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Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
The histories of scurvy, rickets, and osteomalacia, referenced earlier, indicate that attempts to fight deficiency diseases brought vitamins to the fore. Some ailments, known for thousands of years, defied solution until scientists isolated vitamins in the twentieth century. For example, the Chinese, Egyptians, and Greeks documented the failure of vision in poor light, a condition known as night blindness or nyctalopia.85 Greek physician Hippocrates (c. 460–c. 375 BCE)—medicine’s putative founder, though several authors wrote his texts—is thought to have recommended liver’s consumption. In contrast to his recommendation, Egyptians, Indians (not American Indians), and Chinese put liquid from liver into the eyes. Japanese urged ingestion of fish oils and bird livers. As with scurvy, scientists sought the compound effective against nyctalopia common to these treatments. Vitamin A’s 1912 discovery provided the answer.
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Published in Anton Sebastian, A Dictionary of the History of Medicine, 2018
Nyctalopia [Greek: nyx, night + alaos, blind + opia, eye] Night blindness. William Briggs (1642–1704) gave an account of the condition in England in 1684. A classical description was given by William Heberden (1710–1801) in 1768. See night blindness.
Ophthalmology
Published in Janesh K Gupta, Core Clinical Cases in Surgery and Surgical Specialties, 2014
Night blindness (nyctalopia) is a feature of many diseases. Vitamin A is necessary for the conversion of light energy to an electrical signal in the rod outer segments. The rods function at low levels of illumination, so vitamin A deficiency results in night blindness. Difficulty with night vision may indicate an abnormality of rod function and is characteristic of RP. However, any cause of extensive peripheral retinal degeneration, including primary open-angle glaucoma and degenerative myopia, results in peripheral visual field loss and poor night vision. Cataracts cause a general reduction in the amount of light entering the eye and can therefore produce similar symptoms.
Enhanced S-Cone Syndrome Masquerading as TORCH in an Infant and a Toddler
Published in Ocular Immunology and Inflammation, 2023
Ana Navarrete, Milka Matanis-Suidan, Itzhak Hemo, Hadas Mechoulam, Eyal Banin, Radgonde Amer
In the pediatric population, the fundus can be normal or present with white or yellow dots at the level of the RPE.7 Patients typically manifest nyctalopia in early life, with or without decreased VA,7 hypermetropia and clumped pigment in their peripheral retina, characteristically torpedo-like lesions and mottled pigment around vascular arcades.7 Macular manifestations include cystoid changes, retinoschisis,8 circumferential fibrotic scars in the posterior pole with a spared center and subretinal fibrosis8 which can also surround the optic nerve.8 Retinochoroidal neovascularization (RCN) can develop and has been described to occur with an incidence of 15%.9 Subretinal fibrosis and retinochoroidal anastomosis can indicate an early neovascular membrane that involuted.9 Retinal neovascularization is a very rare presentation, reported in one publication only as a sea-fan type.10
An optometrist’s guide to the top candidate inherited retinal diseases for gene therapy
Published in Clinical and Experimental Optometry, 2021
Fleur O’Hare, Thomas L Edwards, Monica L Hu, Doron G Hickey, Alexis C Zhang, Jiang-Hui Wang, Zhengyang Liu, Lauren N Ayton
Across these varying types of IRDs, there is often commonality between the symptoms reported by individuals or noticed by their parents. Individuals with retinal dystrophies commonly report nyctalopia or difficulty seeing at night and this may be reported as inability to see stars in the night sky or a delay in adapting their vison moving from a light to dark room. Upon questioning, symptoms of bumping into objects at dusk or under minimal lighting, sometimes mislabelled as ‘clumsiness’, may have begun in childhood or early adolescence. Inferior field loss may be suggested by difficulty seeing low-lying objects, failing to notice food on a plate or an outstretched hand for a handshake. In the mid-stage of the disease, individuals may report difficulty driving, especially seeing approaching people or cars, and may also complain of glare symptoms, especially under diffuse light, for example on a white, cloudy day.
Low-contrast visual acuity versus low-luminance visual acuity in choroideremia
Published in Clinical and Experimental Optometry, 2021
Laura J Wood, Jasleen K Jolly, Colm D Andrews, Iain R Wilson, Doron Hickey, Jasmina Cehajic‐kapetanovic, Robert E Maclaren
Choroideremia is a progressive X‐linked inherited rod‐cone dystrophy affecting primarily the retinal pigment epithelium (RPE), with secondary degeneration in the photoreceptors and choroid. All males with the CHM gene mutation will show clinical disease signs, although there is some variation in severity and progression rate. Female carriers present with a more varied phenotype, some being mildly affected while others are severely affected with a similar phenotype to male patients.1 Patients present typically during the second decade of life with nyctalopia and progressive visual field loss. Mid‐peripheral retinal degeneration gradually encroaches into the centre affecting visual acuity, while at the same time progressing peripherally. Ultimately this leads to legal blindness, sometimes as soon as the fourth decade. However, the degree of the disease progression is variable.2 Good visual acuity is maintained until very late into the disease process.3 It is therefore necessary to explore alternative visual outcome measures to aid earlier detection of reduced visual function and reliably monitor disease progression. Sensitivity markers play a role in the monitoring of the response to promising gene therapy treatments in patients with milder disease.4,5