by removing these abnormal tissue layers via superficial keratectomy without or with mitomycin C,9 PTK,10 lamellar,11 or penetrating keratoplasty.12 Although intraepithelial microcysts have been reported to recur after such efforts,2,11,12 as the PRK procedure involves not only debridement of the abnormal central corneal epithelium but also photoablation of the underlying thick and multilaminar basement membrane,5,6 it might be anticipated that additional therapeutic
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benefit could result, especially as subepithelial fibrosis might also be accomplished. In the current case, PRK did accomplish a highly satisfactory visual outcome despite eventual recurrence of vesicular populations and sizes similar to preoperative levels. Perhaps this phenomenon could have been anticipated, as the presumably affected limbal stem cells would continue to produce similarly affected epithelial progeny.6 Despite this characteristic epithelial recurrence, the otherwise positive anatomical and visual outcome suggests that in appropriately selected cases, PRK may be appropriately performed in individuals with MECD. Jack V. Greiner, DO, PhD,*,†,‡ Michael E. Lindsay, BA,*,† Kenneth R. Kenyon, MD,*,†,‡,§ John P. Herman, OD,∥ Chaitanya V. Reddy, DO* *The Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts; †Boston Ocular Surface Center, Boston, Massachusetts, USA; ‡Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts; §Cornea Consultants International, Boston, Massachusetts, USA; ||Pittsfield Vision Associates, Pittsfield, Massachusetts, USA. Correspondence to: Jack V. Greiner, D.O., Ph.D., Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 20 Staniford Street, Boston, MA 02114; [email protected] REFERENCES 1. Weiss JS, Moeller H, Aldave AA, et al. The IC3D classification of the corneal dystrophies. Cornea. 2015;34:117-59. 2. Kuwabara T, Ciccarelli EC. Meesmann’s corneal dystrophy. Arch Ophthalmol. 1964;71:676-82. 3. Nakanishi I, Brown SI. Ultrastructure of the epithelial dystrophy of Meesmann. Arch Ophhthalmol. 1975;93:259-63. 4. Fine BS, Yanoff M, Pits E, et al. Meesmann’s epithelial dystrophy of the cornea. Am J Ophthalmol. 1977;83:633-42. 5. Tremblay M, Dube I. Meesmann’s corneal dystrophy: ultrastructural features. Can J Ophthalmol. 1982;17:24-8. 6. Burns RP. Meesmann’s corneal dystrophy. Trans Am Ophthalmol Soc. 1968;66:530-635. 7. Wittebol-Post D, van Bijsterveld OP, Delleman JW. Meesmann’s epithelial dystrophy of the cornea: biometrics and a hypothesis. Ophthalmologica. 1987;194:44-9. 8. Bourne WM. Soft contact lens wear decreases epithelial microcysts in Meesmann’s corneal dystrophy. Trans Am Ophthalmol Soc. 1986;84:170-82. 9. Yeung J, Hodge W. Recurrent Meesmann’s corneal dystrophy: treatment with keratectomy and mitomycin C. Can J Ophthalmol. 2009;44:103-4. 10. Orndahl M, Fagerholm P. Treatment of corneal dystrophies with phototherapeutic keratectomy. J Refract Surg. 1998;14:129-35. 11. Waring GO III, Rodrigues MM, Laibson PR. Corneal dystrophies. I. Dystrophies of the epithelium, Bowman’s layer and stroma. Surv Ophthalmol. 1978;23:71-122. 12. Chiou AG, Florakis GJ, Copeland RL, et al. Recurrent Meesmann’s corneal epithelial dystrophy after penetrating keratoplasty. Cornea. 1998;5:566-70. 13. Stocker FW, Holt LB. Rare form of hereditary epithelial dystrophy. Arch Ophthalmol. 1955;53:536-41.
Case Report 14. Cogan DG, Donaldson DD, Kuwabara T, et al. Microcystic dystrophy of the corneal epithelium. Trans Am Ophthalmol Soc. 1964;62:213-25. 15. Woreta FA, Davis GW, Bower KS. LASIK and surface ablation in corneal dystrophies. Surv Ophthalmol. 2015;60:115-22.
