Delayed Rod-Mediated Dark Adaptation Linked With Doubled Risk of AMD
Patients with delayed rod-mediated dark adaptation were nearly twice as likely as patients with normal dark adaptation to develop AMD by 3 years after initial testing, according to a study published in Ophthalmology.1
Baseline and follow-up visits were completed by 325 patients with stage 1 normal vision as defined by the AREDS AMD classification system. Approximately 81% of participants had normal rod-mediated dark adaptation.
After adjusting for age and smoking status, patients with rod-mediated abnormal dark adaptation were approximately twice as likely to have AMD at follow-up year 3 compared with patients with normal rod-mediated dark adaptation.
“The biological relevance of this test is high,” the study authors wrote, “because it assesses translocation of vitamin A derivatives across the retinal pigment epithelium and Bruch’s membrane, two tissues with prominent age- and AMD-related pathology.”
1. Owsley C, McGwin G, Clark ME, et al. Delayed rod-mediated dark adaptation is a functional biomarker for incident early age-related macular degeneration [published online ahead of print October 30, 2015]. Ophthalmology.