Cognitive visual functions among diabetic and healthy individuals with diabetic family history

Abstract

Purpose : Diabetes Mellitus is a multisystemic disorder having systemic, ocular and cognitive complications. We studied the changes in visual attention, spatio-visual memory and visual search among diabetic individuals and healthy individuals with family history of diabetes.

Methods : Diabetic and healthy individuals with diabetic family history (N=92, Mean age 45±8.8 years) were included after obtaining informed consent. None of the subjects had any ocular diseases and had best corrected visual acuity of 6/9 or better. Visual attention and processing time (APT) was measured using a Stroop task with congruent and incongruent stimuli, with subjects keying in code for the print color. For Spatio-visual memory, subjects were presented targets sequentially at random locations and the maximum number of blocks the subjects could recall in correct sequence was measured. The difference in processing time for congruent and incongruent stimuli was calculated. Visual search time (VST) was measured as choice reaction time. The time taken for the subject to identify an upright orange colored “T” among 15 distractors was collected. All measurements were performed using PsyToolKit on a calibrated monitor in a normal room setting with the subjects viewing the targets binocularly.

Results : All the visual cognitive parameters were degraded in diabetics compared to healthy individuals. The processing time was significantly higher (p<0.0001) for incongruent stimuli (RTInCon_DM: 1593±198msec; RTInCon_HI: 1429±112msec) than congruent stimuli (RTCon_DM: 1312±176msec; RTCon_HI: 1305±105msec) for both group of subjects. The mean APT longer for diabetics (DM: 281±152msec, HI: 124±91msec; p<0.0001) than for healthy individuals. The VST was significantly (p=0.03) delayed for diabetic individuals (3156±389msec) than for healthy individuals (3017±316msec). The mean span for spatio-visual memory in diabetic individuals was (3.6±0.8) which was significantly lesser than that for healthy individuals (5±1.3). The reaction time (irrespective of the task) and span of memory was significantly correlated with the age of the patient (r_RT=0.64, r_span=-0.67, p<0.001).

Conclusions : Diabetics with normal had impaired cognitive functions, when compared to healthy individuals with diabetic family history. Our results imply that cognitive visual impairment can manifest earlier than ocular complications and should be routinely assessed.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.