PURPOSE - To investigate whether there is an association between complement factor H (CFH) or LOC387715 genotypes with response to treatment with intravitreal bevacizumab for exudative age-related macular degeneration (AMD).
DESIGN - Retrospective cohort study.
PARTICIPANTS - The study cohort consisted of 86 patients being treated for neovascular AMD with bevacizumab alone.
METHODS - Genotype determination for the CFH Y402H and LOC387715 A69S polymorphisms was performed by allele-specific digestion of polymerase chain reaction products. All patients were treated with 1.25 mg intravitreal bevacizumab at 6-week intervals until choroidal neovascularization was no longer active.
MAIN OUTCOME MEASURES - CFH Y402H and LOC387715 A69S polymorphisms. Choroidal neovascular lesion characteristics were ascertained by fluorescein angiography. Snellen visual acuity (VA) was measured before and after treatment.
RESULTS - For the CFH Y402H polymorphism, patients with the CFH TT genotype had the largest choroidal neovascular lesions (P = 0.02). With treatment, VA improved from 20/248 to 20/166 for the CFH TT genotype and from 20/206 to 20/170 for the TC genotype, but fell from 20/206 to 20/341 for the CFH CC genotype (P = 0.016). Only 10.5% of patients with the CFH CC genotype demonstrated improved VA with treatment, compared with 53.7% of CFH TT and TC genotypes (P = 0.004). For the LOC387715 A69S variant, patients with the TT genotype had the largest choroidal neovascular lesions (P = 0.012). There was no significant difference in response to bevacizumab treatment according to LOC387715 genotype.
CONCLUSIONS - The AMD-associated CFH Y402H and LOC387715 A69S variants were associated with differences in choroidal neovascular lesion size in this study. Patients with the CFH CC genotype fared significantly worse with intravitreal bevacizumab than did those with the CFH TC and TT genotypes, suggesting a potential pharmacogenetic relationship. Prospective studies to confirm or refute this observation should be considered.