Correction of refractive error in the Victorian population: the feasibility of "off the shelf" spectacles (original) (raw)
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A randomized clinical trial to evaluate ready-made spectacles in an adult population in India
International Journal of Epidemiology, 2010
Background Ready-made spectacles (RMS) have advantages; however, visual performance and satisfaction has not been evaluated. Methods A 1-month, double-masked, randomized clinical trial comparing planned continued use and visual performance of RMS to Custom Spectacles (CS) in adults aged 18-45 years with 51 diopter (D) of uncorrected refractive error (URE). Results A total of 373 of 400 participants (93%) completed; mean age was 30 AE 9 years, and 58% were female. Average URE was 2.21 AE 1.31D and habitual vision was 0.58 AE 0.21 logMAR (logarithm of Minimum Angle of Resolution, 20/63 þ1 Snellen acuity). Ten participants with habitual vision better than 20/40 were excluded (3%). A lower proportion in the RMS group intended to continue to wear the study spectacles after 1 month (165/183, 90% vs 174/180, 97%, P ¼ 0.02). Spectacle vision in the eye with lower URE was 0.08 AE 0.15 vs 0.02 AE 0.08, P < 0.0001 and higher URE was 0.12 AE 0.18 vs 0.02 AE 0.08, P < 0.0001 (logMAR) for RMS and CS. Subgroup analyses excluding participants with astigmatism 52.00D and anisometropia 51.00D (74/363, 20%) found no difference in planned continued use (139/143, 97% vs 141/146, 97%, P ¼ 1.0) for RMS vs CS. Conclusions While vision is slightly better with CS, 90% of an adult population with URE planned to continue to use their RMS at 1 month. Furthermore, if those without high astigmatism or anisometropia are excluded, virtually all are satisfied with RMS and there is no difference when compared with CS. The findings of this study support the use of RMS for the delivery of refractive services in settings where there is a high level of need, limited resources and low access to refractive services.
Uncorrected refractive errors and spectacle utilisation rate in Tehran: the unmet need
British journal of …, 2006
AimTo determine the prevalence of the met and unmet need for spectacles and their associated factors in the population of Tehran.Methods6497 Tehran citizens were enrolled through random cluster sampling and were invited to a clinic for an interview and ophthalmic examination. 4354 (70.3%) participated in the survey, and refraction measurement results of 4353 people aged 5 years and over are presented. The unmet need for spectacles was defined as the proportion of people who did not use spectacles despite a correctable visual acuity of worse than 20/40 in the better eye.ResultsThe need for spectacles in the studied population, standardised for age and sex, was 14.1% (95% confidence interval (CI), 12.8% to 15.4%). This need was met with appropriate spectacles in 416 people (9.3% of the total sample), while it was unmet in 230 people, representing 4.8% of the total sample population (95% CI, 4.1% to 5.4%). The spectacle coverage rate (met need/(met need + unmet need)) was 66.0%. Multivariate logistic regression showed that variables of age, education, and type of refractive error were associated with lack of spectacle correction. There was an increase in the unmet need with older age, lesser education, and myopia.ConclusionThis survey determined the met and unmet need for spectacles in a Tehran population. It also identified high risk groups with uncorrected refractive errors to guide intervention programmes for the society. While the study showed the unmet need for spectacles and its determinants, more extensive studies towards the causes of unmet need are recommended.
The Compliance of Ready-Made Spectacle-Wear and Custom-Spectacle-Wear in Refractive Errors Screening
2021
Background: Uncorrected refractive errors that could seriously affect children’s future. The compliance of spectacle-wear has been a problem in refractive errors management in developing countries in terms of the cost, availability and service range of both medical professionals and optical service. Aim: To study the compliance inferiority of ready-made spectacle-wear compared to custom spectacle-wear in refractive errors screening program.Method: Non-inferiority trial research, cluster-randomized trial was conducted to children aged 11-15 years old. Participants with corrected refractive errors (presenting visual acuity <6/12, spherical equivalent -6.00 until +6.00 Diopter (D), astigmatism ?1.00 D, anisometropic ?1.00 D) without other ocular abnormalities were given ready-made spectacles (RMS) and custom spectacles (CS). The observation was carried out in the first (1st) and third (3rd) month; subsequently, non-inferiority test was conducted with 20% margin. Result: Of 1009 scho...
To determine the prevalence of refractive error (RE) and spectacle wear and to explore the need for spectacle correction in adults (30 years or older) in Pakistan. Methods: Multi-stage, cluster random sampling national survey. Each subject had their medical history taken, visual acuity measured, and underwent autorefraction, biometry and fundus examination. Those that presented with visual acuity of less than 6/12 in either eye underwent more detailed examination, including corrected distance visual acuity measurement (autorefraction results placed in a trial lens frame). Myopia was defined as a spherical equivalent of worse than -0.5D, hypermetropia as greater than +0.5D, and astigmatism as greater than 0.75D. Spectacle need (i.e., those that improved from unaided VA with spectacle correction) was determined along with the spectacle coverage, defined as the proportion of need that was met (by the participant's own spectacles). Results: The crude prevalence of myopia, hypermetropia and astigmatism was 36.5%, 27.1%, and 37%, respectively. The prevalence of spectacle wear in phakic participants was 4.0%, significantly lower than for those who were pseudo/aphakic (41.7%). Just over a quarter (25.8%) of spectacle wearers presenting with visual impairment (<6/12) were able to improve their vision when retested with their autorefraction prescription. The overall spectacle coverage (6/12 cutoff) was 15.1%. Conclusions: This survey provides the first reliable national estimates. RE services are not covering the majority of the population in need and the provision of spectacle correction, as a highly cost effective treatment for visual impairment, needs addressing within the country's national eye care program.
