The effect of religious fasting and dehydration at Ramadan on choroidal thickness and Retinal vessel densities, measured with optical coherence tomography angiography

Abstract

Aim: To investigate the effect of religious fasting and dehydration at Ramadan on choroidal thickness and vessel density in the superficial and deep vascular plexuses with OCTA. Methods: The choroidal thickness, and superficial and deep vessel density indices of fasting healthy subjects were measured with an OCTA device, and compared with non-fasting measurements. Results: The study included 70 eyes of 35 healthy subjects with a mean age of 42.86 ± 8.3 years. The measured choroidal thickness, superficial vessel density index and deep vessel density index were 288.89 ± 67 µm, 40.56% and 41.43%, respectively when measured in the fasting period, compared to 284.62 ± 65 µm, 40.41% and 41.41%, respectively when measured in the non-fasting period. The choroidal thickness under the fovea center was found to be significantly higher in the fasting period than in the non-fasting period ( p = 0.014). The mean total choroidal thickness was found to be reduced in the non-fasting period, although not to a statistically significant degree ( p > 0.05). An analysis of the mean total superficial and deep vascular plexuses revealed no statistically significant difference ( p = 0.368, p = 0.938 respectively). Conclusion: Although a significant increase was noted in central choroidal thickness in the fasting period, no significant change due to fasting was observed in the superficial and deep capillary plexuses. The choroidal layer may vary in thickness due to fasting-related metabolic factors, while retinal vessels are more stable against such effects.