Background Early treatment for diabetic retinopathy is effective at saving
sight, but dependent on pre-symptomatic detection. Although 60% of people w
ith diabetes have their eyes examined annually, few UK health authorities h
ave systematic programmes that meet the British Diabetic Association's stan
dards for sensitivity (>80%) and specificity (>95%). Screening is generally
performed by general practitioners and optometrists, with some camera-base
d schemes, operated by dedicated staff. The National Screening Committee co
mmissioned a group to develop a model and cost estimates for a comprehensiv
e national risk-reduction programme.
Ophthalmoscopy Evidence indicates that direct ophthalmoscopy using a hand-h
eld ophthalmoscope does not give adequate specificity and sensitivity, and
should be abandoned as a systematic screening technique. Indirect ophthalmo
scopy using a slit lamp is sensitive and specific enough to be viable, and
widespread availability in high street optometrists is an advantage, but th
e method requires considerable skill.
Photographic schemes The principal advantage of camera-based screening is t
he capturing of an image, for patient education, review of disease progress
ion, and quality assurance. Digital cameras are becoming cheaper, and are n
ow the preferred option. The image is satisfactory for screening and may be
transmitted electronically. With appropriate training and equipment, diffe
rent professional groups might participate in programme delivery, based on
local decisions.
Cost issues Considerable resources are already invested in ad hoc screening
, with inevitable high referral rates incurring heavy outpatient costs. Tre
atment for advanced disease is expensive, but less likely to be effective.
The costs of a new systematic screening and treatment programme appear simi
lar to current expenditure, as a result of savings in treatment of late-pre
senting advanced retinopathy.
Conclusion A systematic national programme based on digital photography is
proposed.