Self-adjustable glasses in the developing world
Clinical Ophthalmology, 2014
Uncorrected refractive errors are the single largest cause of visual impairment globally. Refractive errors are an avoidable cause of visual impairment that are easily correctable. Provision of spectacles is a cost-effective measure. Unfortunately, this simple solution becomes a public health challenge in low-and middle-income countries because of the paucity of human resources for refraction and optical services, lack of access to refraction services in rural areas, and the cost of spectacles. Low-cost approaches to provide affordable glasses in developing countries are critical. A number of approaches has been tried to surmount the challenge, including ready-made spectacles, the use of focometers and self-adjustable glasses, among other modalities. Recently, self-adjustable spectacles have been validated in studies in both children and adults in developed and developing countries. A high degree of agreement between self-adjustable spectacles and cycloplegic subjective refraction has been reported. Self-refraction has also been found to be less prone to accommodative inaccuracy compared with non-cycloplegic autorefraction. The benefits of self-adjusted spectacles include: the potential for correction of both distance and near vision, applicability for all ages, the empowerment of lay workers, the increased participation of clients, augmented awareness of the mechanism of refraction, reduced costs of optical and refraction units in low-resource settings, and a relative reduction in costs for refraction services. Concerns requiring attention include a need for the improved cosmetic appearance of the currently available self-adjustable spectacles, an increased range of correction (currently -6 to +6 diopters), compliance with international standards, quality and affordability, and the likely impact on health systems. Self-adjustable spectacles show poor agreement with conventional refraction methods for high myopia and are unable to correct astigmatism. A limitation of the fluid-filled adjustable spectacles (AdSpecs, Adaptive Eyecare Ltd, Oxford, UK) is that once the spectacles are self-adjusted and the power fixed, they become unalterable, just like conventional spectacles. Therefore, they will need to be changed as refractive power changes over time. Current costs of adjustable spectacles are high in developing countries and therefore not affordable to a large segment of the population. Self-adjustable spectacles have potential for "upscaling" if some of the concerns raised are addressed satisfactorily.
Can Information on the Purpose of Spectacle Use and Age at First Use Predict Refractive Error Type?
Ophthalmic Epidemiology, 2007
Purpose: To assess the sensitivity and specificity of predicting refractive error type using information from a four-item questionnaire on the purpose of spectacle use and age at first use. Methods: The Sydney Myopia Study examined 1,740 year 1 (78.9% response) and 2,353 year 7 students (75.3% response) from a random cluster sample of 34 primary and 21 secondary schools across Sydney. Parents of participants completed a four-item questionnaire that sought data on parental spectacle use, age at first use, and purpose of use (for clear distant vision, close work, or both). Prescriptions were obtained for 720 of 3,209 (22%) parents (73% of those approached) for validation. A receiver operating characteristic (ROC) curve was used to determine the optimal cutoff age for spectacle use in myopia classification. Results: Using the ROC curve, a cutoff age of 30 years at first spectacle use produced the highest accuracy in determining myopia. We combined information on the purpose for using spectacles (for distant and near vision) and age of first use at 30 years or younger to determine myopia, otherwise hyperopia. Validated against prescriptions, the sensitivity and specificity of these predictions were 0.89 and 0.83, respectively, for myopia. The specificity was 0.92 for hyperopia and 0.80 for astigmatism, though corresponding sensitivities were lower at 0.23 and 0.46, respectively. Conclusions: In a sample of the parents of Sydney Myopia Study participants, information on the purpose of spectacle use with an age-at-first-use criterion can identify myopic refractive error with reasonable sensitivity and specificity. This four-item questionnaire may assist future epidemiological studies of screening for myopia.
Correction of Refractive Error in the Adult Population of Bangladesh: Meeting the Unmet Need
Investigative Ophthalmology & Visual Science, 2004
PURPOSE. To assess the extent of uncorrected refractive error and associated factors in Bangladesh and to suggest ways in which this need can be met. METHODS. A nationally representative sample of 12,782 adults (Ն30 years of age) was selected. Of them, 11,624 subjects underwent a demographic interview, visual acuity (logarithm of the minimum angle of resolution [logMAR]) measurement, automated refraction, and optic disc examination. Subjects with visual acuity less than 6/12 in either eye also had a corrected refraction measurement, cataract grading, and dilated retinal examination. RESULTS. Of the 11,624 subjects examined, 2,469 (22.1%) were myopes (less than Ϫ0.5 D) and 2,308 (20.6%) hyperopes (more than ϩ0.5 D). The spectacle coverage percentage, calculated as [met need/(met need ϩ unmet need) ϫ 100%] was 25.2% and 40.5%, using 6/12 and 6/18 visual acuity cutoffs, respectively, and was higher in men and urban inhabitants. Older subjects and the literate and more highly educated were more likely to wear spectacles; however, most spectacle wearers (81%) had inadequate correction. Of the 1142 subjects who would benefit from spectacles, 827 (72.4%) would be suitable for off-the-shelf spectacles. Subjects without spectacles with less than 6/12 in the better eye (n ϭ 835), would achieve 6/12 or better with correction (unmet need). Extrapolation to the national population yields an estimate that 1.5 million (6.7%) adult men and 1.8 million (9.2%) women have an unmet need for refractive correction. CONCLUSIONS. In Bangladesh, there is low spectacle coverage with a large unmet need. This survey identified risk groups, in particular women and those living in rural areas. This description of the availability of refractive services suggests areas for improvement (e.g., off-the-shelf spectacles) that may enable Bangladesh to achieve the goals of the