Objective To observe the signal intensity and homogeneity of subretinal hyperreflective material (SHRM) in neovascular age-related macular degeneration (nAMD) and preliminarily analyze its relationship with macular neovascularization (MNV) morphology. MethodsA prospective cross-sectional observational study. Forty-six eyes of 46 nAMD patients with SHRM who initially visited Zhongshan Ophthalmic Center, Sun Yat-sen University from January 1, 2022 to March 31, 2023 were enrolled. Optical coherence tomography (OCT) examination was performed according to a standardized protocol, and 3D Slicer software was used for three-dimensional reconstruction of SHRM lesions. Signal intensity was represented by the mean gray value (mGV) of the three-dimensional lesion area, and homogeneity was represented by the standard deviation of gray values (GV-SD). OCT angiography (OCTA) was used to scan the 6 mm×6 mm area of the macula. FIJI and Angio Tool software were used to measure MNV vascular network total area, perimeter, maximum and minimum diameters, maximum vessel diameter, vascular component area, total number of vascular network junctions and endpoints, vessel dispersion, and mean lacunarity. The ratio of maximum to minimum diameter of the vascular network, average vessel length, vessel density, and vessel fractal index were calculated. Using the mean mGV of the total sample as the standard, the eyes were divided into low-density SHRM group (20 eyes) and high-density SHRM group (26 eyes); using the mean GV-SD of the total sample as the standard, the eyes were divided into homogeneous SHRM group (29 eyes) and non-homogeneous SHRM group (17 eyes). The morphological characteristics of MNV between groups were compared. Independent samples t-test or Mann-Whitney U test was used for between-group comparisons; a multivariate regression model was established to analyze independent factors affecting SHRM signal characteristics. ResultsAmong the 46 eyes of 46 patients, there were 26 eyes of 26 males (56.52%, 26/46) and 20 eyes of 20 females (43.48%, 20/26). The mean age was (65.61±7.50) years. The average vessel length and vessel dispersion in the high-density SHRM group and low-density SHRM group were (6.88±4.56), (11.30±6.31) mm−1 and 41.30±67.26, 13.22±11.34, respectively. Compared with the low-density SHRM group, the high-density SHRM group had significantly lower average vessel length (t=2.645) and higher vessel dispersion (t=−2.090), with statistically significant differences (P=0.012, 0.046). Compared with the homogeneous SHRM group, the non-homogeneous SHRM group had significantly higher total area (t=−2.338), maximum diameter (t=−3.137), and minimum diameter (t=−2.173), with statistically significant differences (P＜0.05). The total number of vascular network junctions in the non-homogeneous SHRM group and homogeneous SHRM group were (90.71±67.34) and (49.34±41.91), respectively; the non-homogeneous SHRM group had significantly more junctions than the homogeneous SHRM group, with a statistically significant difference (t=−2.286, P=0.032). Multivariate regression analysis showed that average vessel length was an independent factor affecting SHRM intensity (odds ratio=0.819, 95% confidence interval 0.705-0.951, P=0.009); there were no independent vascular indicators affecting SHRM reflectivity homogeneity (P＞0.05). ConclusionIn nAMD, compared with low-density SHRM, high-density SHRM has significantly lower average vessel length and higher vessel dispersion; compared with homogeneous SHRM, non-homogeneous SHRM has a larger spatial dimension of the vascular network.
ObjectiveTo compare the clinical characteristics of neovascular age-related macular degeneration (nAMD) patients with or without secondary subretinal fibrosis (SF). MethodsA retrospective case-control study. A total of 88 patients (92 eyes) diagnosed with nAMD at Department of Ophthalmology, Xiyuan Hospital of China Academy of Chinese Medical Sciences from January 2020 to January 2024 were enrolled in this study. All eyes underwent best-corrected visual acuity (BCVA), color fundus photography, and optical coherence tomography (OCT) examinations. BCVA was measured using the international standard visual acuity chart and converted to logarithm of the minimum angle of resolution for statistical analysis. SF area was measured on color fundus images. OCT was used to assess the presence of shallow irregular retinal pigment epithelial (RPE) elevation, RPE detachment, ellipsoid zone/external limiting membrane disruption, subretinal fluid and/or intraretinal fluid, thinning of the inner nuclear layer or inner plexiform layer, complete RPE and outer retinal atrophy (cRORA), epiretinal membrane, and suprachoroidal fluid. Device-integrated software measured central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), and the height and width of subfoveal fibrosis in SF eyes. Based on the presence of SF, patients were divided into the SF group (47 eyes) and the non-SF (NSF) group (45 eyes). Baseline characteristics, OCT, and color fundus photography imaging features were compared between groups. Independent samples t tests were used for intergroup comparisons, and multiple linear regression was performed to analyze potential factors influencing SF height. ResultsCompared with the NSF group, the SF group had a longer disease duration, longer symptom onset to initial treatment interval to receiving anti-vascular endothelial growth factor (VEGF) drug treatment, a lower proportion of patients receiving 3 anti-VEGF drug injections within 6 months, worse BCVA, thicker SFCT, higher rates of pigment epithelial detachment and inner nuclear layer or inner plexiform layer thinning, and a lower rate of subretinal fluid (P＜0.05). No significant differences were observed in CRT or the proportions of irregular retinal pigment epithelia, ellipsoid zone/external limiting membrane disruption, cRORA, suprachoroidal fluid, or epiretinal membrane between the two groups (P＞0.05). ConclusionnAMD eyes with secondary SF exhibit distinct OCT imaging features compared to NSF eyes.