Clinical Characteristics and Outcomes of Smartphone Overusers with Acute Acquired Comitant Esotropia

PURPOSE: To evaluate the clinical features and treatment outcomes of smartphone overusers with acute acquired comitant esotropia. METHODS: We retrospectively reviewed the medical records of patients ≥ 15 years of age who used a smartphone for > 4 hours a day for > 1 year, and who were diagnosed with acute acquired comitant esotropia from May 2011 to January 2016. We analyzed sex, age at the time of manifestation and duration of esotropia, refractive error, deviated angle at the first and final visits, and the results of refraining from smartphone use, use of the Fresnel prism, and surgery for esotropia. RESULTS: A total of 13 patients were studied, including 8 males and 5 females. The mean age at development of esotropia was 22.7 ± 9.7 years. The mean duration of esotropia before the first visit was 28.0 ± 33.0 months, and the mean follow-up period was 16.4 ± 16.4 months. The mean angle of esotropia was 21.8 ± 7.0 prism diopters (PD) at distance and 22.2 ± 7.9 PD at near. There were eight myopic patients; the other patients were emmetropia. The esotropia of all patients did not improve after refraining from smartphone use. There was no improvement in five patients who were wearing the Fresnel prism for ≥ 4 months. A total of six patients were treated with bilateral medial rectus recession; only one patient remained orthotropic at postoperative 6 months, three patients were undercorrected, and two had a recurrence. CONCLUSIONS: Esotropia persisted after refraining from smartphone use or wearing a Fresnel prism in acute acquired comitant esotropia patients who were smartphone overusers, and the surgical prognosis of these patients was relatively poor.

Validity of Korean Version Reading Speed Application and Measurement of Reading Speed: Pilot Study

PURPOSE: Reading speed is one of the methods used to measure near visual function. Although several versions of reading charts in different languages have been introduced, there is no Korean version of the reading chart yet. Therefore, we investigated the reading speed of normal-sighted Korean people using a recently developed reading speed application for the iPad tablet in Korea. METHODS: Normal-sighted participants without presbyopia were included and a third generation retina display iPad was used to measure reading speed. The iPad screen was set to maximum brightness and the examination was performed at a distance of 40 cm. Reading speeds were recorded twice: one for reading the sentence silently (reading only) and one for reading the sentence out loud (reading & speaking). RESULTS: The test sentences used in the application had 18.9 ± 2.6 letters and 6.5 ± 0.7 words on average. Twenty-five males and seventeen females were included. The average of the reading only speed was 202.3 ± 88.4 words per minute (WPM), and that of the reading & speaking speed was 129.7 ± 25.9 WPM, showing a statistically significant difference (p < 0.001). CONCLUSIONS: This Korean reading chart application is the first self-reporting reading chart in Korean. This chart could present a new standard for measuring both reading only and reading & speaking speeds.