Changes in retina and choroid after haemodialysis assessed using optical coherence tomography angiography

Reports of choroidal and retinal changes before and after haemodialysis are few and have been controversial. Traditional imaging modalities are insufficient for quantitative assessment. This study aims to use optical coherence tomography angiography to monitor the short-term vascular density and thickness changes in retina and choroid before and after haemodialysis.

Seventy-seven eyes of 77 patients with end-stage kidney disease undergoing haemodialysis were included. Ophthalmologic examinations including optical coherence tomography angiography were performed one hour before and after haemodialysis. The vascular density of retina and choroid were measured and calculated by optical coherence tomography angiography. The retinal thickness and subfoveal choroidal thickness were measured manually using Image J software. The relationships between the changes in ocular and systemic parameters after haemodialysis were evaluated.

The systolic blood pressure decreased from 123.7 ± 19.7 to 116.9 ± 24.6 mmHg (p < 0.05) in all patients. The mean ocular perfusion pressure decreased significantly after haemodialysis in both diabetic and non-diabetic groups (p < 0.05). Mean retinal thickness decreased from 204.7 ± 22.4 μm to 200.8 ± 22.8 μm (p < 0.05) after haemodialysis in all patients. The vascular density of outer retina was decreased from 38.8 ± 5.5 per cent to 37.5 ± 3.4 per cent (p < 0.05) after haemodialysis in all patients. The changes in diastolic blood pressure, intraocular pressure, subfoveal choroidal thickness, vascular density of the superficial capillary plexus, deep capillary plexus and choriocapillaris were insignificant. There was no significant correlation between systolic blood pressure and the vascular density of the outer retina.

In optical coherence tomography angiography, the retinal thickness became thinner and the vascular density in the outer retina decreased after haemodialysis in patients with end-stage kidney disease. The change of subfoveal choroidal thickness showed no significance after haemodialysis. The decreased volume in the retinal vascular bed and deficient choroidal autoregulatory control of ocular blood flow might be involved in the mechanism of these changes.