Eye Dictionary: D
D
dermatochalasis. This is excess skin that forms over the upper (and sometimes lower) eyelids. This skin can droop down to cover theupper eyelashes and even obstruct vision. If bad enough, a blepharoplasty surgery can be performed to surgically remove this skin.
dexamethasone. This is a steroid eye drop that is good at treating ocular inflammation. This medicine is normally found in combination eye drops like Tobradex (dexamethasone and tobramycin) and generic Maxitrol (dexamethasone, neomycin, and polymyxin).
diabetic retinopathy. The term diabetes is used to describe large amounts of sugar floating in your bloodstream. This sugar weakens the blood vessels throughout your body and makes them "leaky." This can cause health problems with major organs, including the eyes. For example, diabetics can develop kidney problems and difficulty with healing. In the eye, diabetic vessel leakage in the retina can affect the vision. The retina is the light-sensing structure inside the eye and can be compared to the film inside a camera. Just like camera film, the retina needs to be perfectly smooth and flat to take a good picture. Blood vessel leakage can make the retina swollen and lumpy. If this swelling occurs near the central visual area (i.e., macular edema) this can have severe visual consequences. Treatment in this case involves focal laser therapy (FLT laser) with a laser to seal off leaky spots. Diabetic leakage can be so bad that the eye fills with blood. This is called a vitreous hemorrhage and may require surgery to remove the blood if it doesn't clear on its own. Finally, long-term diabetic retinopathy can starve the retina of oxygen and can lead to the formation of abnormal retinal blood vessels. This process is called neovascularization and is the most severe stage of diabetic eye disease. These abnormal vessels can bleed, cause traction retinal detachments, and even clog the "drain" inside the eye and create an intractable acute glaucoma. Most of these diabetic problems can be avoided by maintaining good glycemic control and by getting regular dilated eye exams. It's better to detect and treat diabetic retinopathy early before these problems get out of control.
(Common Misspellings: diab, retin)
Diamox. This is the trade name for the oral medication acetazolamide. This is a water pill that is sometimes used in cases of poorly controlled glaucoma and to treat acute eye pressure spikes (such as after a complicated cataract surgery). Diamox can also decrease the pressure around the brain in cases of pseudotumor cerebri. See the entry on acetazolamide for more information.
diclofenac. This is an NSAID eye drop. Like all NSAIDs, diclofenac has a mechanism similar to Motrin or Advil and is good for inflammation. This class of medications is often used after cataract surgery to decrease the chance of retinal swelling (macular edema). This drop is also known under the trade name Voltaren. Diclofenac has gone generic, so it is much cheaper to obtain these days ... though most of my patients tell me it is pretty harsh going in.
dilated pupil. The pupil is the black "hole" in the middle of the iris (the colored part of the eye). The pupil looks black because the inside of the eye is dark. Eye doctors dilate the pupil with eye drops to help them view the retina. There are many causes for a dilated pupil outside of the doctors office, however. Some people have a natural anisocoria where one pupil is naturally larger than the other. Plant irritants, pesticides, and antihistamine medications can also make the pupil dilate. Blockage of sympathetic or parasympathetic nerves to the eye can cause a pupil to dilate - there are some serious medical conditions that can cause this blockage such as Adie's pupil, Horner's Syndrome, or third nerve palsy. A new onset pupil abnormality needs to be evaluated by an eye doctor.
diopter. A diopter is a unit of measurement that describes the power in a pair of glasses or contacts. For example, weak reading glasses have a diopter power of +1.00 while stronger readers have a power of +3.00 diopters. Farsighted people require positive (+) diopter glasses to improve their vision, while nearsightedness requires negative (-) diopter power. Many people have a small amount of astigmatism correction built into their glasses prescription, and this astigmatism correction is also measured in diopters. Finally, prism glasses are used to fix ocular alignment problems in people with double vision (for example, if you are cross-eyed). The amount of prism ground into a pair of spectacles is also measured in “prism diopters.”
