Spectacle Prescription Research Articles

Post operative visual outcomes after cataract surgery in a teaching hospital

An uneventful cataract surgery with intraocular lens implant is capable of providing normal vision. Good visual outcome increases patient’s satisfaction and quality of life. Aim is to evaluate the postoperative complications and visual outcomes after manual small incision cataract surgery at a teaching hospital. In this study 100 patients who underwent uneventful SICS with PCIOL implant were followed up. Patients having pre-existing ocular disease were excluded. IOL power was accurately estimated. Visual acuity, anterior segment and fundus findings were recorded at each postoperative visit upto 6 weeks and in some cases upto 3months. We followed the visual outcome standards set by WHO. 53 males and 47 females in the age group of 45 to 75 and above were selected. On 1st post operative day 38% patients had quiet eyes. In 62% patients, decreased vision and complications observed on 1st post operative day and upto 1st week were: Striate keratopathy and corneal edema, anterior uveitis with pupillary membrane, residual lens matter, macular edema, endophthalmitis, intraocular hemorrhage with secondary glaucoma and IOL related causes. On the 6th postoperative week during spectacles prescription, 60% had uncorrected Astigmatism, 5% consecutive myopia/ hypermetropia and 8% had posterior capsular opacity. At 3 months follow up, 92% had good outcome, 3% patients had borderline outcome. 5% poor visual outcome was seen in patients with Bullous keratopathy, endophthalmitis, vitreous hemorrhage and longstanding macular edema.Our hospital based study reports 5% patients with poor visual outcome 3 months after uneventful cataract surgery.

Passive Verification: A Flawed System Putting Patients' Sight at Risk.

To assess the rate of erroneous or expired (invalid) contact lens prescriptions submitted for passive verification at two practice sites in Cleveland, OH. Passive verification facsimile (FAX) requests were collected from office staff at a county hospital (MetroHealth [MH]), and at a private ophthalmology group office (University Ophthalmology Associates [UOA]) in Cleveland, Ohio, from January 2013 to January 2018. A total of 415 verification requests were evaluated (339 MH, 75 UOA), 28.2% (104 MH, 13 UOA) were expired, 11.8% (48 MH, one UOA) were not under the care of the doctor to whom the request was directed, 8.9% (32 MH, 5 UOA) were incorrect, and 3.9% (16 MH, 0 UOA) did not complete fitting. The total rate of invalid prescriptions was 52.8% (200 MH, 19 UOA). There is a high rate of invalid prescriptions presented for passive verification. Although the majority of prescriptions are simply expired, there is a fraction of prescriptions that contain incorrect specification of lens parameters or no record of prescription by that doctor. The current mechanism of passive verification, with the burden on the provider for denial within a short time window, makes it likely that such prescriptions would be filled, potentially putting patient comfort and safety at risk.

Exploring the effect of optometrist practice type on NHS funded sight test outcome

PurposeThe United Kingdom (UK) National Health Service (NHS) currently provides sight tests at no cost to patients for all those aged <16 or ≥60. Some ‘at-risk’ patients and those in receipt of means-tested benefits are eligible for a NHS sight test between the ages of 16 and 60. In the UK, community optometrists typically either work in independent or national chain practices (multiples). The present study aims to explore whether practice type has any association with sight test outcome. As sight tests are essential in detecting early childhood visual problems, we also aim to explore children's first sight tests. MethodData from 664,480 NHS sight test claims submitted in Essex from April 2015 to September 2016 were analysed using regression analysis. Practice type (multiple, independent) and children's first sight test were examined with respect to socio-economic status (SES, based on index of multiple deprivation rankings), age and sight test outcome. ResultsThe median age for a first NHS sight test was 6 years old and was clinically independent of SES. Children's first sight tests typically resulted in neither a spectacle prescription being issued nor an onwards referral. Patients that attend multiples are significantly more likely to receive a new prescription, relative to no prescription, compared to a patient attending an independent (p<.001). ConclusionsInequalities in sight test outcome appear to exist with differing type of practice (independent or multiple). Choice of practice type appears to be influenced by SES. Children have their first sight test at a later age than recommended.

