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1.
Cochrane Database Syst Rev ; 4: CD007738, 2020 04 02.
Article in English | MEDLINE | ID: mdl-32240551

ABSTRACT

BACKGROUND: 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. OBJECTIVES: To assess the effectiveness of prescription spectacles compared with no intervention for the prevention of strabismus in infants and children with hyperopia. SEARCH METHODS: 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. SELECTION CRITERIA: 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). DATA COLLECTION AND ANALYSIS: 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. MAIN RESULTS: 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). AUTHORS' CONCLUSIONS: 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.


Subject(s)
Eyeglasses , Hyperopia/rehabilitation , Strabismus/prevention & control , Watchful Waiting , Age Factors , Amblyopia/epidemiology , Bias , Child, Preschool , Emmetropia , Humans , Hyperopia/complications , Incidence , Infant , Randomized Controlled Trials as Topic , Sample Size , Strabismus/epidemiology , Strabismus/etiology , Treatment Outcome , Vision Disorders/etiology , Visual Acuity
2.
J Cataract Refract Surg ; 46(3): 485-490, 2020 03.
Article in English | MEDLINE | ID: mdl-32142045

ABSTRACT

A 31-year-old woman was seen at our clinic with dissatisfying hyperopic error after a myopic laser treatment of her left eye in April 2018. The surgery took place 1 year previously. There were no abnormalities in her medical history.The preoperative corrected distance visual acuity (CDVA) in the left eye was 20/16 with -7.50 -0.50 × 75. The refraction in the right eye was -3.50 -1.25 × 90. The cycloplegic correction of the left eye preoperatively was -6.50 -0.50 × 68. A femtosecond-assisted laser in situ keratomileusis procedure was performed with an optical zone of 6.3 mm, an ablation zone of 7.97 mm, and a maximum ablation depth of 121 µm. The laser was set at a correction of -7.50 -0.5 × 75. The temperature and humidity during the laser treatment were 20 degrees and 47%, respectively. shows the excimer laser treatment data (AMARIS 750, SCHWIND eye-tech-solutions).At 1 week postoperatively the uncorrected distance visual acuity (UDVA) was 20/25, and at 1 month postoperatively the CDVA was 20/16 with +2.50. Slitlamp examination showed a clear cornea. No corneal topography was made at that timepoint. At referral 7 months later, the patient's UDVA was 20/100 and CDVA was 20/16 with +2.50 -1.25 × 140 in the left eye. The patient reports decreased vision since the treatment in 2018 and wants to see better without spectacles. shows the postoperative Scheimpflug topography of the left eye, flat keratometry (K1) 36.1 @ 178.4 and steep keratometry (K2) 36.6 @ 88.4. What do you believe could be the cause of this overcorrection? What is your advice in terms of correction of the refractive error for this patient?


Subject(s)
Hyperopia/etiology , Keratomileusis, Laser In Situ/adverse effects , Lasers, Excimer/adverse effects , Myopia/surgery , Adult , Corneal Topography , Female , Humans , Hyperopia/diagnosis , Hyperopia/rehabilitation , Ophthalmologic Surgical Procedures , Refraction, Ocular/physiology , Visual Acuity/physiology
3.
Ophthalmology ; 125(2): 169-178, 2018 02.
Article in English | MEDLINE | ID: mdl-28951074

ABSTRACT

PURPOSE: To compare the accuracy of intraocular lens (IOL) calculation formulas (Barrett Universal II, Haigis, Hoffer Q, Holladay 1, Holladay 2, Olsen, and SRK/T) in the prediction of postoperative refraction using a single optical biometry device. DESIGN: Retrospective consecutive case series. PARTICIPANTS: A total of 13 301 cataract operations with an AcrySof SN60WF implant and 5200 operations with a SA60AT implant (Alcon Laboratories, Inc., Fort Worth, TX). METHODS: All patients undergoing cataract surgery between July 1, 2014, and December 31, 2015, with Lenstar 900 optical biometry were eligible. A single eye per patient was included in the final analysis, resulting in a total of 18 501 cases. We compared the performance of each formula with respect to the error in predicted spherical equivalent and evaluated the effect of applying the Wang-Koch (WK) adjustment for eyes with axial length >25.0 mm on 4 of the formulas. RESULTS: For the SN60WF, the standard deviation of the prediction error, in order of lowest to highest, was the Barrett Universal II (0.404), Olsen (0.424), Haigis (0.437), Holladay 2 (0.450), Holladay 1 (0.453), SRK/T (0.463), and Hoffer Q (0.473), and the results for the SA60AT were similar. The Barrett formula was significantly better than the other formulas in postoperative refraction prediction (P < 0.01) for both IOL types. Application of the WK axial length modification generally resulted in a shift from hyperopic to myopic outcomes in long eyes. CONCLUSIONS: Overall, the Barrett Universal II formula had the lowest prediction error for the 2 IOL models studied.


