A common and effective procedure in the modern era, pars plana vitrectomy (PPV) and its early post-operative effects of elevated intraocular pressure (IOP) have been well documented. Similarly, optic nerve damage caused by raised IOP has also been noted as a potential side-effect of the surgery even years after it has first been performed. But what still remains unclear is how much risk of developing glaucoma patients might be facing when undergoing PPV.
To more accurately determine the long-term vision risks PPV patients might encounter, researchers from the Byers Eye Institute of Stanford University, Palo Alto, CA, have conducted a retrospective cohort study of 42,242 PPV patients.
“There have been numerous smaller studies highlighting a possible increased risk of glaucoma in vitrectomized eyes, but not all studies have yielded the same results,” explains Jonathan Lin, corresponding study author and vitreoretinal surgery fellow at the Byers Eye Institute. “We sought to leverage a large, federated electronic health record network to address this gap of knowledge.”
The data was taken from the TriNetX Health Research Network in Cambridge, MA, a large anonymized electronic health records network featuring information from 67 large US healthcare institutions and comprising clinical data on more than 250 million patients worldwide.
Lin and his team reported that 5.4 percent of the 42,242 PPV patients – all with no prior history of glaucoma – were diagnosed with the condition between three months and five years after the procedure.
“Our findings highlight the need for patients who undergo PPV to be monitored for ocular hypertension and glaucoma, since this can lead to progressive, permanent vision loss if it is not treated adequately,” Lin says.
A further “intriguing finding,” he adds, was that “the risk of glaucoma in vitrectomized eyes was higher in patients who had undergone PPV after a diagnosis of retinal detachment compared to those who had undergone PPV after a diagnosis of either epiretinal membrane or macular hole.” This indicates that surgical factors of the procedure could also play a part in the risk of PPV patients later developing glaucoma, a finding that Lin states “warrants further investigation.”
