Objective Cyclodeviation Measurement in Normal Subjects by Means of Cyclocheck® Application
Piotr Loba; Justyna Simiera
Department of Binocular Pathophysiology and Strabismus, Medical University of Lodz
Introduction: Recently proposed Cyclocheck® application for objective assessment of cyclodeviation occurred to be repeatable and reproducible method (1). Present study aims at evaluating the range of cyclodeviation in normal subjects by means of the above mentioned free web-based software.
Methods: 122 volunteers (75 females, aged 30.7±14.1) were enrolled in the study. The inclusion criteria were ortotropia in all gaze positions, full stereopsis and no past history of strabismus nor amblyopia. Digital fundus photographs of both eyes were obtained using DRS CenterVue nonmydriatic fundus camera. The disc-foveal angle was calculated using Cyclocheck®.
Results: The images were obtainable and of good quality in all subjects. The mean value of disc-foveal angle was 5.34±2.59 degrees(range: -0.40 to 12.55) in the right eye and 7.54±2.43 degrees(range: 1.25 to 12.76) in the left eye. We have found significantly (p= 0.0001) larger excyclodeviation in the left eye in 77% of the studied subjects with a mean difference of 3.4±1.63 degrees.
Discussion: The measurements obtained by Cyclocheck® concur with other studies on objective cyclodeviation (2,3). The disparity between the right and left eye evade simple explanation. It was not related to fixation preference, but on the other hand, natural asymmetry leading to higher prevalence of certain types of strabismus on the left side could be considered as a possible explanation.
Conclusion: Cyclocheck® allows easy assessment of cyclodeviation in normal subjects. Ortotropic subjects present with a positive value of disc-foveal angle with a certain spread of the results. There is a significant asymmetry between eyes with the left eye being more excyclodeviated.
References: 1.Simiera J, Loba P. Cyclocheck: a new web-based software for the assessment of objective cyclodeviation. J AAPOS. 2017; 21:305-308.
2.Rohrschneider K. Determination of the location of the fovea on the fundus. Invest Ophthalmol Vis Sci 2004; 45:3257-3258
3.Shin KH, Lee HJ, Lim HT. Ocular torsion among patients with intermittent exotropia: relationships with disease severity factors. Am J Ophthalmol 2013; 155:177-182