Corneal transplant nomogram may predict long-term graft survival
A new corneal transplant nomogram can predict medium- to long-term graft survival after penetrating keratoplasty, according to a speaker at the virtual American Academy of Ophthalmology annual meeting.
“Outcomes after penetrating keratoplasty can be predicted with a reasonably high accuracy based on the preoperative clinical assessment. Predicting these outcomes would improve patient counseling prior to surgery,” Zeba Syed, MD, co-author of the study, told Healio/OSN.
Syed and colleagues conducted a retrospective, noncomparative cohort study that included 1,029 transplants from 903 eyes of 835 patients. Risk for failure was estimated using the Cox proportional hazards model, Eric J. Shiuey, MS, said at the meeting.
The researchers developed a nomogram based on the 11 most predictive preoperative and intraoperative variables in the patient cohort to accurately foresee graft failure rates.
After internal validation, it was found the nomogram exhibited a 76% accuracy rate for predictive graft survival at 3 years and 5 years, Shiuey said.
Several variables were significant risk factors influencing graft survival. Systemic autoimmune disease, prior anterior segment surgery, active microbial infection, four quadrants of corneal neovascularization, silicone oil present at the conclusion of surgery, and concurrent lensectomy or IOL removal all had hazard ratios greater than 2 and posed significant risks for graft survival.
To use the nomogram, patients are assigned “point values” based on their age and presence of the 11 most predictive variables. Their point totals are then compared with a 3-year or 5-year graft survival scale to predict outcomes.
“I do use this nomogram to predict graft outcomes in my corneal transplant patients. I routinely discuss with patients their existing risk factors and the predicted graft survival based on these variables. The patient then decides based on this data about whether it is worth it for him or her to undergo the surgery. Sometimes we will pursue treatments to reduce the risk factors. For example, we may treat corneal neovascularization with anti-VEGF injections before corneal transplant surgery,” Syed said.
Syed and colleagues are currently working with other academic centers to validate the nomogram in different settings.
“The nomogram is only really valuable if it can be applied more broadly beyond our institution,” she said.
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Shiuey EJ, et al. Development of a nomogram to predict graft survival after penetrating keratoplasty. Presented at: American Academy of Ophthalmology annual meeting; Nov. 13-15, 2020 (virtual meeting).
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