A preliminary trial to determine whether prevention of dark adaptation affects the course of early diabetic retinopathy.
This study was designed to determine whether a new form of treatment of diabetic retinopathy (DR) was acceptable to patients and whether reduction in the maximal activity of rods in diabetes could affect the progress of DR.


METHODS
In 12 patients, trans-lid retinal illumination of one eye was employed during sleep to prevent the depolarisation of rods and thus reduce their metabolic activity.


METHODS
A headband was used to place a source of chemical light over one eye, with its fellow as a control.


METHODS
Colour contrast thresholds were measured before and after a period of treatment in treated eyes, and the changes were compared to those in untreated fellow eyes, and areas of 'dark retinal anomalies' (microaneurysms, dot haemorrhages) were measured at the same time points.


RESULTS
Patients found this intervention to be acceptable, and no adverse effects were noted. In the majority of cases, and for each outcome measure, the treated eyes improved relative to their fellows. The intervention significantly reduced the tritan thresholds in treated eyes relative to their fellows (P=0.03), and the area of dark retinal anomalies decreased in treated eyes and increased in untreated eyes, with a similar probability.


CONCLUSIONS
The study showed that this intervention is safe. Although the study was not powered to study efficacy, the results are promising and consistent with other reports that indicate the retina in DR is suffering from hypoxia; however, further trials should be undertaken.
Department of Optometry and Visual Science, School of Community and Health Sciences, City University, London, UK. g.arden@city.ac.uk
G B
GB
Arden
M K
MK
Gündüz
A
A
Kurtenbach
M
M
Völker
E
E
Zrenner
S B
SB
Gündüz
U
U
Kamis
B T
BT
Oztürk
S
S
Okudan
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003118:Color Perception / Q000528:radiation effects; D015350:Contrast Sensitivity / Q000528:radiation effects; D003623:Dark Adaptation / Q000502:physiology / Q000528:radiation effects*; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods*; D012160:Retina / Q000528:radiation effects*; D012166:Retinal Hemorrhage / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000528:radiation effects; D012684:Sensory Thresholds; D055815:Young Adult