Fundus Autofluorescence in Congenital Aniridia

Abstract

Purpose : To investigate fundus autofluorescence (FAF) and other fundus manifestations in a cohort of congenital aniridia in a matched case-control study.

Methods : Fourteen patients (9 females) with congenital aniridia and 14 age- and sex-matched healthy controls were examined. FAF pictures and color fundus photographs were obtained with an ultra-wide-field scanning laser ophthalmoscope (Optomap Panoramic 200Tx; FAF with 532 nm (green) laser, color images with combined 532 nm and 633 nm laser). FAF intensity was quantified in 1) central macula equivalent to the fovea and 2) the rest of macula corresponding to a ring surrounding fovea, and related to an internal reference in the picture. Fundus color images were evaluated subjectively and classified according to a three-degree scale (dark, normal, light). All aniridia subjects underwent an ophthalmological examination, including systematic slit-lamp biomicroscopy of anterior and posterior segment of the eye. Results from image analyses in aniridia patients were compared to matched controls, and correlated with other clinical findings in the aniridia group.

Results : In both aniridia and control group mean age was 28.4±15.0 yrs. (range 11–64 and 9–64 yrs., respectively). Mean ratio between FAF intensity in the fovea and the internal reference was 3.52±1.18 in aniridia patients and 3.10±0.70 in control subjects (p=0.334). Mean ratio between FAF intensity in the macular ring and fovea was 1.01±0.15 in aniridia vs. 1.18±0.09 in controls (p=0.034). Fovea could be defined by subjective assessment of FAF images in three aniridia patients (21.4%) and in all control subjects (p<0.001). Fundus color was staged as light in 12 aniridia patients, but in only one control (p<0.001). In aniridia, presence of macular hypoplasia evaluated by biomicroscopy correlated with lower ratio between FAF intensity in the macular ring and fovea (p=0.003), lack of foveal appearance by subjective analyses of FAF images (p=0.031), and observation of nystagmus (p=0.009).

Conclusions : Aniridia patients present a lower ratio between FAF intensity in the peripheral and central macula than healthy individuals. Presence of macular hypoplasia evaluated by biomicroscopy correlates with absence of foveal hypoautofluorescence assessed both objectively and subjectively. Hence, FAF imaging could be an additional tool in evaluation of macular function in aniridia.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.