In the Journals

OCTA, functional testing reveal preclinical signs of diabetic retinopathy

Preclinical microvascular changes and functional deficits, detected by OCT angiography and central visual analyzer, may be early signs of developing diabetic retinopathy in patients with diabetes mellitus, according to a study.

Sixty eyes from 35 diabetic patients without diabetic retinopathy and 45 eyes from 31 nondiabetic controls were tested with OCTA for microcirculatory changes in the superficial capillary plexus and deep capillary plexus (DCP) and with central visual analyzer (CVA) for logMAR acuity and contrast sensitivity.

While the mean superficial capillary density was comparable in both groups, the mean deep capillary density was significantly lower in diabetic eyes. In the same group, the mean logMAR visual acuity was worse, with significant decrease of contrast sensitivity in the conditions simulating driving at dusk and dim-light reading.

“These results suggest that diabetic patients may develop an early capillary dropout at the DCP level and experience a decline in contrast sensitivity and visual acuity under glare conditions before the clinical expression of retinopathy compared with patients without diabetes,” the authors wrote.

The high resolution and segmentation abilities of OCTA and the high sensitivity of CVA effectively demonstrated that vascular and functional impairment coexist in diabetic patients and start developing before any manifest sign of diabetic retinopathy. This anatomical-functional coupling suggests that retinal neurons, glial cells and blood vessels should be considered as an integrated vascular unit, the authors noted.

They also observed that functional changes were more significant than the retinal capillary damage.

“This may imply that visual functional impairment is an earlier manifestation and a more sensitive indicator for neovascular damage in diabetes mellitus,” they concluded. – by Michela Cimberle

Disclosure: The authors reported no relevant financial disclosures.

Preclinical microvascular changes and functional deficits, detected by OCT angiography and central visual analyzer, may be early signs of developing diabetic retinopathy in patients with diabetes mellitus, according to a study.

Sixty eyes from 35 diabetic patients without diabetic retinopathy and 45 eyes from 31 nondiabetic controls were tested with OCTA for microcirculatory changes in the superficial capillary plexus and deep capillary plexus (DCP) and with central visual analyzer (CVA) for logMAR acuity and contrast sensitivity.

While the mean superficial capillary density was comparable in both groups, the mean deep capillary density was significantly lower in diabetic eyes. In the same group, the mean logMAR visual acuity was worse, with significant decrease of contrast sensitivity in the conditions simulating driving at dusk and dim-light reading.

“These results suggest that diabetic patients may develop an early capillary dropout at the DCP level and experience a decline in contrast sensitivity and visual acuity under glare conditions before the clinical expression of retinopathy compared with patients without diabetes,” the authors wrote.

The high resolution and segmentation abilities of OCTA and the high sensitivity of CVA effectively demonstrated that vascular and functional impairment coexist in diabetic patients and start developing before any manifest sign of diabetic retinopathy. This anatomical-functional coupling suggests that retinal neurons, glial cells and blood vessels should be considered as an integrated vascular unit, the authors noted.

They also observed that functional changes were more significant than the retinal capillary damage.

“This may imply that visual functional impairment is an earlier manifestation and a more sensitive indicator for neovascular damage in diabetes mellitus,” they concluded. – by Michela Cimberle

Disclosure: The authors reported no relevant financial disclosures.

    Perspective
    Agustin L. Gonzalez

    Agustin L. Gonzalez

    It is exciting to revisit how technology has changed eye care and how often innovations force paradigm shifts that positively impact clinical practice and improve patient outcomes. The recent study published by Meshi and colleagues may be an early indication that we might be charting a new path in diabetic eye care.

    This study suggests that we look at functional changes as equally important as microvascular changes, keeping in mind this is a visually impacting manifestation in diabetic patients. The authors’ takeaway, “…visual functional impairment is an earlier manifestation and a more sensitive indicator for neovascular damage in diabetes mellitus,” does not go unnoticed.

    As OCTA technology adoption increases, it is not a stretch to think we might soon be changing how we consider functional vision changes that affect our diabetic patients as an early part of the microvascular series of events that are characteristic of the disease. If a future predictor of change is the past, it is exciting to marvel on just how OCTA technology will change and improve diabetic eye care management.

    • Agustin L. Gonzalez, OD, FAAO
    • Private practitioner, Dallas
      Adjunct faculty member, IAU School of Optometry
      Primary Care Optometry News Editorial Board Member

    Disclosures: Gonzalez reports no relevant financial disclosures.