diplopia. This is when a person sees double ... that is to say, they see the same object twice. This can be a horizontal side-by-side doubling, a vertical up-down effect, or a combination of the two. Whenever a person has "double vision" the biggest question we ask is whether this is a monocular (oneeyed) diplopia or a binocular (twoeyed) problem. If the doubling goes away when covering either eye, then we know this is a binocular problem where the eyes are out of 'sync' with each other (such as with crossed-eyes). There are many potential causes for binocular diplopia such as a cranial nerve palsy or a stroke. This alignment problem requires a thorough workup and may involve an MRI and neurologic evaluation depending upon our findings. If the double vision persists for many months, prism glasses or strabismus surgery may be required to get the eyes straightened out. Monocular (one-eye) diplopia is simpler and less concerning - if double vision remains, even when the other eye is covered, than we know the problem is located in just the eyeball itself. Monocular diplopia is rarely an emergency and can be caused by astigmatism, dry eye, cataracts, and rarely retinal problems like an epiretinal membrane.
dorzolamide. A glaucoma eye drop used to lower eye pressure. The trade name is Trusopt but this medication has gone generic. This is a carbonic anhydrase inhibitor and works by decreasing the production of aqueous fluid inside the eye. It is usually taken twice a day. This medication is also found in the combination drop Cosopt (dorzolamide/timolol).
double vision. This is also called diplopia, and describes the situation where you see the same object twice. This should not be confused with a ghost image where a dimmer "shadow image" is seen next to the primary object. See diplopia for more information on the causes of double vision.
doxycycline. "Doxy" is an antibiotic pill that is often used in the treatment of blepharitis. With blepharitis (chronic eyelid irritation) one of the causes of eye irritation is from poor oil flow from the meibomian glands that run along the edge of the eyelids. Doxycycline has been found to help oil flow throughout the body, and this may help with the eye irritation. In fact, doxycycline is used for people with rosacea or acne because of a similar mechanism. This medicine shouldn't be used in children or when there is any potential for pregnancy. Also, it may interact with dairy products, and patients have an increased risk of sunburn while on it.
drusen. Drusen are deposits that form under the retina. They look like yellow spots in the retina and their presence is often a precursor to more serious macular degeneration. The retina is located in the back of the eye and functions like film in a camera. The retinal photoreceptors (rods and cones) are metabolically active and require a rich blood supply to function properly. Drusen are accumulations of "debris" that form under the retina, blocking the transfer of nutrients and oxygen between the retina and the supporting choroid (a bed of blood vessels that nourish the retina) underneath. This blockage of nutrition transport causes the retina to slowly atrophy and can lead to significant visual dysfunction over time. This process is called macular degeneration. "Macular drusen" should not be confused with optic nerve drusen which are calcium crystals in the optic disk that rarely cause visual problems.
dry eye. This describes ocular surface irritation that occurs from an irregularity of the tear film. Dry eye causes eye irritation and redness. Many people complain of a feeling that the eyes are "tired," especially in the evenings and when doing activities that require concentration (like reading, driving, or watching TV). Ironically, most people with dry eye complain that their eyes are actually watery. This is because dry eyes tend to sting. This irritation causes a tearing reflex from the lacrimal gland that overloads the eye with fluid. For most people, dry eye happens either because of an insufficiency in the amount of tears produced, or a problem with the quality of the tears produced. Treatment usually begins with over-the-counter rewetting drops. Other treatments include warm compresses (to open the tear glands), nighttime rewetting gels (to moisten the eyes while sleeping), punctal plugs (to keep the tears from draining too quickly), and medications such as Restasis. While dry eye sounds like a simple problem, it can be quite challenging to treat as it tends to be chronic and many of the treatments are short-lived.
dry macular degeneration. Macular degeneration is a progressive aging change to the retina where the retina seems to "wear out" and atrophy with time. Most people have "dry" degeneration, where the retina atrophies very slowly over many years. Gradual loss of central vision causes people to complain of difficult time reading small letters or seeing distant road signs. About 10-15% of people with dry degeneration will go on to develop "wet" degeneration. Wet macular degeneration occurs when blood vessels under the retina actually start to leak blood and serum, leading to rapid and severe vision loss. Even though dry degeneration can cause significant vision loss given enough time, it is considered the safer type of macular degeneration as its progression is
very slow.
(Common Misspellings: macul,degen, macular)
DSEK. This stands for Descemet's Stripping Endothelial Keratoplasty. It is a "partial" corneal transplant surgery where only the inside layers of the cornea are replaced. This is a vast improvement over traditional full thickness transplants, as the surgical and healing time are much shorter and this surgery eliminates much of the risk of more advanced transplants. This type of surgery is primarily used with Fuchs' dystrophy, a condition where the inner corneal "pump cells" are unable to keep the cornea clear and need to be replaced.
