Purpose
Recent studies have demonstrated the utility of genotype assessment to predict future choroidal neovascularization (CNV) in patients with early age-related macular degeneration (AMD). In this study, relevant genetic markers were evaluated for utility in predicting visual prognosis, treatment requirements, and time to resolution in patients with advanced AMD and CNV.
Methods
DNA specimens from 51 subjects with angiographically-confirmed CNV were genotyped for single nucleotide polymorphisms (SNPs) in genes known to be associated with CNV: CFH, CFHR4, CFHR5, F13B, C2, C3, CFB, and ARMS2. Retrospective chart review was performed to collect age, gender, race, smoking status, date of initial conversion to wet AMD, and time to first resolution of wet disease. Visual acuity, central foveal thickness (CFT) and cube average macular thickness (CAT) by optical coherence tomography, and treatments were recorded at each visit. Linear regression analysis was used to assess the effect of genotype and demographic variables on these outcomes over time.
Results
The C-A SNP at rs1750311 (CFHR5) was significant for improved visual acuity over time (p=0.0063). Non-white race (p=0.0353) and SNPs at rs2274700 (CFH, p=0.0176, 0.0032) were associated with decreased CFT over time. SNPs at rs1092253 (CFHR5) were associated with increased CFT (p = 0.0015, 0.0005). CAT increased over time in patients with G-T at rs2990510 (F13B, p=0.0296) and decreased in patients with A-G at rs698859 (F13B, p=0.0100). Greater numbers of monthly anti-VEGF injections were required for patients with SNPs at RS1061170, RS9332739, and RS2990510 (p = 0.033, 0.0256, 0.0355). Fewer treatments were required for patients with SNPs at RS69885 and RS299050 (p = 0.0017, 0.0114). Non-smokers required fewer injections than patients who previously smoked (p = 0.0009). Shorter time to resolution was seen with SNPs at rs641153 (CFB, p=0. 0918) and rs2274700 (CFH, p=0.0267, 0.0421). Hypertension was also associated with shorter time to resolution (p=0.0003). Longer time to resolution was seen with C-A at rs1750311 (CFHR5, p=0.013).
Conclusions
Genotype analysis in patients with newly-diagnosed CNV revealed SNPs associated with certain outcomes of vision, macular thickness, treatment requirement, and time to first resolution. Genotype assessment can aid the ophthalmologist in discussing expectations in patients with wet AMD.