Abstract
Purpose: :
There is evidence that, in glaucoma, diffuse loss of sensitivity occurs for the 24-2 test pattern (Henson et al, 1999). We have assessed the presence of diffuse loss of sensitivity within 10 degrees of fixation, using the 10-2 test pattern in a population of patients with glaucoma.
Methods: :
We tested 46 eyes of 46 subjects, 23 POAG patients with pattern visual loss within 10 degrees of fixation and 23 controls. Each POAG eye was matched with an age-similar control eye. All subjects were experienced with automated perimetry, had clear media, visual acuity of 20/25 or better, and had no concomitant ocular disease, systemic disease or systemic medication known to affect the visual field. The 10-2 test pattern with SITA Standard was used to test differential light sensitivity. Locations with pattern deviation probability values of <5% were identified in each POAG eye, and corresponding locations were eliminated from subsequent analysis for that POAG/control pair of eyes, in order to compensate for the effects of pattern loss on the most sensitive locations. For each POAG/control pair, the ten most sensitive remaining locations in each field were sequenced by sensitivity, ten (control - POAG) threshold differences were calculated, and the average and SD of the ten differences were determined.
Results: :
The overall average of the sensitivity difference at the ten most sensitive locations was 1.9 ± 1.1 dB (significantly > 0, p<0.005). The 23 average differences were normally distributed (center: 2.1 dB; SD = 0.9 dB). For the individual pairs of eyes, the SD of the ten difference values ranged from 0.3 to 0.8 dB (ave = 0.6 dB).
Conclusions: :
Glaucoma patients with pattern visual field loss within 10 degrees of fixation also exhibit diffuse loss of sensitivity averaging approximately 2 dB. We have confirmed the 24-2 findings of Henson and extended them to the central 10-2 visual fields of patients with glaucoma.
Keywords: perimetry • visual fields