Visual Acuity, Visual Field and Visual Scene Characteristics Affect Postural Balance1

Introduction: 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 <6/18 to 3/60 or having visual field loss to <20° in the better-seeing eye. Children defined to have “blindness” have presenting vision of <3/60 or corresponding visual field of <10°. Purpose: 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. Methods: 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. Results: 1,591 students were screened and evaluated from the end of 2016 to mid-2017. About 21.37% (n = 340) had impaired vision with 20.9% (n = 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. Conclusion: A significant number of students were detected to have uncorrected refractive errors among the vision impaired group (59%, n = 197) despite a school-based vision screening program in place. Seventy-eight percent of the amblyopia cases (n = 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.

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Visual performance in behaving cats after prenatal unilateral enucleation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.90.23.11142 ◽

1993 ◽

Vol 90 (23) ◽

pp. 11142-11146 ◽

Cited By ~ 5

Author(s):

S Bisti ◽

C Trimarchi

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Receptive Field ◽

Receptive Fields ◽

Direction Selectivity ◽

Visual Performance ◽

Field Size ◽

Electrophysiological Recordings ◽

Severe Impairment ◽

Orientation Columns

Prenatal unilateral enucleation in mammals causes an extensive anatomical reorganization of visual pathways. The remaining eye innervates the entire extent of visual subcortical and cortical areas. Electrophysiological recordings have shown that the retino-geniculate connections are retinotopically organized and geniculate neurones have normal receptive field properties. In area 17 all neurons respond to stimulation of the remaining eye and retinotopy, orientation columns, and direction selectivity are maintained. The only detectable change is a reduction in receptive field size. Are these changes reflected in the visual behavior? We studied visual performance in cats unilaterally enucleated 3 weeks before birth (gestational age at enucleation, 39-42 days). We tested behaviorally the development of visual acuity and, in the adult, the extension of the visual field and the contrast sensitivity. We found no difference between prenatal monocularly enucleated cats and controls in their ability to orient to targets in different positions of the visual field or in their visual acuity (at any age). The major difference between enucleated and control animals was in contrast sensitivity:prenatal enucleated cats present a loss in sensitivity for gratings of low spatial frequency (below 0.5 cycle per degree) as well as a slight increase in sensitivity at middle frequencies. We conclude that prenatal unilateral enucleation causes a selective change in the spatial performance of the remaining eye. We suggest that this change is the result of a reduction in the number of neurones with large receptive fields, possibly due to a severe impairment of the Y system.

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Arteriovenous malformations in the optic apparatus: systematic literature review and report of four cases

Journal of Neurosurgery ◽

10.3171/2021.1.jns204162 ◽

2021 ◽

pp. 1-11

Author(s):

Visish M. Srinivasan ◽

Phiroz E. Tarapore ◽

Stefan W. Koester ◽

Joshua S. Catapano ◽

Caleb Rutledge ◽

...

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Visual Function ◽

Arteriovenous Malformations ◽

Vascular Malformations ◽

Visual Fields ◽

Optic Tract ◽

Visual Disturbance ◽

Visual Field Defects ◽

Subtotal Resection

OBJECTIVE Rare arteriovenous malformations (AVMs) of the optic apparatus account for < 1% of all AVMs. The authors conducted a systematic review of the literature for cases of optic apparatus AVMs and present 4 cases from their institution. The literature is summarized to describe preoperative characteristics, surgical technique, and treatment outcomes for these lesions. METHODS A comprehensive search of the English-language literature was performed in accordance with established Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all published cases of AVM in the optic apparatus in the PubMed, Web of Science, and Cochrane databases. The authors also searched their prospective institutional database of vascular malformations for such cases. Data regarding the clinical and radiological presentation, visual acuity, visual fields, extent of resection, and postoperative outcomes were gathered. RESULTS Nine patients in the literature and 4 patients in the authors’ single-surgeon series who fit the inclusion criteria were identified. The median age at presentation was 29 years (range 8–39 years). Among these patients, 11 presented with visual disturbance, 9 with headache, and 1 with multiple prior subarachnoid hemorrhages; the AVM in 1 case was found incidentally. Four patients described prior symptoms of headache or visual disturbance consistent with sentinel events. Visual acuity was decreased from baseline in 10 patients, and 11 patients had visual field defects on formal visual field testing. The most common visual field defect was temporal hemianopia, found in one or both eyes in 7 patients. The optic chiasm was affected in 10 patients, the hypothalamus in 2 patients, the optic nerve (unilaterally) in 8 patients, and the optic tract in 2 patients. Six patients underwent gross-total resection; 6 patients underwent subtotal resection; and 1 patient underwent craniotomy, but no resection was attempted. Postoperatively, 9 of the patients had improved visual function, 1 had no change, and 3 had worse visual acuity. Eight patients demonstrated improved visual fields, 1 had no change, and 4 had narrowed fields. CONCLUSIONS AVMs of the optic apparatus are rare lesions. Although they reside in a highly eloquent region, surgical outcomes are generally good; the majority of patients will see improvement in their visual function postoperatively. Microsurgical technique is critical to the successful removal of these lesions, and preservation of function sometimes requires subtotal resection of the lesion.

