Paired-Eye Analysis of Deep Anterior Lamellar Keratoplasty Versus Mushroom Penetrating Keratoplasty Over 5 Years.

Abstract

To evaluate and compare the clinical outcomes of keratoconic patients who received deep anterior lamellar keratoplasty (DALK) in one eye and mushroom penetrating keratoplasty (MK) in the fellow eye. Retrospective interventional case series based on prospectively collected data. Keratoconic patients who underwent keratoplasty at the department of ophthalmology of "Villa Igea," Ospedali Privati Forlì (Forlì, Italy) between July 2006 and December 2023. Patients underwent DALK in one eye and converted MK from intended DALK in the fellow eye. The primary outcomes were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism, and endothelial cell density (ECD). Kaplan-Meier curves were drawn for both DALK and MK to compare the cumulative probability of obtaining a BSCVA < 0.3 LogMAR (Snellen 20/40) within the end of follow-up. We included 46 keratoconic patients that underwent DALK in one eye and MK in the fellow eye. Mean follow-up was 5.4 ± 2.1 years (up to 10 years). During the first two years after surgery, BSCVA was significantly better in the DALK group (0.08 ± 0.11 vs 0.15 ± 0.20 LogMAR, P = .05); however, no significant differences between the 2 groups were found at later follow-up times. At 5 years, BSCVA values were 0.08 ± 0.10 and 0.12 ± 0.18 LogMAR, respectively for DALK and MK (P = .305). The 5-year probability of retaining a BSCVA < 0.3 LogMAR was 85.1% and 83.0%, respectively for DALK and MK (P = .791). Three years postoperatively, refractive astigmatism was significantly lower for DALK (at 5 years, 2.37 ± 1.21 D vs 2.97 ± 1.13 D; P= .04); however, the percentage of eyes with astigmatism higher than 4.5 D did not significantly differ between DALK (n = 3) and MK (n = 2) (P > .99). Five years postoperatively, ECD was 1837 ± 625 cells/mm² for DALK and 1083 ± 378cells/mm² for MK (P < .001). At 1 year, mean ECL was 20.3% for DALK and 35.4% for MK (P = .008). Thereafter, mean annual ECL was 1.4% for DALK and 5.9% for MK (P = .021). This study allowed direct intra-patient comparison between DALK and MK. Compared with MK, our findings showed for DALK better BSCVA during the first 2 years after surgery, lower refractive astigmatism from 3 years postoperatively on, and higher ECD at all time points.