Stable refraction and visual acuity in diabetic patients with variable glucose levels under routine care.
OBJECTIVE
To investigate how refraction and visual acuity may vary in patients with diabetes under routine care.


METHODS
Fifty-three eyes of 53 patients with various degrees of diabetic retinopathy were examined prospectively on four different occasions within a month. Refraction, best-corrected visual acuity (expressed as logMAR score) and blood glucose were measured on each occasion. Intraindividual variability was calculated as the range between the highest and lowest measurements. Associations between blood glucose levels and each of the other variables were tested by linear regression analysis for each patient.


RESULTS
Refraction was completely stable in 43 patients and changed only slightly in 10, in whom the mean intraindividual variability of the spherical equivalent was 0.4 dioptres. Visual acuity test results were also highly reproducible. Mean intraindividual variability in visual acuity was 0.08 logMAR. Mean haemoglobin A1c (HbA1c) was 7.3 ± 1.5% but individual blood glucose levels ranged from 2.8 to > 22.2 mmol/l. Intraindividual variability ranged from 0.5 to 18.1 mmol/l, with a median of 6.0 mmol/l for the entire group. There were no associations between refraction or visual acuity and blood glucose levels or inter- or intraindividual glucose variations.


CONCLUSIONS
Refraction and visual acuity test results were highly reproducible and stable in patients with reasonably well controlled diabetes but variable blood glucose levels under routine care.
Department of Clinical Sciences, Ophthalmology, Malmö University Hospital, Lund University, Sweden. elisabet.agardh@med.lu.se
Elisabet
E
Agardh
Karl-Johan
KJ
Hellgren
Boel
B
Bengtsson
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*
D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human