THE MEASUREMENT OF THE CHOROIDAL THICKNESS DURING ORAL GLUCOSE TOLERANCE TESTS IN PREDIABETIC SUBJECTS: A SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY STUDY

Abstract

Objective: The aim of this study is to investigate how acute hyperglycaemicchanges affect the choroid in patients with prediabetes.Material and Method: Each subject underwent a 75 g oral glucosetolerance test (OGTT) after overnight fasting. The measurementof choroidal thickness (ChT) was done with new generationspectral domain optical coherence tomography (SD-OCT).Results: Fasting Plasma Glucose (FPG) levels of the patients withonly isolated Impaired Fasting Glucose (IGT) patients are higher(all p<0.0001). Mean insulin levels were also higher in patientswith prediabetes than in healthy volunteers during the entire experiment(all p<0.0001). Changes in ChT differed between thegroups, a transient increase was observed in the mean ChT aswell as subfoveal, nasal and temporal locations at the 500 μmdistance to fovea in prediabetes individuals. While the subfovealChT difference was 1.52±4.11 μm (range, -11.00/24.00 μm)in prediabetes, -0.22±1.74 μm (range -2.00/8.00 μm) in the controlgroup at the first hour of the OGTT. A transient choroidalthickening occurred in the prediabetes group, while there was Lunochange in the healthy volunteers.Conclusion: Detecting acute hyperglycemic changes with instantmeasurements may help us to better understand the effectof the disease on ocular structures.