Alterations of color vision and pupillary light responses in age-related macular degeneration

Abstract

IntroductionAge-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in developed countries and one of the leading causes of blindness. In this work, we evaluated color vision and the pupil light reflex (PLR) to assess visual function in patients with early and neovascular AMD (NVAMD) compared with the control group.MethodsWe recruited 34 early patients with dry AMD and classified them into two groups following AREDS: 13 patients with NVAMD and 24 healthy controls. Controls and patients with early dry AMD had visual acuity (VA) best or equal to 20/25 (0.098 logMAR). Color vision was assessed in controls and patients with early dry AMD using the Cambridge Color Test (CCT) 2.0 through the Trivector protocol. The PLR was evaluated using a Ganzfeld, controlled by the RETI–port system. The stimuli consisted of 1s blue (470 nm) and red (631 nm) light flashes presented alternately at 2-min intervals. To assess the cone contribution, we used a red flash at 2.4 log cd.m–2, with a blue background at 0.78 log cd.m–2. For rods, we used 470-nm flashes at –3 log cd.m–2, and for the melanopsin function of ipRGCs, we used 470 nm at 2.4 log cd.m–2.ResultsPatients with early dry AMD had reduced color discrimination in all three axes: protan (p = 0.0087), deutan (p = 0.0180), and tritan (p = 0.0095) when compared with the control group. The PLR has also been affected in patients with early dry AMD and patients with NVAMD. The amplitude for the melanopsin-driven response was smaller in patients with early dry AMD (p = 0.0485) and NVAMD (p = 0.0035) than in the control group. The melanopsin function was lower in patients with NVAMD (p = 0.0290) than the control group. For the rod-driven response, the latency was lower in the NVAMD group (p = 0.0041) than in the control group. No changes were found in cone-driven responses between the control and AMD groups.ConclusionPatients with early dry AMD present diffusely acquired color vision alteration detected by CCT. Rods and melanopsin contributions for PLR are affected in NVAMD. The CCT and the PLR may be considered sensitive tests to evaluate and monitor functional changes in patients with AMD.

The prevalence of red-green color vision deficiency and its related factors in an elderly population above 60 years of age

“…Vemela et al [6] stated that both YB and RG types of CVD were significantly more prevalent in AMD patients compared to healthy people of the same age; the mentioned study uses Color Assessment and Diagnostic Test and relates these defects to choroidal hypoxia and changes in the function of retinal cells. Also, Decleva et al [33] in their study found that with using Cambridge Color Test, color vision defects are seen in all three axes of protan, deutan and triran in patients with AMD. Failure to identify YB defects by the Ishihara test is the most important reason for the difference in the results of the present study compared to other studies in this field.…”

Sleep duration and age-related macular degeneration: a cross-sectional and Mendelian randomization study

“…SCN receives photoperiodic information from intrinsic photosensitive retinal ganglionic cells (ipRGCs) in retina, through the retinal-hypothalamic pathway, and subsequently regulates the sleep-awake cycle of human body ( Crislip et al, 2021 ). Decleva et al (2022) reported the impaired pupil light reflex (PLR) and function of ipRGCs in patients with early and neovascular AMD. Similarly, Maynard et al (2017) found the dysfunction of ipRGCs in patients with advanced AMD.…”