Glaucoma calculator

A new 'glaucoma calculator' designed to help physicians determine the risk of patients with ocular hypertension developing hypertension was unveiled at the recent American Academy of Ophthalmology Annual Meeting.

The calculator, similar to the predictive risk factor tools used for years in heart disease, allows eye specialists to input the various individual risk-factors of a patient into a simple slide rule, then calculate the risk of the patient developing glaucoma within a five-year period.

The individual risks are based on data collected from the 'Ocular Hypertension Treatment (OHT) Study', which identified key patient risk factors predictive of disease progression from ocular hypertension to glaucoma. 

'This aids physicians in establishing the risk of an individual patient in developing glaucoma,' said Felipe Medeiros, MD, an assistant professor of ophthalmology at the University of California, San Diego, during a workshop.

'Assessing the risk allows eye specialists to focus on the patients who are at moderate to high risk of developing glaucoma. These patients are the ones who will most benefit from treatment.'

The calculator, which resembles a slide rule, allows a physician to plug in the patient's age, intraocular pressure, central corneal thickness, vertical cup/disc ratio, and higher visual field pattern standard deviation values. The calculator then predicts the patient's five-year risk for future development of glaucoma.

In the DIGS study, 31 patients (25 per cent) with a moderate to high risk of glaucoma developed glaucoma during follow-up. The average probability of glaucoma conversion at five years was almost 12 per cent, the researchers reported.

Although the OHT study provided a better understanding of the relevant risk factors involved in the progression to glaucoma, physicians were still faced with the challenge of integrating these factors for a global assessment of the risk for an individual patient, Medeiros said.