Poor 1-Month BCVA After Intravitreal Injection Was Primary Predictor of Blindness

Predicting low vision and blindness in patients with retinal vein occlusion-related macular edema (RVO-ME) could be done by assessing 1-month best-corrected visual acuity (BCVA) after being treated with intravitreal injections (IVI), according to a study published in the European Journal of Ophthalmology.

RVO has the highest correlation to hypertension, according to various literature that has previously been published. IVI of anti-vascular endothelial growth factor (VEGF) or dexamethasone is the first-line treatment for RVO-ME. However, this treatment comes with its own risks. Vision results are predicted using optical coherence tomography (OCT). This study aimed to predict unfavorable prognosis by paying attention to the emergence of non-invasive indicators.

Intravitreal Injection Procedure for Macular Degeneration | Image credit: AngeloSouza - stock.adobe.com

This study was performed at Beijing Tsinghua Changgung Hospital. Ophthalmic and systemic examinations were performed from April 2021 to September 2022. Past medical history was collected from the electronic medical record system. Patients were included if they had RVO without a recurrence of RVO-ME for more than 3 months and if they had neovascular glaucoma related to RVO. Patients were excluded if they had a recurrence of RVO-ME of less than 3 months or had an axial length of 26.5 mm or higher. A central retinal thickness of 300 mm or more and a visual acuity of less than 20/30 was defined as a recurrence of RVO-ME.

Patients with a BCVA of 20/60 or higher and without neovascular glaucoma were divided into a favorable group compared with those who had a BCVA below 20/60 or with neovascular glaucoma. The unfavorable group was also divided into a subgroup of patients with a BCVA between 20/400 and 20/60 and without neovascular glaucoma and a second group who had a BCVA of less than 20/400 or with neovascular glaucoma.

There were a total of 73 eyes from 73 patients with RVO who were included in this study, with 42.55% of patients being male in the favorable group. There was no statistically significant difference between laterality distribution and follow-up duration between the groups. The age was different in each group, with the mean (SD) age being 57.26 (12.96) in the favorable group, 65.15 (13.25) in the unfavorable group, 61.92 (12.19) in the first subgroup, and 67.93 (13.93) in subgroup 2.

The highest proportion of central RVO and complete whiteness of 1 or 2 temporal branch retinal arteries (CWTBRAs) was found in subgroup 2 (78.57% and 100% respectively), with the unfavorable group having the second highest (53.85% and 84.62%, respectively), when comparing fundus photographic features. Significant statistical differences in the mean values were found when comparing other clinical characteristics of affected eyes, including BCVA at the first visit and 1-month BCVA after IVI. This included 0.59 (0.43) in the favorable group, 1.13 (0.58) in the unfavorable group, 1.10 (0.52) in the first subgroup, and 1.16 (0.65) in the second subgroup for BCVA at first visit. BCVA after first IVI came to 0.31 (0.17) in the favorable group and 1.24 (0.47) in the unfavorable group.

Age (OR, 1.051; 95% CI, 1.007-1.097), 1-month BCVA after first IVI (OR, 2.247; 95% CI, 1.387-3.642), and BCVA after the first visit (OR, 1.239; 95% CI, 1.092-1.405) were associated with unfavorable results in the univariable regression analysis. A multivariable regression analysis found that 1-month BCVA after first IVI was a risk factor for unfavorable results (OR, 2.313; 95% CI, 1.387-3.858).

The univariable regression analysis also found that CWTBRAs (OR, 53.667; 95% CI, 6.404-449.753), central vs branch RVO (OR, 5.271; 95% CI, 1.573-17.661), and ischemic-RVO (OR, 46.000; 95% CI, 5.493-385.184) were associated with unfavorable results; CWTBRAs were also independent risk factors (OR, 35.192; 95% CI, 2.657-466.072) of unfavorable outcomes.

There were some limitations to this study. There may have been some selective bias due to the retrospective, non-randomized design of the clinical trial. An in-depth analysis of OCT was not conducted, even though diabetic retinopathy, comorbid internal carotid artery disease, and poor ellipsoid zone were associated with poor visual prognosis. These results may not be generalizable to all populations.

The researchers of this study concluded that the “non-invasive dynamic evaluation criteria of poor response to the first IVI for unfavorable outcomes of RVO-ME had a good theoretical and practical value.” This could provide more options for ophthalmologists in treating patients with RVO-ME.

Reference

Si S, Chen A, Ji Y, Wang J. Poor response to first intravitreal injection for predicting unfavorable outcomes of retinal vein occlusion related macular edema. Euro J Ophthalmol. Published online November 15, 2023. doi:10.1177/11206721231214145