Update history
Last edited: 12 June 2026
|
^ Fabry's disease Rare X-linked recessive inherited lysosomal storage disease with multiple possible system disorders including optic neuropathy.
^ FADH2 Dihydroflavine-adenine dinucleotide. Reduced form of FAD [flavine-adenine dinucleotide]. A product of the citric acid cycle and of the beta oxidation cycle. It is used in the mitochondrial electron transport chain for energy production starting at complex II thus bypassing complex I. In the citric acid cycle it is produced with NADH in the ratio of three NADH to one FADH2. In the fat consuming beta oxidation cycle it is produced in the ratio of one NADH to one FADH2. Each FADHâ‚‚ can yield approximately 1.5 ATP, while each NADH can yield about 2.5 ATP. Its production may be a mechanism where faulty complex 1 function such as in LHON may be compensated for. Riboflavin [vitamin B2] is required for its synthesis in eukaryotes.
Youtube. Electron Transport Chain NADH and FADH2
Yen MY, Lee HC , Liu JH, Wei YH. Compensatory elevation of complex II activity in Leber's hereditary optic neuropathy. Br J Ophthalmol, 1996; 80: 78-81. PMID: 8664239
^ Field, Receptive see Centre Surround
^ Field, Visual see Visual Field
^ Flavonoid
^ Flavone
^ Flicker A type of light stimulus
^ Fovea Retinal area at the posterior pole of the eye, seen with an ophthalmoscope as a red spot, where circuitry for central vision is located. This area is packed with cones in a hexagonal pattern of maximum density. It is devoid of blood vessels, getting its nutrients from the choriocapillaris behind it via transport through Bruch's Membrane. The central foveal pit, 200 microns across, is made almost entirely of cones with the rest of the inner retinal layers displaced laterally along the foveal slope into a foveal rim or parafovea. The parafovea has six layers of ganglion cells making this area the thickest part of the retina. Together with the surrounding perifovea, and the xanthophyll carotenoid pigment of cone axons in this area, all these structures are seen as the Macula Lutea with an ophthalmoscope.
^ Founder effect
^ Free Radical see Radical, Free
^ Friedreich's Ataxia
^ Fundoscope or Funduscope An instrument used to look at the back of the eye (ocular fundus) through the pupil. One function of an ophthalmoscope.
^ Fundus, Oculi
Last edited: 12 June 2026
The International Foundation for
Optic Nerve Disease
P. O. Box 777, Cornwall NY 12518, USA.
Phone/Fax: (845)5348606
Email: ifond@aol.com
Web site:
https://www.ifond.org/
IFOND is registered service mark of
The International Foundation for Optic Nerve Disease, est. October 1995.
Copyright 1999-2026, International Foundation for
Optic Nerve Disease.
The information contained on this website should not be considered medical guidance or professional advice. IFOND is not responsible for errors or omissions in information provided on this site or actions resulting from its use. IFOND does not publish all information from all available sources on optic nerve disease. IFOND is not responsible for the validity of the studies or reviews nor is it an advocate of studies or reviews mentioned on or linked from the IFOND web site. IFOND does not endorse or recommend participation in any particular clinical trial or treatment protocol which may be mentioned on this site. Direct any questions concerning your personal health to your appropriate health care professional.