Panel reaches consensus on IOP

Key Points

"IOP is our only modifiable risk factor for glaucoma and is vital to all aspects of glaucoma diagnosis and treatment," said Robert N. Weinreb, MD. "Measurement of IOP is straightforward, but interpretation of the data is not simple and has been limited by what methods have been available for measuring IOP and the limited number of determinations that can be obtained in clinical practice."

Dr. Weinreb is past president of the WGA, chairman of the WGA Consensus Committee, and director of the Hamilton Glaucoma Center and the Distinguished Professor of Ophthalmology at the University of California, San Diego. Dr. Weinreb's co-chairs for the IOP consensus project are James Brandt, MD, University of California, Davis; Ted Garway-Heath, MD, Moorfields Eye Hospital, London; and Makoto Araie, MD, University of Tokyo.

More than 120 authorities from around the world collaborated to develop the consensus on IOP. They were organized into committees to address topics that covered basic science, epidemiology, measurement techniques and interpretation, IOP variation, IOP as a risk factor, clinical trials, and target IOP. In a series of sessions conducted via the Internet over several months, each committee met to review relevant information and then produced a preliminary document.

"Our goal in producing the consensus was to be as comprehensive as possible," Dr. Weinreb said.

A thorough process

The initial documents were circulated to the members of each group and to each of the 70 member societies of the WGA to solicit comments. In Fort Lauderdale, FL, prior to the annual meeting of the Association for Research in Vision and Ophthalmology in May, each consensus committee presented its report at a meeting. All member societies of the WGA were invited to be represented at that program. Following a day of discussion, a consensus panel reviewed the reports and the feedback. Revised reports were generated and sent to the member societies for final feedback. Based on the input received, the final IOP consensus was created and published during the WGC.

A consensus promulgation meeting also was held during the WGC, at which all 70 glaucoma-society members were represented. Each society was provided with a slide set and copies of the IOP consensus and prepared to disseminate the consensus information and educate its ophthalmologist members. The IOP consensus book is published by Kugler Publications and also is available for purchase.

The IOP consensus is designed to be user-friendly, making it a useful tool for practitioners, Dr. Weinreb told Ophthalmology Times. The consensus is an important resource, and some of the points reached by the consensus committees highlight discrepancies with prevailing opinion, he added.

For example, the basic science section includes language stating that uveoscleral outflow makes up 25% to 57% of total outflow in young, healthy humans and decreases with age, he said.

"Many textbooks still say that uveoscleral outflow contributes only 10% to total outflow," Dr. Weinreb said. "The significantly higher proportion suggested by available evidence has important implications for glaucoma treatment."

The section on IOP measurement emphasizes the importance of central corneal thickness and compares newer technologies for IOP measurement with the standard Goldmann applanation technique, he said.