The COVID-19 pandemic: Important considerations for contact lens practitioners

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). As information concerning the COVID-19 disease continues to evolve, patients look to their eye care practitioners for accurate eye health guidance. There is currently no evidence to suggest an increased risk of contracting COVID-19 through contact lens (CL) wear compared to spectacle lens wear and no scientific evidence that wearing standard prescription spectacles provides protection against COVID-19 or other viral transmissions.During the pandemic there will potentially be significant changes in access to local eyecare. Thus, it is imperative CL wearers are reminded of the steps they should follow to minimise their risk of complications, to reduce their need to leave isolation and seek care. Management of adverse events should be retained within optometric systems if possible, to minimise the impact on the wider healthcare service, which will be stretched. Optimal CL care behaviours should be the same as those under normal circumstances, which include appropriate hand washing (thoroughly with soap and water) and drying (with paper towels) before both CL application and removal. Daily CL cleaning and correct case care for reusable CL should be followed according to appropriate guidelines, and CL exposure to water must be avoided. Where the availability of local clinical care is restricted, practitioners could consider advising patients to reduce or eliminate sleeping in their CL (where patients have the appropriate knowledge about correct daily care and access to suitable lens-care products) or consider the option of moving patients to daily disposable lenses (where patients have appropriate lens supplies available). Patients should also avoid touching their face, including their eyes, nose and mouth, with unwashed hands and avoid CL wear altogether if unwell (particularly with any cold or flu-like symptoms).

Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.

Hyperopia in infancy requires accommodative effort to bring images into focus. Prolonged accommodative effort has been associated with an increased risk of strabismus. Strabismus may result in asthenopia and intermittent diplopia, and makes near work tasks difficult to complete. Spectacles to correct hyperopic refractive error is believed to prevent the development of strabismus. To assess the effectiveness of prescription spectacles compared with no intervention for the prevention of strabismus in infants and children with hyperopia. We searched CENTRAL (2018, Issue 12; which contains the Cochrane Eyes and Vision Trials Register); Ovid MEDLINE; Embase.com; three other databases; and two trial registries. We used no date or language restrictions in the electronic search for trials. We last searched the electronic databases on 4 December 2018. We included randomized controlled trials and quasi-randomized trials investigating spectacle intervention or no treatment for children with hyperopia. We required hyperopia to be at least greater than +2.00 diopters (D). We used standard Cochrane methodological procedures. The primary outcome was the proportion of children with manifest strabismus, as defined by study investigators. Other outcomes included the amblyopia, stereoacuity, and the effect of spectacle use of strabismus and visual acuity. We also collected information on change in refractive error as a measurement of the interference of emmetropization. We identified four randomized controlled trials (985 children enrolled who were aged six months to less than 36 months) in this review. Three trials were in the UK with follow-up periods ranging from one to 3.5 years and one in the US with three years' follow-up. Investigators reported both incidence and final status regarding strabismus. Evidence of the incidence of strabismus, measured in 804 children over three to four years in four trials was uncertain although suggestive of a benefit with spectacle use (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.41 to 1.02). We have very low confidence in these results due to high risk of bias, inconsistency, and imprecision. When assessed as the proportion of children with strabismus at the end of three years' follow-up, we found a similar level of evidence for an effect of spectacles on strabismus as reported in one study (RR 1.00, 95% CI 0.31 to 3.25; 106 children). We have very low confidence in these results because of low sample size and risk of bias. One trial reported on the risk for developing amblyopia and inadequate stereoacuity after three years in 106 children. There was unclear evidence for a decreased risk of developing amblyopia (RR 0.78, 95% CI 0.31 to 1.93), and limited evidence for a benefit of spectacles for prevention of inadequate stereoacuity (RR 0.38, 95% CI 0.16 to 0.88). We have very low confidence in these findings due to imprecision and risk of bias. The risk of not developing emmetropization is unclear. One trial reported on the proportion of children not achieving emmetropization at three years' follow-up (RR 0.75, 95% CI 0.18 to 3.19). One trial suggested spectacles impede emmetropization, and one trial reported no difference. These two trials could not be combined because the methods for assessing emmetropization were different. With the high risk of bias and inconsistency, the certainty of evidence for a risk for impeding or benefiting emmetropization is very low. Based on a meta-analysis of four trials (770 children), the risk of having visual acuity worse than 20/30 measured up to three years of age or at the end of three years of follow-up was uncertain for children with spectacle correction compared with those without correction (RR 0.87, 95% CI 0.64 to 1.18; very low confidence due to risk of bias and imprecision). The effect of spectacle correction for prevention of strabismus is still unclear. In addition, the use of spectacle on the risk of visual acuity worse than 20/30, amblyopia,and inadequate emmetropization is also unclear. There may be a benefit on prevention of inadequate stereoacuity. However, these effects may have been chance findings or due to bias.

