Eye Dictionary: V
V
valacyclovir. This is an antiviral pill, used in ophthalmology for cases of herpetic eye disease or with shingles (zoster) outbreaks. This medicine is usually referred to as the trade name Valtrex.
Valtrex. This is the trade name for valacyclovir, an antiviral pill used in cases of viral eye infection (such as herpetic eye disease or a shingles infection). It is longer lasting than the alternative acyclovir, so it doesn't have to be taken as frequently. Valtrex may be slightly more powerful than acyclovir as well.
vancomycin. This is a "hard core" IV antibiotic that is traditionally used for hospitalized patients with MRSA infections. We use vancomycin eye drops when treating bad corneal ulcers. This medicine is not available in eye drop form and must be specially created by a compounding pharmacy as a fortified antibiotic drop.
Varilux. This is a high quality progressive lens used in no-line bifocals. Progressive lenses are a type of no-line bifocal that gets stronger the further down the glasses you look. Many people like progressive lenses because they can "dial in" the amount of bifocal they need by tilting their head. Other people find progressives uncomfortable, however, because of the distortion in their lower vision. The Varilux brand of progressive lenses are of a higher quality and seem to be better tolerated with less distortion.
VEGF. This stands for Vascular Endothelial Growth Factor. VEGF is a hormone released from the retinal cells when they become hungry for oxygen. This hormone is meant to stimulate the formation of new blood vessels. The most common causes of VEGF over production are from diabetic retinopathy or a central retinal vein occlusion. When VEGF is released, new blood vessels form to supply the oxygen demand. This process is called neovascularization. Unfortunately, these new blood vessels are abnormal and have a tendency to bleed, scar, and contract, leading to serious visual consequences. Anti-VEGF medications are the hottest topic in ophthalmology these days because these medications can be injected into the eye to fight off these bad vessels. Anti-VEGF medications also decrease capillary leakage, which has made them a good treatment for wet macular degeneration as well. Avastin is the first of the anti-VEGF drugs. Since its advent, there have been newer drug variations that may be more specific for the eye such as Lucentis and Eylea. All of these medications are injected directly into the eye so that they can target the retina directly with less systemic side effects.
vertex distance. This is the distance measured from the eye surface (the cornea) to the back of a glasses lens. This distance is different for everyone, but on average is about 1.4 centimeters. This measurement can be important when choosing and fitting glasses frames (especially with strong glasses prescriptions). Vertex distance is also important when converting a glasses prescription to a contact lens prescription.
Vigamox. This is a powerful fluoroquinolone antibiotic containing moxifloxacin. This is an excellent antibiotic for treating corneal infections, especially in contact lens wearers. Alternative brands like Moxeza have come out with the same active ingredient. Similar antibiotic medications include Zymaxid (gatifloxacin) and Besivance (besifloxacin).
viral conjunctivitis. Also known as "pink eye," this is a viral infection in the eye that makes the conjunctiva red and irritated. The conjunctiva is the thin layer of skin that covers the white of your eye. This skin layer is extremely thin, but you can see it when looking in the mirror as blood vessels course through the skin. When you get an infection of this delicate skin layer, the blood vessels dilate and the eye appears to be "pink." In adults, the majority of eye infections (conjunctivitis) are from viral sources - it's like getting the flu, but instead of getting head or chest congestion, the eye is involved. Just as with the flu, there is no good treatment for viral infections other than letting the infection run its course. Viral conjunctivitis is highly contagious. If you have it, wash your hands frequently and don't share towels or makeup. It may take up to two weeks for the infection to clear and the conjunctivitis may jump to the other eye before the end. If there are any visual changes, the eye needs to be rechecked to make sure there is no corneal involvement (i.e., corneal ulcer formation).
Viroptic. This is an eye drop containing trifluridine that is used to fight viral infections of the eye, such as in herpetic eye disease. While effective, the drop can be a little harsh on the ocular surface with prolonged use. Sadly, there aren't many antiviral alternatives available in this country. Zirgan is a new antiviral ointment that may be better tolerated as it requires less frequent dosing.
