Retinal sensitivity and gaze fixation evaluated by microperimetry in subjects with type 2 diabetes: two independent parameters that explore different neuronal circuits

Abstract

Background and aims Retinal sensitivity (RS) and gaze fixation (GF) assessed by retinal microperimetry are useful and complementary tools for identifying mild cognitive impairment (MCI) in patients with type 2 diabetes (T2D). The hypothesis is that RS and GF examine different neural circuits: RS depends only on the visual pathway while GF reflects white matter complex connectivity networks. The aim of the study is to shed light to this issue by examining the relationship of these two parameters with visual evoked potentials (VEP), the current gold standard to examine the visual pathway. Materials and methods Consecutive T2D patients > 65 years were recruited from the outpatient clinic. Retinal microperimetry (MAIA 3rd generation) and visual evoked potentials (VEP) (Nicolet Viking ED). RS (dB), GF (BCEA63%, BCEA95%) (MAIA) and VEP (Latency P100ms, Amplitude75–100 uV) were analyzed. Results Thirty three patients (45% women, 72.1 ± 4.6 years) were included. VEP parameters significantly correlated with RS but not with GF. Conclusions These results confirm that RS but not GF depends on the visual pathway, reinforcing the concept that they are complementary diagnostic tools. Used together can further increase the value of microperimetry as screening test for identifying T2D population with cognitive impairment.

Association of macular structure with microperimetry sensitivity following vitrectomy for proliferate diabetic retinopathy

“…15,16 Fixation stability contributes to the complex network of white matter, superior colliculus, parietal, and frontal cortex, while macular sensitivity depends on the conduction of various links in the visual pathway. 17 Zhu et al 18 have found a significant correlation between mean sensitivity and HbA1c in patients with DR, and time in range (the percentage of time that the target glucose is in the range of 3.9–10.0 mmol/L over 24 hours, as one of the markers of continuous blood glucose testing) of glucose was significant positively correlated with mean sensitivity. However, in our study, there was no correlation between mean sensitivity and HbA1c, and duration of DM.…”