Value of routine evaluation in asymptomatic soft contact lens wearers

ObjectivesLimited literature supports the value of routine contact lens examinations. The purpose of this study is to document complications diagnosed when subjectively successful planned replacement soft contact lens patients are evaluated to renew their existing contact lens prescriptions. MethodsAsymptomatic soft contact lens patients who presented to the University Eye Center at Ketchum Health (Anaheim, CA) and the Eye and Vision Center at the Massachusetts College of Pharmacy and Health Sciences (Worcester, MA) for routine contact lens comprehensive exams to renew existing contact lens prescriptions were professionally evaluated and their complications documented. All subjects presented without complaint and had a history of subjectively successful planned replacement soft lens wear for at least 1 year. ResultsA total of 202 subjects were recruited from both sites (age range 16–72 years; 76 male, 126 female; spherical contact lens optical power equivalent range: +7.75D to −19.25D). Considering health issues, one hundred and five (52%) patients were found to exhibit at least one undiagnosed complication (95% CI: 0.45-0.59): 70% were diagnosed with contact lens driven ocular complications; 54% were diagnosed with non-contact lens driven ocular health issues; and 4% showed signs of undiagnosed systemic disease. Of note, complication prevalence increases to 72% overall if both contact lens fit issues and contact lens care compliance problems are included as complications in analysis. ConclusionsA striking ocular health and contact lens complication rate in asymptomatic soft contact lens wearers is demonstrated across two different study sites. This data suggests that asymptomatic as well as symptomatic contact lens wearers require routine professional evaluations.

Motivators and deterrents for seeking eye care in a Canadian region

BackgroundMotivators and deterrents for seeking eye care in a Canadian setting were sought using a qualitative study. Provincial deregulation of eyewear dispensing in 2010 allows consumers to order eyewear without an optical prescription, thus eliminating a potential motivator for obtaining an eye examination.MethodsConvenience sampling was used to obtain 25 members of the public who contributed to one of seven focus groups that were facilitated, audiotaped, anonymised and transcribed. Participants completed a demographic questionnaire. Focus group data analysis employed grounded theory and theme saturation determined the number of focus groups.ResultsNine men and 16 women participated, ranging in age from 18 to 71-years (mean 41.5; median 40.0). Three main themes were identified as influencers for seeking eye care: priority; advice; and capacity. Priority served as a motivator (‘lived experience’, ‘symptoms’, and ‘habit’) and deterrent (‘test distress’, ‘asymptomatic’, ‘don't know’ and ‘other priorities’). Advice was a motivator (‘professional’ and ‘family/friends’), while capacity was a motivator (‘insurance’) and deterrent (‘cost’).ConclusionThe motivators and deterrents of seeking eye care in these focus groups were framed by three themes. Key findings not reported previously included the motivators of ‘habit’, ‘advice’ and ‘insurance’ and the potential deterrent of ‘test distress’. These factors should be added to other previously reported motivators and deterrents in further exploration of Canadian eye‐care seeking behaviours. Such knowledge is needed to develop strategies for improving eye‐care literacy in Canada. This is particularly important because eyewear deregulation and/or online eye examinations may encourage members of the public to bypass comprehensive eye care without fully understanding the implications of this decision for their health and wellness.

Prescription AR: a fully-customized prescription-embedded augmented reality display.

