Quantitative Comparison of the Morphology of Choroidal Neovascularization in Pathologic Myopia versus That in Age-Related Macular Degeneration, Using Optical Coherence Tomography Subanalysis

Abstract

Purpose: : To compare the morphology of choroidal neovascularization (CNV) in pathologic myopia to that of CNV in age-related macular degeneration (AMD), using quantitative OCT subanalysis.

Methods: : 21 cases of patients newly diagnosed with CNV secondary to pathologic myopia, who underwent StratusOCT imaging prior to treatment, were retrospectively collected. These patients satisfied inclusion criteria of: subfoveal CNV, age range of 18-50 years, and an axial length of >= 26.5 mm or pathologic myopia <-6.0 D. 52 consecutive cases of patients newly diagnosed with subfoveal CNV secondary to AMD, who underwent StratusOCT imaging prior to treatment, were also retrospectively collected. Raw exported StratusOCT images were analyzed using publicly available custom software (OCTOR). Manual grading with OCTOR software allowed calculation of the thickness and volume of the neurosensory retina, subretinal fluid (SRF), subretinal tissue (SRT), and pigment epithelial detachments (PEDs) for both study groups.

Results: : Total volume of the neurosensory retina in the pathologic myopia group was significantly less than that in the AMD group (7.10+/-0.50 mm³ versus 7.96+/-1.28 mm³, P=0.0039). The thickness of the neurosensory retina at the foveal center point in the pathologic myopia group was also significantly less than that in the AMD group (240.10+/-47.75 µm versus 309.38+/-155.18 µm, P=0.0492). Total volume of SRF in the pathologic myopia group was less than that in the AMD group, however the difference was not statistically significant (0.33+/-1.38 mm³ versus 0.44+/-0.58 mm³, P=0.6416). Total volume of SRT in the pathologic myopia group was less than that in the AMD group, however the difference was not statistically significant (0.16+/-0.15 mm³ versus 0.40+/-0.65 mm³, P=0.0998). Total volume of PED in the pathologic myopia group was markedly less than that in the AMD group (0.01+/-0.03 mm³ versus 1.01+/-1.82 mm³, P=0.014).

Conclusions: : CNV lesions in pathologic myopia were associated with considerably less retinal edema, subretinal fluid, and subretinal tissue 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.

Keywords: choroid: neovascularization • imaging/image analysis: clinical • myopia