Clinical factors associated with progression of glaucomatous optic disc damage in treated patients

Background: Reducing intraocular pressure (IOP) in glaucomatous eyes does n ot always prevent disease progression. Objective: To determine the clinical factors associated with progressive op tic disc damage in glaucomatous eyes receiving treatment to reduce IOP. Methods: Baseline and follow-up optic disc photographs as well, as demograp hic and clinical data were retrospectively studied in 186 eyes of 93 patien ts with primary open-angle glaucoma, and in 138 eyes of 69 patients with no rmal-pressure glaucoma. The patients with primary open-angle glaucoma were included in the study only if their treated IOPs during a follow-up period of 5 years were less than 21 mm Hg. The patients with normal-pressure glauc oma were included only if their IOPs were reduced by at least 20% during th e follow-up period, The association of progressive optic disc damage with p atient- and eye-specific characteristics was examined using multivariate an alysis. Results: During the 5-year study period, 141 (43.5%) of the 324 eyes exhibi ted progressive optic disc damage defined by at least a 5% decrease in the neural rim area-to-disc area ratio. Using multivariate analysis, the follow ing were found to be strongly associated with progressive neural rim damage : a baseline smaller neural rim area-disc area ratio (P < .001); a baseline larger zone P area-disc area ratio (P=.04); a baseline larger parapapillar y atrophy length-disc circumference ratio (P=.05); a diagnosis of normal-pr essure glaucoma (P=.01); and combined medical and surgical treatment prior to the study period (P=.01). Conclusions: Clinical factors other than IOP may be important indicators of subsequent progression of glaucomatous optic disc damage. Our findings sug gest that eyes with advanced glaucomatous optic disc damage and normal-pres sure glaucoma are more likely to progress despite receiving treatment to re duce IOP.