Diabetic Retinopathy Study Research Group (“DRS”)


1971 NIH initiated trial studying laser photocoagulation for the management of diabetic retinopathy.  Preliminary report published in 1976.  The original “Airlie House” classification was modified and used in the Diabetic Retinopathy Study (DRS). Briefly, it used color stereoscopic photographs of 7 standard fields, evaluating the retinal findings and staging the disease.

Early Treatment Diabetic Retinopathy Study (“ETDRS”)


DRS classification was further modified for use in the ETDRS trials. It has been the gold standard for detecting and staging diabetic retinopathy in research trials. Changes seen in standard retinal photographs determine 13 DR levels ranging from level 10 (absence of retinopathy) to level 85 (severe vitreous hemorrhage or retinal detachment involving the macula) based on the relative risk of vision loss. While excellent for research setting, its clinical applicability was limited due to its complexity. Even though the most accurate way to stage disease, most ophthalmologists do not use this classification in their daily clinical work.

OU Center for Telemedicine


Clinicians and scientists at the University of Oklahoma’s Center for Telemedicine converted and validated the ETDRS Protocol from analog (film-based) photography to a digital imaging and digital reading center for 7 DRS field stereoscopic imaging using the ETDRS protocol. A study done in collaboration with the Chickasaw Nation Health System compared the film and digital system. This validation study was published in the leading peer-reviewed clinical journal Ophthalmology. The approach of using digital data for disease management was patented by OU clinicians and assigned to the University.



Inoveon Corporation,  a University of Oklahoma (“OU”) spin-off company, licensed the digital disease management patent and technology from OU and commercialized the service, delivering retinal evaluations for diabetes patients in primary care settings to detect, stage and make management recommendations from 1997-2016.