Early Macular Infarction Can Foretell Worse Visual Outcomes After Anti-VEGF Therapy

Macular infarction severity at early stages of retinal vein occlusions can be used as a biomarker to determine likely long-term visual outcomes, according to a study published in the American Journal of Ophthalmology. Hyperreflectivity within the middle and inner retina on optical coherence tomography (OCT) imaging can be predictive of worse outcomes in eyes with central retinal vein occlusion (CRVO) or hemi-retinal vein occlusions (HRVO) after treatment of macular edema with anti-vascular endothelial growth factor (VEGF) therapy, according to the report.

To determine whether the anatomic level and severity of infarction on OCT can predict long-term visual acuity outcomes in eyes with CRVO or HRVO after VEGF-treated macular edema, researchers performed a post-hoc analysis of data from participants of the randomized noninferiority trial, Study of COmparative Treatment for REtinal Vein Occlusion 2 (SCORE 2).

Participants with center-involved macular edema, as indicated by a central subfield thickness of at least 300 µm (or at least 320 µm if measured on a Heidelberg Spectralis OCT), and a visual acuity letter score (VALS) between 19 and 73 Early Treatment Diabetic Retinopathy Study (ETDRS) letterswere randomly assigned to receive intravitreal bevacizumab or aflibercept between September 17, 2014, and November 18, 2015. A total of 310 participants had 1-month graded OCT. Of these, 46 were grade 0, 5 were grade 1, 189 were grade 2, and 70 were grade 3. 

More severe OCT grades of macular infarction, specifically grades 2 and 3 with hyperreflectivity in both middle and inner retinal layers, were linked to lower baseline VALS and predicted lower VALS at all follow-up points (months 6, 12, 24, 36, 48, and 60). However, all infarction grades showed similar improvements in VALS, and the number of anti-VEGF injections administered did not differ between grades.

A large reduction in all infarction grades in macular thickness was found at all time points and in all grades after anti-VEGF therapy was started. At baseline,, a larger central subfield thickness (CST) was associated with higher grades of infarction severity, confirmed in measurements taken at month 1, according to the researchers. The increase in CST was statistically significant when comparing grade 0 with grade 2 (P =.003) and when comparing grade 0 and grade 2 with grade 3 (P <.002). However, at 12 months, grade 0 had a significantly greater CST compared with grade 2 and grade 3 (P <.003). There were no significant differences in CST among infarction grades at all other time points (P >.05).

The study’s limitations are that participant retention decreased after 2 years, only individuals with macular edema were included and analyzed, and the OCT-based system of macular infarction necessitates grading at month 1 when macular edema is improved. 

“Our study supports a practical OCT grading system of macular infarction, based on the anatomic level and extent of retinal layer hyper-reflectivity, to predict visual acuity in eyes with CRVO or HRVO,” the researchers report.