REFRACTIVE ERROR AND NEURAL VISUAL ACUITY.

2001 ◽  
Vol 78 (SUPPLEMENT) ◽  
pp. 102
Author(s):  
Tonya Watson ◽  
Nancy Coletta
2021 ◽  
pp. 1-7
Author(s):  
Salam Chettian Kandi ◽  
Hayat Ahmad Khan

<b><i>Introduction:</i></b> Uncorrected refractive errors and amblyopia pose a major problem affecting schoolchildren. We had previously observed that many schoolchildren in the Hatta region presented to the ophthalmology clinic with uncorrected refractive errors and amblyopia, which led us to undertake this research. As per the WHO, the term “visual impairment” can be “low vision” or “blindness.” Based on the presenting vision, “low vision” is defined for children who have vision of &#x3c;6/18 to 3/60 or having visual field loss to &#x3c;20° in the better-seeing eye. Children defined to have “blindness” have presenting vision of &#x3c;3/60 or corresponding visual field of &#x3c;10°. <b><i>Purpose:</i></b> To estimate the magnitude of uncorrected refractive errors and amblyopia among the schoolchildren aged 6–19 years and to assess the efficacy of school-based refractive error screening programs in the Hatta region of the United Arab Emirates. <b><i>Methods:</i></b> An epidemiological, cross-sectional, descriptive study was conducted on the entire student population studying in the government schools of the region. Those who failed the Snellen visual acuity chart test and those who were wearing spectacles were evaluated comprehensively by the researcher in the Department of Ophthalmology of the Hatta Hospital. Data were entered in the Refractive Error Study in School Children (RESC) eye examination form recommended by the WHO, and were later transferred to Excel sheets and analyzed by SPSS. <b><i>Results:</i></b> 1,591 students were screened and evaluated from the end of 2016 to mid-2017. About 21.37% (<i>n</i> = 340) had impaired vision with 20.9% (<i>n</i> = 333) refractive errors, of which 58% were uncorrected. Among the refractive error group, 19% (64 subjects) had amblyopia (4% of total students). The incidence of low vision was 9.5% and blindness was 0.38%. Low vision was found to be 9.5% and blindness 0.38%, taking in to account presenting visual acuity rather than best-corrected visual acuity for defining low vision and blindness. <b><i>Conclusion:</i></b> A significant number of students were detected to have uncorrected refractive errors among the vision impaired group (59%, <i>n</i> = 197) despite a school-based vision screening program in place. Seventy-eight percent of the amblyopia cases (<i>n</i> = 50) were found to be in the 11–19 years age group. Noncompliance with optical corrections was the reason for the high number of cases. A rigorous vision screening program and refractive services, complimented with awareness among parents and teachers, are recommended.


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.


2004 ◽  
Vol 138 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Evelyn A. Paysse ◽  
M.Bowes Hamill ◽  
Mohamed A.W. Hussein ◽  
Douglas D. Koch

2013 ◽  
Vol 5 (1) ◽  
pp. 38-44 ◽  
Author(s):  
K Sapkota ◽  
A Pirouzian ◽  
NS Matta

Introduction: Refractive error is a common cause of amblyopia. Objective: To determine prevalence of amblyopia and the pattern and the types of refractive error in children with amblyopia in a tertiary eye hospital of Nepal. Materials and methods: A retrospective chart review of children diagnosed with amblyopia in the Nepal Eye Hospital (NEH) from July 2006 to June 2011 was conducted. Children of age 13+ or who had any ocular pathology were excluded. Cycloplegic refraction and an ophthalmological examination was performed for all children. The pattern of refractive error and the association between types of refractive error and types of amblyopia were determined. Results: Amblyopia was found in 0.7 % (440) of 62,633 children examined in NEH during this period. All the amblyopic eyes of the subjects had refractive error. Fifty-six percent (248) of the patients were male and the mean age was 7.74 ± 2.97 years. Anisometropia was the most common cause of amblyopia (p < 0.001). One third (29 %) of the subjects had bilateral amblyopia due to high ametropia. Forty percent of eyes had severe amblyopia with visual acuity of 20/120 or worse. About twothirds (59.2 %) of the eyes had astigmatism. Conclusion: The prevalence of amblyopia in the Nepal Eye Hospital is 0.7%. Anisometropia is the most common cause of amblyopia. Astigmatism is the most common types of refractive error in amblyopic eyes. Nepal J Ophthalmol 2013; 5(9):38-44 DOI: http://dx.doi.org/10.3126/nepjoph.v5i1.7820


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Khashayar Mehdizadehkashi ◽  
Shahla Chaichian ◽  
Abolfazl Mehdizadehkashi ◽  
Ebrahim Jafarzadepour ◽  
Zeinab Tamannaie ◽  
...  

