scholarly journals Peripheral refraction of myopic eyes with spectacle lenses correction and lens free emmetropes during accommodation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
António Queirós ◽  
Alejandro Cerviño ◽  
José Manuel González-Méijome

Abstract Purpose To measure axial and off-axis refraction patterns in myopic eyes with spectacle lenses correction and lens free emmetropes in young healthy subjects at different target distances from 2.00 m (0.50 D) to 0.20 m (5.00 D) in terms of sphere, astigmatism, and spherical equivalent refraction. Methods Refraction was measured at the center, 20 and 40 degrees from the line of sight both nasally and temporally in 15 emmetropic and 25 myopic young healthy subjects with an open field, binocular, infrared autorefractor (Grand Seiko WAM-5500, Hiroshima, Japan). Fixation target was a Maltese cross set at 2.00, 0.50, 0.33 and 0.20 m from the corneal plane. Changes in off-axis refraction with accommodation level were normalized with respect to distance axial values and compared between myopic eyes with spectacle lenses correction and lens free emmetropes. Results Off-axis refraction in myopic eyes with spectacle lenses correction was significantly more myopic in the temporal retina compared to lens free emmetropes except for the closest target distance. Relative off-axis refractive error changed significantly with accommodation when compared to axial refraction particularly in the myopic group. This change in the negative direction was due to changes in the spherical component of refraction that became more myopic relative to the center at the 0.20 m distance as the J0 component of astigmatism was significantly reduced in both emmetropes and myopes for the closest target. Conclusion Accommodation to very near targets (up to 0.20 m) makes the off-axis refraction of myopes wearing their spectacle correction similar to that of lens free emmetropes. A significant reduction in off-axis astigmatism was also observed for the 0.20 m distance.

2020 ◽  
Vol 18 (2) ◽  
pp. 46-51
Author(s):  
S. Awasthi ◽  
B.P. Pant ◽  
T. Langaas

Background Uncorrected refractive error is the major cause of visual impairment worldwide. There is no data on refractive error prevalence among school children in hilly region of Far West Nepal. Objective The prevalence of refractive error has been found to vary among children of different caste/ethnic groups and geographical regions. The purpose of this study is to determine the prevalence of refractive error among school children from different caste/ethnic groups in Dadeldhura district of Far West Nepal. Method This is a cross sectional study of refractive error among secondary school children from 2 schools in Dadeldhura district. All children underwent a vision screening consisting of visual acuity, ocular examination and refraction. Myopia was diagnosed for an eye with spherical equivalent refraction (SER) ≤ -0.5 D whereas an eye with SER ≥ +2.0 D was diagnosed as hyperopic. Ethnicity was reported through self administered questionnaire. Result Among children aged 12 to 16 years (14.07 ± 1.4) prevalence of myopia was 3.5%, hyperopia 0.33% and astigmatism 1%. All except three children had spherical equivalent refraction (SER) within ±2 D. Caste/ethnicity was not associated significantly with myopia in either eye (χ2= 0.27, df= 2, p= 0.87). Conclusion The prevalence of refractive error among secondary school children in Dadeldhura district of Far West Nepal is very low in comparison to myopia prevalence reported in studies from other parts of the world, but slightly lower than myopia prevalence found in other, eastern parts of Nepal.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Eghosasere Iyamu ◽  
Joy Edoghogho Iyamu ◽  
Liticia Oghovwerha

Aim. The aim of this study was to investigate the association between anthropometry, amplitude of accommodation assessed by minus-lens to blur (AAPUB) and push-up to blur (AAMLB), and spherical equivalent refraction (SEQ). Method. A total of two hundred and one subjects aged between 17 and 70 years with mean age of years, consisting of 93 males and 108 females were recruited for this study. Anthropometric variables were measured with standard instruments like the free-standing rod for height, weighing balance for body weight, and body mass index (BMI) calculated. The refractive error was measured by static retinoscopy and subjective refraction. Result. An inverse correlation was found between age, AAMLB and AAPUB (, −0.81, both ). BMI increased with age (, ). There was an inverse correlation between BMI, AAPUB and AAMLB (, −0.25, both ), respectively. However, the association between SEQ and anthropometry was not significant . The AAPUB and AAMLB decreased with age while BMI increased. AAPUB and AAMLB decreased with BMI, but were not affected by the SEQ. Conclusion. BMI increased with age while AA measured by the two methods decreased with age, and BMI increased with decreasing AA.


