Retinal Dysfunction and Complement Factor H Polymorphism in Early Age-Related Macular Degeneration

Purpose: To evaluate the association between retinal function and complement factor H (CFH) and ARMS2 gene polymorphisms in patients with early age-related macular degeneration (AMD). Methods: Thirty-three early AMD patients (age range: 55-85 years), with preserved visual acuity (≥ 0.7) and macular lesions belonging to stage 2 of the standard international staging scheme, underwent full clinical and ophthalmic examination, focal electroretinogram (FERG) testing and gene polymorphism analysis for the CFH (Tyr402His) and ARMS2 (del443ins54) AMD susceptibility genes. FERGs were recorded from the macular region (18°) in response to 41 Hz flickering stimuli presented on a light adapting background. The amplitude and phase of the fundamental harmonic response component were measured. Gene polymorphisms were determined by TaqMan assays and polymerase chain reaction amplification. Results: Mean FERG amplitude tended to decrease (p < 0.001) in patients hetero (by 21%)- or homozygous (by 43%) for CFH polymorphism, compared to wild type patients, although visual acuity and funduscopic features were similar across groups. FERG amplitude did not vary significantly across groups for the ARMS2 polymorphism. FERG phase did not change significantly across the different CFH or ARMS2 gene polymorphism groups. Conclusions: The results show that retinal function can vary significantly across early AMD patients with similar fundus lesions and visual acuity, but belonging to different genetic subtypes. CFH abnormality may impact significantly on retinal function in early AMD, supporting a predictive role for progressive visual loss in individual at risk patients.