PCDHB9 and snowflake vitreoretinal degeneration: There were 8 differentially methylated genes (CDH2/PCDHB10/PCDHB11/PCDHB14/PCDHB16/PCDHB3/PCDHB6/PCDHB9) in the LAA subgroup and 1 (CDH2) in the SVD subgroup after adjusting for smoking, drinking, history of hypertension and diabetes, and blood lipid levels (p < 0.05, Table 5).