2021 ◽  
pp. bjophthalmol-2020-316234
Author(s):  
Jan Roelof Polling ◽  
Caroline Klaver ◽  
Jan Willem Tideman

PurposeData on myopia progression during its entire course are scarce. The aim of this study is to investigate myopia progression in Europeans as a function of age and degree of myopia from first prescription to final refractive error.MethodsThe Drentse Refractive Error and Myopia Study assessed data from a branch of opticians in the Netherlands from 1985 onwards in a retrospective study. First pair of glasses prescribed was defined as a spherical equivalent of refraction (SER) ≤−0.5 D to ≥−3.0 D. Subjects with prescriptions at an interval of at least 1 year were included in the analysis.ResultsA total of 2555 persons (57.3% female) met the inclusion criteria. Those with first prescription before the age of 10 years showed the strongest progression (−0.50 D; IQR: −0.75 to −0.19) and a significantly (p<0.001) more negative median final SER (−4.48 D; IQR: −5.37 to −3.42). All children who developed SER ≤−3 D at 10 years were highly myopic (SER ≤−6D) as adults, children who had SER between −1.5 D and −3 D at 10 years had 46.0% risk of high myopia, and children with SER between −0.5 D and −1.5 D had 32.6% risk of high myopia. Myopia progression diminished with age; all refractive categories stabilised after age 15 years except for SER ≤−5 D who progressed up to −0.25 D annually until age 21 years.ConclusionOur trajectories of the natural course of myopia progression may serve as a guide for myopia management in European children. SER at 10 years is an important prognostic indicator and will help determine treatment intensity.


2021 ◽  
pp. 195-200

Background: Micro-esotropia is a small-angle esodeviation typically less than nine prism diopters. Patients with this ocular condition often develop amblyopia due to the presence of a constant unilateral strabismus and an anisometropic refractive error in the deviated eye. Current treatment methods for strabismic and refractive amblyopia include spectacle correction, patching, and vision therapy (VT). Case Summary: A 9-year-old Asian female presented with a constant left primary micro-esotropia with unsteady eccentric fixation, contributing to mild amblyopia and frequent suppression in the left eye. She also had a hyperopic anisometropic refractive error. Combination treatment of in-office VT with short-term patching therapy (two hours per day) was administered, with the goal of improving her binocularity, fixation, and visual acuity. Conclusions: Amblyopia results from binocular dysfunction, therefore monocular patching therapy alone will not improve the underlying issue. VT is necessary to actively treat binocularity and subsequently improve visual acuity, while short-term patching can be used in combination to effectively target monocular accommodation and fixation.


2018 ◽  
Vol 2 (2) ◽  
pp. e14-e21
Author(s):  
Melissa Barnett ◽  
Jonathon Ross ◽  
Blythe Durbin-Johnson

Abstract Objectives: The purpose of this study was to evaluate the performance (i.e. vision, comfort and fit) of spherical and front-surface toric scleral lenses in subjects with regular, healthy corneas. Methods: Scleral lenses were fitin the eyes (n = 16) of healthy subjects (n = 9) with regular corneas, absent of pathology, and studied using an observational, multi-visit design. Lens fit was objectively evaluatedby an experienced practitioner.Following 1 month of successful lens wear, participants completedsubjective satisfaction surveys regarding the scleral lens wearing experience. Results:  According to participant surveys, scleral lenses were subjectively preferred over soft toric or gas permeable contact lenses in 88% of eyes, including in all eyes fit with a front-surface toric scleral lens (n = 3). Seventy-five percent (75%) of eyes achieved visual acuity of 0.1 logMAR or better, while all eyes with prior spectacle wear achieved visual acuity with a scleral lens within 1 Snellen line of spectacle correction. Seventy-five percent (75%) of eyes achieved good subjective comfort with a scleral lens. No participants reported poor subjective vision and/or comfort. Conclusions:  Our findings suggest that subjects preferred the performance of a scleral lens (spherical or front-surface toric) compared to a soft toric or gas permeable contact lens. Moreover, scleral lenses may provide a viable, alternative contact lens modality option for patients considering discontinuation of traditional soft toric and/or rigid contact lens wear; so long as the factors associated with hypoxia remain minimized. Key Words:  scleral lens; scleral contact lens; front-surface toric scleral lens; lens performance; normal eyes; healthy eyes


