The aim of this study is to investigate the influence of age on the distribution of risk factors in patients with branch retinal vein occlusion (BRVO) and its impact on the restoration of retinal and choroidal structures following anti-vascular endothelial growth factor (VEGF) therapy.

A total of 253 consecutive BRVO patients (257 eyes) diagnosed in the Department of Ophthalmology at the Affiliated Central Hospital of Jiangnan University from January 2022 to January 2025 were enrolled, along with 271 consecutive control subjects (271 eyes) who attended the Ophthalmology Department of Jiangnan University Medical Center during the same period and were confirmed not to have BRVO through examinations. Among them, there were included 263 males (267 eyes) and 261 females (261 eyes), with a mean age of ( 54.5±14.3) years (ranging from 20 to 89 years). The clinical data such as gender, age, history of hypertension and diabetes was used only to collect for the control group. Baseline data and post-treatment parametersafter in BRVO patients anti-VEGF treatment for 1 month, 6 months and 12 months were recorded, including central macular thickness (CMT), incidence of ellipsoid zone (EZ) disruption, incidence of external limiting membrane (ELM) disruption, subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), and mean ganglion cell layer-inner plexiform layer complex (GCIPL) thickness. Patients were divided into a young and middle-aged group (≤ 50 years) and an elderly group (> 50 years) based on age at onset. Simultaneously, control subjects were paired based on different age baselines of the BRVO groups. After the Shapiro-Wilk test, age, SFCT, CVI, and mean GCIPL thickness were conformed to normal distribution and presented as ±s and analyzed using repeated measures ANOVA. Non-normally distributed data, such as CMT, were presented as median (interquartile range) [M (Q1, Q3)] and analyzed using a generalized linear mixed model. The absence percentage of EZ and ELM disruption was expressed as percentages and analyzed using generalized estimating equations. The history of hypertension and diabetes was described by case and percentage, and used by Logistic regression analysis to evaluate the impact of hypertension and diabetes on the risk of BRVO.

There were 121 young and middle-aged BRVO patients (125 eyes), with a mean age of (43.27±5.99) years; among them, 65 cases (68 eyes) had hypertension and 11 (11 eyes) had diabetes, accounting for 53.72% and 9.09%, respectively. There were 132 elderly BRVO patients (132 eyes) with a mean age of (65.06±8.39) years; among them, 78 (78 eyes) had hypertension and 18 (18 eyes) had diabetes, accounting for 59.09% and 13.64%, respectively. The young and middle-aged control group comprised 128 subjects (128 eyes), with a mean age of (42.46±6.46) years; 11 subjects (11 eyes) had hypertension and 4 subjects (4 eyes) had diabetes, accounting for 8.59% and 3.13%, respectively. The elderly control group comprised 143 subjects (143 eyes), with a mean age of (66.15±8.53) years; 66 subjects (66 eyes) had hypertension and 20 subjects (20 eyes) had diabetes, accounting for 46.15% and 13.99%, respectively. Logistic regression analysis showed that hypertension significantly increased the risk of BRVO in both young and middle-aged and elderly populations (OR=12.219, 4.485; 95%CI: 5.876 to 25.410, 2.221 to 9.060; P<0.05). The CMT values for the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were 638.00 (390.50, 815.00) μm, 566.50 (395.25, 710.25) μm, 191.00 (167.00, 240.50) μm, 201.00 (197.25, 220.50) μm, 208.00 (172.50, 264.50) μm, 256.00 (214.00, 444.00) μm, 211.00 (199.50, 267.00) μm and 221.00 (201.75, 240.50) μm, respectively. The difference in CMT between the two groups at 6 months after treatment was statistically significant (F=6.795, P<0.05). The overall comparison of CMT at different time points showed statistically significant differences within both the young and middle-aged BRVO group and the elderly BRVO group (F=42.531, 56.664; P<0.05). The incidence rates of EZ disruption in the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were 40.6%, 58.1%, 19.7%, 43.9%, 15.9%, 36.8%, 15.6% and 31.0%, respectively. The differences in the incidence of EZ disruption between the two groups before treatment and at 1 month and 6 months after treatment were statistically significant (χ²=7.383, 14.259, 8.105; P<0.05). The incidence rates of ELM disruption in the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were 40.6%, 56.2%, 18.2%, 41.8%, 15.9%, 36.8%, 15.6% and 28.6%, respectively. The differences in the incidence of ELM disruption between the two groups before treatment and at 1 month and 6 months after treatment were statistically significant (χ²=5.945, 15.626, 8.628; P<0.05). The overall differences in the incidence of EZ disruption at different time points were statistically significant within both the young and middle-aged BRVO group and the elderly BRVO group (χ²=20.882, 16.702; P<0.05). The overall differences in the incidence of ELM disruption at different time points were statistically significant within both the young and middle-aged BRVO group and the elderly BRVO group (χ²=25.609, 14.324; P<0.05). The SFCT values for the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were (367.02±127.05) μm, (337.54±128.88) μm, (359.01±252.95) μm, (305.77±123.10) μm, (329.37±117.19) μm, (301.90±115.01) μm, (340.70±129.01) μm and (317.41±126.62) μm, respectively. There were no statistically significant differences in SFCT between the two groups before treatment and at 1 month, 6 months, and 1 year after treatment (F=0.307, 0.968, 0.047, 0.785; P>0.05). The overall comparison of SFCT at different time points was statistically significant within the young and middle-aged BRVO group (F=6.079, P<0.05). The CVI values for the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were (0.34±0.08), (0.33±0.07), (0.37±0.06), (0.35±0.05), (0.37±0.05), (0.35±0.04), (0.40±0.07) and (0.39±0.20), respectively. The difference in CVI between the two groups at 6 months after treatment was statistically significant (F=6.354, P<0.05). The overall difference in CVI at different time points was statistically significant within the young and middle-aged BRVO group (F=6.033, P<0.05). The mean GCIPL thickness for the young and middle-aged BRVO group and the elderly BRVO group before treatment and at 1 month, 6 months, and 1 year after treatment were (81.62±12.05) μm, (81.48±11.56) μm, (78.38±9.18) μm, (79.96±28.83) μm, (74.77±10.36) μm, (76.10±10.54) μm, (69.69±10.84) μm and (76.15±12.01) μm, respectively. The difference in mean GCIPL thickness between the two groups at 1 year after treatment was statistically significant (F=5.978, P<0.05). The overall comparisons of mean GCIPL thickness at different time points were statistically significant within both the young and middle-aged BRVO group and the elderly BRVO group (F=4.706, 4.432; P<0.05).

Differences exist in the degree of recovery of OCT parameters at various follow-up time points after treatment between young and middle-aged and elderly patients with BRVO. Younger age does not consistently confer a prognostic advantage. Therefore, active intervention and close follow-up are also warranted for younger patients.