Visine. Visine is a brand of over-the-counter eye drops. The original formula contained the drug tetrahydrozoline, a stimulant that makes the blood vessels on the surface of the conjunctiva constrict and shrink. This makes the eyes look whiter and thus it "gets the red out." This effect is short-lived and many people have a rebound effect where the eye turns redder after the drug wears off. Overall, Visine doesn't fix anything and may not be healthy as it decreases blood supply to the irritated tissues. Johnson & Johnson has expanded the Visine brand name to include an entire line of rewetting and allergy drops, so read the label to see what you're actually buying.
vision. The most important component of an eye exam is the measurement of the actual quality of the central vision. We measure this by having you read an eye chart (the Snellen chart) and tweaking the vision by having you look through the phoropter (the machine with all the lenses inside used for checking your prescription). Some patient's vision is so bad that we can't measure and document vision using an eye chart. In these cases we measure other things, like the ability to count fingers and see hand movement. If the vision is really bad, we measure the detection of light. Most of these measurements require feedback from our patients, which makes visual acuity hard to check in young children or non-verbal patients. In these cases we estimate vision by seeing if the eye tracks objects and blinks to bright lights.
visual field. This is a test to measure your peripheral vision. There are many ways to check side vision, but when we say we're going to get a "visual field" we are usually talking about the Humphrey Visual Field. This is a computer-controlled machine that maps out peripheral vision in an objective and precise manner. You wear an eye patch over one eye and sit forward in a bowl of light. While you stare straight ahead at a fixed point, the computer shines a spot of light in various places in your peripheral vision. Every time you see the light, you click the buzzer and the computer maps this data for us. Visual fields are very useful for detecting vision loss in patients with glaucoma. Because a third of the brain is devoted to the visual pathway (and processing of visual images), neurologic problems can be detected and localized with a visual field as well.
vitamins. There has been much research on the effect of vitamins on the eye. Vitamin A in particular seems to be important to the health of the rods and cones as this vitamin is key to the conversion of light images into an electrical signal that can be interpreted by our brain. One of the treatments attempted for people with retinitis pigmentosa (a derangement of the photoreceptors) is high doses of Vitamin A. Other vitamins have been studied in relation to macular degeneration. The AREDS Study found that a combination of Vitamin A (beta-carotene), C, and E (along with the minerals zinc and copper) seemed to slow the progression of vision loss in macular degeneration. See the AREDS Study and AREDS 2 Study for more information on this topic.
vitrectomy. This is a surgery to remove the vitreous fluid from the back of the eye and replace it with saline water. This procedure is performed by a retinal specialist and is commonly performed to help repair retinal detachments. Vitrectomy is also used to remove blood from a vitreous hemorrhage and as part of membrane peel surgery for epiretinal membranes and macular holes. This surgery used to take many hours to perform, but with modern techniques and shrinking instrumentation, it is becoming faster and less traumatic.
vitreous. This is the fluid that fills the back of the eye. The eye is mostly a hollow structure. The large back chamber is filled with vitreous humor, which is a fluid that has the consistency of Jell-O. In fact, if you were to "theoretically" open up a young person's eye and remove the contents, the vitreous would come out as a single glob of clear "goop." As we get older, the vitreous begins to liquefy, with pockets of saline water forming inside the gel. At some point in our life, the mixture gets so watery that the remaining gel will contract inwards upon itself and cause flashes, floaters, and sometimes a retinal detachment. This contraction event is common and called a vitreous detachment.
vitreous detachment. A common cause for flashes and floaters, a vitreous detachment is when the "gel" in the back of the eye contracts inwards upon itself. Let me explain. The eye is mostly a hollow structure. In many ways, the eye is like a water balloon sitting inside your eye socket. The eye is not filled with water, however, but is filled with a clear fluid called the vitreous jelly. This jelly has the consistency very much like Jell-O. In childhood, the vitreous gel is firm and well-formed, but as we get older the gel gets "runny" and "watery." Little pockets of saline water form inside the gel, and while this sounds bad, it really isn't a problem. Both the gel and the water are clear and we can see through them just fine. At some point in our life the vitreous gel can become so watery that one day, without warning, the remaining vitreous gel can suddenly collapse inward upon itself. This causes flashing lights and floaters. If you want to use a metaphor, think of the eyeball like a Tupperware bowl filled to the brim with Jell-O. Now, imagine what would happen if you put that bowl of Jell-O on your kitchen counter and then you went on vacation for several months. With time, the Jell-O will evaporate and dehydrate until it collapses and falls in upon itself like a big "blob" in the middle of the bowl. A similar process happens inside the eye. The vitreous gel peels off the retina inside the eye. The retina detects light, so that as the gel peels off it, many people will see a flash of light like a lightning bolt in their peripheral vision. In addition, many people complain of a new, large floater in their vision. This occurs when a little bit of cellular debris pulls off the optic nerve as the gel peels away from it. This little piece of junk is now floating inside the eye, hovering at the gel-water interface, casting shadows inside the eye that you can see as the gel wobbles around. In rare cases, the vitreous gel can actually rip a small hole in the retina itself. This is bad, because a retinal hole can extend and turn into a full-on retinal detachment with loss of vision. Anyone with new symptoms of flashing lights or new floaters needs a dilated eye exam to look for these retinal tears. If the initial retinal examination shows a healthy retina, I usually have my patients return in a few weeks for a recheck to make sure nothing new has formed. The flashing lights and floaters will diminish with time, though the floater can sometimes take a long time (months or years) to disappear (and sometimes it never does entirely). There is no safe way to make these floaters go away short of a vitrectomy surgery (not recommended).
