Abstract
Purpose :
Preclinical and clinical data has demonstrated that there is selective vulnerability of OFF visual pathways in glaucoma. Here we used a virtual reality multifixation multiple choice perimetry method to assess the ON and OFF pathways using increment and decrement stimuli.
Methods :
Glaucoma/glaucoma suspect patients were enrolled from ophthalmology clinics. Using Vivid Vision Perimetry, participant eyes at 12 test locations were assessed with increment/decrement stimuli. Both eyes were tested concurrently with randomly alternating stimuli. Contrast was controlled by a 1-up, 1-down staircase changing by a factor of 2 or 4 on a white background (10 cd/m2). Statistical testing included standard, Welch, and two-sided paired t-tests.
Results :
69/87 participants completed testing (mean age, 66.9±10.4 years; 50.7% female). Reasons for incompletion included inability to complete tutorial (n=10) and fixation task difficulty (n=6). 1 eye was randomly selected per participant and grouped clinically into: perimetric glaucoma (39 eyes), pre-perimetric glaucoma (22 eyes), and glaucoma suspect/ocular hypertension (22 eyes). Contrast sensitivity (CS; reciprocal of contrast threshold) and mean contrast sensitivity (MCS; mean CS per eye) were recorded in increment and decrement stimuli tests in all 12 test locations per eye. For increment and decrement tests respectively, the MCS for the perimetric glaucoma group was lower than that of both the pre-perimetric glaucoma (4.07 dB, p=0.002; 2.54 dB, p=0.027) and the glaucoma suspect/ocular hypertension group (4.69 dB, p<0.001; 4.48 dB, p<0.001). For perimetric glaucoma, the MCS in the decrement test was 0.74 dB (p=0.046) higher than in the increment test. In a pooled point-wise analysis of all test locations across the perimetric glaucoma, pre-perimetric glaucoma, and glaucoma suspect/ocular hypertension groups, locations with low average CS (≤15 dB) had a CS difference of +2.12, +2.31, and +2.93 dB (all p≤0.001) between the decrement and increment test, when compared those with high average CS (>15 dB).
Conclusions :
Perimetric glaucoma eyes performed better on global metrics in decrement versus increment stimuli testing. Individual locations with higher sensitivity performed better using increment stimuli while those with lower sensitivity performed better using decrement stimuli. These results motivate design of novel visual field stimuli that probe specific visual pathways.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.