Biochemical and microstructural determinants of the development of serous retinal detachment secondary to retinal vein occlusion

To study the alteration of cytokine factors in aqueous humor and retinal microstructure in the formation of serous retinal detachment (SRD) secondary to retinal vein occlusion. The subjects were 39 patients with RVO, of whom 31 patients had SRD (RVO-SRD). Spectral Domain Optical Coherence Tomography (SD-OCT) was used to measure the completeness of photoreceptor inner segment/outer segment (IS/OS) and the external limiting membrane (ELM) as well as the structure of RVO-SRD, including the height and shape of SRD. The aqueous humor was collected before intravitreal injection of Ranibizumab. The concentrations of VEGF, MCP-1, IL-8, IL-6, b-FGF and TNF-α in the aqueous humor were measured. All patients participated in the 6-month follow-up examinations, which included visual acuity, intraocular pressure, ophthalmologic examination, and SD-OCT. The time of recurrence of RVO-SRD was recorded. The formation of SRD was associated with the area of congested vein, disrupted IS/OS, ELM layers and high VEGF, MCP-1, IL-8, IL-6 levels. However, the height and shape of SRD were not relevant to any inflammatory factors. Moreover, high levels of MCP-1, IL-8 and IL-6 were found in large areas of congested veins. High levels of MCP-1 and IL-6 were observed in the patients with incomplete IS/OS and ELM. The recurrence of SRD was related to the high MCP-1 level. High concentrations of cytokine factors in aqueous humor could induce vascular leakage, exacerbate the extent of macular edema, disrupt the structure of ELM and IS/OS, and develop SRD in RVO.