vitreous hemorrhage. This is the term used to describe blood inside the eye, specifically blood in the vitreous fluid that fills the back of the eye. Symptoms of a vitreous hemorrhage include floaters and a "dark cloud" that seems to obscure vision. The most common cause for an internal ocular bleed is neovascularization, abnormal blood vessels inside the eye (usually from diabetes) that bleed easily. Other causes of a hemorrhage are from trauma (obviously) or even a retinal detachment. If the hemorrhage is mild, the blood will usually break down and reabsorb by itself. In these cases, I recommend my patients sleep on their side or with the head of the bed elevated (so that blood doesn't settle in the middle of the vision). Also, you should avoid heavy lifting and blood thinners (if possible) to minimize the chance of rebleeding. Extensive vitreous hemorrhages are more difficult to live with and may require a vitrectomy to restore useful vision in a more timely manner. The underlying cause of any hemorrhage needs to be determined, and if the bleeding IS from something like diabetic retinopathy, treatment with a PRP laser may be the next step.
Voltaren. This is an NSAID eye drop designed to decrease inflammation in the eye (similar to Motrin or Advil). The active ingredient diclofenac is now available as a generic. While effective, this drop can be a little harsh on the ocular surface for some people. Other similar drops include Nevanac (nepafenac) and Bromday (bromfenac).
Valtrex. This is the trade name for valacyclovir, an antiviral pill used in cases of viral eye infection (such as herpetic eye disease or a shingles infection). It is longer lasting than the alternative acyclovir, so it doesn't have to be taken as frequently. Valtrex may be slightly more powerful than acyclovir as well.
vancomycin. This is a "hard core" IV antibiotic that is traditionally used for hospitalized patients with MRSA infections. We use vancomycin eye drops when treating bad corneal ulcers. This medicine is not available in eye drop form and must be specially created by a compounding pharmacy as a fortified antibiotic drop.
Varilux. This is a high quality progressive lens used in no-line bifocals. Progressive lenses are a type of no-line bifocal that gets stronger the further down the glasses you look. Many people like progressive lenses because they can "dial in" the amount of bifocal they need by tilting their head. Other people find progressives uncomfortable, however, because of the distortion in their lower vision. The Varilux brand of progressive lenses are of a higher quality and seem to be better tolerated with less distortion.
VEGF. This stands for Vascular Endothelial Growth Factor. VEGF is a hormone released from the retinal cells when they become hungry for oxygen. This hormone is meant to stimulate the formation of new blood vessels. The most common causes of VEGF over production are from diabetic retinopathy or a central retinal vein occlusion. When VEGF is released, new blood vessels form to supply the oxygen demand. This process is called neovascularization. Unfortunately, these new blood vessels are abnormal and have a tendency to bleed, scar, and contract, leading to serious visual consequences. Anti-VEGF medications are the hottest topic in ophthalmology these days because these medications can be injected into the eye to fight off these bad vessels. Anti-VEGF medications also decrease capillary leakage, which has made them a good treatment for wet macular degeneration as well. Avastin is the first of the anti-VEGF drugs. Since its advent, there have been newer drug variations that may be more specific for the eye such as Lucentis and Eylea. All of these medications are injected directly into the eye so that they can target the retina directly with less systemic side effects.
vertex distance. This is the distance measured from the eye surface (the cornea) to the back of a glasses lens. This distance is different for everyone, but on average is about 1.4 centimeters. This measurement can be important when choosing and fitting glasses frames (especially with strong glasses prescriptions). Vertex distance is also important when converting a glasses prescription to a contact lens prescription.
