Abstract
Purpose: :
To evaluate visual prognosis after pars plana vitrectomy (PPV) in patients with branch retinal vein occlusion (BRVO) associated with macular edema. The relationship between visual prognosis and vitreous levels of interleukin–6 (IL–6) and vascular endothelial growth factor (VEGF) after PPV was also investigated.
Methods: :
Thirty–six patients who scored worse than 0.3 on the minimum angle of resolution (logMAR) visual acuity test, and whose impairment was secondary to BRVO–associated macular edema, were studied Twelve additional patients were studied as controls: Five patients had a macular hole and the remaining seven patients presented with epiretinal membranes.All patients underwent pars plana vitrectomy (PPV). At the time of PPV, vitreous samples were collected from the operated eye. Visual acuity and foveal thickness (FT) were measured every month for up to 6 months after PPV.The relationships between vitreous IL–6 or VEGF levels and two clinical parameters were analyzed: best corrected visual acuity (BCVA), which was measured using a logMAR chart, and FT, which was measured using an optical coherence tomography retinal mapping program before and after PPV. Visual prognosis was measured by subtracting preoperative BCVA from postoperative BCVA and by the preoperative–to–postoperative FT regression ratio. The duration from the onset of BRVO to the PPV procedure, and patient age were also evaluated.
Results: :
Both BCVA and FT significantly improved after PPV. Vitreous IL–6 and VEGF levels were increased compared with those of control patients (p<0.0001). Vitreous IL–6 levels strongly correlated with BCVA improvement (p<0.0001) and FT regression (p=0.0001). In contrast, vitreous VEGF levels only weakly correlated with BCVA improvement (p=0.0551) and FT regression (p=0.1183). Vitreous levels of VEGF were mainly related to BRVO duration; however, neither vitreous VEGF levels nor the BRVO duration were related to visual prognosis.
Conclusions: :
PPV can be an effective treatment for macular edema with BRVO, and visual prognosis strongly correlates with vitreous IL–6 levels.
Keywords: cytokines/chemokines • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • vitreoretinal surgery