Low Vision and Aniridia

2010 ◽  
Author(s):  
Jennifer K. Bulmann
Keyword(s):  
Visual Acuity ◽  
Visual Impairment ◽  
Health Care Providers ◽  
Structural Changes ◽  
Contact Lenses ◽  
Peripheral Vision ◽  
Low Vision ◽  
Normal Person ◽  
Normal Vision ◽  
Functional Changes

Aniridia affects many visual aspects of one’s life. This chapter will highlight many of these effects. Functional changes that occur due to aniridia will be discussed. Once the patient’s vision is assessed and goals are established with a thorough eye examination, numerous avenues can be taken to ensure the support of all the patient’s health care providers. Referrals can be made to appropriate professionals to ensure full understanding and management of the ocular condition. Visual acuity is the measurement used to determine vision levels. Normal vision is 20/20, which means that what a normal person sees at 20 feet, the patient sees at 20 feet. If their vision is 20/40, they would need to be at a distance of 20 feet to see what someone with normal vision can see at 40 feet. The decrease in visual acuity in those with aniridia usually ranges from under 20/60 to as low as approximately 20/400. This is due to the lack of development of the macular area, or fovea. The fovea is responsible for our clearest, most precise vision. Those with visual acuity of 20/200 or worse that is best corrected while wearing spectacles or contact lenses in the better-seeing eye are considered legally blind. While most people who suffer from aniridia are not legally blind, they are visual impaired. Visual impairment is defined as visual acuity of 20/70 in the better-seeing eye when optimally corrected with glasses or contact lenses. The designation of “visual impairment” also has a functionality factor. If a person has a reduction in the ability of the eye or the visual system to perform to a normal ability, he/she is considered visually impaired. Visual field is the measurement of peripheral vision. Those with aniridia may have decreased peripheral vision. This is not directly due to aniridia, but rather to glaucoma, which may develop due to structural changes in the eye. Glaucoma is explained in detail in the glaucoma chapter of this book.

scholarly journals Implications of a Remote Study of Children With Cerebral Visual Impairment for Conducting Virtual Pediatric Eye Care Research: Virtual Assessment Is Possible for Children With CVI

2021 ◽  
Vol 15 ◽  
Author(s):  
Reem Almagati ◽  
Barry S. Kran
Keyword(s):  
Visual Acuity ◽  
Visual Impairment ◽  
Low Vision ◽  
Typically Developing ◽  
Typically Developing Children ◽  
Parent Questionnaire ◽  
Low Vision Clinic ◽  
Age Range ◽  
Vision Function ◽  
E Mail

The Pandemic of 2020 impacted conducting in-person research. Our proposed project already had an asynchronous online component but was later morphed to add a synchronous online component, thereby eliminating the need for in-person assessment. The project compares the results of various tests between a group of children with Cerebral Visual Impairments (CVI) (N = 4) and an age-matched sample of children without CVI (N = 3) from a pediatric low vision clinic. This model was trialed with a small convenient sample of typically developing children in the same age range (N = 4). Given the positive feedback, recruitment for the larger study was done via encrypted e-mail rather than through traditional mailing. The asynchronous components included recruitment, pre-assessment information, the Flemish CVI questionnaire, Vineland-3 comprehensive parent questionnaire for assessment of age equivalent, and vision function tests, such as contrast sensitivity. The synchronous components were administered via Zoom telehealth provided by necoeyecare.org and included assessment of visual acuity via the Freiburg Visual Acuity and Contrast Test (FrACT) electronic software and assessment of visual perceptual batteries via the Children’s Visual Impairment Test for developmental ages 3–6-years (CVIT 3–6). Our virtual testing protocol was successful in the seven participants tested. This paper reviews and critiques the model that we utilized and discusses ways in which this model can be improved. Aside from public health considerations during the pandemic, this approach is more convenient for many families. In a broader perspective, this approach can be scaled for larger N studies of rare conditions, such as CVI without being confined by proximity to the researcher.

Loss of vision

2018 ◽  
Author(s):  
Susan Mollan ◽  
Alastair Denniston
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Low Vision ◽  
Visual Field Loss ◽  
Age Related Macular Degeneration ◽  
World Health ◽  
Clinical Approach ◽  
Loss Of Vision ◽  
P Loss ◽  
Age Related

Loss of vision describes a reduction in vision that cannot be corrected by glasses or contact lenses. Patients who complain of changes in their vision may have loss of visual acuity, distorted vision, or visual field loss. The World Health Organization classifies visual impairment as blindness or low vision. Blindness is defined as visual acuity of less than 3/60 in the better eye. Low vision is present when the visual acuity is less than 6/18 but equal to or better than 3/60, in the better eye. The etiology of permanent visual loss is diverse and depends on the region studied. In the UK, the leading causes are age-related macular degeneration, glaucoma, diabetic retinopathy, optic atrophy, and cataract. This chapter describes the clinical approach to the patient with loss of vision.