Subject(s)
Biometry/methods , Hyperopia/rehabilitation , Lenses, Intraocular , Myopia/rehabilitation , Optics and Photonics/instrumentation , Refraction, Ocular/physiology , Aged , Female , Humans , Hyperopia/physiopathology , Male , Myopia/physiopathology , Postoperative Period , Retrospective Studies
4.
J Spec Oper Med ; 17(2): 60-64, 2017.
Article in English | MEDLINE | ID: mdl-28599035

ABSTRACT

BACKGROUND: This report describes a rapid method of vision correction used by Special Operations Medics in multiple operational engagements. METHODS: Between 2011 and 2015, Special Operations Medics used an algorithm- driven refraction technique. A standard block of instruction was provided to the medics, along with a packaged kit. The technique was used in multiple operational engagements with host nation military and civilians. Data collected for program evaluation were later analyzed to assess the utility of the technique. RESULTS: Glasses were distributed to 230 patients with complaints of either decreased distance or near (reading). Most patients (84%) with distance complaints achieved corrected binocular vision of 20/40 or better, and 97% of patients with near-vision complaints achieved corrected near-binocular vision of 20/40 or better. There was no statistically significant difference between the percentages of patients achieving 20/40 when medics used the technique under direct supervision versus independent use. CONCLUSION: A basic refraction technique using a designed kit allows for meaningful improvement in distance and/or near vision at austere locations. Special Operations Medics can leverage this approach after specific training with minimal time commitment. It can serve as a rapid, effective intervention with multiple applications in diverse operational environments.


Subject(s)
Algorithms , Eyeglasses , Hyperopia/rehabilitation , Military Medicine , Myopia/rehabilitation , Presbyopia/rehabilitation , Vision Disorders/rehabilitation , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Hyperopia/diagnosis , Male , Middle Aged , Myopia/diagnosis , Presbyopia/diagnosis , Refractive Errors/diagnosis , Refractive Errors/rehabilitation , Time Factors , Vision Disorders/diagnosis , Young Adult
5.
Zhonghua Yan Ke Za Zhi ; 53(1): 33-38, 2017 Jan 11.
Article in Chinese | MEDLINE | ID: mdl-28162197

ABSTRACT

Objective: To investigate the effect of wearing long wavelength filter glasses on refractive development of children's hyperopia. Methods: Case control study. Seventeen 5-7 years' old children with high hyperopia from optometry clinic of Eye and ENT Hospital Affiliated to Fudan University were enrolled in this research. The experiment design was self-control between right and left eye, 3 children were lost during two years' period of observation, all the children's hyperopic refraction were more than +6.00 D, cycloplegic by 1% atropine. All the children were required to wear long wavelength filter glasses for 6 hours after waking up, the rest of the time with the conventional glasses. Refraction, axis and red/green match point were tested before the intervention and 3, 6, 12, 18, 24 months, after the intervention. Results: After two years' intervention, hyperopia decreased, eye axis increased, the best corrected visual acuity increased both in experimental eyes and control eyes, but there were no statistically significant difference between the two groups at each time point. All children were with normal color vision, compared to the long-wavelength light, the hyperopic eyes were more sensitive to middle-wavelength light, no significant difference was found between two groups, red/green match points were 42.802±1.216 and 42.889±1.560 respectively. After wearing long wavelength filter, red/green match point were significant decreased in the experimental group in 6 months and 12 months time points (6 months: 0.995±0. 543 vs. 0.104±0.143, t=3.04, P=0.005, 12 months: 1.096±0.392 vs. 0.17±0.248, t=2.725, P=0.008). The experiment eyes were more sensitive to long-wavelength light than the control eyes. But in later time, there was no significant difference between two groups. Conclusion: Wearing long wavelength filter glasses two years has no effect on refractive development on children with high hyperopia, but it can cause short-term chromatic adaptation, making hyperopic eyes more sensitive to the long-wavelength light. (Chin J Ophthalmol, 2017, 53: 33-38).


