Ten-Year Outcomes of Repeat Optical Keratoplasties Performed in a Tertiary Hospital

Abstract

Purpose : The incidence of graft failure as an indication for repeat keratoplasty is on the rise, attributed to the growing number of transplant procedures. Advanced lamellar keratoplasty techniques now allow the selective replacement of only affected corneal layers. For example, endothelial keratoplasties (EK) serve as alternatives to repeat penetrating keratoplasty (PK) in cases of endothelial failure. This study evaluated the clinical outcomes of repeat keratoplasties after the failure of an initial optical keratoplasty in an Asian population.

Methods : All patients undergoing repeat keratoplasties for optical reasons at the Singapore National Eye Centre between 2007 and 2020 were included. Clinical data of patients were recorded from an ongoing prospective Singapore Corneal Transplant Registry.

Results : Analyzing 284 initial regrafts (181 Descemets Stripping Automated Endothelial Keratoplasty, 63 PK, 21 Descemets Membrane Endothelial Keratoplasty, and 19 deep anterior lamellar keratoplasty (DALK)), graft rejection and late endothelial failure were the primary causes of initial graft failure. The most common regraft was EK for failed EK (46.5%) and PK (22.9%). PK/EK and EK/EK had better one-year postoperative visual acuity than PK/PK (p=0.006 and p<0.001, respectively). Ten-year cumulative regraft survival rates were 69.2% for PK/EK, 52.8% for EK/EK, and 43.1% for PK/PK. DALK/PK and DALK/DALK achieved 100% regraft survival at five years, and 100% for DALK/EK at three years. Log-rank test indicated higher survival for PK/EK compared to PK/PK (p=0.002) and EK/PK (p=0.009), and for EK/EK compared to PK/PK (p=0.003) and EK/PK (p=0.005). PK regrafts had significantly more regraft rejection (p=0.001) and glaucoma/increased intraocular pressure episodes (p=0.005) compared to EK and DALK regrafts. Cox multiple regression analysis identified male gender (p=0.023), PK regraft (p=0.003), regraft rejection (p=0.003), and initial graft indications of pseudophakic bullous keratopathy (p=0.005) and aphakic bullous keratopathy (p=0.004) as regraft failure risk factors, while a longer time to regraft was associated with decreased risk (p=0.01).

Conclusions : Performing EK for a failed optical PK or EK significantly enhanced regraft survival compared to repeat PK. Regrafts performed for failed initial DALK grafts demonstrated favorable outcomes across all types.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.