In this paper, we present a fully-customized AR display design that considers the user's prescription, interpupillary distance, and taste of fashion. A free-form image combiner embedded inside the prescription lens provides augmented images onto the vision-corrected real world. The optics was optimized for each prescription level, which can reduce the mass production cost while satisfying the user's taste. The foveated optimization method was applied which distributes the pixels in accordance with human visual acuity. Our design can cover myopia, hyperopia, astigmatism, and presbyopia, and allows the eye-contact interaction with privacy protection. A 169g dynamic prototype showed a 40° × 20° virtual image with a 23 cpd resolution at center field and 6 mm × 4 mm eye-box, with the vision-correction and varifocal (0.5-3m) capability.

Using quality improvement strategies to strengthen regional systems for Aboriginal and Torres Strait Islander eye health in the Northern Territory.

In the Katherine region, Northern Territory, barriers to eye care for Aboriginal and Torres Strait Islander people include unclear eye care referral processes, challenges coordinating patient eye care between various providers, complex socioeconomic determinants and a lengthy outpatient ophthalmology waiting list. Mixed methods participatory approach using a regional needs analysis, clinical file audit and stakeholder survey, to develop, implement and monitor quality improvement strategies. Collaboration with Aboriginal Community Controlled Health Services and regional eye care stakeholders in the Katherine region. Clinical audit data captured frequency and rates of primary eye checks, ophthalmology referrals and spectacle prescriptions. A survey was developed and applied to assess stakeholder perspectives of regional eye care systems. Quality improvement strategies informed by regional data (clinical audits and survey) included increasing service delivery to match eye care needs, primary eye care training for Aboriginal Community Controlled Health Services staff, updating Aboriginal Community Controlled Health Services primary care templates and forming a regional eye care coalition group. Post-implementation, rates and frequency of recorded optometry examinations, number of spectacles prescribed and rates of annual dilated fundus examinations for patients with diabetes increased. There was a decrease in the number of patients with diabetes who had never had an eye examination. Eye care stakeholders perceived a marked improvement in the effectiveness of the regional eye care system. Our findings highlight the importance of engaging services and stakeholders to ensure a systems approach that is evidence-informed, contextually appropriate and reflects commitment to improved eye health outcomes.

A review of glycaemic changes on vision in phakic, aphakic and pseudophakic people with diabetes

Background: One of the leading causes of preventable blindness is cataract affecting approximately 18 million people worldwide. Twenty per cent of cataract operations worldwide are performed on people with diabetes mellitus (PDM).Aim: The aim of this review article is to analyse the scientific literature relating to visual changes associated with diabetes mellitus (DM) in pseudophakic, aphakic and phakic people, and to discuss the consequences of these changes for optometrists.Method: A literature search was conducted on PubMed, the University of KwaZulu-Natal Libraries and Google Scholar databases from August 2017 to August 2018.Results: Acute and chronic hyperglycaemia in DM causes myopia in phakic PDM, whilst in aphakic PDM it causes a hyperopic shift in refraction. It has been reported that contrast sensitivity and visual acuity are affected by changes in blood glucose. People with DM have increased central corneal thickness as compared to non-diabetics, whilst only the posterior corneal curvature is affected by hyperglycaemia in PDM. No evidence exists on the effects of glycaemic changes in pseudophakes.Conclusion: It should be noted that high blood glucose level (BGL) induces transient myopia and hyperopia in chronic phakic PDM and aphakic PDM, respectively. All refractive procedures, including prescription of spectacles, corneal refractive procedures and lens extraction, should be deferred until normalisation of BGL in phakic and pseudophakic PDM, as higher sugar levels affect corneal curvature and thickness and overall vision.