Subject(s)
Eye Diseases, Hereditary/rehabilitation , Eyeglasses , Hyperopia/rehabilitation , Refraction, Ocular , Case-Control Studies , Child , Child, Preschool , Eye Diseases, Hereditary/physiopathology , Female , Follow-Up Studies , Humans , Hyperopia/physiopathology , Light , Male , Mydriatics , Time Factors , Vision Tests , Visual Acuity
7.
Klin Monbl Augenheilkd ; 233(4): 381-6, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27116488

ABSTRACT

BACKGROUND: Glasses for children are recommended and prescribed by different groups of professionals. We set out to compare the prescription practices of ophthalmologists, orthoptists and optometrists/opticians in Switzerland. METHODS: Online questionnaire on the prescription and recommendation of glasses in fictitious cases of children of different ages, refractive values and symptoms. The questionnaire was sent out to members of the Swiss Ophthalmological Society, Swiss Orthoptics and Schweizerischer Berufsverband für Augenoptik und Optometrie. RESULTS: 307 questionnaires were analysed. Optometrists/opticians recommended glasses with a significantly smaller cycloplegic refraction value (p < 0.005) than did orthoptists and ophthalmologists. In the example of a 14-year-old asymptomatic child, ophthalmologists recommended glasses at + 2.64 [Dpt], orthoptists at + 2.44 [Dpt] and optometrists/opticians at + 1.32 [Dpt]. Optometrists/opticians tended to recommend slightly higher correction values in glasses than did ophthalmologists and orthoptists. CONCLUSION: In Switzerland, optometrists/opticians recommend glasses with significantly smaller cycloplegic refraction values than do orthoptists and ophthalmologists, regardless of age or symptoms described in these fictitious cases.


Subject(s)
Eyeglasses/statistics & numerical data , Health Care Surveys , Hyperopia/epidemiology , Hyperopia/rehabilitation , Practice Patterns, Physicians'/statistics & numerical data , Prescriptions/statistics & numerical data , Adolescent , Adult , Aged , Child , Child Health/statistics & numerical data , Child, Preschool , Female , Humans , Hyperopia/diagnosis , Male , Middle Aged , Ophthalmologists/statistics & numerical data , Optometrists/statistics & numerical data , Patient Acceptance of Health Care/statistics & numerical data , Prevalence , Switzerland/epidemiology
9.
Nepal J Ophthalmol ; 8(16): 178-181, 2016 07.
Article in English | MEDLINE | ID: mdl-28478474

ABSTRACT

BACKGROUND: Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens to eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. OBSERVATIONS: This is a case report of a 17 years old female who presented with bilateral gradual progressive visual loss and photophobia at Tilganga Institute of Ophthalmology on 3rd July 2015. Her best corrected visual acuity was 20/300 with +12.00Ds/-1.00Dcyl@180 in the right eye and 20/200 with +12.00Ds/-1.50Dcyl@180 in the left eye. Axial lengths of two eyes were markedly shortened with pigmentary changes at the macula and dull foveal reflex along with retinal flecks in the mid-periphery. Full field ERG showed diminished rod and cone waves suggestive of rod and cone dysfunction. With the use of Rigid Gas Permeable (RGP) contact lenses, the acuity improved to 20/200 and 20/125 in the right and left eye respectively. CONCLUSION: This study proposes the use of contact lenses and light absorptive filters for better visual rehabilitation.


