Overdiagnosed glaucoma poses major challenge to health systems

The Thessaloniki Eye Study provides valuable evidence that the overdiagnosis of OAG is substantial

Dermot McGrath

Posted: Friday, October 6, 2017


Fotis Topouzis MD.

The problem of overdiagnosed glaucoma has not been fully recognised and represents a significant challenge for the health systems of developed countries around the world, according to Fotis Topouzis MD.

“While we have known for quite some time that the prevalence of undiagnosed glaucoma is unacceptably high, the problem of the overdiagnosis of open-angle glaucoma (OAG) has not been previously addressed. The Thessaloniki Eye Study provides valuable evidence that the overdiagnosis of OAG is substantial,” he told delegates attending Glaucoma Day as part of the 35th ESCRS Congress in Lisbon.

Dr Topouzis, Professor of Ophthalmology at the Aristotle University of Thessaloniki, Greece, said that there are many challenges in arriving at a successful diagnosis of glaucoma.

“This is an insidious disease. There is only moderate agreement on optic disc assessment, even among experts. Imaging modalities also have suboptimal diagnostic accuracy, and there are challenges in interpreting visual field results,” he said.

Evidence from population studies suggest that at least half of all glaucoma cases have not been diagnosed, and that many patients suffer severe visual field loss before diagnosis, said Dr Topouzis.

By contrast, there is very limited data in the scientific literature concerning overdiagnosis, even though the issue has potentially major implications for individuals and societies, he said.

“There is the psychological burden to non-affected individuals, the waste of clinical resources and unnecessary healthcare costs,” he said.

In a population of 2,554 participants aged 60 years or older in the Thessaloniki Eye Study, researchers found a 50% rate of undiagnosed glaucoma. Primary open-angle glaucoma was also found to be four times more likely to be undiagnosed compared with exfoliation glaucoma.