Meeting vision needs of children with special educational needs: Case studies of the impact on behaviour and academic achievement

Accessible summary Children with learning disabilities often have problems with their eyesight. We tested the eyes of nine children and checked whether they needed glasses or bigger print. We found that when they got what they needed to see better, their behaviour improved. This is important because children with learning disabilities need to be able to see as well as anyone else. AbstractBackgroundChildren with identified special educational needs are at higher risk than other children of having visual needs that are not adequately met. This paper evaluates the impact of addressing the visual needs of these children on behaviour and academic achievements in a number of case studies.MethodNine children (4–11 years of age, from four classrooms), who attended a special school in a medium‐sized town in the UK, took part in the case studies reported here. The children were part of the Special Education Eyecare (SEE) Project. Six of the children were selected because they had unmet visual needs at baseline and required bespoke interventions to meet these needs; the other three children were selected because their visual needs had been met prior to the study and no further adjustments were needed. Repeated direct observations were conducted to assess the impact of the intervention on the children's behaviour in the classroom. The observer was “blind” with regard to the visual needs of the participants. Parents and teachers completed the Strength and Difficulties Questionnaire (SDQ) for each child, before and after the intervention. School files were analysed to assess effects on academic achievement.FindingsSubsequent to the implementation of bespoke visual adjustments, for example prescription of spectacles or changed seating in classroom, significant and sustained changes were observed with regard to the children's behaviour (i.e., increased engagement with peers and/or teachers and decreased off‐task behaviour). Strength and Difficulties Questionnaire scores showed improvements regarding total difficulties, emotional difficulties, hyperactivity and prosocial (kind and helpful) behaviour. Due to highly variable data in school files, the effects on academic achievement were inconclusive.DiscussionThe case studies reported here explored changes in behaviour of children with identified special educational needs after their visual needs were met. Findings show a positive overall effect on the behaviour of these children.

Multimodal imaging in non-syndromic microphthalmia: a case series

Microphthalmia is a rare congenital or developmental anomaly in which the globe is abnormally small. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. We aimed to describe the clinical and paraclinical features of nonsyndromic microphthalmia through three cases. The first patient was an 8-year-old female child who presented with bilateral refractive accommodative esotropia due to hypermetropia. She was diagnosed with bilateral posterior microphthalmia qualified as non-syndromic and simple. Eyeglasses prescription has been upgraded and a 6-month clinical monitoring has been undertaken. The second case was about a 16-year-old female patient who had a bilateral amblyopia due to a non-syndromic microphthalmia. She presented with unilateral high intra-ocular pressure. Anterior Segment OCT showed unilateral narrow angle with iridotrabecular contact in the right eye. Microphtalmia has been qualified as complex in the right eye and simple in the left eye. The patient has been put under IOP-lowering topical medication for the OD and peripheral YAG laser iridotomy has been performed. IOP reduction was noticed within five days. The third case was a 7-year-old male child with bilateral non-syndromic complex nanophthalmia. Ophthalmic examination revealed bilateral microcornea and OCT of the macula showed bilateral retinal folds with apical surface corrugations. Optical correction and active surveillance were adopted. Non-syndromic microphthalmia is a rare and potentially blinding disease. We highlighted the interest of ocular ultrasound, especially in young hypermetropic children completed by an examination in OCT. Non-invasive, objective and repeatable, OCT seems to be of great interest in both the diagnosis and the monitoring of microphthalmia.

Low Vision Assessment: Complications from Juvenile Rhumethoid Arthritis

Background: Juvenile Rheumatoid Arthritis (JRA) is an inflammatory disease that affects the joints of children and is associated with ocular complications, like uveitis and cataract. Patients with such complications can benefit from a low vision assessment to improve their functionality and their quality of life. In this case study, the importance of early detection and management of ocular complications of JRA, as well as visual rehabilitation through a low vision assessment, are highlighted and discussed. Case Presentation: A 12-year-old female of East Indian descent presented to the Low Vision Center of the University of the West Indies Optometry Eye Unit, bilaterally aphakic (absence of crystalline lens) as a result of complications she developed secondary to a systemic condition diagnosed as JRA. She presented with a distance visual acuity of 2.30 logMAR in the RE, and 1.64 logMAR in the LE, at near she was able to read 8.0 M and 3.2 M at a distance of 8 cm for RE & LE respectively. She has a history of ocular disorder secondary to JRA such as cataract, uveitis, upon low vision assessment a new spectacle prescription and an illuminated stand magnifier of 8D was issued, the patient was satisfied with the outcome of the treatment, management and low vision device issued. Conclusion: At the end of the low vision assessment, the patient was extremely satisfied and looked forward to the prospect of returning to school. Although JRA can have severe ocular complications, with the correct management, a patient’s quality of life can be dramatically improved thus stressing the importance of these types of visual assessments.