In this research, we represent the changes in visual acuity during pregnancy and after delivery. Changes as myopic shift start during second trimester and will be stopped after delivery; however it is obtained that women will have the same refractive error as what they had in the first trimester, after postpartum. So, any change in their spectacle prescription during this period is forbidden. As a result, not only changing in hormones can cause myopic shift in vision, but also overweight has its retributive role. What we are trying to do is to notify gynecologists and optometrists to be aware of these changes, so as to leave spectacle prescription writing to the session after postpartum period.


2021 ◽  
Vol 19 (6) ◽  
pp. 98-106
Author(s):  
Monawar Muhsin Jabr ◽  
Hussain S. Hasan ◽  
Hind Ahmed Mahdi

Background: Chronic kidney disease (CKD) is a public health problem over all the world. CKD may also be defined by the presence of kidney damage or a reduced glomerular filtration rate (GFR), which is the best overall indicator or index of kidney function. CKD patients are usually treated using kidney dialysis (hemodialysis) that uses a blood filtration mechanism (HD). Several metabolic parameters, such as blood urea, sodium, potassium, and glucose levels, can alter during HD. Osmotic alterations in blood, aqueous and vitreous humor, and other extracellular fluids arise from these fluctuations. That also can affect visual acuity, intraocular pressure (IOP), and retinal thickness. Aim of the Study: To evaluate some of the ocular findings undergoing HD to keep prevent the loss of patient vision such as visual acuity (VA), intraocular pressure (IOP), central corneal thickness (CCT), central Foveal Thickness (CFT), retinal nerve fiber layer (RNFL). Patient& Methods: This is a cohort (prospective) design study. This study including Seventy nine patients divided into two groups the first group from one week to six month (9 femal & 18 males) another group over than six month (36 female & 16 male) the average age between (12 to 70 years). This research performed in the three places department of the eye in Al-Hussein hospital in Samawah city, Al-Haboby hospital, Al-Hussein hospital in Dhi Qar city finally in Al-Shaheed Gazy hospital and Baghdad teaching hospital in Baghdad. Examining Visual Acuity by Snellen chart & auto refractometer, IOP& CCT by (CT.1 Computerized Tonometer TOPCON), RNLF and Central Foveal Thickness by OCT (Carl ZEISS, TOPCON). The inclusion criteria were as follows: all the patients undergoing dialysis from one week to over six months. Exclusion criteria were as follows: the patients have diabetic, any patients have a hereditary disease or glaucoma history or laser therapy, or intraocular injection in the eye before dialysis, the patients have a problem in the eye before dialysis such as cataracts or opacity leads to does surgery, the patients who have a refractive error or wear glass had been also excluded. Result: Includes the results of seventy-nine patients (45 females and 34 males) with chronic kidney disease examined ocular findings before a session of dialysis divided into two groups based on their duration of dialysis. Group one with twenty-seven patients (9 female & 18 male) under dialysis from one week to six months with mean & standard deviation (3.2037, ± 1.89259), group tow with fifty tow patients (36 female & 16 male) under dialysis from the duration over than six months with mean & standard deviation (44.2308, ± 26.24367) respectively. Patients aged (12 to 70 years) had mean age & ± standard deviation (35.1481, ± 12.88918), (44.4038, ± 15.42249) for two groups respectively. Patients in two groups had IOP (Right eye), its mean & standard deviation (15, ± 2.34), (15.69, ± 2.56) for group one & group tow respectively. Also, patients had CCT (Right eye) with mean & standard deviation (5.3467E2, ± 39.00296), (5.2312E2, ± 30.44162) for group one & group tow respectively. Patients had CCT (Left) with mean & standard deviation (5.2878E2, ± 37.55748), (5.2179E2, ± 29.58957) for group one & group tow respectively. Patients in two groups had average thickness RNFL (Right eye) with mean & standard deviation (1.0604E2, ± 25.17551), (95.6154, ± 21.27150) for group one & group tow respectively. Also, patients had average thickness RNFL (left eye) with mean & standard deviation (1.0930E2, ±23.80177), (98.7500, ± 23.77334) for group one & group tow respectively. Conclusions: This study found CCT effective with dialysis tend to be thin (53 patient,18 patient in group one &35 in group two) and that will be had a threefold higher risk of developing glaucoma when compared with thick average because of the IOP value affected by it. Refractive error effective with dialysis & become was more prominent that can be shown in the group two have (40 patient from 52) while (15 patient from27) in the group one although a lot of them corrected to the BCVA. In conclusion high value of the C/D ratio formed about (45.57%, 53.16%) to the right &left eye respectively this value will be form important sign of risk factor to progressive of glaucomatous need to be alert in the future. Also our research reveals CFT effective undergoing dialysis the thick value was (56 in the right eye, 55 in the left eye) high compared with the thin (9 in the right&9 in the left eye) & normal (14 in the right eye, 15 in the left eye). All the two groups of patients will be effected by the duration of dialysis with a time.


