Researchers in Vienna believe they have identified a standardized set of OCT biomarkers that can help predict visual acuity outcomes for branch and central retinal vein occlusion (BRVO, CRVO). Of the parameters studied, only central subfield thickness (CST) and age were consistently associated with worse best-corrected visual acuity (BCVA) in treatment‐naïve RVO patients.

The study recruited 381 and 301 treatment‐naïve patients with BRVO and CRVO, respectively. Based on the OCT images, the researchers found that, for BRVO, a 100µm increase in CST was associated with a loss of 3.1 letters in BCVA, while  intraretinal cysts and subretinal fluid (SRF) at the center point led to increases of 4.1 and 3.0, respectively. Hyperreflective foci at the central B‐scan also caused a decrease in visual acuity of 2.2 letters. For CRVO, a 100µm increase in CST was associated with a loss of  3.4 letters.

In the total cohort, a 100µm increase in CST, SRF at the center point and HRF at the central B‐scan correlated with differences of -3.2, +3.2 and -2.0 letters, respectively. A 10‐year increase in age and female sex yielded decreases of 2.0 and 2.5 letters, respectively, in the total cohort.

The researchers note that “the ‘protective’ effect of SRF on vision was an unexpected finding in our study and hints at a more complex etiology and role of SRF in RVO.”

Still, the findings suggest RVO is driven by fluid invasion, the researchers said in their study. “The increase in CRT and the presence of SRF as well as HRF correspond markedly with visual function and differs from other retinal diseases such as nAMD or DME, where other, more complex imaging biomarkers seem to have a more distinct impact on vision.”

The researchers believe that implementing a fully automated approach that detects fluid and assesses change over time should be the end goal, considering clinicians in a busy practice don’t have time for a thorough OCT assessment.

Michl M, Liu X, Kaider A, et al. The impact of structural optical coherence tomography changes on visual function in retinal vein occlusion. Acta Ophthalmol. September 30, 2020. [Epub ahead of print].