Optometry and vision science : official publication of the American Academy of Optometry
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: The purpose of the study was to monitor the efficacy of corneal refractive therapy (CRT) lenses to reduce myopia over a 4-week period. Refractive error, keratometry, high and low contrast acuity, and subjective vision after 28 days of using CRT contact lenses were measured. ⋯ : CRT lenses significantly reduced myopia, improved visual acuity and subjective vision, and flattened central corneal curvature. Maximal effect was achieved after 10 days and was maintained for the rest of the study period.
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Comparative Study
The development of a symptom questionnaire for assessing virtual reality viewing using a head-mounted display.
Virtual reality devices, including virtual reality head-mounted displays, are becoming increasingly accessible to the general public as technological advances lead to reduced costs. However, there are numerous reports that adverse effects such as ocular discomfort and headache are associated with these devices. To investigate these adverse effects, questionnaires that have been specifically designed for other purposes such as investigating motion sickness have often been used. The primary purpose of this study was to develop a standard questionnaire for use in investigating symptoms that result from virtual reality viewing. In addition, symptom duration and whether priming subjects elevates symptom ratings were also investigated. ⋯ Symptom questionnaires to investigate virtual reality viewing can be administered before viewing, without biasing the findings, allowing calculation of the amount of change from pre- to postviewing. However, symptoms dissipate rapidly and assessment of symptoms needs to occur in the first 5 min postviewing. Thirteen symptom questions, eight nonocular and five ocular, were determined to be useful for a questionnaire specifically related to virtual reality viewing using a head-mounted display.
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Innovations in contact lens materials and designs allow patients to wear contact lenses during sleep to flatten the cornea and temporarily to reduce myopic refractive error and improve unaided visual acuity. We conducted the Children's Overnight Orthokeratology Investigation (COOKI) pilot study, a case series, to describe the refractive error and visual changes, as well as the slitlamp observations associated with overnight orthokeratology in children, over a period of 6 months. ⋯ Overnight cornea-reshaping contact lenses are efficacious for young myopic patients, and no children experienced a serious adverse event during the study.
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Comparative Study
Interexaminer difference and the effect of training on the phenol red thread test results in Hong Kong-Chinese.
This study evaluated interexaminer agreement in the measurement of tear volume using the phenol red thread (PRT) test on Hong Kong-Chinese subjects. The effect of an intensive training session on interexaminer agreement was also investigated. ⋯ Our results suggest that the interexaminer agreement of PRT results is influenced by both examiner- and training-specific factors. Intensive training is important for ensuring the highest consistency among examiners. The moderate interexaminer agreement suggests that clinicians should seek a substantial difference in tear volume when making decisions regarding interventions for their Hong Kong-Chinese patients.