Subject(s)
Contact Lenses , Microphthalmos/rehabilitation , Retinal Dystrophies/rehabilitation , Adolescent , Female , Fundus Oculi , Humans , Hyperopia/etiology , Hyperopia/rehabilitation , Microphthalmos/complications , Retinal Dystrophies/complications , Visual Acuity
10.
MEDISUR ; 13(4)2015. tab
Article in Spanish | CUMED | ID: cum-62165

ABSTRACT

La pérdida visual causa un enorme sufrimiento tanto para aquellos que la padecen como para sus familiares. Cerca del 80 por ciento de la ceguera es evitable (prevenible o curable). Por tales razones se presentan cuatro casos atendidos durante varios años en la consulta de baja visión del Hospital General Universitario Gustavo Aldereguía Lima de Cienfuegos, por ser pacientes clasificados con una diversidad funcional secundaria a diferentes entidades oftalmológicas: hipermetropía elevada, miopía elevada, glaucoma crónico simple en estadio 4 y afaquia no corregida. Se empleó la técnica quirúrgica de extracción extracapsular con implante de lente intraocular, en uno de ellos Piggy Back primario; en todos los casos hubo resultados satisfactorios en diversos parámetros como agudeza visual, campo visual y disminución del defecto refractivo, por lo que se logró mejorar la calidad de vida de los pacientes, así como su inclusión social y escolar(AU)


Visual loss causes enormous suffering to both the patients and their families. About 80 percent of blindness is avoidable (preventable or curable). Therefore, we present four cases treated for several years in the low vision consultation of the Gustavo Aldereguía Lima University General Hospital of Cienfuegos due to a functional diversity secondary to various ophthalmologic conditions including high hyperopia, high myopia, chronic simple glaucoma at stage 4 and uncorrected aphakia. An extracapsular extraction with intraocular lens implantation was performed, using a primary Piggyback in one of them. All cases showed satisfactory results in various parameters such as visual acuity, visual field and reduced refractive error; thus, it was possible to improve the quality of life of these patients as well as their social and school inclusion(AU)


Subject(s)
Humans , Hyperopia/rehabilitation , Hyperopia/surgery , Myopia/rehabilitation , Myopia/surgery , Glaucoma/rehabilitation , Glaucoma/surgery , Aphakia/rehabilitation , Aphakia/surgery , Treatment Outcome
11.
Cochrane Database Syst Rev ; (8): CD007738, 2014 Aug 18.
Article in English | MEDLINE | ID: mdl-25133974

ABSTRACT

BACKGROUND: Hyperopia (far-sightedness) in infancy requires accommodative effort to bring images into focus. Prolonged accommodative effort has been associated with an increased risk of strabismus (eye misalignment). Strabismus makes it difficult for the eyes to work together and may result in symptoms of asthenopia (eye strain) and intermittent diplopia (double vision), and makes near work tasks difficult to complete. Untreated strabismus may result in the development of amblyopia (lazy eye). The prescription of spectacles to correct hyperopic refractive error is believed to prevent the development of strabismus. OBJECTIVES: To assess the effectiveness of prescription spectacles compared with no intervention for the prevention of strabismus in infants and children with hyperopia. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2014), EMBASE (January 1980 to April 2014), PubMed (1966 to April 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 April 2014. We also searched the Science Citation Index database in September 2013. SELECTION CRITERIA: We included randomized controlled trials and quasi-randomized trials investigating the assignment to spectacle intervention or no treatment for children with hyperopia. The definition of hyperopia remains subjective, but we required it to be at least greater than +2.00 diopters (D) of hyperopia. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data using the standard methodologic procedures expected by The Cochrane Collaboration. One review author entered data into Review Manager and a second review author verified the data entered. The two review authors resolved discrepancies at all stages of the review process. MAIN RESULTS: We identified three randomized controlled trials (855 children enrolled) in this review. These trials were all conducted in the UK with follow-up periods ranging from one to 3.5 years. We judged the included studies to be at high risk of bias, due to use of quasi-random methods for assigning children to treatment, no masking of outcomes assessors, and high proportions of drop-outs. None of the three trials accounted for missing data and analyses were limited to the available-case data (674 (79%) of 855 children enrolled for the primary outcome). These factors impair our ability to assess the effectiveness of treatment.Analyses incorporating the three trials we identified in this review (674 children) suggested the effect of spectacle correction initiated prior to the age of one year in hyperopic children between three and four years of age is uncertain with respect to preventing strabismus (risk ratio (RR) 0.71; 95% confidence interval (CI) 0.44 to 1.15; very low quality evidence). Based on a meta-analysis of three trials (664 children), the risk of having visual acuity worse than 20/30 at three years of age was also uncertain for children with spectacles compared with those without spectacle correction irrespective of compliance (RR 0.87; 95% CI 0.60 to 1.26; very low quality evidence).Emmetropization was reported in two trials: one trial suggested that spectacles impede emmetropization, and the second trial reported no difference in the rate of refractive error change. AUTHORS' CONCLUSIONS: Although children who were allocated to the spectacle group were less likely to develop strabismus and less likely to have visual acuity worse than 20/30 children allocated to no spectacles, these effects may have been chance findings, or due to bias. Due to the high risk of bias and poor reporting of included trials, the true effect of spectacle correction for hyperopia on strabismus is still uncertain.