scholarly journals Remote vision testing: Validation of a simple home-printable vision screening test for telemedicine

2020 ◽  
Author(s):  
Michael D Crossland ◽  
Tessa M Dekker ◽  
Joanne Hancox ◽  
Matteo Lisi ◽  
Thomas A Wemyss ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Confidence Interval ◽  
Visual Impairment ◽  
Low Vision ◽  
Clinical Test ◽  
Vision Screening ◽  
Tertiary Centre ◽  
Wide Range ◽  
And Control ◽  
Acuity Test

Objectives: to develop and validate a simple paper vision test (the Home Acuity Test or HAT) for ophthalmology telemedicine appointments, which can be used by people who are digitally excluded. Design: Bland Altman analysis of the HAT chart, compared to the last measured visual acuity on a standard clinical test. Setting: Routine outpatient ophthalmology telemedicine clinics in a tertiary centre. Participants: 50 control subjects with no eye disease and 100 consecutive adult ophthalmology outpatients from strabismus and low vision telemedicine clinics. Participants were excluded if they reported subjective changes in their vision. Main outcome measures: For control participants, test/retest variability of the HAT and agreement with standard logMAR visual acuity measurement. For ophthalmology outpatients, agreement with the last recorded clinic visual acuity and with ICD11 visual impairment category. Results: For control participants, HAT test/retest variability was -0.012 logMAR (95% CI: -0.25 to 0.11 logMAR). Agreement with standard vision charts was -0.14 logMAR, with a 95% confidence interval of -0.39 to +0.12 logMAR (figure 3). For ophthalmology outpatients, agreement in visual acuity was -0.10 logMAR (one line on a conventional logMAR sight chart), with the HAT indicating poorer vision than the previous clinic test. The 95% confidence interval for difference was -0.44 to +0.24 logMAR. Agreement in visual impairment category was good for patients (Cohen's K test, K = 0.77 (95% CI, 0.74 to 0.81), and control participants (Cohen's K test, K = 0.88 (95% CI, 0.88 to 0.88). Conclusions The HAT can be used to measure vision by telephone for a wide range of ophthalmology outpatients with diverse conditions, including those who are severely visually impaired. Test/retest variability is low and agreement in visual impairment category is good.

Visual acuity and risk of overall, injury-related, and cardiovascular mortality: the Kangbuk Samsung Health Study

2021 ◽  
Author(s):  
So Young Han ◽  
Yoosoo Chang ◽  
Hocheol Shin ◽  
Chul Young Choi ◽  
Seungho Ryu
Keyword(s):  
Visual Acuity ◽  
Visual Impairment ◽  
Cardiovascular Mortality ◽  
Health Study ◽  
Normal Vision ◽  
Vital Status ◽  
Hazard Ratios ◽  
Risk Of Mortality ◽  
Increased Risk

Abstract Aims  The associations of visual impairment (VI) with cardio-metabolic risk factors have been reported but its association with cardiovascular mortality remains uncertain. Therefore, we evaluated the association of visual acuity (VA) with overall, injury-related, and cardiovascular mortality. Methods and results A cohort study was performed in 580 746 Korean adults (average age, 39.7 years) who were followed for a median of 8.1 years (maximum, 16 years). Presenting VA was measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Visual acuity in the better vision eye was categorized as normal vision (≥0.8), lowered vision (0.5–0.8), mild visual impairment (VI) (0.3–0.5), or moderate to severe VI (<0.3). Vital status and cause of death were ascertained through linkage to national death records. During 4 632 892.2 person-years of follow-up, 6585 overall deaths, 974 cardiovascular deaths, and 1163 injury-related deaths were identified. After adjustment for possible confounders, the multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for overall mortality among participants with lowered vision, minimal VI, and moderate to severe VI were 1.21 (1.13–1.29), 1.26 (1.15–1.37), and 1.54 (1.40–1.68), respectively, compared with those with normal vision. The corresponding HRs (95% CIs) for injury-related mortality were 1.12 (0.96–1.32), 0.98 (0.76–1.26), and 1.36 (1.04–1.79), respectively, and the corresponding HRs (95% CIs) for cardiovascular mortality were 1.32 (1.12–1.57), 1.43 (1.15–1.77), and 2.41 (1.94–2.99). Conclusion  In this large cohort of young and middle-aged individuals, VI was associated with increased risk of mortality especially due to cardiovascular disease.

scholarly journals Prevalence of visual impairment among school children in three primary schools of Sekela Woreda, Amhara regional state, north-west Ethiopia

