Table 1.

Advantages and disadvantages of different modalities for diabetic retinopathy screening

Screening modality	Advantages	Disadvantages
Retinal photography	Effective technique if mydriatic photography is performed with either 35 mm transparencies or digital systems	High capital set-up costs
	Retinal image can be used in patient education	Difficulties in reaching all patients who need to be screened
	Hard copy can be incorporated into patient record	Need to provide regular training for graders
	Amenable to audit	Potential problem retaining motivated personnel for grading
Optometrist screeners	Effective technique if indirect ophthalmoscope/slit lamp biomicroscope used	Requires an elaborate quality control mechanism for the system to be audited
	Accessible, convenient service
	Offers holistic package of eye care to the patient
Combined modalities	Effective techniques	High capital set-up costs
	Retinal image can be used in patient education	Camera systems might have to rotate around practices, potentially limiting accessibility of the service
	Hard copy can be incorporated into patient record
	Amenable to audit
	Accessible, convenient service
	Offers holistic package of eye care to the patient
	Utilizes the well trained, motivated workforce that optometrists represent