Characteristics and Utility of Fundus Autofluorescence in Congenital Aniridia Using Scanning Laser Ophthalmoscopy

Abstract

PURPOSE. To investigate fundus autofluorescence (FAF) and other fundus manifestations in congenital aniridia. METHODS. Fourteen patients with congenital aniridia and 14 age-and sex-matched healthy controls were examined. FAF images were obtained with an ultra-widefield scanning laser ophthalmoscope. FAF intensity was quantified in the macular fovea and in a macular ring surrounding fovea and related to an internal reference within each image. All aniridia patients underwent an ophthalmologic examination, including optical coherence tomography and slitlamp biomicroscopy. RESULTS. Mean age was 28.4 6 15.0 years in both the aniridia and control groups. Fovea could be defined by subjective assessment of FAF images in three aniridia patients (21.4%) and in all controls (P ¼ 0.001). Mean ratio between FAF intensity in the macular ring and fovea was 1.01 6 0.15 in aniridia versus 1.18 6 0.09 in controls (P ¼ 0.034). In aniridia, presence of foveal hypoplasia evaluated by biomicroscopy correlated with lack of foveal appearance by subjective analyses of FAF images (P ¼ 0.031) and observation of nystagmus (P ¼ 0.009). CONCLUSIONS. Aniridia patients present a lower ratio between FAF intensity in the peripheral and central macula than do healthy individuals. Both subjective and objective analyses of FAF images are useful tools in evaluation of foveal hypoplasia in aniridia.

PAX6 Genotypic and Retinal Phenotypic Characterization in Congenital Aniridia

“…Heidelberg Spectralis OCT2 (Heidelberg Engineering GmbH, Heidelberg, Germany) was used to acquire spectral-domain optical coherence tomography (SD-OCT) scans of the macular region as described previously (512–1536 A-scans/B-scans, 49 B-scans over 20° × 20° or 30° × 10°; 30° × 5° for normal controls). 17 , 23 The built-in eye-tracking system was used to compensate for eye-motion artifacts and 5–20 horizontal B-scans were averaged during imaging. The participants’ head posture and gaze direction were adjusted to minimize the amplitude of nystagmus during OCT imaging.…”

Congenital aniridia – A comprehensive review of clinical features and therapeutic approaches

“…In a different prospective study, ONH was observed in four of 14 patients (29%). 85 In this latter study, ONH was more frequent in patients with foveal hypoplasia grade or than in those with either grade 0, or 2. This suggests that ONH coincides with more severe foveal hypoplasia.…”

“…This correlation has also been found in other studies.20, 85 Furthermore, there is an association between impaired red-green color vision and increasing grade of foveal hypoplasia.125 OCT images of aniridia patients with different grades of foveal hypoplasia have previously been published. 85,125,126 Central foveal thickness is increased in aniridia,20, 70, 126 either compared to healthy controls in the same study,126 or to previously published normal values.20, The total length of the outer nuclear layer and the Henle fiber layer in fovea is, however, shorter in aniridia patients than in controls.126 Additionally, the outer segments of the foveal cones are shorter in aniridia. Pedersen and coworkers also reported that aniridia patients with mutations in coding regions of the PAX6 gene have thinner outer retinal layers in the fovea than those with mutations in noncoding regions of the gene.…”

Clinical and molecular aspects of congenital aniridia – A review of current concepts

“…The absence of FAZ may be detected in fundus autofluorescence (FAF) as the absence of the central hypofluorescent spot. [ 22 ] Landsend et al . (2019) found that the mean intensity of the FAF in macula versus fovea was close to 1 in most aniridia patients.…”

“…(2019) found that the mean intensity of the FAF in macula versus fovea was close to 1 in most aniridia patients. [ 22 ] They also reported that 86% of aniridia patients may have a hypopigmented fundus. This can be attributed to the role of PAX6 in retinal pigment epithelium differentiation.…”