Abstract
Purpose :
Amblyopia is a neurodevelopmental disorder due to de-correlated binocular input to the visual cortex. The treatment comprises of occlusion of non-amblyopic eye to promote the development of vision in amblyopic eye. Amblyopes who experienced disruption of binocularity during first six months of life develop fusion maldevelopment nystagmus (FMN). The slow phase velocity (SPV) of FMN increases under monocular viewing conditions. Limited studies have shown that full-time occlusion causes a compensatory decrease in SPV over days, thus it was recommended in patients with FMN.
Methods :
Amblyopic patients with and without FMN were recruited. Part-time occlusion (2-6 hours/day) was prescribed depending on the severity of amblyopia per the PEDIG studies. We analyzed the relationship between the presence of FMN and response to part-time occlusion.
Results :
Forty-eight amblyopic patients were recruited[FMN(n=15) and no FMN(n=33)]. Patients were stratified by severity of amblyopia at the time of diagnosis (mild=3, moderate=34 and severe=11). Compliance to treatment was comparable between the two groups. 33% of patients with FMN and 30% without FMN were treated with no residual amblyopia (chi squared: p=0.886). The number of months of patching was greater in patients with FMN (27±18.5) versus without FMN (22.4±13.5, p=0.024).
Conclusions :
The presence of FMN did not have an impact on treatment compliance. Moreover, occlusion showed efficacy in patients with and without FMN. Interestingly, the duration of treatment in successfully treated amblyopic patients was longer in FMN group than in those without FMN.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.