PURPOSE: To determine whether different coagulation-balance genetic polymorphisms
explain the variable clinical outcomes of photodynamic therapy with verteporfin (PDT-V) in
Caucasian patients with classic or predominantly classic choroidal neovascularization
(CNV) due to age-related macular degeneration (AMD). METHODS: The clinical records
of consecutive AMD patients with classic or predominantly classic CNV, treated with PDTV
according to the Treatment of Age-Related Macular Degeneration with Photodynamic
Therapy study criteria, were retrospectively examined. Eighty-six eligible patients were
subdivided in responder and non-responder basing on the modifications of best-corrected
visual acuity between baseline and 12-month checks. Six gene polymorphisms, i.e. factor V
G1691A, prothrombin G20210A, factor XIII-A G185T, methylenetetrahydrofolate reductase
C677T, methionine synthase A2756G, and methionine synthase reductase A66G, were
genotyped in each patient. Binary logistic regression models were used to explore the
predictive role of phenotypic and genotypic variables for PDT-V effectiveness. RESULTS:
PDT-V responders were more prevalent among the combined carriers for factor V 1691A
and prothrombin 20210A alleles (OR = 5.1 with a 95% CI of 1.0-24.4; P = 0.05),
methylenetetrahydrofolate reductase 677 T-allele (OR = 4.3 with a 95% CI of 1.8-10.8; P =
0.002), and methionine synthase reductase 66 G-allele (OR = 2.8 with a 95% CI of 1.1-6.8;
P = 0.04). Conversely, PDT-V non-responders were over-represented in patients with factor
XIII-A 185 T-allele (OR = 0.22 with a 95% CI of 0.09-0.56; P = 0.001). The other
considered predictors did not significantly modify PDT-V effectiveness. CONCLUSIONS:
Our study provides evidences for the presence of pharmacogenetic relationship between
peculiar coagulation-balance gene polymorphisms and different levels of visual prognosis at
12 months in AMD patients treated with standardized PDT-V protocol for classic subfoveal
CNV
