Comparative study of long-term graft survival between penetrating keratoplasty and deep anterior lamellar keratoplasty

Session Details

Session Title: Cornea Surgical: Keratoplasties

Session Date/Time: Monday 16/09/2019 | 16:30-18:00

Paper Time: 16:30

Venue: Free Paper Forum: Podium 1

First Author: : M.Chew SINGAPORE

Co Author(s): :    A. Arundhati   L. Lim   J. Mehta   S. Young   D. Tan                 

Abstract Details

Purpose:

Penetrating keratoplasty (PK) has been shown to be a safe and effective surgery with good visual outcomes. However, endothelial failure and immunological graft rejection remain persistent long-term complications, leading to late graft failure. Deep anterior lamellar keratoplasty (DALK) has emerged as a viable alternative to PK that enables preservation of the host’s endothelial cells to eliminate the risks of endothelial rejection and failure. However, little information is known regarding comparative long-term graft survival. The aim of this study was to compare the long term graft survival between PK and DALK.

Setting:

A cohort study in which clinical data was extracted from the ongoing prospective Singapore Corneal Transplant Study. To compare the 10-year survival outcomes of PK vs DALK performed for optical indications in a tertiary eye centre in Singapore.

Methods:

We analysed all consecutive primary grafts of DALKs (n=362) and PKs (n=307) performed for optical indications. Cases diagnosed with endothelial pathologies were excluded, as DALK was not performed for such cases. We performed DALK by manual lamellar dissection or modified Anwar’s big bubble technique. The primary outcome measure was graft survival time. The major causes of graft failure were analysed, and high risk characteristics identified. Kaplan-Meier survival plots were utilised with Mantel-Cox Log Rank test used to compare survival curves. Chi-square and Fisher’s exact tests were conducted as appropriate for categorical data.

Results:

The 10-year survival rate was 93.9% for DALK and 72.0% for PK (p=0.001). Postoperative complications were significantly higher for PK as compared to DALK, with a larger proportion developing glaucoma (29.3% vs 11.6%, p<0.001), allograft rejection (16.6% vs 1.7%, p<0.001), epithelial problems (10.4% vs 5.5%, p=0.018), and non-immunological failure (7.8% vs 1.9%, p<0.001). The rate of graft failure attributable to rejection (36.7% vs 5.9%, p=0.015) and endothelial failure (36.7% vs 5.9%, p=0.015) were significantly lower in DALK compared to PK.

Conclusions:

The long-term 10-year graft survival for primary DALK was superior to that of PK for optical indications in corneal pathologies with normal endothelium. Primary DALK results in significantly less post-operative complications and significant lower rates of graft rejection and failure. This study strengthens the case in favour of performing DALK over PK when possible.

Financial Disclosure:

None