The impact of hemodialysis on retinal and choroidal thickness in patients with chronic renal failure.

Background: Patients with chronic renal failure are commonly cared using a blood filtration mechanism like hemodialysis. Little information is available regarding ocular changes following hemodialysis for people with chronic renal failure. Accordingly, this study intended to estimate the pre- and post-hemodialysis thickness of retina and choroid and other ocular findings in patients with chronic renal failure.
Methods: This research is a "before and after" clinical experiment, without control. This prospective study was conducted on patients with chronic renal failure who were in Imam Khomeini Hospital for hemodialysis in 2017. The sample size of this study was estimated to be 67 (134 eyes). In this study, after acquiring consent (by the associated assistant) from all patients, thorough ocular examinations including IOP control, VA and fundus examination, reflection, and macula and choroid OCT were performed 30 min before and after hemodialysis and entered in SPSS V. 16 software by the project manager. Finally, these data were analyzed practicing T-pair tests or their nonparametric equivalent, the Wilcoxon test.
Results: Based on the results of this examination, studying 67 participating patients, 134 eyes were examined, of which 80 eyes (59.8%) belonged to men, and 54 eyes (40.2%) belonged to women. The mean and standard deviation of participants' age in the study was reported to be 57.3 ± 15 years, and the dialysis duration was 3.0 ± 2.11 h. According to the Wilcoxon test, the average rank in terms of weight, patient temperature, pulse, blood sugar, urea, potassium, ocular pressure, 500-micron nasal choroidal thickness, and myopia in diopter vary significantly before and after dialysis (p < 0.05). However, according to the Wilcoxon test, choroidal thickness in the subfoveal area of the eye (p = 0.600), the retinal thickness in the subfoveal area (p = 0.839), the amount of astigmatism in diopter (p = 0.757) and the amount of hypermetropia in diopter (p = 0.068) before and after dialysis do not have a significant difference. Based on the t test, it was reported that the average creatinine score, the best corrected vision, and the 500 and 1000-micron temporal and nasal choroidal thickness had a significant difference (p < 0.05).
Conclusion: Based on the results of the current study, it was settled that the corrected vision, ocular pressure, as well as the 500-micron nasal choroidal thickness, and myopia in diopter and the 1000-micron temporal and nasal choroidal thickness of patients before and after hemodialysis vary. This difference shows the impact of hemodialysis on changes in ocular characteristics in patients with renal insufficiency.