Regression of early diabetic macular oedema is associated with prevention of dark adaptation

Eye (Lond). 2011 Dec;25(12):1546-54. doi: 10.1038/eye.2011.264. Epub 2011 Oct 21.


Hypothesis: Dark-adapted rods consume oxygen at high rates and light adaptation decreases this oxygen burden and can have therapeutic effects on diabetic macular oedema (DMO).

Methods: Patients with mild non-proliferative diabetic retinopathy (DR) and early, untreated non-sight-threatening DMO slept for 6 months wearing masks that illuminated the eyelid of one closed eye by 505 nm light. Exclusion criteria were any concomitant eye disease, DR >ETDRS grade 35, and other systemic diseases.

Primary outcome: change of OCT retinal thickness in the local region where oedema was present.

Results: A total of 34 out of 40 patients completed the study. Mean baseline OCT macular cube thickness was equivalent for study and fellow eyes. But study eyes had a greater mean thickness in the central subfield zone 1 (282±53 μm) vs (256±19 μm) the fellow eyes. Twenty-eight study eyes showed intraretinal cysts compared with nine in the fellow eyes. At 6 months, only 19 study eyes had cysts while cysts were seen in 20 fellow eyes. After 6 months, the worst affected ETDRS zone and the central subfield zone 1 reduced in thickness in study eyes only by 12 μm (95% CI 20 to -7, P=0.01). The secondary outcomes of change in visual acuity, achromatic contrast sensitivity, and microperimetric thresholds improved significantly in study eyes and deteriorated in fellow eyes.

Conclusions: Sleeping in dim light that can keep rods light adapted may reverse the changes of DMO.

MeSH terms

  • Adult
  • Aged
  • Dark Adaptation / physiology
  • Dark Adaptation / radiation effects*
  • Diabetic Retinopathy / complications*
  • Diabetic Retinopathy / physiopathology
  • Female
  • Humans
  • Macular Edema / pathology
  • Macular Edema / physiopathology
  • Macular Edema / therapy*
  • Male
  • Middle Aged
  • Phototherapy / methods*
  • Remission Induction / methods
  • Retina / pathology
  • Retina / radiation effects*
  • Retinal Rod Photoreceptor Cells / metabolism
  • Retinal Rod Photoreceptor Cells / radiation effects*
  • Tomography, Optical Coherence