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Concept: Glasses

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Background: Refractive errors (RE) are the most common cause of avoidable visual impairment in children. But benefits of visual aids, which are means for correcting RE, depend on the compliance of visual aids by end users. Aim: To study the compliance of spectacle wear among rural school children in Pune district as part of the sarva siksha abhiyan (education for all scheme) after 6 - 12 months of providing free spectacles. Settings and Design: Cross-sectional follow-up study of rural secondary school children in western India. Materials and Methods: The students were examined by a team of optometrists who collected the demographic details, observed if the child was wearing the spectacles, and performed an ocular examination. The students were asked to give reasons for non-wear in a closed-ended questionnaire. Statistical Analysis: Chi-square test and multiple logistic regression used for data analysis. Results: Of the 2312 students who were dispensed spectacles in 2009, 1018 were re-examined in 2010. 523 students (51.4%) were female, the mean age was 12.1 years 300 (29.5%) were wearing their spectacles, 492 (68.5%) students claimed to have them at home while 211 (29.4%) reported not having them at all. Compliance of spectacle wear was positively associated to the magnitude of refractive error (P < 0.001), father's education (P = 0.016), female sex (P = 0.029) and negatively associated to the visual acuity of the better eye (P < 0.001) and area of residence (P < 0.0001). Of those that were examined and found to be myopic (N = 499), 220 (44%) wore their spectacles to examination. Factors associated with compliance to spectacle usage in the myopic population included increasing refractive error (P < 0.001), worsening visual acuity (P < 0.001), and higher academic performance (P < 0.001). The causes for not wearing spectacles were 'lost spectacles' 67(9.3%), 'broken spectacles' 125 (17.4%), 'forgot spectacles at home' 117 (16.3%), 'uses spectacles sometimes' 109 (15.2%), 'teased about spectacles' 142 (19.8%) and 'do not like the spectacles' 86 (12%). Conclusion: Spectacle compliance was poor amongst school children in rural Pune; many having significant vision loss as a result.

Concepts: Regression analysis, Refraction, Visual acuity, Ophthalmology, Myopia, Refractive error, Visual impairment, Glasses

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The aim was to evaluate the visual performance provided with a contact lens-based pinhole design against a simultaneous vision multifocal contact lens.

Concepts: Cornea, Myopia, Lens, Contact lens, Corrective lens, Book of Optics, Intraocular lens, Glasses

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A cross-sectional study was undertaken in Nakuru, Kenya to assess the prevalence of refractive error and the spectacle coverage in a population aged ≥50 years. Of the 5,010 subjects who were eligible, 4,414 underwent examination (response rate 88.1 %). LogMAR visual acuity was assessed in all participants and refractive error was measured in both eyes using a Topcon auto refractor RM8800. Detailed interviews were undertaken and ownership of spectacles was assessed. Refractive error was responsible for 51.7 % of overall visual impairment (VI), 85.3 % (n = 191) of subjects with mild VI, 42.7 % (n = 152) of subjects with moderate VI, 16.7 % (n = 3) of subjects with severe VI and no cases of blindness. Myopia was more common than hyperopia affecting 59.5 % of those with refractive error compared to 27.4 % for hyperopia. High myopia (<-5.0 DS) was also more common than extreme hyperopia (>+5.0 DS). Of those who needed distance spectacles (spectacle coverage), 25.5 % owned spectacles. In conclusion, the oldest, most poor and least educated are most likely to have no spectacles and they should be specifically targeted when refractive services are put in place.

Concepts: Visual acuity, Ophthalmology, Myopia, Corrective lens, Refractive error, Hyperopia, Visual impairment, Glasses

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PURPOSE: Recent research suggests multizone/dual-focus (DF) lens corrections may aid in controlling the progression of myopia. Recently, such a soft contact lens has become commercially available in Hong Kong (MiSight, CooperVision). The purpose of the current study was to evaluate the visual acceptability of this new lens design. METHODS: In a double-masked, randomized, crossover trial, 24 subjects (aged 18 to 25 years) wore MiSight contact lenses and Proclear Multifocal +2.00 diopters Add D (MF) soft contact lenses. Patient-reported outcomes (0 to 100 scale) and objective measures of visual performance were acquired for best-spectacle distance correction (BC) and with each contact lens after 1 week of daily use at HIHC (high illumination-high contrast) at distance and LILC (low illumination-low contrast) at distance, intermediate, and near. RESULTS: There were no significant differences in HIHC distance acuity between BC and either the DF or MF lens and no difference between the DF and MF lenses. However, when measured under LILC, there were significant mean differences between each study lens and BC viewed at distance and intermediate. The LILC logMAR visual acuity was not significantly different between the DF and MF lenses at any viewing distance. Although average visual quality and ghosting ratings for both DF and MF study lenses were significantly lower than habitual under all conditions, there were no significant differences between the DF and MF lenses (p = 0.448). CONCLUSIONS: Good acuity, similar to that attainable with typical MF lens correction, is attainable with a new contact lens designed to control myopia progression. However, like other contact lenses that contain multiple refractive zones, some decrease in visual performance may be experienced.

