Diurnal Changes in Accommodation Amplitude and Anterior Segment Parameters During Ramadan Fasting

Abstract

Background: The purpose of this research was to investigate the diurnal effect of Ramadan fasting on the amplitude of accommodation and anterior segment parameters in visually healthy participants.Materials and Methods: The study included 68 healthy individuals, aged 26–42 years. The subjective accommodation amplitude was measured using the "minus lens" technique. Corneal refraction (K1, K2, and Kmax), central corneal thickness, corneal volume, anterior chamber volume, and anterior chamber depth parameters were evaluated using the Scheimpflug camera system. Participants were evaluated twice, at 08:00 and 16:00, while fasting during Ramadan. Data were analyzed by paired sample t-test.Results: The mean age of the participants, of which 28 were women and 40 were men, was 34.38±4.93 (range: 26–42). Comparison of measurements taken at 08:00 and 16:00 during fasting showed that at 16:00, the K1 values (08:00: 42.81±1.51 diopter and 16:00: 42.85±1.50 diopter, P = 0.016) and Kmax values (08:00: 44.29 ± 1.73 diopter and 16:00: 44.38±1.78 diopter, P = 0.020) were significantly steeper. When data collected at 08.00 and 16.00 were compared, there were no significant differences in diurnal changes: amplitude of accommodation (08:00: 7.39±1.40 diopter and 16:00: 7.37±1.40 diopter, P = 0.783), central corneal thickness (08:00: 535.60 ± 30.43 µm and 16:00: 535.25±30.66 µm, P = 0.694), corneal volume (08:00: 59.72±3.85 mm3 and 16:00: 59.60±3.98 mm3, P= 0.344), anterior chamber volume (08.00: 170.91±30.77 mm3 and 16.00: 171.22±32.61 mm3, P = 0.808) and anterior chamber depth (08:00: 2.91 ± 0.28 mm and 16:00: 2.92 ± 0.29 mm, P = 0.053).Conclusions: The results showed that dehydration due to fasting affects some anterior segment parameters, such as corneal refraction; however, it does not affect the diurnal changes of amplitude of accommodation, corneal pachymetry, or anterior chamber anatomy.