Durezol. This is a powerful steroid eye drop occasionally used after cataract surgery. The stuff seems to be more powerful than Pred Forte, so I use it primarily with internal ocular inflammation such as iritis or uveitis.
dexamethasone. This is a steroid eye drop that is good at treating ocular inflammation. This medicine is normally found in combination eye drops like Tobradex (dexamethasone and tobramycin) and generic Maxitrol (dexamethasone, neomycin, and polymyxin).
diabetic retinopathy. The term diabetes is used to describe large amounts of sugar floating in your bloodstream. This sugar weakens the blood vessels throughout your body and makes them "leaky." This can cause health problems with major organs, including the eyes. For example, diabetics can develop kidney problems and difficulty with healing. In the eye, diabetic vessel leakage in the retina can affect the vision. The retina is the light-sensing structure inside the eye and can be compared to the film inside a camera. Just like camera film, the retina needs to be perfectly smooth and flat to take a good picture. Blood vessel leakage can make the retina swollen and lumpy. If this swelling occurs near the central visual area (i.e., macular edema) this can have severe visual consequences. Treatment in this case involves focal laser therapy (FLT laser) with a laser to seal off leaky spots. Diabetic leakage can be so bad that the eye fills with blood. This is called a vitreous hemorrhage and may require surgery to remove the blood if it doesn't clear on its own. Finally, long-term diabetic retinopathy can starve the retina of oxygen and can lead to the formation of abnormal retinal blood vessels. This process is called neovascularization and is the most severe stage of diabetic eye disease. These abnormal vessels can bleed, cause traction retinal detachments, and even clog the "drain" inside the eye and create an intractable acute glaucoma. Most of these diabetic problems can be avoided by maintaining good glycemic control and by getting regular dilated eye exams. It's better to detect and treat diabetic retinopathy early before these problems get out of control.
(Common Misspellings: diab, retin)
Diamox. This is the trade name for the oral medication acetazolamide. This is a water pill that is sometimes used in cases of poorly controlled glaucoma and to treat acute eye pressure spikes (such as after a complicated cataract surgery). Diamox can also decrease the pressure around the brain in cases of pseudotumor cerebri. See the entry on acetazolamide for more information.
diclofenac. This is an NSAID eye drop. Like all NSAIDs, diclofenac has a mechanism similar to Motrin or Advil and is good for inflammation. This class of medications is often used after cataract surgery to decrease the chance of retinal swelling (macular edema). This drop is also known under the trade name Voltaren. Diclofenac has gone generic, so it is much cheaper to obtain these days ... though most of my patients tell me it is pretty harsh going in.
dilated pupil. The pupil is the black "hole" in the middle of the iris (the colored part of the eye). The pupil looks black because the inside of the eye is dark. Eye doctors dilate the pupil with eye drops to help them view the retina. There are many causes for a dilated pupil outside of the doctors office, however. Some people have a natural anisocoria where one pupil is naturally larger than the other. Plant irritants, pesticides, and antihistamine medications can also make the pupil dilate. Blockage of sympathetic or parasympathetic nerves to the eye can cause a pupil to dilate - there are some serious medical conditions that can cause this blockage such as Adie's pupil, Horner's Syndrome, or third nerve palsy. A new onset pupil abnormality needs to be evaluated by an eye doctor.
diopter. A diopter is a unit of measurement that describes the power in a pair of glasses or contacts. For example, weak reading glasses have a diopter power of +1.00 while stronger readers have a power of +3.00 diopters. Farsighted people require positive (+) diopter glasses to improve their vision, while nearsightedness requires negative (-) diopter power. Many people have a small amount of astigmatism correction built into their glasses prescription, and this astigmatism correction is also measured in diopters. Finally, prism glasses are used to fix ocular alignment problems in people with double vision (for example, if you are cross-eyed). The amount of prism ground into a pair of spectacles is also measured in “prism diopters.”
diplopia. This is when a person sees double ... that is to say, they see the same object twice. This can be a horizontal side-by-side doubling, a vertical up-down effect, or a combination of the two. Whenever a person has "double vision" the biggest question we ask is whether this is a monocular (oneeyed) diplopia or a binocular (twoeyed) problem. If the doubling goes away when covering either eye, then we know this is a binocular problem where the eyes are out of 'sync' with each other (such as with crossed-eyes). There are many potential causes for binocular diplopia such as a cranial nerve palsy or a stroke. This alignment problem requires a thorough workup and may involve an MRI and neurologic evaluation depending upon our findings. If the double vision persists for many months, prism glasses or strabismus surgery may be required to get the eyes straightened out. Monocular (one-eye) diplopia is simpler and less concerning - if double vision remains, even when the other eye is covered, than we know the problem is located in just the eyeball itself. Monocular diplopia is rarely an emergency and can be caused by astigmatism, dry eye, cataracts, and rarely retinal problems like an epiretinal membrane.
