Comparison of Central Corneal Graft Thickness to Visual Acuity Outcomes in Endothelial Keratoplasty

Abstract
To evaluate visual acuity outcomes after endothelial keratoplasty (EK) and describe the relationship to postoperative central corneal graft thickness as measured by anterior segment optical coherence tomography (AS-OCT). A retrospective case series of 33 eyes in 28 patients undergoing routine EK using precut eye bank tissue was designed. All patients underwent serial central graft thickness measurements with AS-OCT. Based on the median central graft thickness of all patients, the eyes were divided into 2 groups: thin EK and thick EK. Differences between the groups were compared. The median postoperative graft thickness of all eyes was 131 μm. The eyes were divided into 2 groups based on this median: thin EK (graft thickness: ≤ 131 μm; range: 77-131 μm; average: 109 μm) and thick EK (graft thickness: > 131 μm; range: 138-182 μm; average: 162 μm). There was no statistically significant difference in age, sex, or preoperative best spectacle-corrected visual acuity (BSCVA) between the 2 groups. Average postoperative follow-up was 12.8 months. The thin EK group showed better postoperative BSCVA compared with the thick EK group (P < 0.01). All thin EK eyes had BSCVA greater than or equal to 20/25 with 71% of eyes achieving BSCVA of 20/20. In contrast, only 50% of thick EK eyes reached BSCVA greater than or equal to 20/25 with 19% obtaining BSCVA of 20/20. Thin EK versus thick EK, as measured by AS-OCT in the postoperative period, showed a statistically significant improvement in BSCVA.