Can J Ophthalmol 2017;]:]]]–]]] 0008-4182/17/$-see front matter & 2017 Published by Elsevier Inc on behalf of the Canadian Ophthalmological Society. http://dx.doi.org/10.1016/j.jcjo.2017.05.009
CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Although dystrophy frequently recurs after any of these treatments, in some cases recurrence may be delayed or less severe,6,13 or may not occur.10,14 As de-epithelialization of the central cornea occurs in the course of photorefractive keratectomy, we questioned whether the healing epithelium would demonstrate dystrophic characteristics. Although photorefractive keratectomy (PRK), PTK, and laser-assisted in situ keratomileusis (LASIK) have been studied for more common anterior corneal dystrophies, their application in MECD has yet to be reported.15
CASE REPORT A 32-year-old white male desiring refractive surgery for correction of a myopic refractive error ( 2.25 to 0.75 168 OD and 2.00 to 1.00 15 OS) correctable to 20/20 in each eye was evaluated for surgery. By slit lamp, the corneal epithelium demonstrated myriad minute, discrete, graywhite punctate opacities, clear upon retro-illumination, and diffusely distributed over the corneal surface, particularly in the central 6 mm diameter of the interpalpebral zone (Fig. 1A). The corneas otherwise appeared normal, and corneal sensation was intact. Given the patient’s visual potential and otherwise normal eyes, excimer PRK was judged appropriately, and
Fig. 1 — (A) Preoperative slit-lamp retroillumination of the iris discloses myriad intraepithelial vesicles or microcysts, predominantly in the interpalpebral zone (most readily visible adjacent to pupillary margin). (B) At 6 weeks after PRK, the healed corneal epithelium is free of vesicles within the area of operative epithelial debridement. (C) At 5 months post-PRK, epithelial vesicle density has returned to approximately 30%–40% of preoperative level in the central treatment zone. (D) At 12 months post-PRK, epithelial vesicle density has returned essentially to preoperative levels. PRK, photorefractive keratectomy. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
1
Case Report accordingly this procedure was conducted without difficulty in the left and subsequently right eyes utilizing 20% ethanol-assisted mechanical de-epithelialization of the central cornea and standard PRK ablation with a VISX STAR S2™ (AMO; Abbott Laboratories Inc, Abbott Park, IL) excimer laser. An Acuvue bandage contact lens (Johnson & Johnson, New Brunswick, NJ) was applied, followed by tobramycin 0.3% and dexamethasone 0.1% ophthalmic suspension (Tobradexs; Alcon Laboratories Inc, Fort Worth, TX) and ketorolac tromethamine (0.4%) ophthalmic solution (Acular LSs; Allergan Inc, Irvine, CA), all 4 times daily. The bandage soft contact lens and medications were continued for approximately 1 week postoperatively, during which time the corneal epithelial defects had healed uneventfully in both eyes. At each visit, specifically preoperative and postoperative day 1; week 1, 2, 3, 4, and 6; and month 2, 5, 6, and 12 and utilizing the slit-lamp biomicroscope aided by a magnifying reticule, vesicular counts and size measurements within the central 6-mm-diameter ablation zone were performed by the same observer (J.V.G.). (Given the semiquantitative limits of such observations, vesicular counts were compared as an approximate percentage relative to pretreatment population density.)
RESULTS The healed corneal epithelium demonstrated no abnormality until 6 weeks in the right eye (Fig. 1B) and 3 weeks in the left eye, at which time typical intraepithelial microvesicles again became occasionally apparent. By 2 months, vesicular population density was found to be at 10%–15% of preoperative levels, increasing to 30%–40% between 2 and 5 months (Fig. 1C) and further to 75%– 90% by 6 months. At 12 months (Fig. 1D), vesicular density was equivalent to the preoperative measurement. By 2 months, vesicle diameters measured up to 20 microns and increased up to 30 microns at 5 months. By 6 months, vesicle diameter measured up to 40 microns and by 12 months measured as large as 50 microns. Importantly, no problems of initial epithelial healing or recurrent erosion were encountered, and corneal sensation remained intact. After 1 year, uncorrected visual acuity was 20/20 OD and 20/20 OS with a refractive error of 0.25 OD and plano OS.
