The impact of mesopic conditions to detect functional visual loss in drivers with simulated media opacity

Asare, Frederick Afum

Abstract

Purpose: Although driving encompasses a wide range of rapidly modulating contrast and luminance levels, contrast sensitivity (CS), if assessed, is typically done under photopic conditions. This study evaluated existing measures of CS under photopic and mesopic luminance levels and evaluated the effect of simulated media opacities on such measures.

Methods: Contrast sensitivity was measured in forty-seven drivers aged 18–50 years (mean age ± SD: 25.5 ± 6.5) under photopic and mesopic (10 min adaptation, 0.29 ± 0.02 cd/m2) luminance levels with the Pelli-Robson CS chart and the Mesotest II (without glare). Different levels of media opacity were then simulated using white-opacity containing Lee Fog Filters (1–5) and CS measured under the two luminance conditions in a randomised order.

Results: The mean (±SD) photopic CS (logCS) as measured with the Pelli-Robson chart was significantly reduced by nearly three triplets (1.53 ± 0.16) from baseline (1.95 ± 0.03) when media opacity was simulated with fog 5 (p < 0.001), while mean mesopic CS demonstrated an even greater reduction by 4.4 triplets (1.02 ± 0.15) from baseline (1.67 ± 0.14; p < 0.001). Fog filters 3 and 4 reduced mean mesopic CS by 1.5 triplets (1.45 ± 0.16; p < 0.001) and 2.4 triplets (1.31 ± 0.14; p < 0.001) respectively from baseline (1.67 ± 0.14), but no significant reduction was found for photopic CS. For Mesotest II, only fog 5 media opacity produced a significant two-line reduction (0.20 ± 0.10; p < 0.001) in mean mesopic CS.

Conclusion: The use of mesopic luminance conditions is more effective in revealing CS loss under different levels of simulated media opacity, hence should be considered clinically when investigating vision in older drivers.

• Presentation Conference Type: Conference Abstract
• Conference Name: British Congress of Optometry and Vision Science
• Start Date: Sep 6, 2024
• Acceptance Date: Aug 26, 2021
• Online Publication Date: Oct 26, 2021
• Publication Date: 2022-01
• Deposit Date: Oct 10, 2024
• Journal: Ophthalmic and Physiological Optics
• Print ISSN: 0275-5408
• Electronic ISSN: 1475-1313
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 42
• Issue: 1
• Pages: 230-253
• DOI: https://doi.org/10.1111/opo.12900
• Public URL: https://uwe-repository.worktribe.com/output/13278687
• Additional Information: Published: 2021-10-26