Although corneal transplantation is an extremely successful procedure, it is not one that inevitably lasts forever. As more and more corneal transplants have been performed over the past four to five decades, many have ended up "failing."
Failure can occur for a number of reasons, the most common one being endothelial decompensation, either due to graft rejection or "endothelial exhaustion," where enough of the endothelial cells die off and the cornea becomes edematous. When this occurs, the cornea becomes cloudy and vision worsens. Treatment options include leaving the eye alone or performing a repeat corneal transplant.
Long-term Outcomes From a Recent Dutch Study
A recent paper from the Netherlands studied the results of repeat corneal transplantation.[1] Although the Netherlands is a relatively small country, it has a national database that collects information on all corneal transplants performed there, allowing for a look at what is actually going on in the "real world."
Researchers reviewed data on all repeat corneal transplants from 1994 to 2015 originally performed for Fuchs endothelial dystrophy (FED) and pseudophakic corneal edema (PCE). They found that the number of repeat corneal transplants increased significantly from 2007 to 2015. This coincided directly with the introduction of endothelial keratoplasty (EK), primarily Descemet stripping endothelial keratoplasty, in the Netherlands.
EK is thought to have increased the number of repeat corneal transplantation in two main ways. First, it is likely that many EKs failed during the "learning curves" of surgeons, requiring repeat corneal transplantation. Researchers observed an increase in repeat EKs, while the number of repeat full-thickness penetrating keratoplasties (PKs) remained stable. Second, because the EK procedure is somewhat less involved than PK and leads to much more rapid visual recovery for the patient, repeat EK can also be performed more readily than repeat PK.
The overall cumulative 5-year repeat graft survival was 60%, much lower than that for primary corneal grafts (95% for FED and 85% for PCE). Univariable analysis found a better 5-year survival for repeat corneal transplantation for FED than PCE, but this was not confirmed using multivariable analysis.
Researchers also looked at survival of the four main types of regraft possibilities: PK after PK, EK after EK, EK after PK, and PK after EK. Kaplan-Meier analysis did not demonstrate any significant differences in survival among them.
Deciding Between EK and PK for Repeat Transplantation
EK has become the procedure of choice for most eyes with endothelial dysfunction for many reasons, including more rapid visual recovery, better quality of vision, less change in refraction, less rejection, and a stronger wound compared with PK. These advantages hold true for EK after PK, compared with PK after PK.
The question often arises as to how to treat an eye with endothelial decompensation after PK. In terms of graft survival, this study found no advantage for EK after PK compared with PK after PK.
For me, the decision is based on two factors: how happy the patient was with the quality of vision and method of correction before the graft became edematous, and the quality of the graft-host junction. If there had been significant irregular astigmatism and the patient had not been happy wearing a rigid contact lens, then I would lean toward a repeat PK. Similarly, if there were significant wound ectasia, I would favor a repeat PK, attempting to get around the area of wound thinning. On the other hand, if the patient said they would like to go back to the time before the edema developed, then my first choice would be an EK under the PK, given its many advantages.
Medscape Ophthalmology © 2018 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Christopher J. Rapuano. Corneal Transplantation Failed. What Now? - Medscape - Oct 24, 2018.
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