Optical coherence tomographic comparison of naive macular edema due to ischemic and nonischemic retinal vein occlusion

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

Purpose

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.

Methods

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.

Results

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.

Conclusion

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.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Evaluation of retinal sensitivity and microstructure in areas of capillary nonperfusion of eyes with branch retinal vein occlusion

Background

To evaluate macular microstructure alterations in the parafoveal nonperfusion areas of eyes with branch retinal vein occlusions (BRVO), and to investigate their impact on retinal sensitivity.

Methods

This was a cross-sectional study including thirteen BRVO patients with parafoveal capillary nonperfusion areas (NPA). Multiple modalities including microperimetry, optical coherence tomography angiography, and optical coherence tomography were performed to measure retinal sensitivity and thickness, and to identify the microstructure changes and perfusion status.

Results

The retinal sensitivity and thickness in the NPA were significantly lower than those in the perfusion areas (PA) (P = 0.001, P = 0.003). Microstructure changes, including disorganization of the retinal inner layers (DRIL), disruption of the outer retinal layers, and cysts were more frequently observed in NPA (P = 0.002, P = 0.018, P = 0.068). Within NPA, the retinal sensitivity of areas with DRIL, and outer retinal layers disruption was significantly lower than that of the areas without DRIL (P = 0.016), and with intact outer retinal layers (P < 0.001), respectively. 1dB increase in retinal sensitivity was correlated with 2.2 μm (95 % confidence interval, 1.71–2.7) increase of the thickness (P < 0.001). The retinal sensitivity was significantly lower at points with both DRIL and outer retinal layers disruption than at the points with DRIL or outer retina layers disruption alone (P = 0.001, P = 0.001).

Conclusions

Alterations in the macular microstructure are associated with ischemia, especially DRIL. DRIL and outer retinal layers disruption are imaging features that have important implications for local retinal sensitivity in the ischemic areas, and where the microstructure of both inner and outer retinal layers is disrupted the function is further destructed.