Subject(s)
Eyeglasses , Hyperopia/rehabilitation , Strabismus/prevention & control , Watchful Waiting , Age Factors , Child , Child, Preschool , Emmetropia , Humans , Hyperopia/complications , Infant , Randomized Controlled Trials as Topic , Strabismus/etiology , Treatment Outcome , Vision Disorders/etiology , Visual Acuity
12.
J Biomed Opt ; 18(8): 85001, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23922123

ABSTRACT

Recently, we tested the vision of spectacle corrected subjects using a special hologram (http://dx.doi.org/10.1364/BOE.3.001173). A subject viewing through this hologram sees the images of various numbers at different distances from the eye. Each of these images subtends an angle of 50' at the eye. Each image corresponds to a different amount of divergence or convergence at the eye. The limit of convergence (positive blur) with which a subject can recognize the numbers was measured. Hyperopes could recognize numbers with 0.9 D more of positive blur in comparison with myopes. This difference was not obtained with a standard test chart under white light illumination using positive lenses to provide the blur. The observed difference with the hologram is then attributed to the multivergence nature of the target in the hologram and/or the monochromaticity of the illumination used. Using a hologram of a logMAR chart at a single distance of infinity we have now found that the observed difference is induced by the multivergence target and is due to an effect that is similar to the Mandelbaum effect. We present the details of this experiment and compare the results obtained with our earlier experiment.


Subject(s)
Eyeglasses , Holography/methods , Hyperopia , Myopia , Refraction, Ocular , Vision Tests/methods , Visual Acuity , Accommodation, Ocular , Adult , Female , Humans , Hyperopia/diagnosis , Hyperopia/physiopathology , Hyperopia/rehabilitation , Lighting/methods , Male , Myopia/diagnosis , Myopia/physiopathology , Myopia/rehabilitation , Photic Stimulation/methods , Reproducibility of Results , Sensitivity and Specificity
14.
Optom Vis Sci ; 88(2): E227-33, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21217406

ABSTRACT

PURPOSE: To demonstrate that relatively simple third-order theory can provide a framework which shows how peripheral refraction can be manipulated by altering the forms of spectacle lenses. METHODS: Third-order equations were used to yield lens forms that correct peripheral power errors, either for the lenses alone or in combination with typical peripheral refractions of myopic eyes. These results were compared with those of finite raytracing. RESULTS: The approximate forms of spherical and conicoidal lenses provided by third-order theory were flatter over a moderate myopic range than the forms obtained by rigorous raytracing. Lenses designed to correct peripheral refractive errors produced large errors when used with foveal vision and a rotating eye. Correcting astigmatism tended to give large errors in mean oblique error and vice versa. When only spherical lens forms are used, correction of the relative hypermetropic peripheral refractions of myopic eyes that are observed experimentally, or the provision of relative myopic peripheral refractions in such eyes, appears impossible in the majority of cases. CONCLUSIONS: The third-order spectacle lens design approach can readily be used to show trends in peripheral refraction.


