Predictive Factors of the Optic Nerve Head for Development or Progression of Glaucomatous Visual Field Loss

Abstract

Abstract: : Purpose: To evaluate which morphologic features of the optic disc are predictive factors for the development, or progression, of visual field loss in chronic open–angle glaucoma Methods:The prospective observational clinical study included 776 eyes of 421 Caucasian subjects with chronic open–angle glaucoma. During the follow–up time (mean: 67.4 months; median 65.1 months; range 6.2 to 104.5 months), all patients underwent repeated qualitative and morphometric evaluation of color stereo optic disc photographs and white–on–white visual field examination. Progression of glaucomatous visual field damage was defined by point wise regression analysis for each of the 59 locations in the visual field. Outcome measures were qualitative and quantitative morphologic optic nerve head parameters. Results: Development or progression of glaucomatous visual field defects were detected in 106 (13.9%) eyes. At baseline of the study, neuroretinal rim area was significantly (P<0.002) smaller, beta zone of parapapillary atrophy (p<0.003, nasal sector) was significantly larger, and age was significantly higher (p<0.003) in the progressive study group compared with non–progressive study group. Both study groups did not vary significantly in size of the optic disc and alpha zone of parapapillary atrophy. Cox proportional hazard regression analysis revealed that the progression of glaucomatous visual field loss depended significantly on the area of the neuroretinal rim (p<0.001), and age (p<0.001). It was independent of diameter of the retinal arterioles and veins. Conclusions:Morphologic predictive factors for development or progression of glaucomatous visual field defects in Caucasians are small size of neuroretinal rim and large area of beta zone of parapapillary atrophy. Age is an additional non–morphological parameter. Progression of glaucomatous optic nerve head changes is independent of size of the optic disc and alpha zone of parapapillary atrophy, and retinal vessel diameter.

Keywords: optic disc • intraocular pressure • visual fields