Abstract
Purpose: :
To investigate autofluorescence intensity patterns in patients with autosomal dominant Retinitis Pigmentosa (ADRP) and Stargardt’s disease (SD) using Optomap 200tx, the first ultra-widefield retinal imaging camera.
Methods: :
Optomap 200tx images from 21 right eyes with ADRP and 12 right eyes with SD of patients in the Norwegian quality registry for hereditary retinal degenerations were analyzed using ImageJ (ver 1.43u). Autofluorescence (mean and standard deviation [StDev] of gray value) was measured in three regions of interest (ROIs): the macula (5.5mm diameter selection, 4mm from the papilla), mid-peripheral fundus (1.5mm x 5.5mm selection, 4.75mm temporal to the papilla), and peripheral fundus (1.5mm x 5.5mm selection, 17.3mm temporal to the papilla). StDev of gray value describes the variation in intensities within each ROIs and was computed to indicate the degree of combined hyper/hypo-fluorescence. One-way analysis of variance, followed by Tukey’s post hoc test, was employed for statistical analyses.
Results: :
The mean autofluorescence in ADRP patients did not differ significantly between the macula (102.5 ± 26.3), mid-peripheral fundus (89.1 ± 31.1), and peripheral fundus (98.5 ± 34.0). However, the StDev within each ROIs declined progressively towards the periphery. This number was 34.5 ± 8.6 (P < 0.001) in the macula and 28.1 ± 8.2 (P = 0.002) in the peripheral fundus, compared to 20.2 ± 4.4 in the peripheral fundus. The SD patients displayed lower mean autofluorescence in the peripheral fundus (74.2 ± 25.5; P < 0.001), compared to in the macula (124.7 ± 16.6) and in the mid-peripheral fundus (136.2 ± 22.6). The StDev within each ROIs decreased successively towards the periphery, being 42.6 ± 9.8 in the macula and 31.5 ± 6.2 in the mid-peripheral fundus, compared to 15.4 ± 4.0 (P < 0.001) in the peripheral fundus.
Conclusions: :
Both groups showed a decrease in StDev toward the periphery. Indicating a autofluorescence pattern tendency. Further studies with larger study groups and genotype comparisons are needed for more extensive phenotype-genotype classification for hereditary retinal degenerations.
Keywords: imaging/image analysis: clinical • retinal degenerations: hereditary • retinal pigment epithelium