Adenosine-5-triphosphate (ATP)
Adenosine-5-triphosphate is the full chemical name of ATP. It is the main medium of energy exchange in living things. When a reaction requires energy to drive it, that energy is usually provided, directly or indirectly, by ATP. When energy-rich molecules like starch or sugar are broken down, the energy is captured in ATP so that it can be used elsewhere.
Living things have transport mechanisms for moving selected molecules across membranes (e.g., from outside a cell to inside, or vice versa). Many of those reactions are driven by energy from ATP. In a nutshell, ATP functions as the energy storage system and the energy transport system for the cells of the body.
Antioxidants
Antioxidants (like lutein and zeaxanthin) are nutrients that stop dangerous free radical (oxidative) damage and degeneration to healthy cells that occur when the numbers of positive and negative electrons in a molecule do not exactly balance. Sometimes initiated by normal metabolic processes within the cell and photochemical damage from ultraviolet and high-energy visible blue light, this activity initiates a chain reaction of electron “stealing” resulting in multiple cell degeneration.
Conditions in the outer retina are optimal for these effects because of the high concentrations of polyunsaturated fatty acids in the photoreceptor outer segment membranes. The resulting damage, including incompletely degraded molecules and impaired function of the retinal pigment epithelium, could lead to macular degeneration.
Lutein acts as an antioxidant in the eye and it is the most effective carotenoid to prevent these fat compounds from losing their electrons and oxidizing in the human serum and the eye. Lutein can help protect the macula against this damage and also maintain the normal function of blood vessels that supply the macular region.
In the blood, lutein is 10 times more active as an antioxidant than Vitamin E and helps diminish the harmful effects of LDL cholesterol. In a 1995 study, it was shown to increase respiration and lower the incidence of lung cancer by 75%.
Carotenoids
Carotenoids are a family of antioxidants that give fruits and vegetables their red or yellow color. The dominant carotenoid pigments in the macular portion of the retina are lutein and zeaxanthin. These yellow pigments filter out visible blue light which, can cause oxidative damage to the retina
Lutein and Zeaxanthin
Lutein and Zeaxanthin are the only carotenoid antioxidants found in the eye.
Cornea
Cornea is the transparent structure forming the anterior part of the fibrous tunic of the eye. It consists of five layers: (1) the anterior corneal epithelium, continuous with that of the conjunctiva, (2) the anterior limiting layer (Bowman’s membrane), (3) the substantia propria, or stroma, (4) the posterior limiting layer (Descemet’s membrane), and (5) the endothelium of the anterior chamber, called also keratoderma.
Drusen
Drusen is composed of 11 known proteins. It “looks like” a yellowish-white fatty substance, but in fact is not fat. It appears as small spots on the macula or elsewhere on the retina. Some drusen spots are described as soft, while others are described as hard; however, these terms are based on looking at them, not by touching them.
Drusen is a waste product of the recycling of constituents of the light-sensing reactions that occur in the rod and cone cells of the retina. These deposits interfere with and eventually block the central vision, often creating gray or even black “spots” in the vision.
Iris
The iris is the colorful part of the eye located behind the Cornea. When we say that a person has green eyes, we really mean that the person has green irises. The iris has muscles that adjust to control how much light goes through the pupil.
Lens
The lens is clear and colorless, and after light enters the pupil, it hits the lens. The lens’ job is to focus light rays onto the back of the eyeball (called the retina). The lens is suspended in the eye by a bunch of fibers.
Macular Lutea
The Macular Lutea is a small yellowish area lying slightly behind the center of the retina that constitutes the region of maximum visual acuity — called also yellow spot.
Optic Nerve
The optic nerve comes out of the back of the eye; it brings all the nerve messages from the retina to the brain. But when light passes through the lens and the image hits the retina, the image is upside-down. So the message that the optic nerve brings to the brain is upside-down, but the brain turns the message right side up.
Pupil
The pupil is the black circular hole in the center of the iris, and it lets light enter the eye. When there is less light it gets larger and when there is more light it gets smaller.
Retina
The retina is tiny (about the size of a U.S. postage stamp), but it’s full of millions of cells that are sensitive to light. It receives blood from the retinal vessels in order to allow it to function correctly. The retina takes the light that it receives through the cornea, pupil, and lens, and changes it into nerve signals that the brain can understand.
Sclera
The Sclera is the dense fibrous opaque white outer coat enclosing the eyeball except the part covered by the cornea.