Evaluation of posterior ocular structure during fasting in healthy individuals
S G G Icoz1, S A Usta2, M Icoz1
1Department of Ophthalmology, Yozgat City Hospital, Yozgat, Turkey.
Purpose:
To evaluate the effects of fasting on the retina, choroid, and optic disc in healthy individuals using optical coherence tomography (OCT).
Method:
This prospectively designed study was conducted with 32 healthy healthcare workers. A detailed ophthalmological examination and OCT scans were performed on the participants 10 days before the beginning of Ramadan (the non-fasting period) and in the last 10 days of Ramadan (the fasting period). Using OCT, retinal layer thicknesses (ganglion cell+inner plexiform, retinal nerve fiber, and central retinal), optic disc head measurements (rim area, disc area, mean vertical cup/disc, and cup volume), and choroidal thicknesses (subfoveal, nasal, and temporal quadrants) were evaluated. Choroidal vascular parameters (luminal, stromal, and total choroidal area and choroidal vascular index [CVI]) were calculated using a special software module.
Results:
The mean age of the participants was 31±11 (range: 19-48) years. No statistically significant differences were observed in intraocular pressure, axial length, body mass index, or mean arterial blood pressure evaluated at the visits during the fasting and non-fasting periods (P>0.05 for all). Among the OCT parameters, retinal layer, optic disc head, and choroidal thickness measurements did not significantly differ between the two visits (P>0.05 for all). However, choroidal vascular parameters, namely the luminal choroidal area, total choroidal area, and CVI, were statistically higher during the fasting period (P<0.001, P=0.003, and P<0.001, respectively).
Conclusion:
To our knowledge, this is the first study to evaluate the effects of fasting on choroidal vascular parameters. During the fasting process, possible changes in the choroid may occur due to long-term hunger and dehydration.