Percepción de la rehabilitación visual: Una mirada desde las personas con baja visión

Introducción: la baja visión es una categoría de discapacidad visual que requiere un proceso de rehabilitación para maximizar la función visual y permitir a la persona desarrollar habilidades compensatorias para mejorar su funcionalidad. Objetivo: describir las percepciones de las personas con baja visión que recibieron servicios de rehabilitación funcional visual en dos centros de atención, frente al aporte de los servicios y barreras identificadas en el proceso. Metodología: Estudio cualitativo de tipo exploratorio. Se realizaron 14 entrevistas semiestructuradas a personas que realizaron su rehabilitación visual en dos centros de atención: Uno en Bogotá con un proceso de atención interdisciplinario y otro en Bucaramanga con un proceso de atención de menor interdisciplinariedad. El análisis siguió el proceso de descubrimiento, codificación y relativización de los datos. Resultados: Las personas que asistieron al centro de menor interdisciplinariedad, reconocieron el aporte de la rehabilitación para el desarrollo de actividades cotidianas básicas e instrumentales. Quienes asistieron al centro de mayor interdisciplinariedad destacaron los aportes de psicología, orientación y movilidad, y trabajo social como fundamentales. Pese a lo anterior, en las dos ciudades persisten barreras: dificultades para adquirir ayudas ópticas, de movilidad, arquitectónicas y para la inclusión laboral. Discusión: Se evidencia la necesidad de garantizar una rehabilitación funcional interdisciplinaria que contemple intervenciones adicionales a la prescripción de ayudas ópticas. Conclusiones: Los servicios interdisciplinarios obtienen mejores resultados en cuanto a las transformaciones que logran las personas en: aceptación de la condición de baja visión, movilidad, acceso a tecnología, y reconocimiento de derechos.

Refractive status during pregnancy in the United States: results from NHANES 2005-2008.

Anecdotal reports of refractive changes in pregnancy are familiar to optometrists and ophthalmologists. Refractive stability during pregnancy has implications in both prescribing of refractive correction and candidacy for refractive surgery. This study aims to examine refractive status in a nationally representative sample of US pregnant women. The National Health and Nutrition Examination Survey (NHANES) is a weighted, stratified, cross-sectional survey of the US population conducted every 2 years. During 2005-2006 and 2007-2008, the exam included multiple ophthalmic tests including refraction, keratometry, and lensometry. Female participants aged 20-44years with available vision examination data were included in the study. Subjects were excluded if best obtainable visual acuity was worse than 20/40 or there was prior history of cataract or refractive surgery. The primary outcome was defined as refractive change stratified by trimester of pregnancy. 301 pregnant women were matched with 301 nonpregnant controls based on age, ethnicity, and education. There was no difference in refractive error between pregnant women and matched nonpregnant controls (all p > 0.99). For the refractive change analysis, a subgroup of 60 pregnant subjects with glasses at presentation was matched to 60 nonpregnant controls. Multivariate regression showed a significant increase in refractive change versus prior to glasses prescription by trimester of pregnancy (p = 0.02), though this change was not in a specific direction (i.e., no significant shift toward either myopia or hyperopia). Pregnant women have greater refractive difference from prior spectacle prescription later in pregnancy, but the direction of this change is variable and not significant. This finding may reflect a longer time to last glasses prescription later in pregnancy, given concerns that refractive error fluctuates in pregnancy. Additional longitudinal studies are needed to better characterize the effects of pregnancy on refractive status.

Non-contact characterization of compound optical elements using reflectance confocal microscopy, low-coherence interferometry, and computational ray-tracing

Advances in microscopy have enabled us to see at unprecedented depths and resolutions, even breaking the diffraction-limit by several fold. These improvements have come at the expense of system complexity with microscopes routinely employing multiple objective lenses and custom optical relays. Optimal system design is paramount for imaging performance, but research systems are limited by the use of commercial components because optical prescriptions are often inaccessible. System performance can be further degraded when these components are implemented in nonstandard configurations outside of manufacturer specifications. Here, we describe a method for characterization of compound optical elements including curvatures, material and air-gap thicknesses, and glass types. We present validation data for doublets and a commercial broadband scan lens. Our method is both non-contact and non-destructive, and we believe it addresses a unique gap in optical design that may be extended to broad applications in both research and industrial manufacturing.

