DR Evaluation Procedures for Eye Care (Ophthalmic Simplified DR Grading)
Traditionally, DR is considered as an eye disease, which is now the leading cause of blindness in many developed and developing countries. To prevent DR related blindness is now becoming one of the highest priority issues for public health worldwide. DR Evaluation for prompt ophthalmic intervention is essentially important for the treatment of sight-threatening DR and therefore the prevention of DR-related blindness.
ETDRS has been recognized as the gold standard for grading the severity of diabetic retinopathy and is widely used for diabetes research and clinical trial studies. It is, however, too complex for eye care specialists for their daily clinical practice. In ophthalmic practice, the detection of critical points of sight-threatening retinal pathology that merits ophthalmic intervention is the key issue. The very detailed scale of the ETDRS system is much more beyond the need of the clinical work for blindness prevention and ophthalmic practice.
In order to facilitate the screening of sight-threatening DR and finding out the critical point of the DR pathology for ophthalmic intervention, a simplified, more practical DR classification systems is highly demanded. Many countries and eye care groups had developed their own DR classification system for their eye care clinical practice. However, the application of these unique systems creates problems for data comparison and professional communication.
In 2001, the American Academy of Ophthalmology (AAO) assembled a group of expertise for a consensus for a simplified, standardized practical clinical classification system based on ETDRS system, in order to facilitate communication across countries and practitioners. A five-stage DR severity classification is developed from the consensus, named International Clinical Diabetic Retinopathy and Diabetic Macular Edema Disease Severity Scales.
This simplified DR classification procedure has put the emphasis on the detection of critical risk condition of DR that threats the patient’s sight safety and therefore, the indications for prompt ophthalmic intervention. This International DR classification is now well accepted for ophthalmic clinical practice around the world.
The application of the International DR classification is especially useful for ophthalmic practice. It can also be easily used by other health care professionals for the screening purpose for sight-threatening DR and therefore facilitating prevention of DR related blindness.
It is suggested that eye physicians perform the DR grading by the International DR classification system by themselves. Clinical physicians may request a qualified DR reading center for quality control support for their clinical practice.
With the availability of this International DR classification system, for the purpose of the effectiveness of professional communication, country-specific DR grading systems for routine eye care is not recommended.
If a third-party DR reading service is demanded for eye care practice, it is recommended that the photographs be read by ETDRS standard with converted scale on International DR classification system. This will provide much more information about the patient’s diabetic retinal microvascular complications for general diabetes care, while the eye care need is met.
* Mydiatic standard ETDRS 7-field photographs or wide-field (>90 degree) laser scanning photographs are required for ophthalmic DR evaluation.