A-H
Age-related macular degeneration (AMD):
Disease in which the macula degenerates; the leading cause of vision loss in persons over age 55
Age-Related Eye Disease Study (AREDS):
NIH-sponsored study that proved antioxidants are helpful in slowing the progression of macular degeneration. Part II of this study is ongoing
Amsler grid:
Graph paper-like grid that is used to monitor changes in vision that may indicate age-related macular degeneration
Angiogenesis:
Formation of new blood vessels
Antiangiogenic Treatment:
Treatment that controls disease by stopping new abnormal blood vessels from forming
Antioxidants:
Vitamins and nutrients that can prevent cell damage and help slow the progression of macular degeneration
Anti-VEGF therapy:
Treatment designed to reduce the levels of function of the protein VEGF, which causes new blood vessels to form in wet AMD
Avastin (also Bevacizumab):
See section on Avastin
Bruch’s Membrane:
Thin layer of tissue that helps provide oxygen and nutrition to the retina
Carotenoids:
Naturally-occurring substances found in yellow and orange-colored fruits and vegetables and green, leafy vegetables—beta-carotene and alpha-carotene are responsible for the orange color of carrots, and lycopene for the red color of tomatoes; they are antioxidants that protect against free-radical damage
Cataract:
Clouding of the crystalline lens which results in loss of light transmission to the retina
Central vision:
Images seen from the center of the eye, coming from light received at the macula
Choroid:
A layer in the back of the eye containing blood vessels that nourish the retina; the only source of blood supply for the macula
Choroidal neovascularization (CNV):
Growth of abnormal blood vessels underneath the macula associated with diseases like wet AMD
Clinical trial:
Medical study with patients, to determine if a treatment is safe and effective
Cones:
Specialized light-sensitive cells in the retina that are responsible for sharp central vision and color perception
Cornea:
Clear front surface of the eye responsible for transmitting light to the retina
Dilate:
Temporary enlargement the pupil with special eye drops to allow an eye care specialist to better view the inside of the eye
Drusen:
Yellow deposits comprised of cellular debris and other biological material that accumulate underneath the retina as a person ages; an increase in the number and/or size of drusen is associated with the development and progression of Dry AMD
Dry AMD:
Type of macular degeneration associated with the presence of deposits called drusen that accumulate under the retina; this type of AMD can lead to wet AMD
Endothelial cells:
Cells that make up the lining of blood vessels
Endothelial progenitor cell:
Adult stem cell that resides in bone marrow, and that be called into the circulation and recruited to sites of angiogenesis in wet AMD
Exudative macular degeneration:
Another name for wet AMD
Eylea:
See section on Eylea
Fluorescein angiogram:
Photographic procedure: Colored dye is injected into the patient’s arm, and when the dye reaches the eye, a special camera is used to photograph the blood vessels in the retina
Fovea:
Central part of the macula that provides the sharpest vision
Geographic atrophy:
Deterioration of the light-sensing cells and surrounding tissue in the macula
Fundus Camera and Autofluorescence (AF):
The fundus camera is a low powered microscope with an attached camera—special filters attached to the fundus camera can detect naturally occurring fluorescence (Autofluorescence, AF) in the eye to reveal damaged retinal pigment epithelium cells (RPE); AF is noninvasive and does not require any dye injections
Hot laser:
Laser that is sometimes used for cauterizing the abnormal blood vessels that grow underneath the retina in wet AMD
I-P
Lens:
A clear structure in the front of the eye that bends light to a pinpoint focus on the retina
Low vision specialists:
Specialists who can assist patients who have lost some central vision, through training and use of vision aids
Lucentis:
See section on Lucentis
Macugen:
See section on Macugen
Macula:
Small central area of the retina responsible for the sharp, clear vision needed to look directly at an object
Ocular Coherence Tomography (OCT):
OCT uses light to scan the retina, allowing a doctor to visualize the different layers of the retina and ocular tissues, and it only takes a few minutes to perform; it is noninvasive and no instruments touch the eye, no injections or exposure to intense light is necessary—it monitors the structure of the eye, to evaluate how well different therapies are working
Optic nerve:
Biggest nerve in the eye that connects the retina to the brain, where light is processed into vision
Peripheral vision:
Ability to see objects and movements with side vision, outside the direct line of sight
Photodynamic therapy (PDT):
Type of treatment for wet AMD that involves injections of a light-activated drug that, when exposed to special laser light, destroys abnormal eye blood vessels
Photoreceptors:
Nerve cells in the retina that emit electrical signals when activated by light
Placental growth factor (PlGF):
A protein that stimulates angiogenesis, helps to recruit cells to stabilize newly formed vessels, and recruits bone marrow derived stem cells in wet AMD
Pupil:
Adjustable opening at the front of the eye (the black “hole” in the iris) that expands and contracts to regulate the amount of light entering the eye
Q-Z
Retina:
Light-sensitive lining at the back of the eye that converts light images into nerve signals relayed to the brain
Retinal detachment:
Serious disorder that occurs when part of the retina becomes separated from the back of the eyeball
Retinal pigment epithelium (RPE):
Thin layer of cells deep in the retina that supports and nourishes the light-detecting photoreceptor cells
Retinal Specialist:
Ophthalmologist who specializes in treating diseases of the retina; Retinal Specialists are also surgeons and have completed an additional one to two years of specialty training
Scotomas:
Blind spots in vision
Vascular endothelial growth
factor (VEGF):
Family of proteins that stimulates the growth of new blood vessels—there are four members of the VEGF family, designated -A, -B, -C, -D in humans; VEGF-A is the target for most anti-VEGF therapies, and excess levels of these factors cause new vessels to be leaky
Visual field:
Entire area that can be seen by the eye, including front (central) vision and side (peripheral) vision
Wet AMD:
Serious, advanced form of macular degeneration where new blood vessels grow under the macula and leak fluid and blood; this accumulation of fluid and bleeding causes central vision loss, and if left untreated and scar tissue develops, the vision loss is permanent