Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel.
Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Br J Ophthalmol. 2021 Jan;105(1):37-41. doi: 10.1136/bjophthalmol-2019-315208. Epub 2020 Mar 18.
Stereoacuity relies on accurate binocular alignment. Convergence insufficiency (CI) a binocular motor disorder, interferes with near work.
To investigate the association between convergence amplitude (CA) and stereoacuity in a large paediatric cohort.
Retrospective chart review included patients aged 6-17 years; excluded patients with amblyopia, manifest strabismus or visual acuity <20/30 in either eye. Stereoacuity, measured by Randot test was defined as normal (≤40arcsec), subnormal (50-400arcsec) and poor (>400 arcsec). CA, measured using base out prism bar was defined by fusion break point (BP) and recovery point (RP), as none (BP=0), poor (BP <20 prism diopter (PD)), borderline (BP <30 PD or RP <20 PD), good (BP ≥30 PD and RP ≥20 PD) and excellent (does not break at 40PD).
In 2200 subjects included, we found an increased prevalence of normal stereoacuity as convergence ability improves (χ test, p<0.001) with a negative correlation between stereoacuity and BP (Pearson correlation -0.13, p<0.001).CI was significantly associated with below normal stereopsis OR 1.86 (95% CI 1.3 to 2.7, p<0.001). Conversely, prevalence of CI was similar, whether or not CI-symptoms were reported. Follow-up data of at least 2.5 years from presentation was available for a small subgroup of 21 patients treated for CI. Convergence improved in 14 (66%), rate of normal stereoacuity increased from 29% at baseline to 76% at last follow-up (p=0.006).
CA affects stereoacuity function in children. Evaluation of CA is required in all cases with poor stereoacuity, especially when other etiologies are amiss. The role of convergence improvement exercise on stereoacuity warrants further investigation.
立体视锐度依赖于准确的双眼对准。集合不足（CI）是一种双眼运动障碍，会干扰近距离工作。
在大型儿科队列中研究集合幅度（CA）与立体视锐度之间的关系。
回顾性图表审查纳入年龄在 6-17 岁的患者；排除弱视、显性斜视或双眼视力<20/30 的患者。使用 Randot 测试测量的立体视锐度定义为正常（≤40arcsec）、异常（50-400arcsec）和差（>400 arcsec）。使用基底外棱镜棒测量的 CA 通过融合断点（BP）和恢复点（RP）定义为无（BP=0）、差（BP<20 棱镜屈光度（PD））、边缘（BP<30 PD 或 RP<20 PD）、良好（BP≥30 PD 和 RP≥20 PD）和优秀（在 40PD 时不打破）。
在纳入的 2200 名患者中，我们发现随着集合能力的提高，正常立体视锐度的患病率增加（卡方检验，p<0.001），立体视锐度与 BP 呈负相关（皮尔逊相关-0.13，p<0.001）。CI 与异常立体视觉显著相关，比值比为 1.86（95%CI 为 1.3 至 2.7，p<0.001）。相反，无论是否报告 CI 症状，CI 的患病率相似。对 21 名接受 CI 治疗的患者进行了至少 2.5 年的随访。在 14 名患者（66%）中，集合得到改善，正常立体视锐度的比率从基线时的 29%增加到最后一次随访时的 76%（p=0.006）。
CA 会影响儿童的立体视锐度功能。在所有立体视锐度异常的情况下，都需要评估 CA，特别是在其他病因不明的情况下。进一步研究需要评估集合改善锻炼对立体视锐度的作用。
