Abstract
Purpose: :
To analyze the effect of some key SNPs of the VEGF gene on the anatomic outcome of photodynamic therapy (PDT) for exudative age-related macular degeneration (AMD).
Methods: :
We analyzed retrospectively the clinical course of 86 eyes of 86 patients treated with PDT for exudative AMD in a referral clinic setting. Depending on the clinical outcome the eyes were divided into responders (N=58) and non-responders (N=28). In the 'responders' the lesion was clinically and angiographically dry at a visit scheduled 3 months after the last PDT treatment. In the 'non-responders' the treating physician had halted further PDT sessions due to continuous leakage of the lesion despite repeated PDT sessions. Three SNPs in the VEGF gene, rs699947A>C, rs2146323A>C and rs3025033A>G were analyzed in relation to the response to PDT.
Results: :
The rs699947 AA genotype was present in14% of the non-responders and 40% of responders, AC in 39% and 48% and CC in 46% and 12%, correspondingly ( p=0.0008).The rs2146323 AA genotype was present in 4% of the non-responders and 24% of responders, AC in 32% and 38% and CC in 64% and 38%, ( p=0.0369). The rs3025033A>G was distributed evenly between the response patterns. None of the SNPs correlated with baseline lesion size or configuration (predominantly or minimally classic or occult). The result was not affected by the number of PDT sessions in either group.The visual outcome was better in the PDT-responders.
Conclusions: :
The rs699947A>C and rs2146323A>C SNPs of the VEGF gene are powerful determinants of the anatomic outcome of PDT, but not of lesion size. Possibly these SNPs are more related to the increase in VEGF activity occuring after PDT than to that present during the induction of the wet AMD lesion
Keywords: age-related macular degeneration • vascular endothelial growth factor • photodynamic therapy