TY - JOUR
T1 - Acute hyperglycemia reverses neurovascular coupling during dark to light adaptation in healthy subjects on optical coherence tomography angiography
AU - Kwan, Changyow C.
AU - Lee, Hee Eun
AU - Schwartz, Gregory
AU - Fawzi, Amani A.
N1 - Funding Information:
Supported in part by National Institutes of Health Grant 1DP3 DK108248 (AAF). This work received research instrument support from Optovue, Inc. (Fremont, CA, USA). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Publisher Copyright:
© Copyright 2020 The Authors
PY - 2020/4
Y1 - 2020/4
N2 - PURPOSE. To test the hypothesis that hyperglycemia perturbs neurovascular\ coupling and compromises retinal vascular response during transition from dark to light in healthy subjects using optical coherence tomography angiography (OCTA). METHODS. Ten eyes of 10 healthy subjects were tested, first during fasting and then after receiving a 75-g oral glucose solution. In both sessions, OCTA imaging was done in the dark-adapted state and at 50 seconds, 2 minutes, 5 minutes, and 15 minutes of ambient light. Parafoveal vessel density (VD) and adjusted flow index (AFI) were calculated for the superficial capillary plexus (SCP), middle capillary plexus (MCP), and deep capillary plexus (DCP), and vessel length density was calculated for the SCP. These measurements were compared among conditions after adjusting for age, refractive error, and OCTA scan quality. RESULTS. Hyperglycemia leads to a complete reversal of dark/light adaptation trends in VD and AFI in all layers of the inner retina. In the dark, there is significantly decreased VD in the DCP in hyperglycemia. With a transition to light in hyperglycemia, we observed decreased VD in the SCP, increased vessel density in the MCP and DCP, and decreased AFI in all three layers. CONCLUSIONS. Our results show that hyperglycemia significantly disrupts neurovascular coupling in healthy eyes, with potential metabolic deficits affecting photoreceptor oxygen demands during dark adaptation and the inner retina during light exposure. In pathological states, such as diabetic retinopathy, where the vasculature is already attenuated, retinal neurons may be exquisitely vulnerable to intermittent hyperglycemic challenge, which should be the focus of future studies.
AB - PURPOSE. To test the hypothesis that hyperglycemia perturbs neurovascular\ coupling and compromises retinal vascular response during transition from dark to light in healthy subjects using optical coherence tomography angiography (OCTA). METHODS. Ten eyes of 10 healthy subjects were tested, first during fasting and then after receiving a 75-g oral glucose solution. In both sessions, OCTA imaging was done in the dark-adapted state and at 50 seconds, 2 minutes, 5 minutes, and 15 minutes of ambient light. Parafoveal vessel density (VD) and adjusted flow index (AFI) were calculated for the superficial capillary plexus (SCP), middle capillary plexus (MCP), and deep capillary plexus (DCP), and vessel length density was calculated for the SCP. These measurements were compared among conditions after adjusting for age, refractive error, and OCTA scan quality. RESULTS. Hyperglycemia leads to a complete reversal of dark/light adaptation trends in VD and AFI in all layers of the inner retina. In the dark, there is significantly decreased VD in the DCP in hyperglycemia. With a transition to light in hyperglycemia, we observed decreased VD in the SCP, increased vessel density in the MCP and DCP, and decreased AFI in all three layers. CONCLUSIONS. Our results show that hyperglycemia significantly disrupts neurovascular coupling in healthy eyes, with potential metabolic deficits affecting photoreceptor oxygen demands during dark adaptation and the inner retina during light exposure. In pathological states, such as diabetic retinopathy, where the vasculature is already attenuated, retinal neurons may be exquisitely vulnerable to intermittent hyperglycemic challenge, which should be the focus of future studies.
KW - Dark adaptation
KW - Diabetic retinopathy
KW - Hyperglycemia
KW - Neurovascular coupling
KW - Optical coherence tomography angiography
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U2 - 10.1167/iovs.61.4.38
DO - 10.1167/iovs.61.4.38
M3 - Article
C2 - 32340033
AN - SCOPUS:85084107501
VL - 61
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 4
M1 - 38
ER -