DISCUSSION MECD, a disorder of the corneal epithelium and basement membrane, has been traditionally treated by removing these abnormal tissue layers via superficial keratectomy without or with mitomycin C,9 PTK,10 lamellar,11 or penetrating keratoplasty.12 Although intraepithelial microcysts have been reported to recur after such efforts,2,11,12 as the PRK procedure involves not only debridement of the abnormal central corneal epithelium but also photoablation of the underlying thick and multilaminar basement membrane,5,6 it might be anticipated that additional therapeutic
2
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benefit could result, especially as subepithelial fibrosis might also be accomplished. In the current case, PRK did accomplish a highly satisfactory visual outcome despite eventual recurrence of vesicular populations and sizes similar to preoperative levels. Perhaps this phenomenon could have been anticipated, as the presumably affected limbal stem cells would continue to produce similarly affected epithelial progeny.6 Despite this characteristic epithelial recurrence, the otherwise positive anatomical and visual outcome suggests that in appropriately selected cases, PRK may be appropriately performed in individuals with MECD. Jack V. Greiner, DO, PhD,*,†,‡ Michael E. Lindsay, BA,*,† Kenneth R. Kenyon, MD,*,†,‡,§ John P. Herman, OD,∥ Chaitanya V. Reddy, DO* *The Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts; †Boston Ocular Surface Center, Boston, Massachusetts, USA; ‡Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts; §Cornea Consultants International, Boston, Massachusetts, USA; ||Pittsfield Vision Associates, Pittsfield, Massachusetts, USA. Correspondence to: Jack V. Greiner, D.O., Ph.D., Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 20 Staniford Street, Boston, MA 02114; [email protected] REFERENCES 1. Weiss JS, Moeller H, Aldave AA, et al. The IC3D classification of the corneal dystrophies. Cornea. 2015;34:117-59. 2. Kuwabara T, Ciccarelli EC. Meesmann’s corneal dystrophy. Arch Ophthalmol. 1964;71:676-82. 3. Nakanishi I, Brown SI. Ultrastructure of the epithelial dystrophy of Meesmann. Arch Ophhthalmol. 1975;93:259-63. 4. Fine BS, Yanoff M, Pits E, et al. Meesmann’s epithelial dystrophy of the cornea. Am J Ophthalmol. 1977;83:633-42. 5. Tremblay M, Dube I. Meesmann’s corneal dystrophy: ultrastructural features. Can J Ophthalmol. 1982;17:24-8. 6. Burns RP. Meesmann’s corneal dystrophy. Trans Am Ophthalmol Soc. 1968;66:530-635. 7. Wittebol-Post D, van Bijsterveld OP, Delleman JW. Meesmann’s epithelial dystrophy of the cornea: biometrics and a hypothesis. Ophthalmologica. 1987;194:44-9. 8. Bourne WM. Soft contact lens wear decreases epithelial microcysts in Meesmann’s corneal dystrophy. Trans Am Ophthalmol Soc. 1986;84:170-82. 9. Yeung J, Hodge W. Recurrent Meesmann’s corneal dystrophy: treatment with keratectomy and mitomycin C. Can J Ophthalmol. 2009;44:103-4. 10. Orndahl M, Fagerholm P. Treatment of corneal dystrophies with phototherapeutic keratectomy. J Refract Surg. 1998;14:129-35. 11. Waring GO III, Rodrigues MM, Laibson PR. Corneal dystrophies. I. Dystrophies of the epithelium, Bowman’s layer and stroma. Surv Ophthalmol. 1978;23:71-122. 12. Chiou AG, Florakis GJ, Copeland RL, et al. Recurrent Meesmann’s corneal epithelial dystrophy after penetrating keratoplasty. Cornea. 1998;5:566-70. 13. Stocker FW, Holt LB. Rare form of hereditary epithelial dystrophy. Arch Ophthalmol. 1955;53:536-41.
Case Report 14. Cogan DG, Donaldson DD, Kuwabara T, et al. Microcystic dystrophy of the corneal epithelium. Trans Am Ophthalmol Soc. 1964;62:213-25. 15. Woreta FA, Davis GW, Bower KS. LASIK and surface ablation in corneal dystrophies. Surv Ophthalmol. 2015;60:115-22.
Can J Ophthalmol 2017;]:]]]–]]] 0008-4182/17/$-see front matter & 2017 Published by Elsevier Inc on behalf of the Canadian Ophthalmological Society. http://dx.doi.org/10.1016/j.jcjo.2017.05.009
CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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