Factors Affecting the Difference in Refractive Error According to Pupil Size in Myopia

Purpose : In this study, we investigated the factors that influence the difference in refractive error according to pupil size. Methods : The subjects were 75 eyes(75 adults) of 18 to 58 years of age with myopia and no history of eye disease or surgery except cataract and a best-corrected visual acuity(BCVA) of 1.0 or higher. The i.profilerplus(Zeiss, Germany) was used to obtain the manifest refraction(MR) and corneal and ocular aberration in the 5 mm and 3 mm area of the pupil in the half dark room(5~50 lx). To compare the measured values according to pupil size paired t-test was used. The Spearman correlation test was used to examine the correlation between the difference in spherical equivalent(SE) depending on pupil size and high order aberration. Multiple regression analysis was performed to evaluate the factors affecting the difference in refractive error according to pupil size Results : The mean SE were –4.08±2.90 D and -3.84±2.95 D at 5 mm and 3 mm, respectively (p<0.001). There was a negative correlation between the difference in SE depending on pupil size and ocular higher-order aberration (r=-0.676, p<0.001). After adjusting age and sex, spherical aberration(Z40) and vertical astigmatism(Z4-2) were found to affect the difference in SE depending on pupil size. Conclusion : The interaction of low and high aberrations can cause the differences in mean SE. Therefore, in order to increase satisfaction when wearing glasses, the spectacles prescription considering the high order aberration should be calculated.

국내 안경사를 대상으로 한 멀티포컬 콘택트렌즈 처방 및 피팅 상태 평가 실태 조사

국내 안경사를 대상으로 한 멀티포컬 콘택트렌즈 처방 및 피팅 상태 평가 실태 조사

Comparison of endpoint of subjective cycloplegic refraction with artificial aperture and post-mydriatic test among adults with refractive error.

PURPOSE:There is a need to understand the requirement for the post-mydriatic test (PMT) among adults for the final prescription of spectacles as this test increases the cost of eye care and causes inconvenience to the patient because of the additional visit to an eye care practitioner. We aim to compare the cycloplegic subjective refraction using apertures of various sizes and PMT in an adult population.METHODS:This prospective crossover study was conducted under standard settings in an eye clinic. Adult individuals between 18 and 35 years of with emmetropia and various degrees of ametropia participated in this study. Individuals with known ocular pathology were excluded. Non-cycloplegic objective refraction was performed followed by subjective refraction. Cycloplegic objective refraction was performed followed by subjective refraction with custom designed artificial apertures. After a washout period of cycloplegic, PMT was performed. The distribution of data was tested using the Kolmogorov–Smirnov test. Depending on the distribution of the data, either parametric or nonparametric test was done.RESULTS:Fifty-nine eyes of thirty individuals with a mean (±SD) age of 23(±4) years with a male: female ratio of 1:4 participated in this study. A comparison of measures of PMT and subjective refraction with 2, 3, 4, 5, and 6 mm aperture under cycloplegic effect using the Friedman test rendered a Chi square value (df = 5) of 1.92 which was not statistically different (P = 0.86).CONCLUSION:Performing subjective refraction with an appropriate spherical and cylindrical endpoint under cycloplegic effect with appropriate aperture overcomes the necessity of PMT.

Dioptres for a myopic eye from a photo

This paper is inspired from a scene in the movie Memento (2000), where the eyeglass prescription for a myopic eye can be estimated since the virtual image of a distant wall seen through the lens and a nearby actor outside the view of the lens are located at the same distance. The estimate illustrates that there are times when the power of physics allows one to arrive at a sophisticated measured result with no equipment. This fascinating example also provides for a nice interdisciplinary connection between physics and medical optics. Due to copyright restrictions on incorporating a movie in class, teachers may use the author’s photo and video included here or have their students make similar media with their smartphones.