Abstract
Purpose :
There is increasing evidence that dark adaptation (DA) is a useful functional parameter for both detection and staging of AMD. Patients with Age-related Macular Degeneration (AMD) have a high prevalence of peripheral changes, thus suggesting that this disease may not be limited to the macula. Therefore, this study was designed to evaluate the relationship between peripheral changes in AMD and DA.
Methods :
Prospective, cross-sectional study, including patients with AMD and a control group (> 50 years). All eyes were graded using AREDS system for AMD staging. All participants were also imaged with ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) (Optos Inc, Marlborough, MA). A grid with three concentric circles centered on the fovea was placed on all UWF images, defining the following zones - perimacular, mid- and far-periphery. The UWF images were then assessed by two independent graders for the presence of several peripheral changes. For all study participants, both eyes were tested with the AdaptDx® (MacuLogix, Middletown, PA) DA 20 minutes protocol. Multilevel mixed effect models (accounting for correlated outcomes between 2 eyes) were used for analyses. The primary outcome was rod-intercept time (RIT), as a continuous variable.
Results :
We included 128 eyes (96 AMD and 32 control). Multivariable analysis revealed that the presence of reticular pigmentary changes in the mid- (ß= 4.3, p=0.012) and far- (ß= 8.4, p<0.001) peripheral zones was associated with delayed RIT, even after adjusting for confounding factors. The presence, number and extent of peripheral classic drusen did not show any association with RIT. Reticular drusen could not be reliably assessed with this imaging modality. FAF images analysis revealed that the presence of a mottled hypofluorescent pattern in the mid peripheral zone was also associated with prolonged RITs (β= 4.4, p= 0.031).
Conclusions :
Our results suggest a significant association between time to dark-adapt and the presence of peripheral reticular pigmentary changes, as well as the presence of a peripheral mottled hypofluorescent FAF pattern. This work provides new insight into the clinical significance of peripheral changes in AMD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.