refractive error
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Author(s):  
Hiba Khan

Abstract: India has done a very much towards to become a developed country but still India is a part of developing countries and for this reason most of the factors are responsible and from these one of the factor is poverty and their index. Poverty index, directly affect the standard of living in a population , that why various major and minor diseases are occur in the various age groups of people, and Hypermetropia is one of these that can occur due to unhealthy life style. Hyperopia, also termed hypermetropia or farsightedness, is a common refractive error in children and adults. Its effect on an individual and the symptoms produced varies greatly, depending on the magnitude of hyperopia, the age of the individual, the status of the accommodative and convergence system, and the demands placed on the visual system. Individuals with uncorrected hyperopia may experience symptoms such as blurred vision, asthenopia (e.g., headaches and eyestrain) while reading, accommodative/binocular dysfunction, amblyopia, and/or strabismus. This article outlines several discussion points as related to hyperopia: definition and classifications, prevention, clinical presentations, importance of early detection, examination techniques, risks of uncorrected hyperopia, and management strategies. Keywords: Amblyopia, Hyperopia, Refractive error, Strabismus, Visual development.


2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Ammar M Khan ◽  
Derek M. Waldner ◽  
Micah Luong ◽  
Emi Sanders ◽  
Andrew C. S. Crichton ◽  
...  

Abstract Background Accumulating evidence suggests that refractive stabilization occurs rapidly following small incision cataract surgery. Nonetheless, many guidelines still suggest waiting four to 6 weeks before prescribing corrective lenses. This study was undertaken to supplement the existing literature regarding refractive stabilization, and evaluate multiple contributing factors that could dissuade clinicians from confidently correcting refractive error in the early post-operative course following routine cataract surgeries. Methods Adult patients undergoing phacoemulsification cataract surgery with uncomplicated surgeries and post-surgical courses at the Calgary Ophthalmology Centre (Calgary, Alberta, Canada) were included in this prospective observational case series. Exclusion criteria included known corneal dystrophies, infectious keratitis, complicated surgery or toric/multifocal IOLs. Data was collected at weekly intervals for a total of 6 weeks. Collected data included autorefraction, visual acuity, corneal pachymetry, and effective lens position. Results One hundred six eyes of 104 patients were included in this study. Post-operative sphere, cylinder and spherical equivalent were not significantly different at any post-operative week compared with week six, and 80–86% of patients were within 0.5D of last follow-up spherical equivalent at any week. The secondary outcomes of central corneal thickness, effective lens position and visual acuity did, however, exhibit significant differences between early post-operative weeks and last follow-up values. Conclusions These data suggest that refractive error can be effectively measured and corrected as early as one-week post-operatively in the majority of patients, though other measures of post-operative stability including central corneal thickness, effective lens position and visual acuity can require up to 4 weeks to stabilize. Thus a conservative and pragmatic approach may be to wait until 4 weeks post-operatively prior to obtaining refractive correction following uncomplicated phacoemulsification cataract surgery.


Author(s):  
Zahra Tajbakhsh ◽  
Mohammad Reza Talebnejad ◽  
Mohammad Reza Khalili ◽  
Masoumeh Sadat Masoumpour ◽  
Hamideh Mahdaviazad ◽  
...  
Keyword(s):  

2022 ◽  
pp. 126-154
Author(s):  
Marilyn Vricella

Accurate determination of refractive error is one of the most critical components of a pediatric eye examination. According to the National Eye Institute, refractive errors are the most common causes of correctable reduced vision in children. Children with uncorrected refractive error are more likely to have developmental delays, visual-related academic problems, and poor social skills or interactions. In addition to difficulty seeing, uncorrected refractive errors can contribute to developmental deficits of accommodation, binocular vision, and certain forms of strabismus, amblyopia, and perceptual function. The author provides the clinician an in-depth guide on how to determine the refractive error in pediatric patients. The chapter focuses on the specific techniques, advantages and disadvantages, equipment required, and step-by-step procedures for performing retinoscopy, objective refraction, and subjective refraction on children.


2021 ◽  
Vol 3 (4) ◽  
pp. 103-106
Author(s):  
Muhammad Asif Memon ◽  
Naman Akhtar ◽  
Mehak Nazeer ◽  
Nabila Noor ◽  
Kanwal Parveen ◽  
...  

This was a cross-sectional study conducted to explore the patterns of refractive errors found in infantile esotropia patients from newborns to the age of 15 years, attending the Pediatric clinic of Al-Ibrahim Eye Hospital, Karachi, Sindh, Pakistan. Data was collected on a pre-designed proforma.  A total of 79 patients (total of 158 eyes) including 44 males (55%) and 36 females (45%) were recruited. All these patients had infantile esotropia. The study showed out of 79 patients (158 eyes), 89 eyes had hyperopia, 15 eyes had myopic astigmatism, 44 eyes had hyperopic astigmatism, while 4 eyes had mixed astigmatism, and 6 eyes had myopia. The hypermatropia was found to be the most commonly occurring refractive error in infantile esotropia resulting in inward eye deviation.


