The establishment of a regional DR reading center to provide third-party independent DR reading service to other medical institutions is encouraged in medical institutions where resource permits. A regional DR reading center may provide services of either General Diagnostic Reading or Quantitative Diagnostic Reading (ETDRS), or both, to other medical institutions.
In general, conventional non-mydriatic photographs will be graded with general diagnostic reading procedure. Mydriatic ETDRS 7-field standard photographs will be graded with ETDRS quantitative diagnostic reading procedure.
Wide-field (>90 degree) laser scanning fundus photograph can be graded with either general diagnostic reading procedure or ETDRS procedure, based on the request of clinical physicians.
In a DR reading centers, General Diagnostic Reading will be performed by a primary reader. Sampling of the primary reading will then be taken, and evaluated by a second independent reader. Consistency between these two readers will be analyzed automatically by the system. The performance of the two readers will then be evaluated by a physician-on-duty. Adjudication is indicated if clinical significant differences between the two readers are detected. Final reports will be issued by the physician-on-duty based on his/her evaluation of the performance of the primary reader. 
Quantitative Diagnostic Reading (ETDRS standard) could be performed with mydriatic ETDRS 7-field standard photographs or non-mydriatic wide-field (>90 degree) laser scanning fundus photographs. The ETDRS score of the DR severity can be converted to a conventional ophthalmic DR grading scale (such as International DR Grading System) in the reading center’s image diagnosis report for general ophthalmic practice purpose.
In DR reading centers, a multi-step evaluation is required for quality control purpose for Quantitative Diagnostic Reading, as described in Diabetic Retinopathy (DR) Color Photograph Evaluation Procedures from Fundus Photograph Reading Center of University of Wisconsin School of Medicine and Public Health.
In brief, this consists of two independent evaluations performed by different readers by using the MedLink DR evaluation module. Consistency between these two readers will be analyzed automatically by the system. Adjudication is indicated if differences between the two readers are detected. Final report will be issued by a physician-on-duty based on the evaluation of the primary reading after the adjudication evaluation.