Objective cyclodeviation measurement in normal subjects by means of Cyclocheck^® application

Abstract

Purpose: To evaluate the range of cyclodeviation in normal individuals by means of Cyclocheck® application recently designed by the authors and freely available at www.cyclocheck.com . Methods: Healthy subjects with normal muscle balance, best-corrected visual acuity of ⩾0.8, and stereopsis on Randot charts of ⩽100 s of arc were included in the study. Two separate digital fundus photographs were taken of each eye of every patient. The disk-foveal angle was calculated using the Cyclocheck® application. The average result of the disk-foveal angle measurements were considered for data analysis. Results: A total of 131 patients met inclusion criteria for the study population. The mean value of the disk-foveal angle in the whole study group (both right and left eye) was 6.39° ± 2.72° with 5.26° ± 2.56° (range from −0.4° to 12.55°) in the right eye and 7.52° ± 2.39° (range from 1.25° to 12.76°) in the left eye. The mean value of the disk-foveal angle of the left eye was greater by 2.26° than that of the right eye. Conclusion: Cyclocheck® software allows easy assessment of cyclodeviation. Normal individuals present with a positive value of the disk-foveal angle with a certain spread of the results. The analysis of obtained measurements revealed a significant asymmetry between both eyes with the left eye being more excyclodeviated in an otherwise orthotropic population, which remains a subject for further investigations.

Automatic Estimation of Objective Cyclodeviation in Fundus Image Using Machine Learning

“…However, the angle between the fovea and the center of the ONH from 4° to 9° exists in healthy individuals. 9 CNN could not learn the features of cyclodeviation from fundus images because the control data was nothing.…”

“…Recently, Simiera et al developed web-based software to assess objective cyclodeviation. 8,9 Methods for calculating objective cyclodeviation from fundus images and software to assist in the analysis are valuable for quantitative evaluation of cyclotropia. However, the conventional methods and software de ne the fovea and center of ONH by an examiner visually checking the fundus images.…”

Automated measurement of the disc-fovea angle based on DeepLabv3+

“…center error, and the formula (in pixels) is shown in Equation (7). The following points are defined as: (OX1, OY1) as the true optic disc center, (MX1, MY1) as the true macular center, (OX2, OY2) as the segmented obtained optic disc center, and (MX2, MY2) as the segmented obtained macular center.…”

“…The DFA of patients with rotational strabismus is usually beyond the normal range; therefore, DFA measurement is an important tool for the diagnosis of rotational strabismus. The measurement of the rotational strabismus angle is divided into subjective and objective examinations; the former examination utilizes the Maddox method (1), Jackson crossed columnoscopy (2), and manual corneal margin marking (3), while the latter examination is measured using fundus images (4)(5)(6)(7)(8). Currently, DFA measurement based on fundus images are mainly measured manually and suffer from an average error of 2.0 (±1.8) (9).…”

Development and Preliminary Validation of a Virtual Reality Approach for Measurement of Torsional Strabismus

“…Another strategy has been extraction of strabismus measurements based on color photographs, video, or infrared-eye movement recordings during binocular viewing and cover testing (9)(10)(11). Cyclodeviation measurements have been obtained by automated analysis of fundus photographs (objective) (12) and by having a patient manipulate red and green lines on a computer (13) or smartphone (14) screen while wearing red-green glasses to dissociate the eyes (subjective). We implemented a novel approach at sensory-based strabismus testing, specifically using a virtual reality (VR) headset to display different inputs to each eye while the patient manipulates these to achieve perceived alignment.…”