Purpose: The primary objective was to evaluate whether postoperative alterations in corneal shape (as reflected by keratometry values) affect endothelial cell profile measurements after deep anterior lamellar keratoplasty (DALK) in a group of patients with keratoconus. Secondary objective was to describe the pattern of changes in corneal endothelial cell profile measurements during the first 3 years after DALK.
Methods: In this prospective interventional case series, we enrolled patients who had significant keratoconus and were scheduled for DALK (Melles technique). Cases with concomitant intraocular surgeries, intra-/postoperative complications, and poor quality of images were excluded.
Results: Two hundred one eyes and 45 eyes (of the original 201) were enrolled for evaluating the primary and the secondary objectives, respectively. At 3 months post DALK, the mean endothelial cell density (ECD) had significantly increased and the mean cell area had decreased compared with preoperative measurements (2721 vs. 2823 cells/mm2, P = 0.015; and 378 vs. 362 μm2, P = 0.005, respectively). Regression analysis revealed a weak but significant nonlinear association between changes in mean keratometry and ECD changes at 3 months (R2 = 0.039, P = 0.02). Standard deviation of mean cell area had significantly decreased at 12 months after DALK compared with measurements taken at 3 months after surgery (P = 0.023) and remained stable thereafter.
Conclusions: Apparent measurements of ECD may not show a decrease but instead even a slight increase in some cases after uncomplicated DALK (Melles technique) for keratoconus. This finding along with a later decrease in standard deviation of mean cell area suggests that notable postoperative changes in corneal biomechanical forces may affect endothelial cell profile measurements.