Improved visual function in IDDM patients with unchanged cumulative incidence of sight-threatening diabetic retinopathy.
OBJECTIVE
To evaluate trends in visual acuity and the cumulative incidence of diabetic retinopathy in a clinic-based observational follow-up study.


METHODS
All patients visiting Hvidore Hospital in 1984 whose diagnosis of IDDM had been made before 41 years of age and between 1965 and 1979 (n = 356) were followed until 1994 or until their deaths. All patients were Caucasians and resided in Copenhagen. Patients were divided into three prevalence cohorts based on time of diabetes onset: group A, 1965-1969 (n = 113); group B, 1970-1974 (n = 130); and group C, 1975-1979 (n = 113).


RESULTS
Fifteen years after diabetes onset, the visual acuity was significantly improved in patients with increasing calendar year of the disease onset. The median (interquartile range) visual acuity was 1.0 (0.8-1.0), 1.0(0.9-1.0), and 1.0 (1.0-1.0) in groups A, B, and C, respectively (P < 0.01 overall; P = 0.28 for group A vs. group B; and P < 0.01 for group A vs. group C) with 60, 66, and 93 having a visual acuity of 1.0 in groups A, B, and C, respectively. The cumulative incidence (+/-SEM), expressed as a percentage and calculated according to the life-table method, of proliferative retinopathy, maculopathy, and laser-treated retinopathy 15 years after onset of diabetes were, respectively, 13+/-3, 11+/-3, and 12+/-3 in group A; 16+/-3, 12+/-3, and 21+/-4 in group B; 11+/-3, 5+/-2, and 12+/-3 in group C, respectively (NS). The development of proliferative retinopathy was associated with the degree of retinopathy and albuminuria at baseline and the mean HbA1c during follow-up.


CONCLUSIONS
The study revealed an improvement in visual acuity with increasing calendar year of diabetes onset but an unchanged cumulative incidence of diabetic retinopathy.
Rossing
K
K
Steno Diabetes Center, Gentofte, Denmark.
Jacobsen
P
P
Rossing
P
P
Lauritzen
E
E
Lund-Andersen
H
H
Parving
H H
HH
D000328:Adult; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D019370:Observation; D009887:Ophthalmoscopy; D015995:Prevalence; D012307:Risk Factors; D014792:Visual Acuity