Superficial keratectomy, PTK, and mitomycin C as a combined treatment option for Salzmann's nodular degeneration: a follow-up of eight eyes

Abstract

To analyze the treatment outcomes (safety and efficacy) of manual superficial keratectomy, phototherapeutic keratectomy (PTK), and intraoperative application of mitomycin C (MMC) for Salzmann nodular degeneration (SND). In this retrospective study, we analyzed the records of eight eyes of five patients with Salzmann nodular degeneration (SND) who were treated between December 2006 and May 2008 at the University Eye Clinic Hamburg, Eppendorf, Germany. This case study includes data previously published within a single case report. Patients were followed-up pre- and postoperatively by slit-lamp biomicroscopy, digital photography, and corneal topography. All of the eight eyes were followed-up for at least 12 months, whereas in four eyes, follow-up was done for more than 24 months. PTK was performed with a 193-nm Ar-F excimer laser (Allegretto 200; WaveLight AG, Erlangen, Germany) within a 7-mm optical zone. Mitomycin C 0.02% was applied after PTK for 30 s. Postoperatively, a therapeutic contact lens was administered until corneal epithelial healing, which occurred usually at the forth postoperative day. Then local steroid therapy (prednisolone 1%) eye drops fours times per day was given for the following 4 weeks. Mean BCVA preoperatively was 0.61 logMAR (i.e., 20/80 Snellen equivalent or 0.25 decimal). There was a significant increase of BCVA by average of four reading lines (far distance) up to ten reading lines (p < 0.001). Mean BCVA postoperatively was 0.2 logMAR (i.e., 20/32 Snellen equivalent or 0.63 decimal). Treatment of SND led to a dramatic reduction of hyperopia (myopic shift) corresponding to a marked increase of best-corrected visual acuity (BCVA). Preoperatively documented hyperopic progression was stopped and refraction remained stable during the follow-up period in all eyes. Corneal topography showed regular astigmatism. During follow-up after treatment, the corneas appeared clear on slit-lamp examination. Our follow-up and the small treatment numbers are not sufficient to finally prove the superiority of the combined treatment modality (superficial keratectomy, PTK, and MMC) for SND, but the results of our study are promising. Longer follow-up and a larger cohort are warranted for proving MMC to be an effective, successful, and safe method in the armamentarium for treating and preventing Salzmann degeneration.