Subject(s)
Eyeglasses , Models, Theoretical , Optics and Photonics , Refractive Errors/rehabilitation , Astigmatism/rehabilitation , Equipment Design , Humans , Hyperopia/rehabilitation , Myopia/rehabilitation , Optics and Photonics/methods
15.
Eye Contact Lens ; 37(1): 26-30, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21178697

ABSTRACT

PURPOSE: To examine the refractive and keratometric response of corneal refractive therapy (CRT) contact lenses for hyperopia (CRT) after a single night of contact lens wear with the goal of reducing hyperopia by +3.50 D. METHOD: Twenty participants were fitted with a CRT HDS 100 contact lens, in one eye only. The back optic zone radius of the CRT lens was designed to correct 3.50 D of hyperopia. The eyes were randomly selected. The Nikon Auto Refractor was used to measure refractive error. Corneal topography and simulated K readings were measured using the Humphrey Atlas topographer. The lens was subsequently worn overnight, and the lens was assessed the next morning on awakening. RESULTS: Refractive error changed by 1.50±0.71 D (mean ± SD, range 0.50-2.75 D) immediately after lens removal in the experimental eye. Similarly, there was a change in flat K readings of 0.58±0.62 D with a range of -0.25 to +1.87 D. These results were significantly different from the baseline measurements (P<0.0001). CONCLUSIONS: The fitting of CRT HDS for hyperopia has a significant effect on corneal shape and refractive error. There was a moderate yet significant steepening of the cornea.


Subject(s)
Contact Lenses , Gases/pharmacokinetics , Hyperopia/physiopathology , Hyperopia/rehabilitation , Orthokeratologic Procedures , Adult , Female , Humans , Male , Orthokeratologic Procedures/standards , Permeability , Refraction, Ocular , Treatment Outcome , Young Adult
16.
Strabismus ; 18(4): 142-5, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21091335

ABSTRACT

INTRODUCTION: Patients with Down syndrome have characteristic features including ocular manifestations. Guidelines exist for ophthalmic surveillance of people with Down syndrome, but locally (North Staffordshire) there is no formal program in place. METHODS: Hospital records were used to detect children with Down syndrome. Data were extracted retrospectively to determine which children had been seen by ophthalmic services, the mode of assessment used, and the frequency of ophthalmic disorders. RESULTS: Of the 96 children with Down syndrome, 38% received no ophthalmic assessment. Of those seen, the mean age at first appointment was nearly 3 years, with a number of children being more than 5 years old. Most children (96%) had at least one ophthalmic abnormality, the commonest being hyperopia. Requested follow-up was routinely exceeded by almost a year with 19% of children receiving no follow-up. DISCUSSION: Ocular disorders are common in the two thirds of children who are currently seen by ophthalmic services. Locally, we are falling short of the targets set by the 2006 recommendations for basic medical care of people with Down syndrome. A screening program might have a beneficial impact on the vision of children with Down syndrome.


Subject(s)
Down Syndrome/complications , Eye Diseases/diagnosis , Eye Diseases/etiology , Ophthalmology/methods , Orthoptics/methods , Adolescent , Astigmatism/etiology , Child , Child, Preschool , Databases, Factual , Down Syndrome/epidemiology , Eyeglasses , Follow-Up Studies , Humans , Hyperopia/etiology , Hyperopia/rehabilitation , Prevalence , Referral and Consultation , Retrospective Studies , United Kingdom , Vision, Low/etiology
17.
Optom Vis Sci ; 87(9): 642-55, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20601913

ABSTRACT

PURPOSE: Peripheral refractive error degrades the quality of retinal images and has been hypothesized to be a stimulus for the development of refractive error. The purpose of this study was to investigate the changes in refractive error across the horizontal visual field produced by contact lenses (CLs) and to quantify the effect of CLs on peripheral image blur. METHODS: A commercial Shack-Hartmann aberrometer measured ocular wavefront aberrations in 5 degrees steps across the central 60 degrees of visual field along the horizontal meridian before and after CLs correction. Wavefront refractions for peripheral lines-of-sight were based on the full elliptical pupil encountered in peripheral measurements. Curvature of field is the change in peripheral spherical equivalent relative to the eye's optical axis. RESULTS: Hyperopic curvature of field in the naked eye increases with increasing amounts central myopic refractive error as predicted by Atchison (2006). For an eccentricity of E degrees, field curvature is approximately E percent of foveal refractive error. Rigid gas permeable (RGP) lenses changed field curvature in the myopic direction twice as much as soft CLs (SCLs). Both of these effects varied with CLs power. For all lens powers, SCL cut the degree of hyperopic field curvature in half whereas RGP lenses nearly eliminated field curvature. The benefit of reduced field curvature was partly offset by increased oblique astigmatism. The net reduction of retinal blur because of CLs is approximately constant across the visual field. CONCLUSIONS: Both SCL and RGP lenses reduced the degree of hyperopic field curvature present in myopic eyes, with RGP lenses having greater effect. The tradeoff between field curvature and off-axis astigmatism with RGP lenses may limit their effectiveness for control of myopia progression. These results suggest that axial growth mechanisms that depend on retinal image quality will be affected more by RGP than by SCL lenses.