2019 ◽  
Vol 7 ◽  
pp. 205031211984976 ◽  
Author(s):  
Mengistu Zelalem ◽  
Yekoye Abebe ◽  
Yilikal Adamu ◽  
Tewodros Getinet
Keyword(s):  
Visual Acuity ◽  
Confidence Interval ◽  
Visual Impairment ◽  
Color Vision ◽  
School Children ◽  
Odds Ratio ◽  
Adjusted Odds Ratio ◽  
Low Vision ◽  
Color Vision Deficiency ◽  
Factors Associated

Background: Although there are limited studies, recent data are lacking to determine the prevalence of eye problems in Ethiopia accurately and there is no scientific evidence of such study in Sekela Woreda. The purpose of this study was to determine the prevalence of visual impairment among school children in Sekela Woreda, Ethiopia. Methods: The study design was a community-based analytical cross-sectional with a multi-stage cluster random sampling technique from September to November 2016.Visual acuity was tested using Snellen’s “E” chart while color vision was tested using Ishihara chart. The data were analyzed using SPSS version 20 software, and binary logistic regression was used to identify factors associated with visual impairment. Results: A total of 875 participants, 466 (53.3%) males and 409 (46.7%) females, with an age range of 8–18 years were screened for visual acuity and color vision deficiency. The prevalence of visual impairment (visual acuity ⩽ 6/12) in “either eye” was 70 (8.0%). Among these, 37 (52.9%) were males and 33 (41.1%) were females. The prevalence of low vision (visual acuity [Formula: see text]) and blindness (visual acuity < 3/60) in “either eye” were 28 (3.2%) and 10 (1.1%), respectively. Thirty two (3.7%) had mild visual impairment [Formula: see text]. The prevalence of color vision deficiency was 36 (4.1%). Among these, 27 (3%) were males and 9 (1.1%) were females. The variables age (adjusted odds ratio (95% confidence interval) = 1.14 (1.01–1.28) and color blindness (adjusted odds ratio (95% confidence interval) = 3.93(1.69–9.09) were significantly associated with visual impairment. Conclusion: The prevalence of blindness and low vision in school children were higher than the national prevalence in Ethiopia. Increasing age and color defective vision were factors associated with the children’s visual impairment. The Woreda health office ought to work with responsible stakeholders to tackle the situation in early childhood.

scholarly journals The Prevalence of Visual Acuity Impairment among School Children at Arada Subcity Primary Schools in Addis Ababa, Ethiopia

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Haile Fentahun Darge ◽  
Getahun Shibru ◽  
Abiy Mulugeta ◽  
Yinebeb Mezgebu Dagnachew
Keyword(s):  
Visual Acuity ◽  
Visual Impairment ◽  
School Children ◽  
Primary Schools ◽  
Low Vision ◽  
Addis Ababa ◽  
Care Service ◽  
Health Care Service ◽  
Cross Sectional Study ◽  
Cross Sectional

Background. Visual impairment and blindness are major public health problems in developing countries where there is no enough health-care service. Objective. To determine the prevalence of visual impairment among school children. Materials and Methods. A school-based cross-sectional study was conducted between 15 June 2015 and 30 November 2015 at Arada subcity primary schools, Addis Ababa, Ethiopia. Two schools were selected randomly, and 378 students were screened from grades 1 to 8 using systematic random sampling method. Snellen chart was used for visual acuity test. Students who had visual acuity of ≤6/12 were further examined by an ophthalmologist to diagnose the reason for low vision. Data was analyzed using SPSS version 20. Results. A total of 378 students were screened, and 192 (50.8%) were females and the remaining 186 (49.2%) were males. The prevalence of visual impairment (VA) of ≤6/12 on either eye was 5.8%, VA < 6/18 on either eye was 1.1%, and VA < 6/18 on the better eye was 0.53%. In this study, color blindness [OR: 19.65, 95% CI (6.01–64.33)] was significantly associated with visual acuity impairment. Conclusion. The prevalence of visual impairment among school children in the study area was 5.8% and school screening is recommended.

scholarly journals Comparitive clinical study on the effect of Mahatriphaladi Ghrita Tarpana and Jeevantyadi Ghrita Tarpana in Parathama Patalagata Timira w.r.t. Keratoconus

2019 ◽  
Vol 4 (06) ◽  
Author(s):  
Jyothi S. ◽  
Ravindra Angadi ◽  
Vikram S.
Keyword(s):  
Clinical Study ◽  
Visual Impairment ◽  
Structural Changes ◽  
Contact Lenses ◽  
Conical Shape ◽  
Progressive Myopia ◽  
Degenerative Disorder

