Amblyopia (pronounced am blee OPE ee ah): A condition also known as lazy eye. This loss or lack of normal development in central vision during infancy and early childhood is a leading cause of decreased vision among children.
Anti-VEGF medications: Elevated vascular endothelial growth factor (VEGF), a soluble factor that can be produced in eyes with poor circulation can lead to swelling and the growth of abnormal new blood vessels in the eye. Leaky blood vessels cause swelling such as macular edema and are prone to bleeding, both of which cause decreased vision. Anti-VEGF drugs which inactivate VEGF have revolutionized treatment allowing retina specialists to reduce new blood vessel growth and swelling with periodic injections of anti-VEGF drugs including bevacizumab (Avastin®), ranibizumab (Lucentis®), and aflibercept (Eylea®).
Asteroid hyalosis: Degenerative condition characterized by spherical-shaped opacities within the clear gel (vitreous humor) that fills the eye cavity between the lens (front) and the retina, which lines the back wall of the eye. This can cause floaters and blurred vision.
Contractile membrane: Scar tissue on the surface of the retina that can wrinkle, distorting the retina and causing blurred vision. In some cases, the scar tissue can pull hard enough on the retina to create a retinal hole.
Corneal edema: Swelling of the cornea which is the transparent coating of the eye that covers the iris and pupil. The cornea becomes cloudy like a dirty windshield and this may cause decreased vision.
Cryotherapy: A technique in which a pencil-like probe is placed on the white of the eye (sclera). The tip of the probe becomes very cold and can freeze structures inside the eye. This can be used to create a seal around a retinal tear.
Diabetic macular edema: The term used for swelling in the macula in eyes with diabetic retinopathy, or the center part of the retina which is responsible for providing the sharp, straight-ahead vision used for reading and recognizing faces.
Diabetic retinopathy: A complication of diabetes that causes damage to the blood vessels of the retina—the light-sensitive tissue that lines the back part of the eye, allowing you to see fine detail. Read more >>
Ehlers-Danlos – A genetic connective tissue disease where joints are hyper-extendable and skin is abnormally elastic. This disease is associated with an increased risk of lattice degeneration and retinal detachment.
Epiretinal membrane: A layer of scar tissue that forms over the macula that reduces vision and can warp and contract causing a wrinkling of the retina known as macular pucker. Read more >
Floater: Mobile blurry shadow that partially obscures vision. Floaters are most bothersome when near the center of vision and less annoying when they settle to the side of the vision. They may appear like cobwebs, dust, or a swarm of insects--or in the shape of a circle or oval, called a Weiss ring.
Fluorescein angiography (FA): An imaging technique where a yellow dye called sodium fluorescein is injected into a vein in the arm, allowing a special camera to record circulation in the retina and choroid in the back of the eye. This test can be very useful in diagnosing a number of retinal disorders.
Focal and grid laser photocoagulation: A surgical technique that uses a highly targeted laser light to seal retinal blood vessels and reduce macular edema (swelling).
General anesthesia: The patient is put to sleep using intravenous or inhaled anesthetic drugs. The patient remains unconscious throughout the procedure until the anesthesia is reversed, waking the patient up. This type of anesthesia is typically used for major/prolonged surgical procedures or in patients who cannot tolerate remaining awake during surgery.
Indocyanine green angiography (ICGA): A diagnostic procedure that uses a green dye to illuminate blood flow in the choroid, which is a layer of blood vessels located between the white of the eye (sclera) and the retina that supplies nutrients to the inner eye.
Intraocular pressure (IOP): The pressure in the eye. The eye must have a positive pressure or it would collapse like a hot air balloon without hot air. If the pressure is too high, this can damage the optic nerve as in glaucoma.
Lattice degeneration: A condition that involves abnormal thinning of the retina, most often around the edge. The condition makes patients more vulnerable to developing retinal tears, breaks or holes that could lead to a visually debilitating retinal detachment. Lattice degeneration is characterized by oval or straight patches of thinned retina, sometimes accompanied by pigment clumps or a crosshatching pattern formed by sclerotic vessels.
Macular edema: The term used for swelling in the macula in eyes, or the center part of the retina which is responsible for providing the sharp, straight-ahead vision used for reading and recognizing faces as well as color vision. Read more >
Macular hole: The macula is the small area at the center of the retina where light is sharply focused to produce the detailed color vision needed for tasks like reading. A full-thickness defect in the macula is referred to as a macular hole. Read more >
Marfan syndrome: A connective tissue disease where those affected are abnormally tall with long limbs, fingers and toes. Some with this disease develop life-threatening problems with their aorta and have an increased risk of lattice degeneration and retinal detachment.
MRI (magnetic resonance imaging): A non-invasive imaging technique that uses magnetic fields and radio waves to create images of body tissues and organs that cannot be normally visualized. The patient receives no radiation with this imaging procedure.
Perfluorocarbon liquid: A heavier than water clear liquid that can be injected into the eye to help push the retina back against the eye wall. It is typically placed temporarily into the vitreous during vitrectomy to hold the retina while the retinal surgeon repairs the retina.
Photodynamic therapy (PDT): A treatment for macular degeneration in which a light-activated medicine (verteporfin) is injected into the bloodstream followed by application of a cold laser which targets abnormal blood vessels growing in the macula at the center of the retina.
