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


METHODS
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.
School of Community and Health Sciences, City University, London, UK. geoffreyarden@aol.com
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Arden
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Jyothi
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Hogg
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Lee
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Sivaprasad
D000328:Adult; D000368:Aged; D003623:Dark Adaptation / Q000502:physiology / Q000528:radiation effects*; D003930:Diabetic Retinopathy / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008269:Macular Edema / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010789:Phototherapy / Q000379:methods*; D012074:Remission Induction / Q000379:methods; D012160:Retina / Q000473:pathology / Q000528:radiation effects*; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism / Q000528:radiation effects*; D041623:Tomography, Optical Coherence