Lack of predictive value of retinal oxygen saturation for visual outcome after angiostatic treatment of branch retinal vein occlusion

Abstract

Purpose Previous studies have shown that the retinal oxygen saturation in central retinal vein occlusion treated with anti‐VEGF compound has no predictive value for visual outcome after 12 months. It is of interest to evaluate whether this conclusion is similar for patients with branch retinal vein occlusion among whom only some patients are treated. Methods Retinal oxygen saturation, visual acuity and central retinal thickness were studied at the time of referral and after six and 12 months in 111 patients successively referred to the Department of Ophthalmology, Aarhus University Hospital, with a venous occlusion affecting branches peripheral from the central retinal venule. The predictive value of the oxygen saturation at referral was investigated in treated and untreated patients. Results Seventy‐three patients with visual acuity between 35 and 70 ETDRS letters at referral were treated with intravitreal injection of anti‐VEGF compound. Over 12 months, the venous oxygen saturation improved in parallel with central retinal thickness and visual acuity but had no predictive value for visual outcome. In 12 untreated patients with visual acuity >70 ETDRS letters, younger age and high oxygen saturation at the time of referral were positive predictors for the visual outcome after 12 months. Conclusion Oxygen saturation, visual acuity and central retinal thickness improve in parallel during treatment of branch retinal vein occlusion with intravitreal anti‐VEGF medication. Retinal oximetry at referral cannot predict visual acuity after 12 months in treated patients but may perhaps become a tool for predicting the visual prognosis in a subgroup of patients where treatment is omitted because of a too high visual acuity at the time of diagnosis of the disease.

Predictive value of retinal oximetry, optical coherence tomography angiography and microperimetry in patients with treatment-naïve branch retinal vein occlusion

“…They did not evaluate predictive value of arteriolar saturation, whereas we report a tendency of arteriolar saturation to predict need for re-treatment with aflibercept. This finding seems paradoxical to recent findings of lower linear blood flow velocity being associated with higher retinal saturation measurement [ 21 ], and with another study finding correlation between larger area of affected retina and higher arterial saturation [ 7 ], thus the mechanism behind our results remain unclear.…”

“…In BRVO, increased arteriolar saturation of affected vessels have been consistently reported [ 16 , 19 , 20 ]. A recent study found no predictive value of venous oxygen saturation on visual acuity outcomes in BRVO after treatment [ 7 ]. They did not evaluate predictive value of arteriolar saturation, whereas we report a tendency of arteriolar saturation to predict need for re-treatment with aflibercept.…”

“…Retinal oximetry is a metabolic marker associated with retinal ischemia, which is a key factor in BRVO [ 4 ]. While it has been identified as a predictor of disease activity in diabetic macular edema [ 5 ], conflicting preliminary results have been presented in BRVO [ 6 , 7 ], with relevant clinical outcomes not sufficiently examined.…”

Clinical implications of retinal oximetry in retinal vein occlusion: a review

“…However, the group concluded that while these correlations do exist and are related to CRVO, retinal oximetry cannot yet replace other functional measures in predicting visual outcome after anti‐VEGF treatment (Jeppesen et al 2021). Yet, over the 12‐month study period, SvO 2 did improve in parallel with VA and central retinal thickness, while having no predictive value (Jeppesen & Bek 2021).…”

“…More recently, a study found that oxygen saturation was significantly higher in arterioles and lower in venules of the affected eye as compared with the unaffected eye in CRVO patients (Jeppesen et al 2021). Additionally, they noted that oxygen saturations and BCVA were significantly negatively correlated for arterioles and significantly positively correlated for venules and AV difference (Jeppesen & Bek 2021; Jeppesen et al 2021). However, the group concluded that while these correlations do exist and are related to CRVO, retinal oximetry cannot yet replace other functional measures in predicting visual outcome after anti‐VEGF treatment (Jeppesen et al 2021).…”