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Distracted Driving and Driving Patterns in Older Drivers With Glaucoma

American Journal of Lifestyle Medicine ◽

10.1177/15598276211042825 ◽

2021 ◽

pp. 155982762110428

Author(s):

Purva Jain ◽

Jonathan T. Unkart ◽

Fabio B. Daga ◽

Linda Hill

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Visual Fields ◽

Distracted Driving ◽

Night Vision ◽

Driving Ability ◽

Safe Driving ◽

Ability To Drive ◽

Acuity Score

Limited research exists examining self-perceived vision and driving ability among individuals with glaucoma, and this study assessed the relationship between glaucoma, visual field, and visual acuity with driving capability. 137 individuals with glaucoma and 75 healthy controls were asked to evaluate self-rated vision, self-perceived driving ability, and self-perceived distracted driving. Visual acuity and visual field measurements were also obtained. Multivariable linear regressions were run to test each visual measure with driving outcomes. The average age was 72.2 years, 57.3% were male, and 72.5% were White. There were significant associations for a one-point increase in visual field and quality of corrected vision (RR = 1.06; 95% CI = 1.03–1.10), day vision (RR = 1.05; 95% CI = 1.03–1.08), night vision (RR = 1.08; 95% CI = 1.05–1.13), visual acuity score and higher quality of corrected of vision (RR = .41; 95% CI = .22-.77), day vision (RR = .39; 95% CI=.22–.71), and night vision (RR = .41; 95% CI = .18–.94); visual acuity score and ability to drive safely compared to other drivers your age (RR = .53; 95% CI = .29–.96). Individuals with poorer visual acuity and visual fields rate their vision and ability to drive lower than those with better vision, and this information will allow clinicians to understand where to target interventions to enhance safe driving practices.

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Visual Acuity, Visual Field and Physical Ability

Ophthalmologica ◽

10.1159/000307457 ◽

1975 ◽

Vol 171 (1) ◽

pp. 100-108 ◽

Cited By ~ 5

Author(s):

M.C. Colenbrander

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Physical Ability

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A preliminary study of the clinical application of optic pathway diffusion tensor tractography in suprasellar tumor surgery: preoperative, intraoperative, and postoperative assessment

Journal of Neurosurgery ◽

10.3171/2015.6.jns1546 ◽

2016 ◽

Vol 125 (3) ◽

pp. 759-765 ◽

Cited By ~ 7

Author(s):

Mohamadreza Hajiabadi ◽

Madjid Samii ◽

Rudolf Fahlbusch

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Diffusion Tensor ◽

Tumor Resection ◽

Visual Pathway ◽

Optic Chiasm ◽

Control Group ◽

Optic Pathway ◽

Dti Tractography ◽

Mass Lesions

OBJECT Visual impairments are the most common objective manifestations of suprasellar lesions. Diffusion tensor imaging (DTI) is a noninvasive MRI modality that depicts the subcortical white matter tracts in vivo. In this study the authors tested the value of visual pathway tractography in comparison with visual field and visual acuity analyses. METHODS This prospective study consisted of 25 patients with progressive visual impairment due to suprasellar mass lesions and 6 control patients with normal vision without such lesions. Visual acuity, visual field, and the optic fundus were examined preoperatively and repeated 1 week and 3 months after surgery. Visual pathway DTI tractography was performed preoperatively, intraoperatively immediately after tumor resection, and 1 week and 3 months after surgery. RESULTS In the control group, pre- and postoperative visual status were normal and visual pathway tractography revealed fibers crossing the optic chiasm without any alteration. In patients with suprasellar lesions, vision improved in 24 of 25. The mean distance between optic tracts in tractography decreased after tumor resection and detectable fibers crossing the optic chiasm increased from 12% preoperatively to 72% postoperatively 3 months after tumor resection, and undetectable fibers crossing the optic chiasm decreased from 88% preoperatively to 27% postoperatively 3 months after tumor resection. Visual improvement after tumor removal 1 week and 3 months after surgery was significantly correlated with the distance between optic tracts in intraoperative tractography (p < 0.01). CONCLUSIONS Visual pathway DTI tractography appears to be a promising adjunct to the standard clinical and paraclinical visual examinations in patients with suprasellar mass lesions. The intraoperative findings, in particular the distance between optic tract fibers, can predict visual outcome after tumor resection. Furthermore, postoperative application of this technique may be useful in following anterior optic pathway recovery.