2021 ◽  
Vol 12 (3) ◽  
pp. 045-056
Author(s):  
Kedar N Prasad

The major eye diseases refractive error, cataract, age-related macular degeneration (ARMD), glaucoma, and diabetic retinopathy can lead to blindness without an early intervention. The treatments include eye glasses for refractive error, surgery for cataract, and medications for glaucoma and ARMD. These therapies do not address oxidative stress and inflammation that contribute to these eye diseases. Therefore, supplementation with antioxidants could be useful. However, administration with single or multiple dietary antioxidants with or without carotenoids (zeaxanthin and lutein), and omega-3-fatty acids, produced no benefits or only modest benefits in certain eye diseases. The problems associated with such antioxidant’s approaches were identified, and potential causes for not producing optimal benefits were presented. The major objectives are to show that enhanced oxidative stress and inflammation contribute to the age-related major eye diseases. This review presents rationales for using a comprehensive mixture of micronutrients containing dietary and endogenous antioxidants, vitamin D3, and carotenoids such as lutein, zeaxanthin, astaxanthin, all B-vitamins, and minerals Zn and Se for simultaneously reducing oxidative and inflammatory damage. Since elevated levels of vascular endothelial growth factor (VEGF) are found in the wet ARMD and diabetic retinopathy, this mixture has ingredients, which reduce VEGF levels. Supplementation with this micronutrient mixture may delay the onset and progression of major eye diseases, and may improve the effectiveness of standard therapy.


2021 ◽  
Vol 15 (1) ◽  
pp. 283-287
Author(s):  
Sulaiman Aldakhil

The choroid is a heavily vascularized tissue located between the retina and sclera and plays a primary role in ocular metabolism. It has recently been suggested that the choroid has the ability to change its thickness and secretion of growth factors. This may play an important role during visual development by adjusting retinal position during growth to support emmetropisation; however, the mechanism by which changes in choroidal thickness (ChT) occur is unclear. This relationship becomes an interesting topic in the clinical field, although conflicting evidence found that these changes in the choroidal thickness may not be associated with the development of refractive errors. Many reports have investigated the changes in the choroid and related factors that affect the ChT. Thus, this review will summarize the current literature related to choroidal thickness in different refractive error groups, determine the factors that influence the thickness of the choroid, and discuss in detail the relationship between the changes in the ChT and ocular elongation, and therefore, the effect of optical defocus on ChT and the development of the refractive error.


2021 ◽  
Vol 12 (1) ◽  
pp. 201
Author(s):  
Yu-Kuei Teng ◽  
Chi-Wu Chang ◽  
Shin-Da Lee

Purpose. This study evaluated whether 3D-based vision training (VT) with visual cortex-activated auditory frequency entrainment and bilateral orbital electrical stimulation (ES) could prevent the progression of myopia among schoolchildren. Methods. In this two-stage, randomized, crossover, single-blind study, pre- and post-logMAR visual acuity and refractive error from 27 schoolchildren with myopia (≤−0.50 D) were evaluated among four groups: (1) sham control with no VT, frequency following response (FFR), or ES (control group); (2) 3D-based VT only (VT group); (3) VT with FFR generated through visual cortex-activated auditory entrainment (VT-FFR group); and (4) VT with FFR and bilateral orbital ES (VT-FFR-ES group). In stage 1, the intervention was administered for 30 min to all groups using a randomized crossover design. In stage 2, the intervention was administered for 30 min/day, 3 days a week, for 4 weeks to evaluate the effectiveness of intervention. Results. Compared with the pre-test, post-test logMAR visual acuity after a single intervention was not significantly different in control and VT groups, but significantly improved in the VT-FFR (−0.08 ± 0.11) and VT-FFR-ES groups (−0.13 ± 0.14). Compared with the pre-test, post-test refractive error by spherical equivalent in VT-FFR-ES group for the 4-week intervention was significantly (<0.001) improved (0.21 D) compared with the control group (−0.1 D). Conclusions. The multicomponent physiotherapeutic intervention of 3D-based VT with auditory FFR and bilateral orbital ES can inhibit the progression of myopia. This intervention can be used as a noninvasive physiotherapeutic approach to prevent or reduce the severity of myopia.


2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Divya Shukla ◽  
Lisa Ostrin

Purpose: The purpose of this study is to understand how the visual activity of highschool students in Houston changed due to quarantine and online learning during the COVID-19 pandemic, and whether these behaviors were different between myopes and non-myopes. Methods: Thirty-one participants (16.3±0.8 years, 8 females), including 12 myopes and 8 non-myopes, wore a Clouclip and Actiwatch for a week. The Clouclip records working distance and the Actiwatch measures light exposure, physical activity, and sleep duration. A questionnaire was also completed regarding demographics, ocular history, and visual behaviors. Results: Data showed that myopic participants engaged in near work (working distances of 10 to <60 cm) for 8.4±2.6 hours on a week day and 6.5±2.1 hours on a weekend day. Non-myopic participants engaged in near work for 6.1±2.7 hours on a week day and 4.5±1.9 hours on a weekend day. While weekend near work was significantly different between refractive error groups (P<.05), weekday near work (P=.08) was not. There were no differences between refractive error groups for daily light exposure (P = .89), time outdoors (P = .44), or sleep duration (P = .80). Conclusions: There was no significant change in sleep duration and physical activity regardless of refractive error over the pandemic, while results revealed a significant decrease in outdoor light exposure and the increase in near and intermediate work, especially with electronic devices such as the computer.


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