Subretinal Drusenoid Deposits and the Loss of Rod Function in Intermediate Age-Related Macular Degeneration

Abstract

METHODS. In this cross-sectional study, retinal sensitivities within the central 248 retina were obtained twice using a dark-adapted chromatic perimeter, both with 505-and 625-nm stimuli. Tests were performed after 30 minutes of dark-adaptation either with or without a preceding photobleach. Multimodal imaging was performed to grade AMD and SDD status, and other retinal changes considered being risk factors for progression to late AMD. The sensitivity difference between both stimuli was used to assess rod function. The average point wise sensitivity difference (PWSD) was compared among the study groups.RESULTS. Twenty-nine control subjects and 20 iAMD without SDD and 17 iAMD with SDD cases were recruited. The average PWSD of the SDD group was significantly reduced (more with photobleach) compared with that of the control (P < 0.001) and no-SDD groups (P < 0.001), but only within the central 88. The average PWSD of the non-SDD group was also reduced compared with the control group but only for measurements with photobleach (P ¼ 0.020). There was no difference in average PWSD between the presence and absence of hyperreflective foci and/or nascent geographic atrophy in iAMD eyes without SDD (P ¼ 0.60) or with SDD (P ¼ 0.12).CONCLUSIONS. iAMD eyes with SDD are associated with worse static rod function compared with eyes without SDD. The greatest abnormality in rods is observed within the central 88 and when tested with a preceding photobleach.

Longitudinal Assessment of Rod Function in Intermediate Age-Related Macular Degeneration With and Without Reticular Pseudodrusen

“…This has been described in our previous paper. 14 To examine the extent of rod dysfunction as a function of eccentricity, the average PWSD between 505-and 625-nm stimuli, the RIT and the rod recovery rate for each concentric ring were calculated and compared between the study groups using 1-way ANOVA test. For RIT analysis, test points which did not recover to the criterion threshold after 30 minutes of DA were arbitrarily assigned a RIT of 30 minutes.…”

“…The diagnosis of RPD on SD-OCT has been prescribed in our previous study. 14 Briefly, definitely present RPD required the presence of at least five clear round or coneshaped subretinal deposits between external limiting membrane (ELM) and RPE on SD-OCT in more than one B-scan and in at least one en face modality (CFP, FAF, NIR) or RPD present on two en face modalities in the absence of SD-OCT findings (including outside the SD-OCT grid).…”

“…Many cross-sectional studies have demonstrated that rod function is abnormal early in AMD 3,[8][9][10] and more recently it has been found that AMD cases with the additional phenotype of reticular pseudodrusen (RPD, also known as subretinal drusenoid deposits) have particularly poor rod function. 2,[11][12][13][14][15] This finding is particularly significant as RPD are very common in AMD 16,17 and are highly correlated with disease progression to late AMD; geographic atrophy and neovascular AMD. [18][19][20][21][22][23][24][25] In addition, RPD are more likely distributed at superior perifoveal retina, while the common drusen in AMD are more at central fovea.…”

Relationship Between Rod-Mediated Sensitivity, Low-Luminance Visual Acuity, and Night Vision Questionnaire in Age-Related Macular Degeneration

“…Participants with unilateral reticular pseudodrusen (RPD) were also excluded, as RPD is known to affect dark adaptation and may be a confounding factor when investigating the relationship between uniocular rod function and NVQ-10 score (which relates to binocular vision). 19 Exclusion criteria for both groups included people with grade 2 cataract or worse (World Health Organi-zation [WHO] grading system), diabetic retinopathy, glaucoma, neck or spinal problems preventing completion of DACP, or medications that might affect retinal function such as hydroxychloroquine. 20 In addition, participants with medical conditions that could affect dark adaptation (such as liver disease and renal disease) were excluded.…”

A Pilot Study Evaluating the Effects of 670 nm Photobiomodulation in Healthy Ageing and Age-Related Macular Degeneration

“…None of these signs affect visual acuity but rod-recovery time from a bright flash is delayed and this test can accurately discriminate between healthy ageing of the retina and eyes with AMD [5,6]. Eyes with SDD experience a longer delay in rod-recovery time compared to eyes that do not [6][7][8][9]. These early changes in AMD may progress to the advanced forms of the disease, namely the atrophic type called geographic atrophy and neovascular AMD.…”