Vigamox. This is a powerful fluoroquinolone antibiotic containing moxifloxacin. This is an excellent antibiotic for treating corneal infections, especially in contact lens wearers. Alternative brands like Moxeza have come out with the same active ingredient. Similar antibiotic medications include Zymaxid (gatifloxacin) and Besivance (besifloxacin).
viral conjunctivitis. Also known as "pink eye," this is a viral infection in the eye that makes the conjunctiva red and irritated. The conjunctiva is the thin layer of skin that covers the white of your eye. This skin layer is extremely thin, but you can see it when looking in the mirror as blood vessels course through the skin. When you get an infection of this delicate skin layer, the blood vessels dilate and the eye appears to be "pink." In adults, the majority of eye infections (conjunctivitis) are from viral sources - it's like getting the flu, but instead of getting head or chest congestion, the eye is involved. Just as with the flu, there is no good treatment for viral infections other than letting the infection run its course. Viral conjunctivitis is highly contagious. If you have it, wash your hands frequently and don't share towels or makeup. It may take up to two weeks for the infection to clear and the conjunctivitis may jump to the other eye before the end. If there are any visual changes, the eye needs to be rechecked to make sure there is no corneal involvement (i.e., corneal ulcer formation).
Viroptic. This is an eye drop containing trifluridine that is used to fight viral infections of the eye, such as in herpetic eye disease. While effective, the drop can be a little harsh on the ocular surface with prolonged use. Sadly, there aren't many antiviral alternatives available in this country. Zirgan is a new antiviral ointment that may be better tolerated as it requires less frequent dosing.
Visine. Visine is a brand of over-the-counter eye drops. The original formula contained the drug tetrahydrozoline, a stimulant that makes the blood vessels on the surface of the conjunctiva constrict and shrink. This makes the eyes look whiter and thus it "gets the red out." This effect is short-lived and many people have a rebound effect where the eye turns redder after the drug wears off. Overall, Visine doesn't fix anything and may not be healthy as it decreases blood supply to the irritated tissues. Johnson & Johnson has expanded the Visine brand name to include an entire line of rewetting and allergy drops, so read the label to see what you're actually buying.
vision. The most important component of an eye exam is the measurement of the actual quality of the central vision. We measure this by having you read an eye chart (the Snellen chart) and tweaking the vision by having you look through the phoropter (the machine with all the lenses inside used for checking your prescription). Some patient's vision is so bad that we can't measure and document vision using an eye chart. In these cases we measure other things, like the ability to count fingers and see hand movement. If the vision is really bad, we measure the detection of light. Most of these measurements require feedback from our patients, which makes visual acuity hard to check in young children or non-verbal patients. In these cases we estimate vision by seeing if the eye tracks objects and blinks to bright lights.
visual field. This is a test to measure your peripheral vision. There are many ways to check side vision, but when we say we're going to get a "visual field" we are usually talking about the Humphrey Visual Field. This is a computer-controlled machine that maps out peripheral vision in an objective and precise manner. You wear an eye patch over one eye and sit forward in a bowl of light. While you stare straight ahead at a fixed point, the computer shines a spot of light in various places in your peripheral vision. Every time you see the light, you click the buzzer and the computer maps this data for us. Visual fields are very useful for detecting vision loss in patients with glaucoma. Because a third of the brain is devoted to the visual pathway (and processing of visual images), neurologic problems can be detected and localized with a visual field as well.
vitamins. There has been much research on the effect of vitamins on the eye. Vitamin A in particular seems to be important to the health of the rods and cones as this vitamin is key to the conversion of light images into an electrical signal that can be interpreted by our brain. One of the treatments attempted for people with retinitis pigmentosa (a derangement of the photoreceptors) is high doses of Vitamin A. Other vitamins have been studied in relation to macular degeneration. The AREDS Study found that a combination of Vitamin A (beta-carotene), C, and E (along with the minerals zinc and copper) seemed to slow the progression of vision loss in macular degeneration. See the AREDS Study and AREDS 2 Study for more information on this topic.