Posterior vitreous detachment (PVD): A natural change that occurs during adulthood, when the vitreous gel that fills the eye separates from the retina, which is the light-sensing nerve layer at the back of the eye responsible for sight. Read more >
Primary tumor: The first, or original tumor in the body. Also called primary cancer.
Proliferative diabetic retinopathy (PDR): An advanced stage of diabetic retinopathy in which new abnormal blood vessels and scar tissue form on the surface of the retina. The scar tissue can pull on the retina and cause retinal detachment and loss of vision. If blood vessels grow on the iris it can clog the drainage system of the eye causing glaucoma (high pressure in the eye), pain and vision loss.
Pseudoexfoliation syndrome (PEX): Also called exfoliation glaucoma, pseudoexfoliation glaucoma, pseudoexfoliation of the lens, and exfoliation syndrome. An age-related condition in which microscopic white protein ‘flakes’ are deposited primarily on the lens of the eye. These deposits can build up and cause blockage of the eye’s drainage system leading to increased ocular (eye) pressure and glaucoma.
Retina: A thin layer of light-sensitive nerve tissue that lines the back of the eye (or vitreous cavity). Images are focused at its center (known as the macula) and converted to electrical impulses that are carried to the brain by the optic nerve, resulting in sight.
Retinal detachment: A condition where the retina separates from the back of the eye cavity. This may be caused by vitreous gel or fluid leaking through a retinal tear or hole and collecting under the retina causing it to separate from the tissue around it. Read more >
Retinal prosthesis: A method to restore vision in eyes using microelectronic chip technologies to convert light rays to neuronal impulses that can be conveyed to the brain via preserved connections. This method is also referred to as artificial vision, retinal chip, and bionic eye. Read more >
Retinal tear: A rip or discontinuity in the retina, which is the thin layer of light-sensitive nerve tissue that lines the back of the eye and is responsible for sight. Read more >
Retinal vein occlusions: Complication that occurs when there is a blockage of veins carrying deoxygenated blood back from the retinal arteries to the optic nerve. A blockage in the retina’s main draining vein is referred to as a central retinal vein occlusion (CRVO), while a blockage in a smaller vein is called a branch retinal vein occlusion (BRVO). Read more >
Retinitis pigmentosa (RP): A group of inherited (passed down from parents) diseases causing retinal degeneration and blindness. Individuals with RP lose their vision because photoreceptor (light-sensing) cells of the retina gradually degenerate and then die. In most forms of RP (rod-cone dystrophy), night blindness is one of the earliest and most frequent symptoms. Read more >
Scleral buckle: A piece of silicone rubber or sponge sutured to the outer wall of the eye posterior to the rectus eye muscles. The scleral buckle helps to indent the eye to support the peripheral retina and pushes the outer eye against the retina in eyes with a retinal detachment.
Scleral depression: A diagnostic technique where a pencil-like tool is used to press on the outside of the eye while the retina specialist looks inside the eye with an indirect ophthalmoscope. The pressure can be mildly uncomfortable, but allows the retina specialist to see portions of the peripheral retina that cannot otherwise be visualized.
Sedation: A drug-induced state of deep relaxation, sometimes called “twilight sleep,“ where patients are able to respond to commands. This can vary from minimal to deeper sedation, depending on the requirements of the procedure. This type of anesthesia is typically used for shorter surgical procedures if the body tissue being operated can be adequately anesthetized to prevent pain.
Stickler syndrome: A genetic disorder characterized by flattened nose and cheekbones, problems with the skeletal system, hearing loss and lattice degeneration. The vitreous jelly is abnormally liquified which can lead to early onset retinal detachment.
Spectral Domain Optical Coherence Tomography (SD-OCT): A non-invasive test where light rays are bounced off the retina like sonar off the ocean floor or the way ultrasound is used to image structures in the body. The reflected light rays form an image of the layers of the retina and show any abnormalities that may exist.
Ultrasound: An imaging technique that uses high-frequency sound waves to produce images of structures inside the body.
Vaso-occlusive crisis: A painful episode that occurs when sickle-shaped red blood cells in the small blood vessels block the oxygen supply to tissues in the body. This causes inadequate blood flow and permanent injury to that tissue.
Visual hallucinations: A visual perception that has the sense of reality but occurs without external stimulation of the visual system.
• Formed visual hallucination: Includes seeing objects such as people, animals, buildings, etc.
• Unformed visual hallucination: Includes seeing flashes of light, patterns, colors, etc.
Vitrectomy surgery: A procedure undertaken by a specialist where the vitreous gel that fills the eye cavity is removed to provide better access to the retina. This allows for a variety of repairs, including the removal of scar tissue, laser repair of retinal detachments and treatment of macular holes. Once surgery is complete, saline, a gas bubble or silicone oil may be injected into the vitreous cavity to help hold the retina in position while the eye heals.
There are different types of vitrectomy:
- Pars plana vitrectomy is performed by retina specialists to address diseases of the ‘posterior’ (back) segment of the eye cavity, also referred to as the pars plana.
- Anterior vitrectomy is performed by ophthalmologists or retina specialists to address leakage of vitreous gel into the front (anterior) chamber of the eye.
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Vitreomacular traction: Shrinking and pulling away of the eye’s vitreous gel from the macula. This condition, which appears with normal aging, can create a loss of vision if the traction persists in the macula.
YAG laser capsulotomy: Laser procedure used to make a small hole in the posterior capsule which sits directly behind an intraocular lens after cataract surgery. The posterior capsule may become spontaneously cloudy and this procedure can help clear up the vision.