Research on Ocular Fatigability Induced by Multimedia and Instrument Features

PURPOSE: The aim of the present study was to evaluate the different features of such instruments and how they cause ocular fatigability. METHODS: Under the same settings and circumstances, 75 participants were asked to read the novel, "You without me?" in different formats including paper book, E-book (biscuit(R), Interpark Inc., LG INNOTECK LTD, Korea) and LCD reader (iPad(R), Apple Inc., United States). For every 10 minutes of reading, 10 minutes of rest was provided. After finishing the novel, the participants were asked to complete a questionnaire, and the data obtained were statistically analyzed using univariate analysis. RESULTS: Compared to paper book readers (1.93), LCD readers (2.40) complained of insufficient lubrication in the eye (p = 0.038), and experience more letter-floating illusions (1.92) than did paper book readers (1.49) (p = 0.043). Moreover, compared to the other formats including the E-book (20%) and paper book (8%), LCD readers (72%) experienced more significant glare symptoms (n = 23) and could read at a faster rate than the other groups of readers (n = 26). CONCLUSIONS: In the present study, the I-Pad caused ocular fatigability more easily than the other formats examined. No statistical significance of ocular discomfort or fatigability was observed among the different format groups. Further investigation with a greater number of age-controlled participants should be conducted prior to designing a study to determine the best format for reading.

Attempts to Reduce the Progression of Myopia and Spectacle Prescriptions during Childhood: A Survey of Eye Specialists

PURPOSE: To determine methods tried in clinical trials to reduce the progression of myopia in children, and spectacle prescribing patterns of hospital ophthalmologists. METHODS: A multi-sectioned survey composed of Likert items relating to the methods of reducing myopia progression (orthokeratology lenses [O-K lenses], undercorrected glasses, and topical atropine) and the patterns of prescribing spectacles for children (including two cases involving a 5-year-old girl and an 8-year-old boy) were distributed to members of the Korean Ophthalmological Society, and the collected data was statistically analyzed. RESULTS: A total of 78 out of 130 ophthalmologists returned the survey. On a scale of 1 to 5, the mean rates of whether the ophthalmologists think O-K lenses arrest myopia progression, and whether they recommend their patients to wear O-K lenses if indicative, were 3.06 and 2.75, respectively. Moreover, the mean rates of whether they consider that wearing glasses which are undercorrected would slow down the progression of the myopia, or if they think topical atropine helps in arresting myopia progression in children, were 2.34 and 1.27, respectively. In response to the case studies, the majority of practitioners preferred to prescribe the full amount found in cycloplegic refraction to pediatric patients with myopia. CONCLUSIONS: Ophthalmologists in clinical practice encouraged children to wear O-K lenses more than undercorrected glasses as a way to retard myopia progression. However, the application of atropine is rarely tried in clinical trials. In managing pediatric patients with myopia (case specific), the majority of the practitioners chose to prescribe glasses with full cycloplegic correction.

The Relationship between the OCT Parameters and Visual Acuity after Occlusion Therapy in Hyperopic Anisometropic Amblyopia

PURPOSE: We measured the macular and peripapillary retinal nerve fiber layer (RNFL) thickness in patients with hyperopic anisometropic amblyopia using optical coherence tomography (OCT) to determine the relationship between final visual acuity after occlusion therapy and these OCT parameters. METHODS: This prospective study comprised 41 patients with unilateral hyperopic anisometropic amblyopia treated from April 2004 to August 2005. According to the final visual acuity after occlusion therapy, we divided our patients into two groups and compared the macular and peripapillary RNFL thicknesses between normal and amblyopic eyes. RESULTS: The mean refractive error was +4.3 diopters (D) in amblyopic eyes, and +1.3 D in normal eyes. The mean macular thickness of group A (patients with final visual acuity equal to or better than 20/25) and group B (patients with final visual acuity worse than 20/25) was 256.8+/-17.7 micrometer and 259.3+/-14.5 micrometer in amblyopic eyes, and 253.8+/-17.3 micrometer and 254.6+/-16.7 micrometer in normal eyes respectively. The mean peripapillary RNFL thickness of group A and group B was 118.6+/-12.9 micrometer and 111.5+/-9.0 micrometer in amblyopic eyes, and 112.9+/-9.2 micrometer and 108.3+/-6.5 micrometer in normal eyes respectively. In group A, there was a significant difference in peripapillary RNFL thickness between amblyopic and normal eyes (P=0.0003, 0.04). However, the RNFLestimated integral of both groups after correction of refractive error and axial length showed no significant difference (P=0.34, 0.45). CONCLUSIONS: There was no significant relationship between OCT parameters and final visual acuity after occlusion therapy in hyperopic anisometropic amblyopia.

Comparison of Autorefraction and Clinical Refraction with or without in Children

PURPOSE: The difference in the values between autorefraction and clinical refraction with or without cycloplegia in children were analyzed as a function of age. METHODS: One hundred and twenty five children (230 eyes) with myopia or hyperopia were classified into three age groups. Their ages ranged from 2 to 14. They were examined with a Cannon RK-5 autorefractor, and experienced personnel the clinical refraction before and after cycloplegia. Discrepancies beyond 0.5 diopter in spherical equivalent, spherical and cylinder power were regarded as being significant and the discrepancy rates (%) were calculated. The mean absolute differences in the values of each refractive component in myopia and hyperopia were also compared separately according to. RESULTS: All the differences by cycloplegia were significantly smaller in the myopia patients over 5 years old. However, only the discrepancy rates of the spherical equivalent and the sphere component between the clinical manifest refraction and the cycloplegic refraction were significantly smaller in the higher age groups. The comparisons between the clinical and autorefraction revealed significant difference between the age groups only in those with myopia with cycloplegia. CONCLUSIONS: There were differences between the cycloplegic refraction and non-cycloplegic refraction values particularly in myopia patients under five years old and in all hyperopic patients. Autorefraction showed differences from the clinical refraction in both myopia and hyperopia regardless of their ages particularly in those without cycloplegia. Therefore, autorefraction and clinical refraction should be used with caution in children.