vitrectomy. This is a surgery to remove the vitreous fluid from the back of the eye and replace it with saline water. This procedure is performed by a retinal specialist and is commonly performed to help repair retinal detachments. Vitrectomy is also used to remove blood from a vitreous hemorrhage and as part of membrane peel surgery for epiretinal membranes and macular holes. This surgery used to take many hours to perform, but with modern techniques and shrinking instrumentation, it is becoming faster and less traumatic.
vitreous. This is the fluid that fills the back of the eye. The eye is mostly a hollow structure. The large back chamber is filled with vitreous humor, which is a fluid that has the consistency of Jell-O. In fact, if you were to "theoretically" open up a young person's eye and remove the contents, the vitreous would come out as a single glob of clear "goop." As we get older, the vitreous begins to liquefy, with pockets of saline water forming inside the gel. At some point in our life, the mixture gets so watery that the remaining gel will contract inwards upon itself and cause flashes, floaters, and sometimes a retinal detachment. This contraction event is common and called a vitreous detachment.
vitreous detachment. A common cause for flashes and floaters, a vitreous detachment is when the "gel" in the back of the eye contracts inwards upon itself. Let me explain. The eye is mostly a hollow structure. In many ways, the eye is like a water balloon sitting inside your eye socket. The eye is not filled with water, however, but is filled with a clear fluid called the vitreous jelly. This jelly has the consistency very much like Jell-O. In childhood, the vitreous gel is firm and well-formed, but as we get older the gel gets "runny" and "watery." Little pockets of saline water form inside the gel, and while this sounds bad, it really isn't a problem. Both the gel and the water are clear and we can see through them just fine. At some point in our life the vitreous gel can become so watery that one day, without warning, the remaining vitreous gel can suddenly collapse inward upon itself. This causes flashing lights and floaters. If you want to use a metaphor, think of the eyeball like a Tupperware bowl filled to the brim with Jell-O. Now, imagine what would happen if you put that bowl of Jell-O on your kitchen counter and then you went on vacation for several months. With time, the Jell-O will evaporate and dehydrate until it collapses and falls in upon itself like a big "blob" in the middle of the bowl. A similar process happens inside the eye. The vitreous gel peels off the retina inside the eye. The retina detects light, so that as the gel peels off it, many people will see a flash of light like a lightning bolt in their peripheral vision. In addition, many people complain of a new, large floater in their vision. This occurs when a little bit of cellular debris pulls off the optic nerve as the gel peels away from it. This little piece of junk is now floating inside the eye, hovering at the gel-water interface, casting shadows inside the eye that you can see as the gel wobbles around. In rare cases, the vitreous gel can actually rip a small hole in the retina itself. This is bad, because a retinal hole can extend and turn into a full-on retinal detachment with loss of vision. Anyone with new symptoms of flashing lights or new floaters needs a dilated eye exam to look for these retinal tears. If the initial retinal examination shows a healthy retina, I usually have my patients return in a few weeks for a recheck to make sure nothing new has formed. The flashing lights and floaters will diminish with time, though the floater can sometimes take a long time (months or years) to disappear (and sometimes it never does entirely). There is no safe way to make these floaters go away short of a vitrectomy surgery (not recommended).
vitreous hemorrhage. This is the term used to describe blood inside the eye, specifically blood in the vitreous fluid that fills the back of the eye. Symptoms of a vitreous hemorrhage include floaters and a "dark cloud" that seems to obscure vision. The most common cause for an internal ocular bleed is neovascularization, abnormal blood vessels inside the eye (usually from diabetes) that bleed easily. Other causes of a hemorrhage are from trauma (obviously) or even a retinal detachment. If the hemorrhage is mild, the blood will usually break down and reabsorb by itself. In these cases, I recommend my patients sleep on their side or with the head of the bed elevated (so that blood doesn't settle in the middle of the vision). Also, you should avoid heavy lifting and blood thinners (if possible) to minimize the chance of rebleeding. Extensive vitreous hemorrhages are more difficult to live with and may require a vitrectomy to restore useful vision in a more timely manner. The underlying cause of any hemorrhage needs to be determined, and if the bleeding IS from something like diabetic retinopathy, treatment with a PRP laser may be the next step.
Voltaren. This is an NSAID eye drop designed to decrease inflammation in the eye (similar to Motrin or Advil). The active ingredient diclofenac is now available as a generic. While effective, this drop can be a little harsh on the ocular surface for some people. Other similar drops include Nevanac (nepafenac) and Bromday (bromfenac).