Components of Nutrition
Christopher Cumo in 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.
Ophthalmology
Janesh K Gupta in 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.
N
Anton Sebastian in 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.
Voretigene neparvovec-rzyl for treatment of RPE65-mediated inherited retinal diseases: a model for ocular gene therapy development
Published in Expert Opinion on Biological Therapy, 2020
Thomas A. Ciulla, Rehan M. Hussain, Audina M. Berrocal, Aaron Nagiel
FST is a global measure of retinal sensitivity to light. Given that RPE65 mutation-associated IRD commonly presents with impaired low light sensitivity, FST serves as a relevant visual function test to measure improvement in photoreceptor function. Furthermore, nyctalopia results in decreased ability to perform tasks, including independent navigation, in moderate or low light conditions. The connection between light sensitivity and navigation under low light conditions is proven by the strong relationship found between the post-intervention ability to pass the MLMT at the lowest illuminance level tested (1 lux) and an improvement of FST of >1 log10 units [9,39]. Maguire et al. noted that the ceiling effect associated with the MLMT can partially limit assessment of improvement in functional vision. Pairing the MLMT with the FST overcomes this limitation and corrects for any improvements due to maturation or a learning effect on the MLMT in those in the control group [36].
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.
Retinal dystrophy associated with a Kizuna (KIZ) mutation and a predominantly macular phenotype
Published in Ophthalmic Genetics, 2019
Yue Zhao, Razek Georges Coussa, Meghan J. M. DeBenedictis, Elias I. Traboulsi
A 32-year-old female was referred to the retinal dystrophy clinic at the Cole Eye Institute (Cleveland Clinic, Ohio, USA) for evaluation of a diagnosis of “rod-cone dystrophy”. The patient reported nyctalopia with difficulty navigating in dimly lit environments since her teenage years. Furthermore, she noticed central vision loss followed by progressive peripheral field loss and light-sensitivity during her early twenties. Her medical history was significant for a nonspecific dysautonomia, with episodes of lightheadedness, tachycardia, and diaphoresis, for which evaluations with cardiology and neurology were unrevealing of an underlying etiology. Family history was notable for an older brother diagnosed with “rod-cone dystrophy” at 33 years of age. The patient also had a deceased paternal grandfather who was reportedly night-blind (Figure 1). The patient’s family was of Ashkenazi Jewish of German, Russian, and Ukrainian origins. The patient grew up in Russia prior to immigrating to the United States.
Related Knowledge Centers
- Adaptation
- Congenital Stationary Night Blindness
- Peripheral Vision
- Retina
- Retinol
- Rod Cell
- Vitamin A Deficiency
- Retinitis Pigmentosa
- Injury
- Hemeralopia