Aqueous erythropoietin level in retinal vein occlusion

Abstract

AbstractPurpose To investigate the aqueous level of erythropoietin (EPO) and associated factors in patients with retinal vein occlusion (RVO).Methods The aqueous EPO level was measured prospectively with chemiluminescent immunoassay in consecutive patients with macular edema (ME) secondary to branched retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). Aqueous fluid of cataract patients served as control. Patients taking anti‐hypertensive medication with angiotensin converting enzyme inhibitor or angiotensin II receptor blocker, prior intraocular surgery or injection of steroid or antiangiogenic factors, or longstanding (3> months) BRVO or CRVO were excluded. We also evaluated whether aqueous EPO was associated with factors such as serum EPO concentration, non‐perfusion area, and arterio‐venous (AV) transit time, and central macular thickness (CMT).Results Aqueous level of EPO was higher in RVO (27 eyes; BRVO 16 eyes/CRVO 11 eyes) than in control subjects (RVO, 68.1 [19.8‐190] mU/ml vs. control, 12.9 [5.4‐24.4] mU/ml, P<0.001). More specifically, aqueous EPO was higher in CRVO than in BRVO (CRVO, 118.9 [31.8‐190] mU/ml vs. 33.3 [19.8‐62.5] mU/ml, P<0.001). However, no differences were found in serum levels of EPO among controls, BRVO, and CRVO groups (CRVO, 11.1mU/ml[5.4‐16.4] vs. BRVO, 10.0mU/ml[6.7‐16] vs. control, 9.2mU/ml[5.7‐11.2], P=0.091). CMT in RVO patients had positive correlation with the aqueous level of EPO in RVO (P=0.003). Also, in terms of non‐perfusion area, there was a significant difference in the aqueous level of EPO between ischemic and non‐ischemic subtypes of CRVO (ischemic, 172 [156‐190] mU/ml vs. non‐ischemic, 83.6 [56.3‐142.5] mU/ml, P=0.0027).Conclusion In RVO, aqueous levels of EPO are elevated and could be associated with retinal ischemia and ME