Visual functions and multimodal imaging of patients with idiopathic focal choroidal excavation

Abstract

This study aimed to evaluate visual function and perform multimodal imaging on patients with focal choroidal excavation without any chorioretinal disease (idiopathic focal choroidal excavation [iFCE]). Seventeen eyes of 15 patients with iFCE (8 men, 7 women; mean ± standard deviation age, 56.0 ± 10.8 years) were assessed for visual function including visual acuity, metamorphopsia, aniseikonia, and retinal sensitivity. Multimodal imaging included optical coherence tomography (OCT), fundus autofluorescence (FAF), and OCT angiography. This study found that the maximum width and depth of the excavation were 597 ± 330 (238-1809) µm and 123 ± 45 (66-231) µm, respectively, and that FAF showed normal or hypoautofluorescence corresponding to iFCE. The fundus examination findings were stable during the follow-up period (96 ± 48 months). None of the eyes showed any abnormalities in central retinal sensitivity or aniseikonia. Metamorphopsia was detected using Amsler grid testing and M-CHARTS in two eyes. Therefore, this study is the first to quantitatively and qualitatively study metamorphopsia of patients with iFCE. Our results showed that most patients with iFCE did not have visual impairments, despite the presence of morphological changes in the outer retina and choroid.

Keywords: Idiopathic focal choroidal excavation; Metamorphopsia; Visual function.

Figure 1

Images of the left eye of a 56-year-old man (patient number 9) with a conforming focal choroidal excavation of the left eye. The best-corrected visual acuity was 0.05 the logarithm of the minimum angle of resolution. (a) Enhanced depth imaging spectral domain optical coherent tomography centered on the fovea horizontally (from nasal to temporal) revealed a subfoveal choroidal excavation with a maximum width and depth of 933 µm and 156 µm, respectively, in the left eye. A pachychoroid vessel (arrow) was observed near the excavation site. (b) Color fundus photograph showed no abnormalities, except the orange color, originating from the choroidal vessels, was remarkable at the fovea. (c) Fundus autofluorescence did not show any abnormalities. No abnormalities were detected using the Humphrey Field Analyzer 10–2 program. The results of the Amsler grid testing, M-CHARTS, and New Aniseikonia Test were normal.

Figure 2

Images of the left eye of a 69-year-old man (patient number 4) with a non-conforming focal choroidal excavation. The best-corrected visual acuity was 0.00, the logarithm of the minimum angle of resolution. (a) Enhanced depth imaging spectral domain optical coherent tomography vertically centered on the fovea (from inferior to superior) revealed a choroidal excavation just superior to the fovea with a maximum width and depth of 434 µm and 231 µm, respectively, in the left eye. There was a separation (arrow) between the photoreceptor tips and the retinal pigment epithelium. Hyperreflective material was seen in the separated space. (b) Color fundus photograph showing an orange color in the fovea, probably originating from the choroidal vessels. (c) Fundus autofluorescence did not show any abnormalities corresponding to the FCE. No abnormalities were detected using the Humphrey Field Analyzer 10–2 program. The results of the Amsler grid testing, M-CHARTS, and the New Aniseikonia Test were normal.

Figure 3

Images of the eyes of a 44-year-old woman (patient number 7) with bilateral focal choroidal excavations. The best-corrected visual acuity (logarithm of the minimum angle of resolution) was − 0.08 in the right eye and − 0.18 in the left eye. (a) and (b) Enhanced depth imaging spectral domain optical coherent tomography centered on the fovea vertically (from inferior to superior) showed a subfoveal choroidal excavation in the left eye (a) and two extrafoveal excavations in the right eye (b). (c) Color fundus photograph of the left eye showed an orange appearance in the foveal area. (d) Fundus autofluorescence of the left eye demonstrated hypoautofluorescence corresponding to the excavation area. (e) Amsler grid test of the left eye, wherein the central four squares were fine but the grid lines in the other parts, especially superior quadrants to the center of the grid looked like “precisely handwritten lines rather than printed lines” per her report. Horizontal and vertical scores of metamorphopsia using M-CHARTS were 0.5 and 0.3, respectively. During the follow-up period, her visual acuity and fundus examination findings were stable in both eyes.