Characteristics of periconus choroidal neovascularization in pathologic myopia

To examine the clinical characteristics of periconus choroidal neovascularizations (CNVs) in eyes with pathologic myopia.

Retrospective observational case series.

We reviewed the medical records of 260 eyes of 254 patients with a myopic CNV and selected those with a periconus CNV. A periconus CNV was defined as a CNV that is located next to a myopic conus. To differentiate a periconus CNV from a subfoveal CNV that has expanded to the edge of the disc, eyes whose CNV involved the fovea were excluded. The data of the eyes with a subfoveal CNV were used for comparison.

Eleven eyes (4.2%) of 11 patients had a periconus CNV. These CNVs had a triangular or oval shape whose base was directed toward the myopic conus. The eyes with a periconus CNV had a significantly larger myopic conus than eyes with a subfoveal myopic CNV. The degree of myopia and axial length were not significantly associated with the incidence of periconus CNV. In 5 of the 11patients, the periconus CNV had a spontaneous regression without treatment, and none had a recurrence. The other 6 patients received treatment and obtained an angiographic closure after a single treatment. A chorioretinal atrophy (ChRA) developed in 3 eyes, and the ChRA enlarged over the fovea in 2 of these eyes, which led to a significant decrease of vision.

A periconus CNV is rare (4.2%) among the eyes with a myopic CNV and is more likely to develop in eyes with a large myopic conus. The absence of a significant association between the degree of myopia and incidence of periconus CNV suggests that the morphologic characteristics of the eye are not the causes of the periconus CNV. Although an angiographic closure can be easily attained with or without the treatment, the later development and progression of ChRA can impair vision.