Changes in fundus autofluorescence in young subjects with different types of refraction. Report 2

Purpose: To assess the possible quantitative indicators of the loss of density of retinal pigmented epithelium (RPE) in the macular area using digital technologies for processing the results of fundus autofluorescence (AF) in young subjects with high visual acuity and different types of clinical refraction. Material and methods: 104 healthy volunteers (208 eyes) aged 20 to 30 years, mean age (24,5 ± 0,4) y.o., 34 males and 70 females, were examined. All patients had high visual acuity (1.0 or higher) and no signs of macular pathology. Three observation groups were formed with distribution according to the types of clinical refraction: emmetropia, hyperopia and myopia. The latter group was further divided into three subgroups depending on their severity: mild, moderate and high. The division into AF-patterns was first carried out in the mode of visual assessment by the medical researcher in accordance with the classification of Bindewald A. et al. (2005), then using a program to search for the percentage of pathology area in the fundus AF photograph (Adamov A.A. et al., 2021). Results: Automatic typing of AF-patterns using the proposed program showed no discrepancies with the division of patterns into groups, which was carried out in the “manual mode”. Quantitative assessment of the state of RPE density was carried out according to a criterion called «area of losses» and was calculated in %. With the «minimal changes» pattern, the greatest losses were observed in the groups of mild and moderate myopia, the values were comparable to each other: (11,3 ± 0,3) and (10,8 ± 1,1) %, respectively (p 0,5). The most significant areas of losses were observed in low and moderate myopes in the «focal changes» group of (22,5 ± 4,1) and 29,8 %, respectively. The reticular pattern which was prevalent in all groups showed losses that ranged from (3,0 ± 0,1) % in hyperops to (12,7 ± 0,4) % in low-grade myops (p 0,001). Conclusion: AF-fundus digital image processing program is a standardized tool for detecting early and clinically insignificant changes in the condition of the central retina and can be used to accurately assess the dynamics of pathological process progressing.