Aim: To compare the retinal morphologic characteristics of eyes with choroidal neovascularization (CNV) secondary to pathologic myopia versus eyes with CNV secondary to age-related macular degeneration (AMD), using quantitative optical coherence tomography (OCT) subanalysis.
Methods: Twenty-one eyes of 21 patients newly diagnosed with CNV secondary to pathologic myopia, and 43 consecutive cases of eyes with newly diagnosed subfoveal CNV secondary to AMD were retrospectively collected. In all patients, StratusOCT images and fluorescein angiograms (FA) were available for analysis. StratusOCT images were analyzed using custom software (termed "OCTOR"), which allowed calculation of the thickness/volume of the neurosensory retina, subretinal fluid (SRF), subretinal tissue (SRT), and pigment epithelial detachments (PEDs). FA images were used to calculate CNV leakage area and CNV lesion size for each eye.
Results: Total volume of neurosensory retina in the pathologic myopia group was significantly less than in the AMD group (7.10 ± 0.50 mm3 versus 7.76 ± 0.93 mm3, P=0.004). Total volume of SRF in the pathologic myopia group was less than in the AMD group, however the difference was not statistically significant (0.33 ± 1.38 mm3 versus 0.55 ± 0.82 mm3, P=0.434). Total volume of SRT in the pathologic myopia group was less than in the AMD group, however the difference was not statistically significant (0.16 ± 0.15 mm3 versus 0.36 ± 0.60 mm3, P=0.144). Total volume of PED in the pathologic myopia group was markedly less than in the AMD group (0.01 ± 0.03 mm3 versus 1.09 ± 1.89 mm3, P<0.001). On FA, the total leakage of CNV in the AMD group was significantly greater than in the pathologic myopia group (4.17 ± 3.29 DAs versus 0.53 ± 0.58 DAs P<0.001).
Conclusions: CNV lesions in pathologic myopia were associated with considerably less retinal edema, SRF, and SRT compared with CNV associated with AMD. PEDs were almost negligible in myopic lesions compared with AMD. These findings are consistent with previous clinical and angiographic descriptions of myopic CNV as relatively small lesions with modest exudation.