Keratonus is one of the important causes of progressive myopia and its incidence is 1 in 500 worldwide. Keratoconus is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than the more normal gradual curve. Keratoconus typically starts at puberty as a progressive myopia causing substantial distortion of vision and marked astigmatism rapidly. This results in significant visual impairment leading to problems in doing routine works like driving and reading. Only temporary measures like Contact lenses and Surgery are available. In Ayurvedic terms, it can be correlated with Prathama Patalagata Timira. As Tarpana is considered to be supreme among all the Kriyakalpas in treating timira, it has been selected for the study. Giving due importance to the doshas and the site of pathology involved, Jeevantyadi Ghrita and Mahatriphaladi Ghrita are selected. Hence a clinical study has been done to compare the efficacies of Mahatriphaladi ghrita tarpana and Jeevantyadi Ghrita tarpana in Keratoconus.

scholarly journals Eyewear for Rugby Union: Wearer Characteristics and Experience with Rugby Goggles

2020 ◽  
Vol 41 (05) ◽  
pp. 311-317
Author(s):  
Julie-Anne Little ◽  
Fabienne Eckert ◽  
Marc Douglas ◽  
Brendan T. Barrett
Keyword(s):  
Visual Impairment ◽  
Contact Lenses ◽  
Peripheral Vision ◽  
Rugby Union ◽  
Positive Experience ◽  
Eye Protection ◽  
Item Questionnaire ◽  
Increased Risk ◽  
Refractive Correction ◽  
Common Problems

AbstractUnlike many other sports, Rugby Union has not permitted players to wear spectacles or eye protection. With an industrial partner, World Rugby developed goggles suitable for use while playing rugby for the purposes of growing participation amongst those that need to wear corrective lenses. This study reports on the profile and experiences of goggle wearers. 387 players received the goggles. Data were obtained from 188 (49%) using an online, 75-item questionnaire. 87% “strongly agreed/agreed” that goggles are beneficial and 75% are happy with goggle performance. Common problems reported by 49.7 and 32.6% of respondents were issues with fogging-up and getting dirty. 15 (8%) players stopped wearing the goggles because of fogging-up, limits to peripheral vision and poor comfort/fit. Injuries were reported in 3% of respondents. In none of these cases did the player stop wearing the goggles. From the positive experience of players in the trial, the goggles were adopted into the Laws of the game on July 1, 2019. As the need to correct vision with spectacles is common, and contact lenses are not worn by 80%+of spectacle wearers, the new Rugby goggles will widen participation for those that need to wear refractive correction, or have an existing/increased risk of uniocular visual impairment.

The Effect of Visual Impairment on the Strength of Children's Hip and Knee Extensors

1997 ◽  
Vol 91 (1) ◽  
pp. 40-46 ◽  
Author(s):  
L. Wyatt ◽  
G.Y. Ng
Keyword(s):  
Body Weight ◽  
Visual Impairment ◽  
Low Vision ◽  
Knee Extensors ◽  
Lean Body Weight ◽  
Normal Vision ◽  
Body Build ◽  
Blind Children ◽  
Congenitally Blind ◽  
Leg Extensors

A test of the strength of children's hip and knee extensors found that children who were congenitally blind or had low vision had weaker knee extensors than did sighted children, but that after the correction for lean body weight (LBW), these differences were not significant. The children who were blind or had low vision also had weaker hip extensors, but after LBW correction, only the blind children's hip extensors were weaker than those of the children with normal vision. The findings indicate that congenitally blind children may be prone to develop weak leg extensors because of poor body build or the constraints of blindness and that they require extensive physical intervention during infancy.

scholarly journals Mild Visual Impairment and Its Impact on Self-Care Among Older Adults

2016 ◽  
Vol 30 (3) ◽  
pp. 327-341 ◽  
Author(s):  
Rachel O’Conor ◽  
Samuel G. Smith ◽  
Laura M. Curtis ◽  
Julia Yoshino Benavente ◽  
Daniel P. Vicencio ◽  
...  
Keyword(s):  
Older Adults ◽  
Primary Care ◽  
Visual Acuity ◽  
Visual Impairment ◽  
Task Performance ◽  
Health Information ◽  
Health Care Systems ◽  
Self Care ◽  
Normal Vision ◽  
Care Systems

Objective: To determine the prevalence of mild visual impairment (MVI) among urban older adults in primary care settings, and ascertain whether MVI was a risk factor for inadequate performance on self-care health tasks. Method: We used data from a cohort of 900 older adults recruited from primary care clinics. Self-management skills were assessed using the Comprehensive Health Activities Scale, and vision with corrective lenses was assessed with the Snellen. We modeled visual acuity predicting health task performance with linear regression. Results: Normal vision was associated with better overall health task performance ( p = .004). Individuals with normal vision were more likely to recall health information conveyed via multimedia ( p = .02) and during a spoken encounter ( p = .04), and were more accurate in dosing multi-drug regimens ( p = .05). Discussion: MVI may challenge the performance of self-care behaviors. Health care systems and clinicians should consider even subtle detriments in visual acuity when designing health information, materials, and devices.

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