Corneal collagen cross-linking effects on pseudophakic bullous keratopathy

Abstract

AIM: To evaluate the efficacy of riboflavin administration and ultraviolet A (UVA) cross-linking on advanced symptomatic bullous keratopathy. METHODS: Fifteen patients with symptomatic pseudophakic bullous keratopathy (PBK) were included. Slit-lamp examination, visual acuity, foreign body sensation (FBS) questionnaire, corneal clarity grading, ocular pain intensity scale and corneal thickness measures with Pentacam and ultrasound pachymetry (UP), were performed before corneal cross-linking and 1 and 6 mo thereafter. After using sodium chloride solution, for one week, the central 8 mm (diameter) of the corneal epithelium was removed, and cross-linking, with riboflavin instillation every 3 min for 30 min, and UVA irradiation for 30 min was performed. RESULTS: Five males and 10 females with mean age of 66آ±13y were included. Mean follow up time was 6.2 mo. Corneal transparency in all eyes was statistically significantly better 1 month after treatment than preoperatively (P<0.05). At 6 mo, however, corneal transparency was better in 8 eyes, the same in 5 eyes, and worse in 2 eyes compared with preoperative levels (P=0.218). Foreign body sensation subsided in 70% of patients. The average CCT decreased within 1mo after the procedure (P<0.05). At 6mo, all but 3 eyes had progressive swelling, and the CCT increased; however, the CCT was still statistically significantly thinner than preoperatively (P=0.006). The improvement in mean CDVA from preoperatively to 1mo postoperatively was statistically significant (P=0.010). At 6mo, no significant differences were observed (P=0.130). The pain scores at 1mo were statistically significantly better than preoperatively (P=0.007). At 6mo, however the mean pain score was higher than at 1mo and not statistically significantly different from the preoperative score (P=0.070). CONCLUSION: Corneal CXL significantly improved corneal transparency, corneal thickness, and ocular pain 1 month postoperatively. However, it did not seem to have a long-lasting effect in decreasing pain and maintaining corneal transparency in patients with PBK. This procedure extends the time interval for corneal transplantation and increases visualization at DSAEK procedure.