Primary and secondary focal choroidal excavation morphologic phenotypes, associated ocular disorders and prognostic implications

Abstract

Aims: To characterise and classify the morphological, clinical and tomographic characteristics of focal choroidal excavation (FCE) lesions to determine their prognostic implications.

Methods: 36 eyes with FCE (32 patients) underwent multimodal imaging, including spectral domain optical coherence tomography and fundus autofluorescence. FCE lesions were classified into three subtypes: (1) type 1: myopic (central choroidal thickness: <100 µm), (2) type 2: suspected congenital (central choroidal thickness: 100-200 µm, without associated chorioretinal pathology) and (3) type 3: secondary or acquired (central choroidal thickness: >200 µm, with associated chorioretinal pathology).

Results: 80.6% of eyes were followed longitudinally (26.8±18.8 months). There were 9 type 1 FCEs (myopic), 8 type 2 FCEs (U-shaped, congenital) and 19 type 3 FCEs (V-shaped, secondary). Type 2 FCEs trended towards larger maximum widths (p=0.0563). Type 3 FCEs were associated with central serous chorioretinopathy or pachyvessels (47.4%), but were also seen in pattern dystrophy, geographic atrophy, inactive choroiditis, torpedo maculopathy and adult-onset vitelliform dystrophy. Choroidal neovascular membranes (CNVMs) were more prevalent in type 3 FCE (41.2% compared with 11.1% for type 1 FCE, p=0.251, and 0% for type 2 FCE, p=0.043).

Conclusions: The FCE types, stratified by central choroidal thickness, demonstrated distinct morphological characteristics and associated findings. The classification scheme held prognostic implications as type 3 FCE with V shapes were associated with other chorioretinal conditions and were more likely to develop CNVM.

Keywords: choroid; imaging; macula; retina; vision.