In this retrospective analysis, the authors examined corneal transplant survival rates based on patients’ primary corneal diagnosis and type of regraft surgery.
Study design
This study included patients who had a diagnosis of keratoconus, Fuchs endothelial dystrophy and pseudophakic bullous keratopathy (PBK). Using data from the United Kingdom national transplant registry, investigators examined all surgery and follow-up data for 9,925 patients who underwent regrafting over a 17-year period.
All keratoconus patients had penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK); Fuchs endothelial dystrophy and PBK patients underwent PK and endothelial keratoplasty (EK). Main outcome measures were actuarial regraft 5-year survival rates
Outcomes
There were 7,261 PK regrafts—making it the most common type of regraft—and 1,710 EK regrafts. The median time to first regraft was 28 months across the entire cohort. Overall, survival rates were highest for the first regraft compared with subsequent grafts (all P<0.001). The most common cause of failure of the first graft across the entire cohort was endothelial decompensation (defined as endothelial failure that occurs in the absence of secondary complications such as rejection or glaucoma).
For Fuchs dystrophy, regraft survival was higher in eyes that underwent PK than those that underwent EK (71% vs. 55%; P<0.001). When considering PBK, 5-year survival was higher for first PK grafts compared with the second PK graft (57% vs. 45%; P<0.001) but no differences were detected for EK grafts. However, there were very few EK procedures for both Fuchs dystrophy and PBK. The first regrafts in keratoconus and PBK had similar survival after DALK or PK procedures.
Limitations
Since the corneal transplant registry only included the United Kingdom’s national transplant database, there are limitations in extrapolating the results to other countries. Some study groups only contained about 20 eyes and there were within-study and terminal losses during follow-up. Graft follow-up intervals were not even and there were differences in methods of receiving data for surviving and failed grafts. Limiting the study to patients with unilateral procedures and excluding grafts that failed within 6 months further restricted the sample pool. The study failed to consider topical corticosteroids or perform multivariate analyses for glaucoma, corticosteroid use and surgeon grade.
Clinical significance
This study was a large registry-based investigation that has provides useful information regarding corneal regraft survival. While there may be questions about the widescale application of the results, the findings still provide guidance for the management of failed corneal transplants.