Rates of visual field progression in distinct optic disc phenotypes

Background: To determine if optic disc phenotype is correlated with the rate of glaucomatous visual field progression. Design: Retrospective cohort. Participants or Samples: Treated glaucoma patients. Methods: The optic disc stereophotographs of glaucoma patients were reviewed by two investigators masked to all clinical and perimetric data. Each disc was classified as focal ischaemic, myopic, senile sclerotic and generalized enlargement. Visual field progression (defined as at least two adjacent test points in the same hemifield progressing by more than 1.0 dB/year at P < 0.01) was evaluated using automated pointwise linear regression. Main Outcome Measures: Association between optic disc phenotypes and other clinical variables and rates of visual field progression. Results: 264 optic disc stereophotographs (127 generalized enlargement, 41 focal ischaemic, 54 myopic and 42 senile sclerotic) were evaluated. In the univariate analyses, it was found that patients with senile sclerotic discs were older (p = 0.002) and those with generalized enlargement had better baseline visual field mean deviation (p < 0.001) and higher intraocular pressure (p = 0.006) compared with the other groups. More disc haemorrhages were detected in the focal ischaemic and senile sclerotic groups (p = 0.010). After adjusting for other risk factors (intraocular pressure, age, central corneal thickness, disc haemorrhage), there were no differences among groups regarding the risk (p = 0.58) and velocity (p = 0.21) of visual field progression. Conclusions: Visual field progression was similar among the four optic disc phenotypes in treated glaucoma after adjusting for other known risk factors. The division of disc appearance into clinical phenotypes does not appear to provide independent information regarding the risk of progression in clinical practice.