Résumé
Age-related macular degeneration(ARMD)is a neurodegenerative disease associated with oxidative stress. It is characterized by progressive death of photoreceptors and retinal pigment epithelium(RPE), and is one of the leading causes of irreversible loss of central vision in patients over the age of 65 years old. MicroRNA(miRNA)is a class of regulatory short-chain non-coding RNA that can bind and inhibit multiple gene targets in the same biological pathway. This unique property makes microRNA an ideal target for exploring the pathogenesis, diagnosis and treatment of non-exudative ARMD. Previous studies have found that the pathogenesis of non-exudative ARMD involves age, genetics, environment, oxidative stress, lipid metabolism, autophagy and immunity. However, the exact mechanisms have not been fully clarified. As biomarkers of non-exudative ARMD, miRNA play a role in oxidative stress and lipid metabolism. This article summarizes the role of various miRNA in targeting Nrf2 and HIF-1α to inhibit hypoxia-related angiogenesis signaling, thereby affecting oxidative stress. Additionally, miRNA regulate lipid uptake and the expression of ABCA1 in RPE and macrophages, thereby influencing lipid metabolism. This deepens the understanding of the role of miRNA in oxidative stress and lipid metabolism in non-exudative ARMD, and provides directions for further improving the understanding of the pathogenesis and prevention of non-exudative ARMD.
Résumé
PURPOSE: We evaluated the progression of geographic atrophy (GA) based on fundus autofluorescence (FAF) pattern and atrophy size using the fundus camera in non-exudative age-related macular degeneration (ARMD). METHODS: We acquired FAF images in non-exudative ARMD patients over a 2-year period. According to The Fundus Autofluorescence in Age-related Macular Degeneration (FAM) study, FAF patterns of geographic atrophy were classified into 5 categories. Examiners quantified the areas of GA in FAF images and analyzed the progression of atrophy based on FAF pattern and atrophy size. RESULTS: In 86 non-exudative ARMD eyes, elderly patients had faster progression rate of GA. The growth rates of GA were 1.51 mm2/year in 'Diffuse', 1.49 mm2/year in 'Banded', 1.05 mm2/year in 'Patchy', 0.59 mm2/year in 'Focal' and 0.16 mm2/year in 'None' pattern groups. In addition, the growth rate was 0.38 mm2/year in which initial the GA area was smaller than 1 disc area. This was the slowest progression rate among all categories according to initial GA area. CONCLUSIONS: As a result of evaluating the progression of geographic atrophy using FAF over a 2-year period, the growth rate of GA was the fastest in the 'Diffuse' pattern group. Additionally, as the initial GA area became smaller, the progression of GA atrophy was slower (p < 0.002). Although limitations such as short follow-up period and measurement error of GA atrophy area using fundus photography were compensated, the results in the present study were similar to the outcomes of studies on progression of GA based on FAF pattern using the scanning laser ophthalmoscope over several years and the fundus camera for 1 year. In conclusion, the fundus camera is a useful tool for the prediction of long-term progression of GA in patients with non-exudative ARMD.