Effect of Ramadan fasting in tropical summer months on ocular refractive and biometric characteristics
Version of Record online: 17 JAN 2012
© 2012 The Authors. Clinical and Experimental Optometry © 2012 Optometrists Association Australia
Clinical and Experimental Optometry
Volume 95, Issue 2, pages 173–176, March 2012
How to Cite
Nowroozzadeh, M. H., Mirhosseini, A., Meshkibaf, M. H. and Roshannejad, J. (2012), Effect of Ramadan fasting in tropical summer months on ocular refractive and biometric characteristics. Clinical and Experimental Optometry, 95: 173–176. doi: 10.1111/j.1444-0938.2011.00698.x
- Issue online: 2 MAR 2012
- Version of Record online: 17 JAN 2012
- Submitted: 26 March 2011; Revised: 28 October 2011; Accepted for publication: 4 November 2011
- intraocular lens power;
- power calculation;
- Ramadan fasting;
Background: Islamic Ramadan is the month of fasting, in which intake of food and drink is restricted from sunrise until sunset. The objective of the present study was to find out the effect of altered eating habits during Ramadan fasting on ocular refractive and biometric properties.
Methods: In this prospective case series, 40 eyes of 22 healthy volunteers with a mean age of 60.55 ± 12.20 years were enrolled. Patients with any systemic disorder and eyes with pathology or previous surgery were excluded. One month before Ramadan (at 8.00 am), during Ramadan fasting (at 8.00 am and 4.00 pm) and one month later during the non-fasting period (at 8.00 am), ocular refractive and biometric characteristics were measured using an autokeratorefractometer (Auto-Kerato-Refractometer KR-8900; Topcon Co, Tokyo, Japan) and contact ultrasonic biometry (Nidek Echoscan US 800; Nidek Co, Tokyo, Japan).
Results: Anterior chamber depth was significantly increased during fasting compared with baseline measurements and returned to baseline one month after Ramadan (3.22 ± 0.07 mm and 4.33 ± 0.17 mm for non-fasting and fasting, respectively; p < 0.001). The anterior chamber depth measurements were significantly larger at 8.00 am during fasting compared with 4.00 pm (p = 0.01). Axial length was significantly decreased during fasting and returned to baseline one month after Ramadan (23.09 ± 0.14 mm and 22.65 ± 0.18 mm, for non-fasting and fasting, respectively; p < 0.001). Intraocular lens power calculations were significantly increased during fasting and returned to baseline one month after Ramadan (SRK-T formula: 21.46 ± 0.27 D and 22.92 ± 0.46 D, for non-fasting and fasting, respectively; p < 0.001). There were no significant differences in spherical equivalent, corneal astigmatism, mean keratometry and flatter and steeper corneal radii of curvature between time intervals.
Conclusions: Ramadan fasting is associated with statistically significant alterations in anterior chamber depth and axial length that result in both statistically and clinically significant changes in intraocular lens power calculations. Therefore, relying on measurements taken during this month might lead to refractive errors after cataract surgery.