Third or greater penetrating keratoplasties: indications, survival, and visual outcomes.
PURPOSE
The purposes of this study were to report the indications, graft survival, risk factors for graft failure, and visual outcomes for third or greater penetrating keratoplasties (PKP).


METHODS
Six years of Wills Eye Institute Cornea Service charts (2000-2005) were retrospectively reviewed to identify all patients who had undergone three or more PKPs. Graft survival rates by initial diagnosis and risk factors for graft failure were analyzed.


RESULTS
Forty-five patients who had three or more PKPs were identified. The total number of grafts identified in these 45 patients was 152, including 45 third PKPs, 11 fourth, three fifth, two sixth, and one seventh. The most common indication for the initial PKP was pseudophakic bullous keratopathy in 18 of 45 patients (41%) followed by Fuchs dystrophy (seven of 45 patients [16%]) and stromal dystrophies (five of 45 patients [11%]). Approximately half of third grafts (24 of 45 [53%]) and one fourth of fourth grafts (three of 11 [27%]) survived at the last follow-up visit with a median follow up of 4.3 years for the third grafts and 8.4 years for the fourth grafts. One-, 2-, and 5-year graft survival rates were 89%, 78%, and 53% for the third grafts and 73%, 73%, and 64% for the fourth grafts, respectively. The median survival time for the third graft was 12.8 years in Fuchs dystrophy, 5.2 years in herpetic keratitis, 4.0 years in keratoconus, 3.0 years in pseudophakic bullous keratopathy, 2.3 years in iridocorneal endothelial syndrome, and 2.0 years in stromal dystrophies. There is no statistically significant difference between groups (P = 0.46). Risk factor analysis on the third grafts showed that previous glaucoma procedures and corneal neovascularization are statistically significant risk factors for graft failure (P = 0.04 and 0.02, respectively).


CONCLUSION
Over 50% of third and fourth grafts were clear at 5 years postoperatively. Outcomes of third grafts were better in patients with Fuchs dystrophy, keratoconus, and herpetic keratitis. Absence of previous glaucoma surgery and/or corneal neovascularization is associated with better outcomes of multiple PKPs.