Background: Typical exudative age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) are two of the major macular diseases found in Asians. Although genomic studies have shown a contribution by CFH and LOC387715/HTRA1 polymorphisms to the development of these two diseases, the correlation of the clinical phenotypes to these genotypes has not been determined in Asian patients.
Methods: The prevalence of the CFH Y402H and HTRA1 rs11200638 genotypes was determined in 116 patients with typical exudative AMD and in 204 patients with PCV. Potential correlations of these polymorphisms were tested retrospectively and cross-sectionally for bilaterality of the disease, final visual acuity and the greatest linear dimension of the choroidal neovascular (CNV) lesion.
Results: There was no significant difference in the incidence of CFH Y402H (P = 0.598) and HTRA1 rs11200638 (P = 0.290) between eyes with typical exudative AMD and with PCV. There was a significant association between the lesion size and HTRA1 rs11200638. For eyes with typical AMD, the size of the lesion (6363 +/- 2837 microm) was significantly larger in the high-risk homozygous group (AA), than in the low-risk homozygous group (GG) (3866 +/- 1947 microm; P = 0.0003). The same tendency was observed for the size of the lesion in PCV cases (homozygous group: 6347 +/- 2673 microm, non-risk homozygous group: 4405 +/- 2066 microm, P = 1.3 x 10(-5).
Conclusions: A common genetic background may exist between typical exudative AMD and PCV patients. Among the patients with these two clinical entities, those with a homozygous HTRA1 rs11200638 risk allele had larger CNV lesions.