Evaluation of the effect of religious fasting on eye in healthy volunteers

Every year millions of peoplefastandvarious changes occurin human body, primarily dehydration. Therefore, eye and its functions can also be affected by fasting. The purpose of this study is to investigate the effects of fasting on eye in healthy individuals. The study included right eyes of eighty fasting healthy volunteers. Refraction, intraocular pressure using the pneumotonometry, central corneal thickness, anterior chamber depth, lens thickness, average corneal refractivity, axial length using optical biometry device, retina and choroidal thickness from foveal, nasal and temporal sections using the optical coherence tomography device were measured at 8.00 and 16.00 o'clock. The control measurements of the subjects were repeated 1 month after Ramadan. Comparing the measurements obtained during fasting period with the control measurements, we observed that central corneal thickness was thicker (p<0.001), average corneal refractivity was lower (p=0.03), and temporal choroidal thickness was thinner (p=0.005) at 8.00 o'clock. Besides, at 16.00 o'clock, central corneal thickness was still thicker (p=0.007), and all areas of retina and choroid were significantly thinner during the fasting period (p<0.05).When we compare the diurnal variations between Ramadan measurements and control measurementsnasal and temporal retinal thicknesses and foveal and temporal choroidal thicknesses were significantly different (p<0.05).There was no significant difference in other parameters(p>0.05). The results demonstratethat retina and choroid were significantly thinner during fasting and it is supposed that tissues with dense vascular component may be more affectedduring fasting. Keywords: Central corneal thickness, Choroidal thickness, Diurnal variation, Fasting, Retinal thickness.