Comparison of Regional Differences in the Choroidal Thickness between Patients with Pachychoroid Neovasculopathy and Classic Exudative Age-related Macular Degeneration

Purpose: To compare the regional differences in the choroidal thickness (CT) between patients with pachychoroid neovasculopathy (PNV) and classic exudative age-related macular degeneration (ceAMD).Materials and Methods: We included both eyes of patients with unilateral macular neovascularization (MNV) due to ceAMD or PNV. Unilateral eyes of normal subjects were also included as a normal control group. The regional difference in CT was defined as a difference between the macular and extramacular areas, and calculated as the ratio of subfoveal CT (SFCT) to nasal peripapillary CT (PCT).Results: In normal subjects, the choroid was 2.25 ± 0.10 times thicker at the macula than at the extramacular area. The SFCT and PCT were significantly affected by age (P < .001 and P < .001, respectively), whereas the regional difference in CT were independent of age (P = .076). Analysis of covariance including age, sex, and MNV group showed that regional difference in CT were significantly affected by sex, nasal peripapillary CT, and MNV group (P = .023, P < .001, and P < .001, respectively). The estimated marginal mean of the regional difference in CT was significantly smaller in the ceAMD group (1.671 ± 0.103) than in the normal control (2.250 ± 0.095, P = .003) and PNV groups (2.0880 ± 0.086, P < .001).Conclusions: Regional differences in CT were consistent with aging. However, the difference varied with the presence of PNV or ceAMD. Measurement of regional differences in CT provides additional information for characterizing the choroid in patients with MNV.