Bowman's layer transplantation in advanced keratoconus; 18-months outcomes.

Abstract

To assess the outcome of isolated Bowman's layer transplantation (BLT) in advanced keratoconus in the patients not suitable for ultra violet cross-linking and intra stromal corneal ring segments. Nonrandomized Quasi-Experimental. Mid corneal stromal dissection followed by implantation of manually isolated bowman layer from a donor into the recipient stromal pocket was performed in the Department of Ophthalmology Khyber Teaching Hospital Peshawar from September 2018 to October 2018 and followed up over 18months. Eleven eyes of 11 patients, 8 male and 3 female within the age range of 7-28years with progressive keratoconus went under BLT All keratometry values decreased after surgery. Mean anterior pre-operative SimK changed from 69.05 ± 10.85D to 61.14 ± 6.23D at 18months post-operatively (P = 0.005). Means pre-operative Kmax value decreased from 77.24 ± 7.58D to 71.07 ± 5.37D at 18months post-operatively (p = 0.060). The mean pre-operative posterior keratometry value changed from - 10.03 ± 0.88 to - 8.96 ± 1.06D at 18months post-operatively (P = 0.002). Mean pre-operative thinnest corneal thickness increased from 281.64 ± 196.86um to 355.27 ± 19.17um at 18th months post-operatively (P = 0.001). Pachymetry p-value pre-operative to 18months (P = 0.001) was statistically significant. Mean anterior SimK at 6months post-operatively, 60.55 ± 5.56D changed to 61.14 ± 6.23D at 18months post-operatively (P = 0.000), Kmax at 6months postoperative 71.60 ± 5.01D changed to 71.07 ± 5.37D at 18months post-operatively (P = 0.008). Both anterior K values at 6months and 18months post-operatively showed less significant change, and the same was true for Kmax data at 6months and 18months post-operatively. P-values at 6months to 18months post-operatively for cornea back data remained (P = 0.001) unchanged. No complications were observed intra-operatively or post-operatively. Bowman layer transplantation is a unique surgical treatment for advanced keratoconus to stabilize progressive ectasia with fewer complications avoiding the need for penetrating or deep anterior lamellar keratoplasty.