Using the spectral domain optical coherence tomography (SD-OCT), we studied the difference in the choroidal morphology between the choroidal neovascularization (CNV) area and the area surrounding CNV.

This retrospective study consisted of 19 patients with myopic CNV lesion in eye; fellow eyes were used as controls. All eyes were analyzed by measuring the choroidal thickness and large choroidal vessel size using SD-OCT. Eyes with CNV were divided into groups; the neovascular lesion was defined as group 1, the surrounding area as group 2. Subfovea of the fellow eye was defined as group 3.

The choroidal thickness was 80.00 ± 68.31 in group 1, 63.44 ± 67.75 in group 2 and 71.11 ± 65.69 µm in group 3. There was a significant difference between group 1 and group 2 ( p = 0.038). There were no significant differences between group 1 and 3 or between group 2 and 3 ( p = 0.365, p = 0.314). The large choroidal vessel size was 57.47 ± 39.78 in group 1, 40.45 ± 34.69 in group 2 and 45.63 ± 37.00 µm in group 3. There was a significant difference between group 1 and group 2 ( p = 0.025). There were no significant differences between group 1 and 3 or between group 2 and 3 ( p = 0.123, p = 0.325).

Choroidal thickness and large choroidal vessel size at the center of the CNV were greater than in the area surrounding CNV. The results suggest that although the CNVs were due to a thinned choroid caused by severe choroidal ischemia, the development of CNV requires maintenance of choriocapillaris and large choroid vessels.