The Effect of Hypoglycemia on Central Retinal Function in Patients with Diabetes

Abstract Background According to the International Diabetes Federation report for 2021, approximately 537 million individuals are living with diabetes, and it is projected to reach 783 million by 2045. Diabetic ocular complications are asymptomatic at early stages and cause visual impairment unless diagnosed early and treated. In addition to the well-known effect of hyperglycemia, previous studies highlighted the possible structural and functional effects of profound hypoglycemia in both the central (CNS) and the peripheral nervous system (PN). Objective The aim of this study was to explore the effect of recurrent hypoglycemic attacks and its effect on central retinal function in human's eye. Methods This was a prospective case control study which was conducted on 20 eyes of diabetic patients type 2 at diabetes outpatient clinic at Ain Shams university Hospital, over a period of 10 months from Jan 2023 to October 2023, divided into two groups: group A which included type 2 diabetic patients who experienced minimal level 1 hypoglycemic episodes within 3 months and group B which included type 2 diabetic patients who experienced recurrent episodes of level 2/level 3 hypoglycemia within 3 months, to explore the effect of recurrent hypoglycemia on central retinal function in type 2 diabetic patients. Results the present study suggests that recurrent hypoglycemia affects the function of retina by the decrease in p1 amplitude mainly in central retina in a sequential manner evident by affection of rings 1 and 2 in first visit then rings 2 and 3 in follow up visit, and that stage of hypoglycemia is the most determinant factor Conclusion Hypoglycemia affects the central retinal function as evident by decrease in p1 amplitudes and retinal response densities in rings 1 and 2 by MF-ERG corresponding to fovea and parafovea. Recurrent attacks of hypoglycemia has a sequential effect that it affects perifovea ring 3 P1, N1 amplitude with no effect on peripheral retina.