The purpose of this study is to evaluate the efficacy of intravitreal ranibizumab by determining the pathogenesis of macular edema, which cause a direct effect on visual function. In particular, we focus on the correlation between the treatment effectiveness of ranibizumab and the role of the cytokines involved in the cause of macular edema.

Methodology:

Aqueous humor samples (0.1ml) were obtained during intravitreous injection of ranibizumab to measure the levels of cytokines. Targeted cytokines are follows; IL-1, IL-2, IL-6, IL-8, IL-9, IL-10, IL-12, IL-13, IP-10, MCP-1, MMP-1, MIP-1β, PDGF, VEGF, PlGF, ICAM-1, TNF-α, RANTES, VEGFR-1, VEGFR-2, which has been reported that the expression level is increased in macular edema associated with RVO. Cytokines are measured by multiple ELISA (Luminex). Aqueous humor samples are obtained in the same manner from patients recurred after the first injection or continuous monthly injections. Statistical analysis is conducted to examine the difference of cytokine levels between early or late/incomplete responders of ranibizumab, and predict the number of injections to stabilize cytokine levels.

Number of centers & patients: Single center, 100 patients

Sample size justification: Sample size calculation was not done, since this study is a single-arm, observational study.

Population: Inclusion criteria: patients with RVO and macular edema

Inclusion Criteria:

• Foveal thickness > 300 μm
• Best corrected visual acuity < 20/30

Exclusion Criteria:

• History of retinal diseases other than BRVO, glaucoma, uveitis, diabetes mellitus, rubeosis iridis, ocular infections, laser photocoagulation, and intraocular surgery