Impact of Hemodialysis on Subfoveal Choroidal Thickness Measured by Optical Coherence Tomography: A Systematic Review and a Pooled Analysis of Self-Controlled Case Series

INTRODUCTION: Hemodialysis (HD) has various effects on the body, including optimizing body fluid composition and volume, which may have an impact on subfoveal choroidal thickness (SCT) in individuals with end-stage kidney disease (ESKD). However, previous studies have produced conflicting results regarding the effect of HD on SCT in patients with ESKD. Therefore, we conducted a meta-analysis to investigate the influence of HD on SCT. METHODS: A comprehensive search of relevant studies and bibliographies was conducted using Embase, PubMed, and Web of Science databases up to September 2022. Weighted mean difference (WMD) and 95% confidence interval (CI) were used to summarize the SCT change. Heterogeneity and publication bias were assessed, and a random-effects model was employed for the meta-analysis. Subgroup analyses were also performed to evaluate the influence of factors such as diabetes mellitus (DM), the severity of diabetic retinopathy (DR), diurnal variation adjustment, optical coherence tomography (OCT) types, and OCT scan modes. RESULTS: A total of 15 studies involving 1010 eyes were eligible for this meta-analysis, including 552 diabetic eyes, 230 non-diabetic eyes, and the remaining 228 eyes were uncategorized. The meta-analysis revealed a significant reduction in SCT after HD (WMD = −13.66 μm; 95% CI −24.29 to −3.03 μm; z = −5.115, P < 0.0001). Subgroup analysis indicated a significant difference between the DM and non-DM groups (WMD = −24.10 μm vs. −15.37 μm, 95% CI −27.39 to −20.80 μm vs. −19.07 to −11.66 μm; P = 0.001). Additionally, the group with proliferative diabetic retinopathy (PDR) exhibited a more pronounced reduction in SCT (WMD = −28.66 μm; 95% CI −37.10 to −20.23; z = −6.660, P < 0.0001). Adjusting for diurnal variation, different types or scan modes of OCT did not significantly affect the results. CONCLUSION: HD leads to a significant decrease in SCT among patients with ESKD, especially in patients with DM with PDR. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40123-023-00761-6.