Analysis of the learning curve of big bubble-deep anterior lamellar keratoplasty by a single corneal surgeon

Abstract

PurposeThe aim of the study was to identify the duration of surgery, the incidence of Descemet’s membrane (DM) perforation during deep anterior lamellar keratoplasty (DALK), and the incidence of conversion to a penetrating keratoplasty (PKP) surgery when the procedure are performed by a single corneal surgeon during his learning curve.SettingThis study was conducted in a specialized eye hospital from March 2013 to April 2014.DesignThis was a retrospective noncomparative case series study.Patients and methodsWe conducted a retrospective analysis of the first 52 cases of planned DALK that used the big-bubble (BB) technique, focusing on the 10 cases that were converted to PKP (19.23%). The cases were subdivided into four groups, categorized chronologically from A to D, comprising 13 patients each.ResultsDM perforation occurred during initial trephination in one case (10% of converted cases), during BB (over) injection with escape through (iatrogenic) DM break in one case (10% of converted cases), and during air injection with escape through a pre-existing big DM break in one case (10% of converted cases). During initial stab/deroofing of the BB using a superblade, perforation occurred in two cases (20% of converted cases). Perforation was most commonly encountered during supradescematic cleavage plane dissection, which happened in five cases (50% of converted cases). However, microperforations that occurred during dissection into the bare DM in six cases (11.53% of total cases) were managed successfully without conversion to PKP. Of the successful DALK cases, five were converted to manual DALK with complete baring of DM.ConclusionDespite a learning period needed to successfully perform DALK with the BB technique, complications related to this technique and total surgery duration decrease significantly after the first 10 cases.