Ability to predict risk of progression varies along glaucoma continuum

Significant progress has been made in the ability to predict progression from ocular hypertension to glaucoma, but the same cannot be said for predicting whether patients with detectable disease will progress to severe visual impairment or blindness, said Kuldev Singh, MD, MPH, at Glaucoma Day at the American Society of Cataract and Refractive Surgery meeting.

"Despite the recent advances in diagnostics and therapeutics, management of glaucoma still remains more of an art than a science," said Dr. Singh, professor of ophthalmology, and director glaucoma service, Stanford University School of Medicine, Stanford, CA.

Advances in risk assessment for ocular hypertension derive largely from data collected in the Ocular Hypertension Study (OHTS) and have led to the development of several risk calculators, including the validated tool that was recently described in a paper published in 2005 by Medeiros and colleagues.

From OHTS it is known that the risk of progression to glaucoma is age-related, is higher among persons with a higher baseline IOP and a thinner central cornea, and depends on visual field parameters and optic nerve cupping. Diabetes surprisingly was found to be protective, although its role in decreasing risk has not been confirmed in other studies, and family history had no importance, although that unexpected finding may relate to the method of assessment, said Dr. Singh.

However, the large randomized clinical trials of patients with glaucoma have not provided solid information on risk factors for progression. In speaking with patients, glaucoma specialists may do best to remember that they will unlikely need to make a split-second decision.

"One problem in glaucoma consultation is that specialists feel forced to give patients information on risk based on a single visit. The reality is that you will have a much better understanding of the likelihood of whether the patient is at increased risk to go on to severe visual impairment after 2 to 3 years of follow-up, and that is what most of us should be doing as we care for these individuals," Dr. Singh said.