Incidence of Intraocular Pressure Elevation and Glaucoma after Lamellar versus Full-Thickness Penetrating Keratoplasty

Abstract

Purpose: To analyze the cumulated incidence of glaucoma after penetrating keratoplasty (PK), anterior lamellar keratoplasty (ALK), and endothelial keratoplasty (EK).

Design: Cohort study. Data were recorded prospectively and analyzed retrospectively.

Participants: A total of 1657 consecutive eyes of 1657 patients undergoing corneal transplantation between 1992 and 2013.

Methods: Penetrating keratoplasty (date range, 1992-2013), ALK (date range, 2002-2013), and Descemet's stripping automated EK (date range, 2006-2013).

Main outcome measures: Postoperative intraocular pressure (IOP), glaucoma treatments, and glaucoma-related loss of vision (loss of central visual function resulting in absence of light perception or light perception limited to the temporal visual field). Cox proportional hazard regression model was used to analyze risk factors for glaucoma after keratoplasty.

Results: The 10-year cumulated incidence of elevated IOP and elevated IOP requiring treatment was 46.5% and 38.7%, respectively. In multivariate analysis, 4 variables were significantly associated with a higher incidence of elevated IOP requiring treatment after keratoplasty: preoperative glaucoma or IOP >20 mmHg (adjusted hazard ratio [HR], 1.56; P < 0.001), penetrating keratoplasty (PK) (adjusted HR, 1.12 vs. ALK and 1.10 vs. EK; P < 0.001), postoperative lens status (adjusted HR vs. phakic eyes: 1.15 for posterior chamber intraocular lens, 1.43 for anterior chamber intraocular lens [IOL], 2.83 for aphakic eyes; P < 0.001), and IOL exchange or removal during surgery (adjusted HR, 1.48; P < 0.001). Recipient age, preoperative diagnosis, filtering surgery before keratoplasty, vitrectomy associated with keratoplasty, and filtering surgery associated with keratoplasty were significantly associated with a higher incidence of elevated IOP requiring treatment after keratoplasty in univariate analysis but not in multivariate analysis. The 10-year probability of loss of vision related to glaucoma was 1.0% after EK, 2.1% after ALK, and 3.6% after PK (P = 0.036).

Conclusions: The incidence of elevation of IOP after keratoplasty and development of glaucoma are significantly decreased with ALK and EK compared with PK. We believe this is due to diminished surgery-induced damage to the anterior chamber angle and trabecular meshwork, and reduced postoperative use of steroids.