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Quantitative assessment of the effect of fasting on macular microcirculation: an optical coherence tomography angiography study
  1. Yalçın Karaküçük1,
  2. Abdullah Beyoglu2,
  3. Ayşegül Çömez3
  1. 1 Department of Ophthalmology, Selcuk Universitesi, Konya, Turkey
  2. 2 Department of Ophthalmology, Kahramanmaras Sutcu Imam Universitesi, Kahramanmaras, Turkey
  3. 3 Department of Ophthalmology, Kahramanmaras Sutcu Imam Universitesi, Kahramanmaras, Turkey
  1. Correspondence to Dr Yalçın Karaküçük, Opthalmology, Selcuk Universitesi, Konya 42050, Turkey; drkarakucuk83{at}


Aim To analyse the effect of fasting on the retinal vascular plexus and choriocapillaris structures in healthy subjects via Optical Coherence Tomography Angiography (OCTA).

Methods In this prospective study, OCTA scans of 98 eyes in 49 healthy subjects were compared in fasting and non-fasting period. All cases had a full ophthalmological examination, with OCTA parameters measured, including superficial flow area (SCP) (mm2), deep flow area (DCP) (mm2), choriocapillaris flow area (CC) (mm2), superficial and deep vascular density (SVD and DVD, respectively) (%), superficial foveal avascular zone area (FAZs) (mm2), deep foveal avascular zone area (FAZd) (mm2), subfoveal choroidal thickness (SFCT) (µm) and central macular thickness (CMT) (µm).

Results The mean SCP, DCP and CC flow area values were induced to be significantly lower in a fasting than a non-fasting period (p<0.001, p<0.001, p=0.049, respectively). The mean VD in a fasting period was statistically significantly lower than in a non-fasting period at the SCP level (p=0.009). No statistically significant difference was found between the two periods in respect to DVD, FAZd and CMT (p=0.068, p=0.653 and p=0.531, respectively); however, FAZs were significantly lower in a non-fasting than fasting period (p=0.038). The SFCT was determined to be statistically significant and thicker during a fasting period (p<0.001).

Conclusion The current study documented several physiological changes in a fasting period, such as changes in SCP, DCP, CC flow, SVD and DVD, via OCTA.

  • fasting
  • optical coherence tomography angiography (OCTA)
  • macular circulation
  • vessel density
  • foveal avascular zone (FAZ)

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  • Correction notice This article has been corrected since it was published Online First. Minor formatting has been corrected.

  • Contributors YK is the lead author, and was responsible for the conception of the research idea. YK, AB and AÇ have contributed to the literature review, data collection, analysis of results and formulation of the manuscript. All authors read and approved the final manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval The study was approved by the Ethics Committee of Sutcu Imam University, Kahramanmaras, Turkey (Protocol No: 07/ 2019-02) and all procedures were applied in accordance with the Declaration of Helsinki.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon request.