Background/aims Recent work has called into question the ability of visual acuity (VA) to accurately represent changes in visual function in infantile nystagmus (IN). This systematic review investigated factors affecting visual performance in IN, to guide development of suitable alternatives to VA. Methods Included studies used an experimental manipulation to assess changes in visual function in people with IN. Interventional studies, case series and case studies were excluded. Six databases were searched in August 2023. Selection, detection, attrition and measurement bias were assessed. Due to heterogeneous methodologies, narrative synthesis was undertaken. Results Eighteen relevant papers were identified, 11 of which complied with the review criteria. Articles were grouped according to the factor manipulated to evoke within-participant changes in performance (motion blur, psychological state, gaze angle or visual crowding). Optotype, image, grating and moving stimuli have been employed under varying lighting conditions and exposure duration. Conclusion Several factors affecting visual performance should be considered when assessing visual function in IN. While maximum VA is a useful metric, its measurement deliberately minimises nystagmus-specific factors such as changes in visual performance with gaze angle and the ‘slow to see’ phenomenon. Maximum VA can be measured using the null zone, providing unlimited viewing time, reducing stress/mental load and minimising visual crowding. Gaze-dependent functional vision space is a promising measure which quantifies the impact of the null zone but does not consider temporal vision. Although no complete measurement technique has yet been proven, this review provides insights to guide future work towards development of appropriate methods. Data sharing not applicable as no datasets generated and/or analysed for this study.

中文翻译：

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婴儿眼球震颤视觉功能的测量：系统评价


背景/目标 最近的工作对视敏度 (VA) 准确表征婴儿眼球震颤 (IN) 视觉功能变化的能力提出了质疑。本系统综述调查了影响 IN 视觉表现的因素，以指导开发合适的 VA 替代品。方法 纳入的研究使用实验操作来评估 IN 患者视觉功能的变化。干预研究、病例系列和案例研究被排除在外。 2023 年 8 月检索了六个数据库。对选择、检测、流失和测量偏倚进行了评估。由于方法论的异质性，进行了叙事综合。结果共筛选出相关论文18篇，其中符合评审标准的论文11篇。文章根据引起参与者内部表现变化的因素（运动模糊、心理状态、注视角度或视觉拥挤）进行分组。在不同的照明条件和曝光时间下采用了视标、图像、光栅和移动刺激。结论 在评估 IN 视功能时应考虑影响视觉功能的几个因素。虽然最大视敏度是一个有用的指标，但其测量有意最小化眼球震颤特定因素，例如注视角度引起的视觉性能变化和“看东西慢”现象。最大视安可以使用零区进行测量，提供无限的观看时间，减少压力/精神负担并最大限度地减少视觉拥挤。依赖注视的功能性视觉空间是一种有前途的测量方法，它量化了零区的影响，但不考虑时间视觉。 尽管尚未证实完整的测量技术，但本综述提供了见解，可指导未来开发适当方法的工作。数据共享不适用，因为本研究没有生成和/或分析数据集。