Effect of Hemodialysis on Peripapillary Choroidal Thickness Measured by Swept-Source Optical Coherence Tomography

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.

Effects of Hemodialysis on Intraocular Pressure and Ocular Biological Parameters in Different Angle Structures

Purpose

This study is aimed at evaluating the effects of hemodialysis on intraocular pressure (IOP) and exploring the possible factors affecting IOP.

Methods

Fifty-two patients with hemodialysis (HD) that were diagnosed with chronic renal failure by nephrology were divided into four groups: wide angle, narrow angle, extremely narrow angle, and closed angle. IOP, central anterior chamber depth (ACD), lens thickness (LT), angle opening distance (AOD), trabecular-iris angle (TIA), iris thickness (IT), and ciliary body thickness (CBT) were recorded before and after HD. The Pearson coefficient test was used to determine correlations among changes in IOP and AOD, ACD, TIA, IT, CBT, and LT.

Results

The IOP in the extremely narrow angle group had significant difference compared with that in the wide angle group and narrow angle group (P < 0.05, P < 0.01). In the narrow angle group, change in LT was positively correlated with change in IOP (P < 0.05). In the extremely narrow angle group, change in LT was positively correlated with change in IOP (P<0.01), whereas changes in AOD and TIA were negatively correlated with change in IOP (P < 0.01; P < 0.05).

Conclusion

The effect of HD on IOP varies with the structure of the anterior chamber. The increasing of IOP in the extremely narrow-angle group is related with the changes of structure of anterior chamber.

Choroidal Thickness Profile in Chorioretinal Diseases: Beyond the Macula

Enhanced depth imaging optical coherence tomography (EDI-OCT) and swept-source OCT (SS-OCT) have emerged as essential diagnostic tools in the study and management of various chorioretinal diseases. Evidence from early clinical studies using EDI-OCT and SS-OCT indicates that choroidal dysfunction plays a major role in the pathogenesis of chorioretinal diseases. Measurement of choroidal thickness (CT) has already become a major research and clinical method, and CT is considered as an indicator of choroidal status in a variety of ophthalmic diseases. Recently, CT measurement has also been proposed as a non-invasive marker for the early detection and monitoring of various systemic diseases. Among the several possible CT measurement locations, subfoveal CT has rapidly become a reliable parameter for measuring CT in healthy and diseased eyes. Moreover, recent advancements in OCT technology have enabled faster and wider imaging of the posterior part of the eye, allowing the various changes in CT as measured outside the macula to be shown accordingly. In this review, we first provide an overview of the results of clinical studies that have analyzed the healthy macular choroid and that in various chorioretinal diseases, and then summarize the current understanding of the choroid outside the macula. We also examine the CT profile as an index that encompasses both within and outside of the macula. Furthermore, we describe the clinical applications of ultrawide OCT, which enables visualization of the far periphery, and discuss the prospects for the development of more reliable choroidal parameters that can better reflect the choroid's characteristics.