Investigating the Arden hypothesis: a one-year trial investigating the prevention of dark adaptation as complementary therapy for diabetic macular edema

Abstract

Purpose : Light-at-night is an effective method to arrest the dark adaptation of rod photoreceptors and thereby reduce the metabolic activity of the retina, with the aim of reducing oxygen consumption associated with hypoxia that is present in the retina of patients with diabetic retinopathy. The present study evaluated the feasibility of wearing an illuminated sleep mask in patients with diabetes treated for clinically-significant macular edema (CSME) with intravitreal injections.

Methods : Patients with diabetic retinopathy initiating monthly injections of bevacizumab or ranibizumab for CSME were enrolled in a pilot study that used light masks to deliver light-at-night. Patients were randomized to one of two different light regimens in order to differentiate the tolerability of the device from that of the light-at-night treatment. One group received masks equipped with green LEDs (520nm) with an intensity chosen to inactivate the dark current (100 LUX). The other set of masks were configured with red LEDs (670nm) below the threshold necessary to prevent dark adaptation (<5 LUX). Primary outcome was the ability to use the device continuously over the 12-month trial. Secondary outcome was the number of anti-vascular endothelial growth factor (VEGF) injections.

Results : Out of 30 patients consented, 11 participants (37%) failed to adopt the light mask, returning the device within the first week. Five out of nine participants (56%) assigned to masks with red LEDs withdrew or failed to complete the 12 monthly study visits, while two out of ten participants (20%) assigned to the masks equipped with green LEDs did not complete the trial (OR 0.10 CI 0.01 to 0.95, P = 0.046). Using an intention-to-treat analysis found no difference in the number of intravitreal injections administered to participants with red versus green masks (12.3 versus 10.8, P = 0.122). Self-reported compliance with nightly use of the sleep mask was poor. Only an average of 63% of logs documenting nightly battery changes were returned by participants who completed the trial (range 19% to 100%).

Conclusions : Use of a lighted sleep mask poses a challenge for a majority of patients treated for CSME with anti-VEGF injections. There is insufficient evidence to evaluate the effectiveness of light-at-night delivered by this means as a complementary therapy for diabetic retinopathy.

This is a 2021 ARVO Annual Meeting abstract.