Abstract
Purpose :
Delayed rod-mediated dark adaptation is reported as one of the characters of patients with diabetic retinopathy. We examined the dark adaptation function between patients with different severity of diabetic retinopathy.
Methods :
Dark adaptation was performed by using the AdaptDx dark adaptometer (MacuLogix, Inc.) in an observational study among the groups: subjects with diabetic mellitus without diabetic retinopathy (N=23, mean age: 65), background diabetic retinopathy (N= 22, mean age: 71), proliferative diabetic retinopathy (N=25, mean age: 60) and healthy controls (N=30, mean age: 56). The rod-mediated dark adaptation was automatically measured after a photobleach with targets centered at 12° on the inferior vertical meridian. All subjects are ≥ 18 years old and with best corrected visual acuity ≥ 20/400. The speed of rod-mediated dark adaptation was characterized by the rod intercept time and the value is ≤ 6.5 minutes in normal healthy subjects. ANOVA and multiple comparison with Tukey HSD method were used to compare the differences between groups, and the significance difference was defined as p<0.05.
Results :
The rod intercept time of healthy controls, diabetic mellitus without diabetic retinopathy, background diabetic retinopathy, and proliferative diabetic retinopathy were 4.55± 4.3 minutes, 6.85± 6.3 minutes, 7.28± 4 minutes, and 9.1± 5.06 minutes, respectively. There were significant differences among the four groups (ANOVA, p< 0.01). Multiple comparisons with Tukey HSD showed there was a significant difference between healthy controls and patients with proliferative diabetic retinopathy (p< 0.01).
Conclusions :
The results of this study revealed that there is a significant impairment of rod-mediated dark adaptation in patients with diabetic retinopathy, especially patients with proliferative diabetic retinopathy. Test of the function of rod-mediated dark adaptation may be a useful indicator to monitor progression of diabetic retinopathy.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.