In their case series, Fong and coauthors1 describe 6 eyes that developed visually significant subepithelial fibrosis following radial keratotomy (RK). Their results following debridement and excimer laser phototherapeutic keratectomy (PTK) vary considerably. Of the 6 eyes, 3 (50%) experienced recurrence of fibrosis. In addition, as the authors readily admit, the length of follow-up of the remaining eyes (range 7 weeks to 10 months) is too short to draw any valid conclusions, as corneal scarring is often a late finding.
Our interest in this subject began several years ago when we presented our results using mitomycin-C (MMC) to prevent recurrent subepithelial fibrosis following RK.2 In our report of 2 eyes, we attempted multiple debridements (4) in each eye over 4 years, which resulted in recurrences after varying lengths of time. The fibrosis was permanently eradicated following a single application of MMC.
Subsequently, our case series of 8 eyes with visually significant subepithelial fibrosis following RK (n = 4) and photorefractive keratectomy (PRK) (n = 4) reported results that corroborated our initial hypothesis that MMC prevented the recurrence of a scar after a single debridement.3
Fong and coauthors used debridement in conjunction with PTK, and this is truly a novel approach. However, our experience with post-PRK haze leads us to believe that the additional laser energy, while certainly instrumental in removing the scar, may also promote further activation of anterior stromal keratocytes in the setting of pre-existing fibrosis and lead to increased deposition of collagen and ground substance, resulting in a clinical recurrence.
We congratulate Fong and coauthors on their efforts to shed light on this underreported complication of corneal refractive surgery. However, we feel that a more cost-effective, permanent, and therefore more appropriate approach to the problem of post-RK scarring would be to perform manual epithelial debridement and scar removal, followed by a single application of MMC.
Parag A. Majmudar MD
Tal Raviv MD
Richard F. Dennis MD
Randy J. Epstein MD
aChicago, Illinois, USA
1. Fong Y-C, Chuck RS, Stark WJ, McDonnell PJ. Phototherapeutic keratectomy for superficial corneal fibrosis after radial keratotomy. J Cataract Refract Surg 2000; 26:616-619
2. Majmudar PA, Brenart R, Epstein RJ. Topical mitomycin-C for massive subepithelial fibrosis following radial keratotomy. Cornea 1998; 17:242-243
3. Majmudar PA, Forstot SL, Nirankari VS. Topical mitomycin-C for subepithelial fibrosis after refractive corneal surgery. Ophthalmology 2000; 107:89-94