Diurnal variation in retinal thickening measurement by optical coherence tomography in center-involved diabetic macular edema

Arch Ophthalmol. 2006 Dec;124(12):1701-7. doi: 10.1001/archopht.124.12.1701.

Abstract

Objective: To evaluate diurnal variation in retinal thickness measured with optical coherence tomography (OCT) in patients with center-involved diabetic macular edema.

Methods: Serial OCT3 measurements were performed in 156 eyes of 96 subjects with clinically diagnosed diabetic macular edema and OCT central subfield retinal thickness of 225 microm or greater at 8 am. Central subfield thickness was measured from OCT3 retinal thickness maps at 6 points over a single day between 8 am and 4 pm. A change in central subfield thickening (observed thickness minus mean normal thickness) of at least 25% and of at least 50 microm at 2 consecutive points or between 8 am and 4 pm was considered to have met the composite outcome threshold.

Results: At 8 am, the mean central subfield thickness was 368 microm and the mean visual acuity was 66 letters (approximately 20/50). The mean change in relative central subfield retinal thickening between 8 am and 4 pm was a decrease of 6% (95% confidence interval, -9% to -3%) and the mean absolute change was a decrease of 13 microm (95% CI, -17 to -8). The absolute change was significantly greater in retinas that were thicker at 8 am (P<.001) but the relative change was not (P = .14). The composite threshold of reduction in central subfield thickening (as defined above) was observed in 5 eyes of 4 subjects (3% of eyes; 95% CI, 1% to 8%) while 2 eyes of 2 subjects (1%; 95% CI, 0% to 5%) had an increase in central subfield thickening of this same magnitude. The maximum decrease was observed at 4 pm in all 5 eyes.

Conclusion: Although on average there are slight decreases in retinal thickening during the day, most eyes with diabetic macular edema have little meaningful change in OCT central subfield thickening between 8 am and 4 pm.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Anthropometry
  • Circadian Rhythm*
  • Diabetes Mellitus, Type 1 / complications
  • Diabetes Mellitus, Type 2 / complications
  • Diabetic Retinopathy / diagnosis*
  • Female
  • Humans
  • Macular Edema / diagnosis*
  • Male
  • Middle Aged
  • Retina / pathology*
  • Time Factors
  • Tomography, Optical Coherence*
  • Visual Acuity