Retinal vein occlusion (RVO) is fairly easy to see funduscopically, but for a more nuanced understanding of a patient’s condition and prognosis, OCT can provide much useful information, New research links the condition to increased retinal thickness and the presence of subretinal fluid and hyperreflective foci. The cross-sectional, post-hoc analysis included OCT images from two prospective, multicenter studies that enrolled 381 and 301 treatment-naïve patients with branch RVO (BRVO) and central RVO (CRVO), respectively.
Of all parameters studied, only central subfield thickness and age were consistently associated with worse best-corrected visual acuity (BCVA) in treatment-naïve RVO patients, the research team from Austria noted.
Considering all OCT biomarkers included in the investigation, an increase in central retinal thickness was associated with a loss in baseline BCVA of up to -3.4 ETDRS letters and was related to an accumulation of intraretinal (98%) and subretinal fluid (54%).
In the BRVO group, the researchers observed statistically significant associations between BCVA and a 100µm increase in central subfield thickness (-3.1 letters), intraretinal cysts at center point (+4.1), subretinal fluid at center point (+3.0) and hyper-reflective foci at the central B-scan (-2.2). For patients with CRVO, a 100µm increase in central subfield thickness was associated with a loss of -3.4 letters.
In the total cohort, a 100µm increase in central subfield thickness, subretinal fluid at center point and hyper-reflective foci at the central B-scan correlated with a difference of -3.2,+3.2 and -2.0 letters, respectively. Additionally, a 10-year increase in age and female gender resulted in a -2 and -2.5 letter decrease in the total cohort, respectively.
Morphology on OCT explained only a modest part of functional loss, the researchers said.
Michl M, Liu X, Kaider A, et al. The impact of structural optical coherence tomography changes on visual function in retinal vein occlusion. Acta Ophthalmologica. September 30, 3020. [Epub ahead of print].