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Twenty-year outcomes in patients with newly diagnosed glaucoma: mortality and visual function

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2017-311595 ◽

2018 ◽

Vol 102 (12) ◽

pp. 1663-1666

Author(s):

Christopher King ◽

Justin C Sherwin ◽

Gokulan Ratnarajan ◽

John F Salmon

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Open Angle Glaucoma ◽

Survival Curve ◽

Visual Outcome ◽

Field Analysis ◽

Time To Death ◽

Kaplan Meier ◽

Two Stages

Background/aimsTo determine the mortality within 20 years of diagnosis of chronic open-angle glaucoma (COAG) and visual acuity and visual field progression of a cohort followed for 20 years.MethodsTwenty years following the diagnosis of COAG in 68 of 436 (16%) patients seen in a glaucoma case-finding clinic, visual and mortality outcomes were audited from medical records. Causes of death were obtained from general practitioner records and death certificates. Probability of death was calculated using a Kaplan-Meier survival curve. The visual field of each eye of survivors was graded using a nine-stage severity scale. Visual outcome was analysed at the 20-year follow-up visit.ResultsFrom 68, 14 (21%) were lost to follow-up. In the remaining 54, 20 (37%) were alive 20 years after diagnosis. Of 63% who died, mean age of death was 84 years, most commonly due to vascular disease. Mean age at presentation of those who died was 73.7 years versus 63.2 years for survivors (P=0.001). The median time to death was 16 years. On visual field analysis, nearly half (48.9%) of eyes did not deteriorate, but 28.3% eyes deteriorated by more than two stages. Those who died had worse final visual acuity than survivors (P<0.001). Three who died were registered severely visually impaired mainly from macular disease, but no survivors were registered (P<0.001).ConclusionIn this cohort, approximately two-thirds of patients with glaucoma died within 20 years of diagnosis. In most older patients with glaucoma, the overall goal of preventing visual handicap and blindness is achievable 20 years after diagnosis.

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Charles Bonnet syndrome as first manifestation of occipital infarction

European Journal of Ophthalmology ◽

10.1177/11206721211069736 ◽

2022 ◽

pp. 112067212110697

Author(s):

Marta Isabel Martínez-Sánchez ◽

Gema Bolívar

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Field Tests ◽

Visual Field Loss ◽

Visual Hallucinations ◽

Correct Treatment ◽

Cerebral Magnetic Resonance Imaging ◽

Full Field ◽

Charles Bonnet Syndrome ◽

The Right

Purpose To describe a case of Charles Bonnet syndrome as the first manifestation of occipital infarction in a patient with preserved visual acuity. Observations We report a 78-year-old man followed in our department with a two-month-long history of visual hallucinations based on the vision of flowers and fruits intermittently, being perceived as unreal images. Best-corrected visual acuity was stable in the follow-up time being 20/20 in the right eye and 20/25 in the left eye. Extraocular muscle function testing, pupillary reflexes, biomicroscopy, fundus and optical coherence tomography examinations did not reveal any interesting findings. In order to rule out occipital pathology, orbital-cerebral magnetic resonance imaging was performed, showing an image compatible with the chronic ischemic right occipital lesion. The patient was diagnosed with Charles Bonnet syndrome secondary to occipital infarction and neurology decided that no treatment was required. 24-2 and 10-2 visual field tests showed no remarkable alterations and Full-field 120 point screening test showed nonspecific peripheral defects. Hallucinations improved over the months, being described as not annoying and increasingly infrequent. Conclusions and Importance Charles Bonnet syndrome is a condition characterized by the presence of recurrent and complex visual hallucinations in patients with visual pathway pathologic defects. Visual acuity or visual field loss is not a requirement for diagnosis. Charles Bonnet syndrome should be suspected in all patients with non-disturbing visual hallucinations, even though they present good visual acuteness. It will be essential to perform complementary explorations to identify the underlying pathology that allows the starting of a correct treatment option.

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Neuro-ophthalmology: Disorders of Visual Perception, Pupils, and Eyelids

10.1093/med/9780197512166.003.0093 ◽

2021 ◽

pp. 821-833

Author(s):

Shivram Kumar ◽

Kelly D. Flemming

Keyword(s):

Visual Acuity ◽

Visual Field ◽

Visual Perception ◽

Visual Loss ◽

Visual Field Defects ◽

Clinical Disorders ◽

Physical Findings ◽

Abnormal Visual ◽

Visual Changes ◽

Field Defects

Visual loss may develop acutely, subacutely, or insidiously. The course may be transient, static, or progressive. This chapter reviews the causes, diagnosis, and treatment of various disorders resulting in visual loss or abnormal visual perception. In addition, it reviews clinical disorders of the eyelids and pupils. Disorders of visual perception involve visual acuity, color perception, visual field defects, and other visual changes. Historical information and physical findings on examination can help to localize the problem and define the cause.

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