Abstract
Purpose: :
Complement Factor H Y402H polymorphism which affects the alternate complement pathway has been implicated in nearly 50% cases of Age related macular degeneration (AMD). We hypothesised that this uncontrolled complement activation may possibly affect the outcome/s of current treatments like Verteporphin – Photodynamic therapy (V–PDT) for AMD. This study tested whether Y402H CFH gene variants influence visual outcomes following V–PDT in a UK cohort of AMD.
Methods: :
24 patients with predominantly classic neovascular AMD who underwent V–PDT at Southampton Eye Unit from April 2003 to July 2005 were identified for the study. All patients had documented ETDRS logMAR visual scores, stereoscopic fundus photographs, fluorescein angiographs, and optical coherence tomographs at all visits. DNA samples were obtained after consent and analysed for the presence of the Y402H CFH gene variant using a 5' nuclease Taqman assay. Individual CFH genotypes were then analysed for any association with the degree of visual acuity lost or gained following V–PDT (P values by Mann–Whitney 2–tailed analysis). CFH groups were also analysed by logistic regression analysis controlling for age, sex, body mass index, and smoking status.
Results: :
The overall average number of PDT treatments received was 2.17± 1.27 times, with a mean follow up of 10.65 ± 4.57 months. The mean logMAR letters lost after V–PDT treatments did not differ significantly between the homozygous CFH CC and heterozygous CT genotype groups (26.09 ± 32.60, CI=4.19–47.99 vs. 26.36 ± 36.00, CI=2.14–50.58, P=0.98). In total, 50% of cases in the CC group had lost 15 or more logMAR letters as compared to 45% in the CT group (RR=1.10, CI=0.46–2.59). The actual numbers were too small in the TT group to be included in the analysis. Comparative CNV morphology in the individual CFH genotype groups following V–PDT therapy will be presented.
Conclusions: :
Y402H CFH gene variant does not appear to influence the degree of visual loss or final visual outcomes following V–PDT therapy for neovascular AMD.
Keywords: age-related macular degeneration • genetics • photodynamic therapy