Rates of visual field progression vary considerably in Swedish study

A large inter-patient variation in the rate of glaucomatous progression was seen in a representative group ofpatients with open-angle glaucoma who received conventional clinical care in Sweden. A substantial minority ofpatients had progression rates indicating that they could progress from normal vision to blindness very rapidly,said Anders Heijl, MD, PhD, professor and director of the Department of Ophthalmology, Lund University, MalmoUniversity Hospital, Malmo, Sweden.

In this retrospective chart review that included 583 patients with a mean follow-up of 7.8 years, the mean rateof progression for the entire cohort was a loss of 0.80 dB/year. However, the distribution of progression rateswas negatively skewed. While the mean rate of progression overall corresponded to degeneration from normalvision to blindness in about 35 years, investigators found that 99 patients (17%) had a rate of progression thatexceeded 1.5 dB/year, corresponding to worsening to blindness in less than 20 years, and 26 patients (4.5%) hada progression rate of over 2.5 dB/year, corresponding to progression to blindness in a dozen years or less. Datawere analyzed with simple linear progression analysis.

Most of the patients had received primary glaucoma care from the Department of Ophthalmology at MalmoUniversity, as there are few private ophthalmic practitioners in Sweden. The patients thus were representativeof the glaucoma population throughout Sweden but may not be representative of other Western countries because ofa high rate of pseudoexfoliation glaucoma in Sweden, Dr. Heijl said.

Discussing the impact of treatment on progression, Dr. Heijl noted that the mean reduction in IOP levels was similar to that seen in other retrospective chart reviews performed in Europe, althoughperhaps about 1 mm lower. In addition, the rate of cataract surgery among the patients likely had only a smallimpact overall and no impact on the rapidly progressing patients.