dorzolamide. A glaucoma eye drop used to lower eye pressure. The trade name is Trusopt but this medication has gone generic. This is a carbonic anhydrase inhibitor and works by decreasing the production of aqueous fluid inside the eye. It is usually taken twice a day. This medication is also found in the combination drop Cosopt (dorzolamide/timolol).
double vision. This is also called diplopia, and describes the situation where you see the same object twice. This should not be confused with a ghost image where a dimmer "shadow image" is seen next to the primary object. See diplopia for more information on the causes of double vision.
doxycycline. "Doxy" is an antibiotic pill that is often used in the treatment of blepharitis. With blepharitis (chronic eyelid irritation) one of the causes of eye irritation is from poor oil flow from the meibomian glands that run along the edge of the eyelids. Doxycycline has been found to help oil flow throughout the body, and this may help with the eye irritation. In fact, doxycycline is used for people with rosacea or acne because of a similar mechanism. This medicine shouldn't be used in children or when there is any potential for pregnancy. Also, it may interact with dairy products, and patients have an increased risk of sunburn while on it.
drusen. Drusen are deposits that form under the retina. They look like yellow spots in the retina and their presence is often a precursor to more serious macular degeneration. The retina is located in the back of the eye and functions like film in a camera. The retinal photoreceptors (rods and cones) are metabolically active and require a rich blood supply to function properly. Drusen are accumulations of "debris" that form under the retina, blocking the transfer of nutrients and oxygen between the retina and the supporting choroid (a bed of blood vessels that nourish the retina) underneath. This blockage of nutrition transport causes the retina to slowly atrophy and can lead to significant visual dysfunction over time. This process is called macular degeneration. "Macular drusen" should not be confused with optic nerve drusen which are calcium crystals in the optic disk that rarely cause visual problems.
dry eye. This describes ocular surface irritation that occurs from an irregularity of the tear film. Dry eye causes eye irritation and redness. Many people complain of a feeling that the eyes are "tired," especially in the evenings and when doing activities that require concentration (like reading, driving, or watching TV). Ironically, most people with dry eye complain that their eyes are actually watery. This is because dry eyes tend to sting. This irritation causes a tearing reflex from the lacrimal gland that overloads the eye with fluid. For most people, dry eye happens either because of an insufficiency in the amount of tears produced, or a problem with the quality of the tears produced. Treatment usually begins with over-the-counter rewetting drops. Other treatments include warm compresses (to open the tear glands), nighttime rewetting gels (to moisten the eyes while sleeping), punctal plugs (to keep the tears from draining too quickly), and medications such as Restasis. While dry eye sounds like a simple problem, it can be quite challenging to treat as it tends to be chronic and many of the treatments are short-lived.
dry macular degeneration. Macular degeneration is a progressive aging change to the retina where the retina seems to "wear out" and atrophy with time. Most people have "dry" degeneration, where the retina atrophies very slowly over many years. Gradual loss of central vision causes people to complain of difficult time reading small letters or seeing distant road signs. About 10-15% of people with dry degeneration will go on to develop "wet" degeneration. Wet macular degeneration occurs when blood vessels under the retina actually start to leak blood and serum, leading to rapid and severe vision loss. Even though dry degeneration can cause significant vision loss given enough time, it is considered the safer type of macular degeneration as its progression is
very slow.
(Common Misspellings: macul,degen, macular)
DSEK. This stands for Descemet's Stripping Endothelial Keratoplasty. It is a "partial" corneal transplant surgery where only the inside layers of the cornea are replaced. This is a vast improvement over traditional full thickness transplants, as the surgical and healing time are much shorter and this surgery eliminates much of the risk of more advanced transplants. This type of surgery is primarily used with Fuchs' dystrophy, a condition where the inner corneal "pump cells" are unable to keep the cornea clear and need to be replaced.
Durezol. This is a powerful steroid eye drop occasionally used after cataract surgery. The stuff seems to be more powerful than Pred Forte, so I use it primarily with internal ocular inflammation such as iritis or uveitis.