The effect of starvati̇on on contrast sensi̇ti̇vi̇ty of eye

PURPOSE: To evaluate the effect of Ramadan fasting on the contrast sensitivity of the eye on the fasting healty male individuals during Ramadan fasting. For this reason, we comparied pre-Ramadan satiety contrast sensitivity with contrast sensitivity of first and fourth weeks of Ramadan. MATERİAL AND METOD: This study was randomized and prospective. Fourty five healthy male subjects age ranging between 20-40 years, working in the same environment of the Inonu University Medical Faculty Hospital participated in the study. In the first evaluation subjects with complete bilateral corrected visual acuity and no ocular pathology proving the including criteria of the study was determined. The contrast sensitiviy test was performed on subjects with best visual acuity were complete and had noocular pathology. Contrast sensitivity functions were assessed by "Functional Acuity Contrast Test" (F.A.C.T.) in five frequencies including 1.5, 3, 6, 12 and 18 cpd in fotopic conditions. Evaluation was performed for five spatial frequencies in the test. Contrast sensitivity measurements of the satiety in the last week before pre-Ramadan compared with the first and fourth weeks at least 12 h after the onset of starvation. RESULTS: Contrast sensitivity measurements in pre-Ramadan in the form of safiety and in the first week of Ramadan were compared; the average value of B (3cpd) level in 5 spatial frequencies was higher in the first week of Ramadan (p=0,03). There was increase in others patial frequencies but no statistically significance was detected (respectively the frequency of A (1.5 cpd) p=0,95, the frequency of C (6 cpd) p=0,75, the frequency of D (12 cpd) p=0,29, the frequency of E (18 cpd) p=0,28). Contrast sensitivity measurements in pre-Ramadan in the form of satiety and in the forth week of Ramadan were compared; the average values of B (3cpd) level and D (12 cpd) level in 5 spatial frequencies was higher in the forth week of Ramadan ( respectively 128,84± 24,42, p=0,01, 76,35±27,61, p=0,01). There was increase in others patial frequencies but no statistically significance was detected (respectively the frequency of A (1.5cpd) p=0,17, the frequency of C (6 cpd) p=0,49, , the frequency of E (18cpd) p=0,13). The comparison of the contrast sensitivity measurements in the first and fourth week of Ramadan was no significant difference (respectively, the frequency of A (1.5cpd) p=0,10, the frequency of B (3 cpd) p=0,91, the frequency of C (6 cpd) p=0,47, the frequency of D (12 cpd) p=0,83, the frequency of E (18 cpd) p=0,76). CONCLUSION: Contrast sensitivity measurements in Ramadan showed higher values in some frequencies than the measurements before Ramadan in the form of satiety. Learning effect or some metabolites resulting from starvation may cause this result. We need further studies to determine the exact reason. We believe that this increase may primarily arise from the learning effect. Key Words: Starvation, Ramadan fasting, contrast sensitiviy, FACT, metabolism in starvation