Subject(s)
Contact Lenses , Refractive Errors/physiopathology , Refractive Errors/rehabilitation , Visual Acuity , Visual Fields , Aberrometry , Adult , Astigmatism/complications , Astigmatism/physiopathology , Astigmatism/rehabilitation , Contact Lenses, Hydrophilic , Female , Fovea Centralis/physiopathology , Gases , Humans , Hyperopia/physiopathology , Hyperopia/rehabilitation , Male , Myopia/physiopathology , Myopia/rehabilitation , Permeability , Refraction, Ocular , Refractive Errors/complications , Retina/physiopathology , Treatment Outcome , Young Adult
18.
Optom Vis Sci ; 87(9): 631-41, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20622703

ABSTRACT

PURPOSE: To report the results of 12-month wear of three novel spectacle lens designs intended to reduce peripheral hyperopic defocus and one standard design control lens and their effect on the progression of myopia in Chinese children aged 6 to 16 years. METHODS: Chinese children (n = 210) with myopia (-0.75 D to -3.50 D sphere, cylinder

Subject(s)
Eyeglasses , Myopia/physiopathology , Myopia/rehabilitation , Adolescent , Age Factors , Asian People , Child , Disease Progression , Equipment Design , Female , Fixation, Ocular , Humans , Hyperopia/physiopathology , Hyperopia/rehabilitation , Interviews as Topic , Linear Models , Male , Medical Records , Myopia/ethnology , Myopia/genetics , Parents , Refraction, Ocular , Surveys and Questionnaires , Time Factors
19.
Eye Contact Lens ; 35(3): 159-62, 2009 May.
Article in English | MEDLINE | ID: mdl-19421024

ABSTRACT

PURPOSE: To report the case of a patient with high hyperopia and bilateral keratoconus. METHODS: A high hyperopic patient was evaluated using Orbscan corneal topography and slitlamp biomicroscopy to confirm suspected keratoconus. RESULTS: A male patient (32 years old) with a long history (10 years) of daily hydrogel contact lens wear with severe hyperopia was examined (RE +8.25-5.00 x 070 degrees , visual acuity [VA] 0.7 and LE +8.00-3.00 x 100 degrees , VA 0.9). The patient's Orbscan topography was compatible with bilateral asymmetric keratoconus (asymmetry of central dioptric power, irregular astigmatism, high anterior (110 and 63 microm for RE and LE, respectively) and posterior (200 and 128 microm for RE and LE, respectively) corneal elevation values; and corneal thinnest point (450 and 471 microm for RE and LE, respectively, in the cone). Slitlamp biomicroscopic findings included Vogt striae in RE. High Dk rigid gas-permeable CLs with keratoconus design (Z-B4P, Menicon, Japan) were fitted in both eyes (in RE the back optic zone radius [BOZR] was 7.70 mm, the total diameter was 10.00 mm, and the power was +4.00D, which provides a VA of 1.0; the LE BOZR was 7.65 mm, the total diameter was 10.00 mm, and the power was +4.25D, which provides a VA of 1.0). CONCLUSIONS: Although rare, keratoconus may occur in cases of high hyperopia. Management of hyperopic keratoconus with rigid gas-permeable contact lens fitting may be similar to that applied with other cases of keratoconus.


Subject(s)
Contact Lenses , Hyperopia/complications , Keratoconus/etiology , Keratoconus/therapy , Adult , Contact Lenses, Hydrophilic , Corneal Topography , Diagnostic Techniques, Ophthalmological , Humans , Hyperopia/rehabilitation , Keratoconus/diagnosis , Male
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