Abstract
Purpose :
To determine the influence of different health conditions and lifestyle factors on dark adaption (DA) in Age-related Macular Degeneration (AMD).
Methods :
We conducted a prospective, cross-sectional study, including patients with AMD and a control group. AMD was graded according to the Age-Related Eye Disease Study (AREDS) classification system. We obtained data on medical history, medications, and lifestyle factors. DA was assessed with the extended protocol (20 minutes) of AdaptDx® (MacuLogix). The subject’s eye was bleached by exposure to a 505-nm photoflash, with sensitivity measurements beginning immediately after bleaching. Subjects indicated when a stimulus light was visible using a hand-held button. Sensitivity was estimated using a three-down/one-up modified staircase threshold estimate procedure. Successive intensity threshold measurements were taken. When subject’s sensitivity thresholds were twice consecutively above 5 x 103 scot cd/m2 or test duration lasted 20 minutes, the time to reach this point was defined as rod intercept time (RIT). For analyses, the right eye or the eye with more advanced AMD was selected. Multivariate linear and logistic regressions were performed, accounting for age and AMD stage, with RIT as the outcome.
Results :
Seventy-eight subjects (75.6% with AMD, n=59; 24.4% controls, n=19) were included. Multivariate assessments revealed that body mass index (BMI; ß=0.30, p=0.045) and family history of AMD (ß=2.68, p=0.039) were significantly associated with worse rod intercept times (RIT). Abnormal DA (RIT≥6.5 minutes) was also significantly associated with family history of AMD (ß=1.84, p=0.006) and alcohol intake (ß=0.07, p=0.017). The use of AREDS vitamins was statistically linked with impaired RIT, most likely due to an increased severity of disease in those taking vitamins.
Conclusions :
In addition to age and AMD stage, a higher BMI, higher alcohol intake, and a family history of AMD appear to be linked with impairments in dark adaptation.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.