Effects of Monocular Flicker on Binocular Imbalance in Amblyopic and Nonamblyopic Adults

• Published in: Investigative ophthalmology & visual science 2024-03, Vol.65 (3), p.33
• Main Authors: Lu, Yiqiu, Zou, Liying, Wang, Wenjing, Chen, Ruyin, Qu, Jia, Zhou, Jiawei
• Format: Article
• Language: English
• Subjects: Adult; Amblyopia; Animals; Birds; Eye Movements, Strabismus, Amblyopia and Neuro-Ophthalmology; Female; Humans
• ISSN: 1552-5783; 0146-0404; 1552-5783
• DOI: 10.1167/iovs.65.3.33

This study aimed to evaluate the effects of monocular flicker stimulation on binocular imbalance in both amblyopic and nonamblyopic adults. Seven amblyopic patients (28.3 ± 3.3 years; four females) and seven normally sighted participants (27.3 ± 4.1 years; five females) participated in the study. We used liquid crystal spectacles to create externally-generated monocular flicker (4, 7, 10, 15, or 20 Hz) and used the metric of log balance point (logBP) to determine whether imposed flicker could change the eyes' equilibrium interocular contrast ratio. Flicker was applied to either the fellow eye vs. the amblyopic eye or dominant eye (DE) vs. non-DE (non-DE) of amblyopic and nonamblyopic participants, respectively. We defined a logBP of 0 to indicate complete binocular balance and an increase in logBP relative to baseline to indicate a relative strengthening of the non-DE or amblyopic eye. Monocular flicker applied to the DE or fellow eye increased logBP, whereas when applied to the non-DE or amblyopic eye, reduced the logBP. These effects were more pronounced at low temporal frequencies than that at high temporal frequencies. The interaction between eye and temporal frequency was significant in both normals, F(4, 24) = 58.082, P