Smartphone as a tool for evaluating oblique muscle dysfunction

ABSTRACT Purpose: The aim of this study was to describe a simple, accessible, and reliable method using a smartphone for evaluating oblique muscle dysfunctions. Methods: The photograph rotation tool in the iPhone PHOTO app was used by 75 examiners to evaluate 22 photographs from only 9 patients, captured in infra- and supra-dextroversion, and infra- and supra-levoversion, as not all the patients were photographed in the 4 positions mentioned. Each patient received a score for the superior and inferior oblique muscle functions, ranging from -4 (hypofunction) to 4 (hyperfunction) or 0 (normal function), using preediting and postediting photographs. These values were compared with the scores previously given by trained personnel in strabismus screening. The difference in score between the two groups was expressed in natural (whole and non-negative) numbers. The mean and pattern deviation were then calculated. Results: The scores of most of the edited photos showed a lower mean than those of the unedited ones, except for a patient with left superior oblique hyperfunction. The patients with no oblique dysfunction and those with right superior oblique hyperfunction demonstrated (after editing the photograph) scores with greater similarity with their initial scores (p<0.05 and p<0.01, respectively). Similar results were found in the patients with oblique hypofunctions and right inferior oblique hyperfunction (p<0.01). Conclusion: The proposed method for assessing muscular function in vertical strabismus is reproducible, accessible, simple, and reliable, and provides better consistency to the admeasurement.摘要 目的：本研究旨在描述一种简便易用、可靠的智能手机评估方法，用于检测斜肌功能异常。 方法：本研究纳入9名患者拍摄的22张照片，因并非所有患者均完成了外旋上转、外旋下转、内旋上转、内旋下转四种体位的拍摄，故仅涵盖其中部分体位。75名检查者使用iPhone照片应用（iPhone PHOTO app）中的照片旋转工具对上述照片进行评估，通过预编辑与后编辑照片，为每位患者的上斜肌与下斜肌功能赋值，评分范围为-4（功能低下）至4（功能亢进），0代表功能正常。将上述评分与此前斜视筛查中受训人员给出的评分进行对比，两组评分的差值以自然数（正整数与零）形式呈现，并计算均值与模式偏差。 结果：经编辑的多数照片评分均值低于未编辑组，仅1名左上斜肌功能亢进的患者例外。编辑照片后，无斜肌功能异常以及右上斜肌功能亢进的患者，其评分与初始评分的一致性更高（分别为p<0.05与p<0.01）。斜肌功能低下以及右下斜肌功能亢进的患者也得到了相似结果（p<0.01）。 结论：本研究提出的垂直斜视肌功能评估方法具备可重复性、易用性、简便性与可靠性，可提升斜视评估的一致性。