Estimation of visual outcome without treatment in patients with subfoveal choroidal neovascularization in pathologic myopia

Objective: To clarify prognostic factors of long-term visual outcome without treatment in patients with myopic choroidal neovascularization (CNV) and estimate a regression equation to predict visual acuity at 5 years after CNV onset. Methods: Fifty-four eyes of 54 consecutive patients with high myopia and subfoveal CNV who did not receive treatment were identified using clinical records from 1988 to 2004. Photodynamic therapy not approved for myopic CNV in Japan during this period. The association of best-corrected visual acuity (BCVA) at 5 years after CNV onset with patient age, refractive error, axial length, initial BCVA, myopic retinopathy grade, duration of persistent hemorrhage, CNV size at onset, and size of hemorrhage around the CNV was analyzed using Spearman's correlation and multiple linear regression analysis. Results: BCVA at 5 years after onset was significantly associated with patient age, CNV size, and initial BCVA (P < 0.05, Spearman's correlation). The regression equation estimating BCVA at 5 years after CNV onset was based on age and initial BCVA (R-2=0.43). When subjects were divided into groups according to age (< 40 and >= 40 years), CNV size, axial length and duration of persistent hemorrhage influenced BCVA at 5 years in patients under 40 years; while only initial BCVA was an influence in those at least 40 years old. Conclusions: We developed a linear predictive model to estimate BCVA at 5 years after onset of myopic CNV without treatment based on the identified prognostic factors. This information might be important for managing patients with myopic CNV.