Vision loss

Humans visually process the world with varying spatial resolution and can program their eye movements optimally to maximize information acquisition for a variety of everyday tasks. Diseases such as macular degeneration can change visual sensory processing, introducing central vision loss (a scotoma). However, humans can learn to direct a new preferred retinal location to regions of interest for simple visual tasks. Whether such learned compensatory saccades are optimal and generalize to more complex tasks, which require integrating information across a large area of the visual field, is not well-understood...

OBJECTIVES: To summarise and discuss recent findings and future perspectives concerning mitochondrial disorders (MIDs) affecting the retinal ganglion cells and the optic nerve and (mitochondrial optic neuropathy. MON). METHOD: Literature review. RESULTS: MON in MIDs is more frequent than usually anticipated. MON may occur in specific as well as non-specific MIDs. In specific and non-specific MIDs, MON may be a prominent or non-prominent phenotypic feature and due to mutations in genes located either in the mitochondrial DNA (mtDNA) or the nuclear DNA (nDNA)...

Intraocular pressure (IOP) is the most consistent risk factor for progressive vision loss in glaucoma. Cats with recessively inherited feline congenital glaucoma (FCG) exhibit elevated IOP with gradual, painless progression of glaucoma similar to humans and are studied as a model of glaucoma in humans and animals. Here, post-natal development of IOP was characterized in normal domestic cats and in cats with FCG caused by a homozygous LTBP2 mutation. Rebound tonometry (TonoVet(®), ICare Oy, Finland) was used to measure IOP non-invasively, 2-3 times weekly in 63 FCG and 33 normal kittens, of both sexes, from eyelid opening until 3-6 months of age...

Purpose: AMD is the leading cause of human vision loss after 65 years of age. Several mechanisms have been proposed: (1) age-related failure of the choroidal vasculature leads to loss of RPE; (2) RPE dysfunctions due to accumulation of phagocytized, but unreleased A2E (N-retinylidene-N-retinylethanolamine); (3) zinc deficiency activation of calpain and caspase proteases, leading to cell death. The purpose of the present study is to compare activation of calpain and caspase in monkey RPE cells cultured under hypoxia or with A2E...

The Late Pleistocene Shanidar 1 older adult male Neandertal is known for the crushing fracture of his left orbit with a probable reduction in vision, the loss of his right forearm and hand, and evidence of an abnormal gait, as well as probable diffuse idiopathic skeletal hyperostosis. He also exhibits advanced external auditory exostoses in his left auditory meatus and larger ones with complete bridging across the porus in the right meatus (both Grade 3). These growths indicate at least unilateral conductive hearing (CHL) loss, a serious sensory deprivation for a Pleistocene hunter-gatherer...

SIGNIFICANCE: Our study provides the much-needed evidence on causes of childhood blindness in Eritrea. This will assist authorities to plan appropriate strategies and implement preventive, curative, and rehabilitative services to address these causes of vision loss in children in this resource-limited country. PURPOSE: This study aims to identify the causes of severe vision impairment and blindness in children attending the only school for the blind in Eritrea. METHODS: All children enrolled in the school were examined, and the World Health Organization form for the examination of visually impaired children was used to record the data...

BACKGROUND: Chemical irritants used in crowd control, such as tear gases and pepper sprays, are generally considered to be safe and to cause only transient pain and lacrimation. However, there are numerous reports that use and misuse of these chemicals may cause serious injuries. We aimed to review documented injuries from chemical irritants to better understand the morbidity and mortality associated with these weapons. METHODS: We conducted a systematic review using PRISMA guidelines to identify injuries, permanent disabilities, and deaths from chemical irritants worldwide between January 1, 1990 and March 15, 2015...

OBJECTIVES: Visual impairment and blindness are major public health problems causing significant suffering, disability, loss of productivity, and diminishing quality of life for millions of people. This study explored the factors associated with the overall vision-related quality of life (VRQoL) and its different domains in the adult population of Nagorno Karabakh and assessed the independent contribution of specific eye diseases to VRQoL. STUDY DESIGN: A cross-sectional study...

Purpose: Listeners with hearing loss, as well as many listeners with clinically normal hearing, often experience great difficulty segregating talkers in a multiple-talker sound field and selectively attending to the desired "target" talker while ignoring the speech from unwanted "masker" talkers and other sources of sound. This listening situation forms the classic "cocktail party problem" described by Cherry (1953) that has received a great deal of study over the past few decades. In this article, a new approach to improving sound source segregation and enhancing auditory selective attention is described...

