Effect of monocular fixation in binocular field (MFBF) on amblyopia – a pilot study comparing it with patching

ABSTRACT

Patching is the gold standard in amblyopia therapy. However, all children are not compliant with patching. We compared the efficacy of 2.5 hours per week of HTS Amblyopia I Net software (Amb I Net) using MFBF principle (delivered under binocular viewing conditions where the amblyopic eye is preferentially stimulated) with 14–42 hours per week of patching therapy.

54 children with anisometropic amblyopia of ages 4–15 years were included in the study – 24 children in the patching and 30 children in the MFBF group. The study ran for a period of 6 months with BCVA assessed at each visit of follow up.

In the patching group, visual acuity (VA) gain was 0.37 ± 0.26 log Mar over the course of 6 months with continuous improvement in vision across the three time points (0.20 log mar in the first month, 0.11 log Mar from month1 to 3 and 0.06 log Mar from months 3 to 6).In the Amb I Net group, visual acuity gain was 0.54 ± 0.38 log Mar over the same course of time. A continuous improvement in vision was also noted, with gains of 0.16 in the first month, 0.19 from month 1 to 3 and 0.19 from month 3 to 6. The difference in log Mar gains in VA was not statistically significant between the treatment arms and the final VA was similar (0.25 log Mar for patching and 0.18 log Mar for Amb I net). However, clinically the patching group showed 3 log MAR lines, whereas the MFBF group showed 5 log MAR lines of vision improvement at the end of therapy.

MFBF was not superior to patching as far as efficacy is concerned in anisometropic amblyopia. However, the combination of more game options to sustain interest, a shorter duration of therapy over the course of a week and software directed compliance monitoring system favors the Amb I Net system from both patient and parental perspective. Amb I Net also negated discomfort, social stigma, and parental monitoring needed with patching regimens. It can be considered as a good alternative to patching in reluctant/non – compliant children with anisometropic amblyopia. This is the first large cohort study based on this therapy.

KEYWORDS:

• Amblyopia
• amblyopia I Net software
• monocular fixation in binocular field
• stereopsis
• failed patching regimens
• compliance

Acknowledgments

Acknowledge the support of optometry team Ms Christy and Ms Inbah of Dr Agarwals Eye hospital.

Authors’ contribution

First author: Dr Manjula Jayakumar – concept and design of the study, definition of intellectual content, data acquisition, manuscript preparation

Second author Ms Helen Gracy Raju –Data analysis, statistical analysis

Third author – Prof. Amar Agarwal intellectual content, literature search, manuscript review and editing

Conflicts of interest

There are no conflicts of interest.