Evaluation of the Effect of Fasting on Glaucoma Patients

OBJECTIVES: The aim of this research was to evaluate the effect of daytime Ramadan fasting and dehydration on intraocular pressure (IOP) and biometric parameters in primary open-angle glaucoma (POAG) patients. METHODS: This prospective study included 30 eyes of 30 POAG patients who were fasting during Ramadan (Group 1), 40 healthy participants who were fasting (Group 2), and 40 healthy individuals who were not fasting (Group 3). The eyes were evaluated twice a day at approximately 8 am and 4 pm during Ramadan and 1 month after Ramadan. RESULTS: IOP values at 4 pm were higher in Group 1 than Groups 2 and 3 in Ramadan (p=0.029 and 0.007, respectively). The diurnal reduction in IOP was significantly smaller during fasting in the glaucoma patients compared with Groups 2 and 3 (p=0.012 and 0.007, respectively). Comparisons of biometric parameters revealed less reduction in central corneal thickness (CCT) values from 8 am to 4 pm in glaucoma patients than in Groups 2 and 3 (p<0.05 for all comparisons) during Ramadan and after Ramadan. CONCLUSION: POAG patients had a higher IOP at 4 pm during the fasting period than was seen following Ramadan. In addition, the diurnal reduction of IOP and CCT was smaller in patients with POAG compared with healthy subjects.