Abstract
Purpose :
To evaluate the use of a neutral density filter (NDF) to aid in the comparison of a conventional (Humphrey Visual Field Analyzer; HVFA) and a novel visual field (VF) testing system (Custom Television Visual Field Analyzer; TV-VFA) with different luminance capabilities.
Methods :
Eighty-seven participants (median age = 73; range 40 to 87) were recruited from a glaucoma clinic: 28 healthy controls, 29 patients with early glaucoma (mean deviation (MD) > -6 dB, no central defect), and 30 patients with advanced glaucoma (MD < -6 dB with central scotoma). All participants underwent VF testing on one randomly selected, eligible eye using a 10-2 full threshold strategy on both the HVFA and TV-VFA, with and without a NDF with 1.56% transmittance. The TV-VFA was composed of a 55” OLED TV with maximum brightness of 445 cd/m2, running custom software, which corresponds to HVFA equivalent scale of 10 to 33 dB. Statistical comparisons were performed with t-tests and Bonferroni corrections as appropriate.
Results :
There was almost no significant difference with regards to the 10-2 mean sensitivity (MS) for healthy controls between testing systems, with (t(27) = -2.86, p=.048) or without NDF (t(27) = -1.24, p=1; Table 1). MS in glaucoma patients was higher in TV-VFA than HVFA (p<0.05). The use of NDF led to a significant reduction in MS for all groups (HVFA: -8.4, -7.4, and -6.3 dB; TV-VFA: -7.6, -6.7, and -4.3 dB for controls, early, and advanced glaucoma patients; p<0.05). Pointwise comparisons for patients with no central scotoma (control and early glaucoma) showed that NDF improved the linearity of the relationship between the testing systems and illuminated greater variability between systems at the extremes of sensitivity thresholds (Figure 1).
Conclusions :
A novel TV-VFA system produced MS dB values that were comparable to those obtained with the conventional HVFA system in healthy controls. Use of a NDF was successful in reducing the MS in all groups, successfully modeling generalized reduced sensitivity. Additionally, the NDF shifted results into a more linear, useful range for comparison for participants without a central scotoma. The use of NDF may be useful to facilitate comparisons between VF testing systems in the development of new perimeters.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.