Systematic screening for diabetic retinopathy (DR) in Hong Kong: prevalence of DR and visual impairment among diabetic population.
OBJECTIVE
To determine the prevalence of diabetic retinopathy (DR), sight threatening DR (STDR), visual impairment and other eye diseases in a systematic DR screening programme among primary care Chinese patients with diabetes mellitus (DM) in Hong Kong.


METHODS
Screening for DR was provided to all subjects with DM in public primary care using digital fundus photography according to the English national screening programme. STDR was defined as preproliferative DR (R2), proliferative DR (R3) and/or maculopathy (M1). The presence of other eye diseases was noted. Visual impairment was classified as none (visual acuity in the better eye of 6/18 or better), mild (6/18 to >6/60) and severe (6/60 or worse).


RESULTS
Of 174 532 subjects screened, most had never been screened before. The prevalence of DR was 39.0% (95% CI 38.8% to 39.2%) and STDR 9.8% (95% CI 9.7% to 9.9%). The most common DR status was R1 (35.7%), followed by M1 (8.6%), R2 (3.0%) and R3 (0.3%). The prevalence of mild and severe visual impairment was 4.2% and 1.3%, respectively. Subjects with STDR had a higher prevalence (9.8%) of visual impairment than those without (3.5%).


CONCLUSIONS
DR was prevalent in this population and one in 10 had STDR. This suggests the need for systematic screening to ensure timely referral to an ophthalmologist for monitoring and/or treatment.
Department of Ophthalmology, The University of Hong Kong, Hong Kong, Hong Kong Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, Hong Kong.
Jin Xiao
JX
Lian
Department of Ophthalmology, The University of Hong Kong, Hong Kong, Hong Kong.
Rita A
RA
Gangwani
School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.
Sarah M
SM
McGhee
Department of Ophthalmology, The University of Hong Kong, Hong Kong, Hong Kong.
Christina K W
CK
Chan
Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong, Hong Kong.
Cindy Lo Kuen
CL
Lam
Department of Ophthalmology, The University of Hong Kong, Hong Kong, Hong Kong.
David Sai Hung
DS
Wong
D000368:Aged; D044466:Asian People / Q000208:ethnology*; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000208:ethnology*; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000208:ethnology*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011320:Primary Health Care; D014786:Vision Disorders / Q000208:ethnology*; D015351:Vision Screening; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*
Epidemiology; Public health; Retina; Vision