1997 ◽  
Vol 7 (3) ◽  
pp. 203-210 ◽  
Author(s):  
R. Brancato ◽  
F. Carones ◽  
A. Morico ◽  
E. Venturi ◽  
L. Vigo ◽  
...  

Purpose. This paper presents the results of the first human trial on the correction of hyperopia using an erodible mask excimer laser delivery system coupled to an axicon. Methods. We treated 17 eyes of 17 patients (age range 34–62 years) for the correction of +3.21 ± 1.04 D (range +1.00 to +4.00 D). The hyperopic correction was made using an erodible mask inserted on the laser optical pathway, to produce a circular ablation measuring 6.5 mm in diameter. An axicon was then used to create a blend transition zone from 6.5 mm up to 9.4 mm in diameter. Eyes were evaluated at one, three and six months after surgery. Results. Reepithelization was always observed by the fifth postoperative day, despite the large area of deepithelization (diameter 9.5 mm). Mean refractive error one month after treatment was −2.44 ± 1.59 D (range 0.00 to −6.50 D). Five eyes (29.4%) had a best corrected visual acuity loss more than two to three lines; all eyes showed mild annular haze not involving the central part of the cornea. Six months after treatment, mean refractive error was −0.88 ± 0.99 D (range +0.50 to −3.00 D). Compared to preoperative status, 13 eyes (76.5%) showed an improvement in uncorrected distance visual acuity (1–8 lines), and 14 eyes (82.4%) showed an improvement in uncorrected vision at reading distance (3–7 lines). Two eyes (11.7%) showed a best corrected visual acuity loss of two of three lines. Conclusions. These preliminary results indicate this approach is effective in reducing hyperopia, while its predictability has still to be proved in a larger treatment group with longer follow-up. A cautious approach to this technique is still advisable, especially for higher hyperopic corrections, in view of the large best corrected visual acuity loss seen in two eyes at six months.


2019 ◽  
Vol 104 (5) ◽  
pp. 616-622 ◽  
Author(s):  
Ching-Yu Cheng ◽  
Ningli Wang ◽  
Tien Y Wong ◽  
Nathan Congdon ◽  
Mingguang He ◽  
...  

BackgroundTo determine the prevalence and causes of blindness and vision impairment (VI) in East Asia in 2015 and to forecast the trend to 2020.MethodsThrough a systematic literature review and meta-analysis, we estimated prevalence of blindness (presenting visual acuity <3/60 in the better eye), moderate-to-severe vision impairment (MSVI; 3/60≤presenting visual acuity <6/18), mild vision impairment (mild VI: 6/18≤presenting visual acuity <6/12) and uncorrected presbyopia for 1990, 2010, 2015 and 2020. A total of 44 population-based studies were included.ResultsIn 2015, age-standardised prevalence of blindness, MSVI, mild VI and uncorrected presbyopia was 0.37% (80% uncertainty interval (UI) 0.12%–0.68%), 3.06% (80% UI 1.35%–5.16%) and 2.65% (80% UI 0.92%–4.91%), 32.91% (80% UI 18.72%–48.47%), respectively, in East Asia. Cataract was the leading cause of blindness (43.6%), followed by uncorrected refractive error (12.9%), glaucoma, age-related macular degeneration, corneal diseases, trachoma and diabetic retinopathy (DR). The leading cause for MSVI was uncorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, corneal disease, trachoma and DR. The burden of VI due to uncorrected refractive error, cataracts, glaucoma and DR has continued to rise over the decades reported.ConclusionsAddressing the public healthcare barriers for cataract and uncorrected refractive error can help eliminate almost 57% of all blindness cases in this region. Therefore, public healthcare efforts should be focused on effective screening and effective patient education, with access to high-quality healthcare.


Author(s):  
Michael X. Repka ◽  
Trevano W. Dean ◽  
Raymond T. Kraker ◽  
David K. Wallace ◽  
Erick D. Bothun ◽  
...  

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