Abstract
Purpose:
Amblyopia is a neurological development disorder that presents with deficits in spatiotemporal vision processing resulting from an active suppression process. The current standard of care for amblyopia involves visual penalization (using patching, often for several hours a day, or atropine) of the “good”, non-amblyopic, eye. We propose and evaluate an alternative treatment method that does not penalize the patient’s ability to see while being treated and promotes normal binocular vision: the Eyetronix Flicker Glasses (EFG). The objective of this study is to evaluate the feasibility and efficacy of the novel EFG Therapy for amblyopia.
Methods:
20 children (ages 6-17 years) participated in this initial open-label, multi-center study. Inclusion criteria included: mild to moderate anisometropic amblyopia [difference in logMAR best-corrected visual acuity (BCVA) of 0.2 logMAR (2 lines) or more between the amblyopic and fellow eye]; amblyopic eye BCVA +0.2 to +0.7 logMAR; anisometropia of >1.00DS or >1.50DC; full-time wear of glasses with best-correction for at least 8 weeks prior to the EFG Therapy. EFG is a spectacle frame with liquid crystal lenses and an electronic shutter that allows accurate and rapid alternating rate of occlusion. For this study the EFG were preprogrammed to 7Hz, 50% duty cycle. Subjects were instructed to wear the EFG daily for 1-2 hours during near vision activities. The primary outcome measure was the change of logMAR VA in the amblyopic eye between the dispensing and 3-month visit. Secondary outcome measures included changes in stereopsis and fusion.
Results:
All but one subject showed improved VA in the amblyopic eye (Mean group improvement -0.09 ± 0.10 logMAR; 1 line). This improvement was significantly larger (p=0.04) than the variation in VA in the non-amblyopic eye. All but two subjects improved stereopsis. Several subjects reported improvement in daily tasks such as playing hockey.
Conclusions:
Preliminary data yield promising benefit of the EFG Therapy, comparable to previous studies using patching or atropine. In addition, the improvement in stereopsis and daily activities noted in many subjects suggest that the EFG Therapy promotes the development of normal binocular vision.
Keywords: 417 amblyopia •
434 binocular vision/stereopsis •
611 neuro-ophthalmology: cortical function/rehabilitation