Relationship between reading performance and saccadic disconjugacy in patients with convergence insufficiency type intermittent exotropia

Self-Reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire

PURPOSE

To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population.

METHODS

The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS.

RESULTS

The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery.

CONCLUSIONS

The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.

Reading speed in school-age children with intermittent exotropia

Reading speed in intermittent exotropia (IXT) children has been minimally examined. This study assessed reading speed in school-age children with IXT and determined clinical characteristics of IXT that impacted their reading ability. We compared the reading speed of 63 school-age (10–14 years) children with IXT to 44 age-matched normal counterparts. In addition, the correlation between reading speed and clinical characteristics of IXT were evaluated. The reading speed in children with IXT was 231 ± 51 CPM, while reading speed in normal counterparts was 257 ± 33 CPM. Age, gender were found to be factors associated with reading speed in children with IXT. After adjusting for the age and gender, we found a significant correlation between the LogTNO and reading speed in IXT group based on a generalized linear model (p = 0.014). These data show that reading speed was slower in school-age children with IXT assessed with the International Reading Speed Texts. When age and gender were adjusted, poor stereo function at near was found to be related with a slower reading speed.

An Overview of the Korean Intermittent Exotropia Multicenter Study by the Korean Association for Pediatric Ophthalmology and Strabismus

The Korean Intermittent Exotropia Multicenter Study (KIEMS), which was initiated by the Korean Association of Pediatric Ophthalmology and Strabismus, is a collaborative multicenter study on intermittent exotropia in Korea. The KIEMS was designed to provide comprehensive information, including subjective and objective findings of intermittent exotropia in a large study population. A total of 65 strabismus specialists in 53 institutions contributed to this study, which, to date, is one of the largest clinical studies on intermittent exotropia. In this article, we provide a detailed methodology of the KIEMS to help future investigations that may use the KIEMS data.

Soft, wireless periocular wearable electronics for real-time detection of eye vergence in a virtual reality toward mobile eye therapies

Recent advancements in electronic packaging and image processing techniques have opened the possibility for optics-based portable eye tracking approaches, but technical and safety hurdles limit safe implementation toward wearable applications. Here, we introduce a fully wearable, wireless soft electronic system that offers a portable, highly sensitive tracking of eye movements (vergence) via the combination of skin-conformal sensors and a virtual reality system. Advancement of material processing and printing technologies based on aerosol jet printing enables reliable manufacturing of skin-like sensors, while the flexible hybrid circuit based on elastomer and chip integration allows comfortable integration with a user's head. Analytical and computational study of a data classification algorithm provides a highly accurate tool for real-time detection and classification of ocular motions. In vivo demonstration with 14 human subjects captures the potential of the wearable electronics as a portable therapy system, whose minimized form factor facilitates seamless interplay with traditional wearable hardware.

A quantitative analysis method for comitant exotropia using video-oculography with alternate cover

Background

The purpose of this study was to evaluate the efficacy of a quantitative analysis method for comitant exotropia using video-oculography (VOG) with alternate cover.

Methods

Thirty-four subjects with comitant exotropia were included. Two independent ophthalmologists measured the angle of ocular deviation using the alternate prism cover test (APCT). The video files and data of changes in ocular deviation during the alternate cover test were obtained using VOG. To verify the accuracy of VOG, the value obtained using VOG and the angle of a rotating model eye were compared, and a new linear equation was subsequently derived using these data. The calculated values obtained using VOG were compared with those obtained using the APCT.

Results

Rotation of the model eye and the values obtained using VOG demonstrated excellent positive correlation (R = 1.000; p < 0.001). A simple linear regression model was obtained: rotation of the model eye = 0.978 × value obtained using VOG for a model eye – 0.549. The 95% limit of agreement for inter-observer variability was ±4.63 prism diopters (PD) for APCT and that for test-retest variability was ±3.56 PD for the VOG test. The results of APCT and calculated VOG test demonstrated a strong positive correlation. Bland-Altman plots revealed no overall tendency for the calculated values obtained from VOG to differ from those obtained using APCT.

Conclusions

VOG with alternate cover is a non-invasive and accurate tool for quantitatively measuring and recording ocular deviation. In particular, it is independent of the proficiency of the examiner and, can therefore, be useful in the absence of skilled personnel.

Trial registration

ClinicalTrial.gov, NCT03119311, Date of registration: 04/17/2017, Date of enrolment of the first participant to the trial: 04/25/2017.