Real-World Survival Rates of Keratoplasty

A new study presented at the American Academy of Ophthalmology (AAO) 2019 Annual Meeting in San Francisco has found long term, real-world survival rates of keratoplasty may be lower than previously reported.

Led by Sumayya Ahmad, MD, assistant professor of ophthalmology at Icahn School of Medicine, a team of investigators conducted a retrospective cohort analysis of data from the IBM MarketScan database. Investigators examined a period from 2011 to 2017 that included 10 million patients.

Investigators included patients with no history of prior transplants in order to determine rates of success using Kaplan Meier modeling. Results of the analysis revealed the survival rate was 81% at year 3, 80% at year 5, and 78% at year 7—nearly 20% lower than the survival rate published in previous research.

For more on her interpretation of the results of the analysis, MD Magazine® caught up with Ahmad between sessions at AAO 2019.

MD Mag: What did you find when examining real-world survival rates of penetrating keratoplasty?

Ahmad: So, penetrating keratoplasty is basically a full-thickness corneal transplant it has been around for a very long time and it's one of the most commonly performed transplants in the world and the published results in the United States have been very good. They published about a 90% survival rate of these corneal transplants at 5 years, which is very good and very high when we say survival, which means the transplant is doing well, the patients seem well, generally—but in our clinical experience we were finding that might not necessarily be the case.

So, what we decided to do is look at a big database of medical claims data—it's a commercial database from all of them a big commercial payers—and we were able to look at medical coding and then look at the patients who had gotten this type of transplant and followed them over time and we looked at which patients failed and we found a very different percentage. We were actually looking at more of a 78% percent survival rate at 5 years instead of 90. This parallels the findings of other countries, like Australia, that have a graft registry in which there's a centralized database where all of these surgeons can publish their results, which we don't have in the United States.

So, this big 12% difference in survival of 5 years I think was really interesting, because it shows that these transplants are maybe not as successful as we thought in the US and that also what tends to happen in a lot of published studies is that people tend to publish the results that they like. They're not going to necessarily put in all the failures or all of the people sort of getting it and so I think this study will make people think a little bit harder about doing these transplants and educating the patient when they're getting the surgery to let them know that "Here's what our average survival rate is," but let's say you have a younger patient you might not necessarily want to jump to do the transplant as soon as possible versus an older person who might do well.