Concepts: Visual acuity, Cornea, Myopia, Lens, Contact lens, Contact lenses, Corrective lens, Glasses

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PURPOSE: The aim of this article is to analyze the effect of the base curve on progressive power lens performance by means of the Sheedy scoring technique. We expect to find strong differences on this effect depending on the definition of lens power and on the lens optimization method. METHODS: We have used six different back side progressive lens designs. Three of them have been optimized for improving the power perceived by the user in the actual position of use. The other three have been optimized to provide prescription power when measured with a focimeter or a mapper. We have used exact ray tracing to compute both the user power maps and the focimeter power maps. We have applied the Sheedy method to these maps and analyzed the results. RESULTS: When this scoring technique is run with focimeter power maps, the performance of customized lenses is highly base curve dependent. Instead, classical lens performance is quite stable against base curve changes. On the contrary, if we run the test with user power maps, we find the opposite behavior. CONCLUSIONS: Progressive lens scoring is highly dependent on how the lens has been designed and how the lens is measured. Besides, customization of progressive lenses by real ray tracing guarantees that prescription and design parameters are preserved at the position of use regardless the base curve selected to make the lens.

Concepts: Progressive lens, Corrective lens, Glasses

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To evaluate a method for measuring the cylinder, sphere, and wavefront of progressive addition lenses (PALs) in eyeglass frames.

Concepts: Java, Progressive lens, Corrective lens, Corrective lenses, Glasses

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Myopia is an important public health issue, and high myopia may lead to severe complications if left untreated. Orthokeratology lenses, worn overnight to reshape the cornea, are one of many recent modalities used to slow down the progression of myopia in children. This treatment has been proven successful, as evidenced by decreased spherical refractive error and axial length relative to the control at interval follow-up ranging from 6 months to 5 years. In this systematic review, the authors collected published controlled studies that analyzed the efficacy of orthokeratology lens wear and calculated longitudinal relative changes in axial length, revealing a weighted average of -45.1% change in axial length at the 2-year follow-up. The exact mechanism by which orthokeratology lenses reduce myopia progression is unknown, but research shows that the corneal reshaping decreases peripheral hyperopic defocus and therefore increases peripheral myopic defocus to likely reduce stimuli for axial elongation and subsequent development of myopia. Use of orthokeratology lenses is generally safe, but cases of associated infectious keratitis may have a higher incidence of virulent organisms such as Pseudomonas, Acanthamoeba, and antibacterial-resistant strains of Staphylococcus, partially due to the required overnight use of these lenses. Orthokeratology is regarded as one of the most effective non-pharmacologic measures to slow progression of myopia in children and, with regular follow-up to ensure safety, continues to be one of the most effective treatments for myopia management around the world. [J Pediatr Ophthalmol Strabismus. 201X;XX(X):XX-XX.].

Concepts: Cornea, Myopia, Refractive surgery, Lens, Astigmatism, Orthokeratology, Contact lens, Glasses

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Prevalence of myopia is increasing worldwide. Outdoor activity is one of the most important environmental factors for myopia control. Here we show that violet light (VL, 360-400nm wavelength) suppresses myopia progression. First, we confirmed that VL suppressed the axial length (AL) elongation in the chick myopia model. Expression microarray analyses revealed that myopia suppressive gene EGR1 was upregulated by VL exposure. VL exposure induced significantly higher upregulation of EGR1 in chick chorioretinal tissues than blue light under the same conditions. Next, we conducted clinical research retrospectively to compare the AL elongation among myopic children who wore eyeglasses (VL blocked) and two types of contact lenses (partially VL blocked and VL transmitting). The data showed the VL transmitting contact lenses suppressed myopia progression most. These results suggest that VL is one of the important outdoor environmental factors for myopia control. Since VL is apt to be excluded from our modern society due to the excessive UV protection, VL exposure can be a preventive strategy against myopia progression.

Concepts: Ultraviolet, Light, Myopia, Lens, Orthokeratology, Contact lens, Corrective lens, Glasses

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Previous studies on soft multifocal contact lens myopia control published in the peer-reviewed literature reported findings of noncommercial contact lenses worn for 1 year or less. This study sought to determine the progression of myopia and axial elongation of children fitted with commercially available distance center soft multifocal contact lenses for 2 years.

Concepts: Academic publishing, Cornea, Myopia, Lens, Orthokeratology, Contact lens, Corrective lens, Glasses