New paradigm in the way glaucoma is diagnosed

Suggesting a change in the way physicians diagnose glaucoma, Robert Weinreb, MD, outlined a new paradigm for diagnosis of the disease in his Glaucoma Society of International Ophthalmology Congress (GCIOC) Day Lecture, presented Monday at the World Ophthalmology Congress.

Dr. Weinreb said that the glaucoma field is undergoing a revolution in diagnosis. He said there is a transition from reliance solely on visual fields to the increased use of structural analysis of the optic disk and RNFL.

"It's something that was initiated 20 years ago," explained Dr. Weinreb. "Changes are very, very slow in glaucoma, as it does in all medical disciplines. We have reached an infliction point in glaucoma diagnosis where we are about to reap the benefits of this revolution."

Dr. Weinreb, director of the Hamilton Glaucoma Center at the University of California, San Diego, proceed to discuss the diagnosis of glaucoma. Citing that glaucoma is a continuum where a patient progresses from a non-detectable disease to asystematic disease, glaucoma is detected by a change in visual function or change in the appearance of the optic disk or RNFL.

The number of patients who have glaucoma worldwide is not really known, Dr. Weinreb pointed out. It's estimated that between 70 million to 100 million people have glaucoma. "The key point is that at least half of the patients with glaucoma are not recognized. Between 90% to 95% who have glaucoma don't know they have glaucoma, and have not yet been diagnosed with it."

He then reviewed the standard by which glaucoma is currently detected, including the assessment of standard visual field and standard automatic perimetry, with years of long follow-up periods to monitor the progression of glaucoma in patients.

Dr. Weinreb explained that the paradigm for glaucoma diagnosis and the changing concept would center on the assessments of the optic disk and RNFL along with visual function. They will be essential elements to quality glaucoma diagnosis.

"Glaucoma can be defined as a common structural or structural-functional abnormality," Dr. Weinreb said. "Glaucoma can also be defined as a progressive structural or functional change, such as the progressive change in the disk, RNFL, or the visual field. That's probably the most specific diagnosis for glaucoma."

He concluded that slight functional testing complements standard automated perimetry and facilitates the earlier diagnosis. The evaluation of the documentation of the optic disk and the RNFL enhance glaucoma diagnosis. Structural and functional testing provides complementary information for sensitive and specific glaucoma diagnosis.