Importance: Age-related macular degeneration (AMD) is a leading cause of irreversible blindness among the elderly population globally. Currently, knowledge of the epidemiology of AMD in Australia remains scarce because of a paucity of recent population-based data. Objective: To examine the prevalence of AMD in Australia. Design, Setting, and Participants: In this population-based, cross-sectional survey performed from March 11, 2015, to April 18, 2016, a sample of 3098 nonindigenous Australians 50 years and older and 1738 indigenous Australians 40 years and older from 30 geographic areas across Australia were examined...

Importance: Vision loss is the third most common impairment worldwide. Although cost-effective interventions are available for preventing or curing most causes of vision loss, availability of these interventions varies considerably between countries and districts. Knowledge of the association between vision loss and socioeconomic factors is informative for public health planning. Objectives: To explore correlations of the prevalence of visual impairment with socioeconomic factors at country levels and to model and estimate a socioeconomic-adjusted disease burden based on these data...

More than 26 million Americans suffer with cataracts, and with 3.6 million cataract extractions performed annually in the United States, it is the most common surgical procedure. The integrity of the delicate structures of the eye that mediate vision is dependent on the intraocular pressure (IOP). Yet, IOP acts to compress the vessels within the globe-akin to a Starling resistor-and is a key component that determines the ocular perfusion pressure, defined as the difference between arterial pressure and IOP...

BACKGROUND: The use of weight loss drugs and dietary supplements is common, but safety profiles for these drugs are largely unknown. Reports of toxicity have been published, and the use of these agents should be considered in clinical differential diagnoses. METHODS: We report the case of a patient with toxic leukoencephalopathy and hyponatremia associated with oral consumption of a thermogenic dietary supplement and essential oils. RESULTS: A 30-year-old woman presented after 2 days of headache, blurred vision, photophobia, vomiting, and hand spasms...

Circadian clocks regulate various aspects of photoreceptor physiology, but their contribution to photoreceptor development and function is unclear. Cone photoreceptors are critical for color vision. Here, we define the molecular function of circadian activity within cone photoreceptors and reveal a role for the clock genes Bmal1 and Per2 in regulating cone spectral identity. ChIP analysis revealed that BMAL1 binds to the promoter region of the thyroid hormone (TH)-activating enzyme type 2 iodothyronine deiodinase (Dio2) and thus regulates the expression of Dio2...

No abstract text is available yet for this article.

PURPOSE: Diabetic retinopathy (DR) is one of the most widespread causes of preventable blindness in the world. The most dangerous stage of this condition is proliferative DR (PDR), in which the risk of vision loss is high and treatments are less effective. Fractal features of the retinal vasculature have been previously explored as potential biomarkers of DR, yet the current literature is inconclusive with respect to their correlation with PDR. In this study we experimentally assess their discrimination ability to recognize PDR cases...

Usher syndrome type III (USH3) characterized by progressive loss of vision and hearing is caused by mutations in the clarin-1 gene (CLRN1). Clrn1 knockout (KO) mice develop hair cell defects by postnatal day 2 (P2) and are deaf by P21-P25. Early onset profound hearing loss in KO mice and lack of information about the cochlear cell type that requires Clrn1 expression pose challenges to therapeutic investigation. We generated KO mice harboring a transgene, TgAC1, consisting of Clrn1-UTR (Clrn1 cDNA including its 5' and 3' UTR) under the control of regulatory elements (Atoh1 3' enhancer/β-globin basal promoter) to direct expression of Clrn1 in hair cells during development and down regulate it postnatally...

Bilateral optic disc edema in a diabetic patient may be caused by diabetic papillopathy. We herein report on a patient with bilateral optic disc drusen simulating diabetic papillopathy. A 55-year-old patient with type 2 diabetes presented with decreased vision of 1-month. Diabetic papillopathy was initially considered as there was disc edema in both eyes with focal hemorrhages at the disc margin and mild visual loss. Ultrasound of the optic nerve head revealed optic disc drusen in both eyes and this was also confirmed by the control photograph...

A 75-year-old man presented to us with sudden onset of profound vision loss in his right eye and was identified as suffering from an ophthalmic artery occlusion. Apart from the retinal whitening and box-carring of the retinal arteries, there were characteristic triangular patches of retinal whitening in the midperipheral temporal fundus indicating a previous lateral posterior choroidal artery occlusion. The patient was a chronic smoker and had dyslipidemia. The carotid Doppler study showed complete occlusion of the internal carotid artery...

Traumatic endophthalmitis is a devastating condition that can occur following an open globe injury and result in loss of vision. The use of prophylactic antibiotics is empirical as most surgeons fear complications associated with the same. No systematic review has been performed in English on the role of intravitreal/intracameral antibiotics in preventing traumatic endophthalmitis. We searched for randomized controlled trials and controlled clinical trials comparing intracameral/intravitreal antibiotics with placebos on PubMed, Google Scholar, Science Direct, and Cochrane Library using keywords open globe/trauma/penetrating/perforating injuries endophthalmitis...