Evaluation of the effect of fasting on intraocular pressure, anterior segment parameters and density of crystalline lens and cornea

Abstract

Purpose To evaluate the effect of fasting on anterior chamber depth, anterior chamber volume and corneal and lens density by Scheimpflug technology and to measure intraocular pressure changes. Methods Totals of 50 healthy fasting individuals in Ramadan (study group) and 50 healthy non-fasting subjects (control group) were included. Central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), corneal density (CD) and lens density (LD) were evaluated with Scheimpflug technology. Intraocular pressure (IOP) was measured with applanation tonometry. Both eyes of each participant were examined and also compared.

Intermittent Fasting to the Eye: A New Dimension Involved in Physiological and Pathological Changes

“…Intermittent fasting alters anterior chamber depth and volume, which is mostly due to dehydration This difference may be noticed in both fasting and non-fasting groups, and at various moments during the fasting period. Compared to the non-fasting group, anterior chamber depth and axial length were dramatically reduced in the fasted group ( 34 , 47 ). Furthermore, during IF, the depth and volume of the anterior chamber were variable at different times of the day.…”

“…Norepinephrine and cortisol produced during sympathetic excitation are elevated, and resistance to atrial outflow increases, causing IOP to rise. However, most studies have shown a significant decrease in IOP values during IF ( 34 , 39 – 44 ). Kerimoglu et al ( 42 ) found that in the Ramadan fasting population, IOP tended to be higher in the morning (fasting vs. non-fasting: 14.19 ± 3.53 mmHg vs. 12.03 ± 2.99 mmHg) and lower in the afternoon (fasting vs. non-fasting: 11.74 ± 2.39 mmHg vs. 13.13 ± 2.39 mmHg).…”

“…The choroidal thickness under the fovea increased by nearly 3% during the fasting period compared to the non-fasting period ( 25 ). Insulin sensitivity may influence the thickness of the choroidal layer at IF ( 34 ). There is a substantial thinning of choroidal thickness in diabetic patients and diabetic retinopathy (DR) patients ( 35 ).…”

“…The depletion of lipid stores during this period may reduce prostaglandin secretion, which leads to a decrease in IOP ( 45 ). In addition, IOP reduction may also be associated with increased body dehydration, neuro-endocrine system function, and inflammatory mediators in the uveoscleral channels ( 34 ).…”

“…In addition, Beyoğlu et al ( 34 ) evaluated corneal density and lens density changes in IF During IF, subjects were found to have a decrease in corneal density (fasting vs. non-fasting: right/left eye: 12.81 ± 0.76/12.73 ± 0.73 vs. 13.28 ± 1.01/13.07 ± 0.77) ( 34 ), an expression likely due to changes in corneal inflammatory mediators and increased osmolarity as a result of dehydration ( 50 , 51 ). However, lens density did not differ significantly between the fasting and non-fasting groups ( 34 ), probably because of lens microcirculatory water channels ( 52 ), which maintain a more stable density even during longer periods of dehydration.…”