Ultra-Widefield Fundus Imaging May Improve DR Diagnostic Ability  

Ultra-widefield fundus imaging may improve clinicians’ abilities to diagnose diabetic retinopathy (DR) and determine the condition’s severity, according to a study published in Eye. This technology may replace the Early Treatment Diabetic Retinopathy Study (ETDRS) 7-field imaging method that is currently used if future investigations continue to substantiate this claim, the report suggests.

Researchers compared and graded fundus examinations of 202 patients (69.3% men; mean age, 52.1 years) with DR using ERDRS 7-field and 2 different ultra-widefield fundus imaging devices. The team evaluated DR severity and visible retinal areas imaged by the 3 devices and noted the number and types of lesions outside of the ETDRS 7-field scope that were captured with the 2 ultra-widefield imaging methods. 

A comparison between the ETDRS 7-field and first ultra-widefield device showed moderate agreement between the 2 imaging methods (weighted K, 0.485; 95% CI, 0.421-0.523) for detecting DR severity, with exact matches in 59.3% (n=229) of eyes. Comparison between the ETDRS 7-field imaging and the second ultra-widefield device yielded an almost perfect agreement (weighted K, 0.924; 95% CI, 0.893–0.952), with 93.8% of eyes (n=362) showing an exact match. Comparing DR severity between the 2 ultra-widefield fundus imaging devices showed moderate agreement (weighted K, 0.461; 95% CI, 0.392–0.514) and exact matches in 57.3% of eyes.

Relative visible retinal area was larger with the 2 ultra-widefield fundus imaging devices compared with ETDRS 7-field imaging, with a 7-field image occupying 53% of the relative visible retinal area of the 1 ultra-widefield device and between 33% and 75% for the second device according to the number of imaging montages.

In total, 2015 and 4200 peripheral lesions were detected in the first and second ultra-widefield fundus imaging devices, respectively (P < .001), suggesting more severe DR in approximately 10% and 12% of eyes, respectively, compared with ETDRS 7-field assessment. 

The investigators highlight the advantage of replacing the current ETDRS 7-field imaging method with ultra-widefield fundus imaging.

“[T]he standard ETDRS seven-field imaging procedure is time-consuming, and requires trained photographers and highly cooperative patients,” the study authors explain. “Additionally, it is limited to approximately the central posterior 75 degrees of the retina,
which represents approximately 30% of the entire retinal surface.”

Study limitations include a single center design, short study duration, and failure to obtain information pertaining to patients’ DR progression.