Study Finds Imaging Technique Could Replace Riskier Diagnostic Method for Diabetic Retinopathy

A noninvasive imaging method, high-definition optical coherence tomography (HD-OCT) could be used to measure key preclinical markers of diabetic retinopathy (DR) in patients with type 1 diabetes (T1D), according to a new study from Poland.

Fluorescein angiography requires an injection of fluorescent dye to highlight blood vessels in the back of the eye and can cause mild to severe reactions, from nausea to hives, breathing difficulty or even cardiac arrest. Finding an alternative would allow patients to avoid these risks, and HD-OCT may also let physicians identify retinal damage and treat it “at the earliest possible stage.”

Authors from the Medical University of Lodz, reporting in the journal Diagnostics, wrote that until recently, DR “has been considered to be mainly a vascular complication; however, it is now known that neurogenerative processes take place in the retina before the clinical retinopathy, which is its preclinical period.”

While treatments for DR have improved, they can be costly to health systems; the condition costs the United States $6.2 billion a year. Thus, better screening techniques that can catch neurodegeneration at even earlier stages have the potential to cut costs and improve quality of life for patients.

The study by sought measure retina thickness in patients with T1D compared with a control and evaluate what factors were linked with the advancement of DR. Researchers evaluated 111 patients, including 82 children and 29 adults who had lived with T1D an average of 6 years. Scans included a macular scan centered on the fovea, where the center of the field of vision is focused; thickness of the retinal nerve fiber layer (RNFL); several measures of the optic nerve head (ONH); and a measure of choroidal thickness. All measures were performed with HD-OCT Cirrus 5000.

Results showed the following:

• Negative correlations were found between a patient’s age and the neuroretinal rim area of the optic nerve.
• Negative correlations were found between superior RNFL thickness and duration of diabetes.
• Positive correlation was noted between center thickness and standard deviation for average glycemia.
• Temporal choroidal thickness was positively correlated with age at examination.

“These results,” the authors concluded, “indicate a relationship between age of patients, duration of diabetes, chronic hyperglycemia, glycemia fluctuations and the size of ONH parameters, thickness of superior and inferior RNFL quadrant, center macular thickness and subfoveal and temporal choroidal thickness.”

The authors noted that more studies are needed on larger groups of patients, but that simultaneously measuring choroidal thickness and several other neurodegenerative parameters using HD-OCT “may be promising, “ and shows the potential usefulness of imaging as a diagnostic tool.

Reference

Kolodziej M, Waszczykowska A, Korzeniewska-Dyl I, et al. The HD-OCT study may be useful in searching for markers of preclinical stage of diabetic retinopathy in patients with type 1 diabetes. Diagnostics. 2019;9:105. doi:10.3390/diagonostics9030105.