Author(s):  
Feride Tuncer Orhan ◽  
Haluk Huseyin Gürsoy

Aim To evaluate consecutive measurements of the biometric parameters, age, and refraction error in a Turkish population at primary school age. Materials and Methods A total of 197 children aged between 7-12 years were included. The data of three consecutive measurements of children, who were examined at least once a year for three years using both cycloplegic auto-refractometry and optical biometry, were used in this retrospective study. Spherical equivalent <-0.50D was considered to be myopic; >+0.75D was considered to be hypermetropic. Age, gender, body mass index, spherical equivalent, axial length, anterior chamber depth, central corneal thickness, keratometry, and lens thickness were analyzed. The onset data obtained in 2013 whereas, the final data were from 2015. Logistic and Cox regression analyses were performed (p<0.05). Results The mean of the onset and the final spherical equivalents were 0.19D (0.56), and 0.08D (0.80), respectively. The myopia prevalence was increased among refractive errors in observation periods (univariable analysis p=0.029; multivariable analysis p=0.017). The onset axial length (HR:4.55, 95%CI:2.87-7.24, p<0.001), keratometry (HR:2.04, 95%CI:1.55-2.67, p<0.001) and age (HR:0.73, 95%CI: 0.57-0.92, p=0.009) correlated myopia progression. To calculate the estimated spherical equivalent, the onset data were included in the logistic regression model. The onset data of spherical equivalent (β=0.916, p<0.001), axial length (β=-0.451, p<0.001), anterior chamber depth (β=0.430, p=0.005) and keratometry (β=-0.172, p<0.001) were found to be significantly associated with the mean SE at the final data. Conclusions To calculate the estimated spherical equivalent following three years, an equation was proposed. The estimated refractive error of children can be calculated by using the proposed equation with the associated onset optical parameters.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2803
Author(s):  
Kareem Allinjawi ◽  
Sharanjeet-Kaur Sharanjeet-Kaur ◽  
Saadah Mohamed Akhir ◽  
Haliza Abdul Mutalib

Aim: The purpose of this study was to determine the changes in the relative peripheral refractive error produced by soft single vision contact lenses in myopic schoolchildren. Methods: 27 myopic schoolchildren aged between 13 to 15 years were included in this study. The measurements of central and peripheral refraction were made only on the right eye using a Grand-Seiko WR-5100K open-field autorefractometer without contact lens (WL), and with wearing single vision contact lens (SVCL). Refractive power was measured at center and horizontal eccentricity between 35° temporal to 35° nasal visual field (in 5° steps). Results: SVCL showed an increase in peripheral hyperopic defocus at the nasal and temporal visual field compare with baseline, but this change was not statistically significant (p=0.129). Conclusion: Wearing single vision soft contact lenses increases the relative peripheral hyperopic defocus in myopic schoolchildren.


2019 ◽  
Author(s):  
Piotr Kanclerz ◽  
Christoph Leisser ◽  
Andrzej Grzybowski ◽  
Paweł Lipowski

Abstract Background Cataract development is common in phakic eyes filled with silicone oil (SO), necessitating subsequent cataract removal. This study evaluated the refractive outcome in eyes filled with SO undergoing phacoemulsification cataract surgery (PCS). Methods This retrospective study evaluated patients with SO tamponade who were scheduled for PCS. Results Subjects (n=26) were followed-up for 29.5 ± 13.9 months after cataract surgery. The median spherical equivalent refraction (SER) was +5.3 D (interquartile range [IQR] +2.9 to +6.7) before PCS, and +3.4 D (IQR +2.0 to +4.4) after PCS. Within the follow-up period retinal reattachment after SO removal was achieved in 15 out of 26 eyes (57.7%). In 13 eyes assessment of refraction after SO-removal was possible, and showed a myopic shift of -4.6 D (IQR -2.9 to -7.3) in the SER. After SO removal, 5 of 13 eyes (38.5%) were within ±1.0 D of the target refraction, while 9 out of 13 eyes (69.2%) were within ±2.0 D. Conclusions The refractive outcome after PCS for eyes filled with SO is less predictable than that for normal eyes. Some of the eyes undergoing silicone oil injection may require long-term tamponade.


2019 ◽  
pp. bjophthalmol-2019-315020 ◽  
Author(s):  
Laurence Shen Lim ◽  
Saiko Matsumura ◽  
Hla Myint Htoon ◽  
James Tian ◽  
Shin Bin Lim ◽  
...  

PurposeTo evaluate posterior eye shape variations across a wide refractive error range using brain MRI in a multiethnic cohort.MethodsAdult subjects in the multiethnic Singapore Epidemiology of Eye Disease study were included. Spherical equivalent (SE) was measured using subjective refraction, and axial length (AL) was measured using optical biometry. MRI was performed using a 3-Tesla whole body scanner with a 32-channel head coil. The radii and asphericity based on fitting of the posterior two-thirds of the eye (240°) were calculated. The refractive error status was categorised as myopic (SE<−0.5 D) or non-myopic (SE≥−0.5 D).ResultsA total of 450 adult participants (mean age 64.2±6.5 years old) were included. Less oblate asphericity was associated with more myopic SE, longer AL and with a refractive error categorisation of myopia (p<0.001 for all). Asphericity values were less oblate in myopic compared with non-myopic eyes (p<0.001). Multivariate analysis showed that Chinese subjects had less oblate eyes than Malay and Indian subjects, especially in non-myopic eyes.ConclusionsA less oblate posterior eye shape was associated with myopic eyes. Chinese eyes have less oblate shapes than Malay and Indian eyes, especially in non-myopic eyes.


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