The Prevalence of Diabetic Retinopathy in Trang Province Determined by Retinal Photography and Comprehensive Eye Examination
Supachai Supapluksakul MD*, Paisan Ruamviboonsuk MD**, Wansa Chaowakul MD**
Affiliation : * Department of Ophthalmology, Trang Provincial Hospital, Trang **Department of Ophthalmology, Rajavithi Hospital, Bangkok
Objective : To determine the prevalence of diabetic retinopathy (DR) in Trang province using retinal photography
and comprehensive eye examination.
Method: Seven hundred fourteen patients with diabetes (7% of the total number of diabetes in the province)
were examined by single-field digital retinal photography interpreted by a retinal specialist and a stereoscopic
method using indirect ophthalmolscopy and slit lamp biomicroscopy with wide field contact lens. The latter
method was performed by an experienced ophthalmologist assisted by the same retinal specialist.
Results : There was 19.2% nonproliferative diabetic retinopathy (NPDR), and 1.1% proliferative diabetic
retinopathy (PDR), identified by the comprehensive examination for the right eyes. This modality also identified
18.5% NPDR, and 1.3% PDR, for the left eyes. There was 23.8% nonproliferative diabetic retinopathy (NPDR),
and 1.4% proliferative diabetic retinopathy (PDR) identified by retinal photography for the right eyes. This
modality also identified 22.6% NPDR, and 1.3% PDR for the left eyes. The sight-threatening cases were
identified by both modalities with approximately 3% for both eyes. The photography had moderate agreement
(K = 0.5, both eyes) with the comprehensive examination for the identification of diabetic macular edema with
78.6% and 68.8% sensitivity for the right and left eyes. For the identification of moderate NPDR, severe NPDR,
and PDR, the photography had substantial agreement (K = 0.7, both eyes) with 88.2% and 83.3 sensitivity for
the right and left eyes.
Conclusions: Trang province may have approximately 300 sight-threatening DR patients. This may project to
180,000 patients nationwide. Retinal photography may determine more cases than clinical examination.
Combination of both modalities for DR identification may yield a closer estimate to the real prevalence.
Keywords : diabetic retinopathy screening, digital retinal photography, prevalence of diabetic retinopathy
