Evaluation of Big Bubble Technique for Deep Anterior Lamellar Keratoplasty in Patients with Radial Keratotomy

Purpose: To report the outcome of deep anterior lamellar keratoplasty (DALK) and success rates of the big-bubble (BB) technique or manual dissection after a failed use of the BB technique in eyes that underwent prior radial keratotomy (RK). Methods: A retrospective chart review of patients who underwent DALK after RK at Toronto Western Hospital, Canada, between 1999 and 2017 was performed. Demographic characteristics, success rates of the BB technique and manual dissection, intraoperative and postoperative complications, and best spectaclecorrected visual acuity before and after corneal transplant were analyzed. Results: Ten eyes of 9 patients were included in the analysis. The average age was 64 6 10 years (range 49-82). The average time between the RK surgery and the corneal transplant was 20 6 5 years (range 8-24). Indications for corneal transplant were significant irregular astigmatism in 5 eyes (50%), central scarring or haze in 4 eyes (40%), and progressive hyperopia with visual fluctuation in one eye (10%). BB was successfully achieved in one eye (10%). In 6 eyes (60%), manual dissection was performed, and in 3 eyes (30%), DALK surgery was converted to penetrating keratoplasty. The average best spectacle-corrected visual acuity on the last follow-up visit was 0.26 6 0.08 logMAR (Snellen equivalent 20/36). One eye that underwent manual DALK and one eye that underwent penetrating keratoplasty developed a rejection episode 4 and 2 months after keratoplasty, respectively. In both cases, rejection resolved with topical steroids. Conclusions: In eyes that underwent prior RK, DALK by manual dissection should be considered as a preferable surgical technique.