Eye Dictionary: I-J
I
I-CAPS. This is one of the eye vitamins based on the AREDS Study used to decrease the rate of progression of macular degeneration. Just like the competing vitamin brands (Ocuvite and PreserVision) there are many variations in the formula. They appear to all follow the general AREDS formula, with several adding lutein and omega-3. If you are a smoker, look for a vitamin that doesn't contain beta-carotene ... betacarotene is the precursor to Vitamin A and is thought to increase the risk of lung cancer in smokers.
ICG angiography. This is a type of angiography used by a retina specialist to look for problems in the retina. With this test, indocyanine green dye is injected into a blood vessel in the arm. As the dye travels through the circulatory system, it will eventually reach the eye's circulation. Photographs are then taken every few seconds to track how the dye flows and illuminates structures inside the eye. ICG is particularly good for examining deep structures in the retina, especially in cases of retinal bleeding where the view is otherwise obscured. Fluorescein angiography is a similar test, and more commonly performed. It looks for problems in the more superficial layers of the retina.
Ilevro. This is a new formulation of the anti-inflammatory eye drop Nevanac. This formulation contains three times the concentration of the drug nepafenac, allowing the medication to be dosed once a day. These NSAID eye drops are useful after cataract surgery to decrease the chance of retina swelling.
implant. This is a plastic lens that is placed inside the eye during cataract surgery and is sometimes called an IOL (intraocular lens). With cataract surgery, the natural lens inside the eye has become cloudy and needs to be removed. If a new lens is not put back in the eye, the vision will remain blurry and be completely out of focus. Before the invention of modern intraocular lenses, patients with no lenses (aphakia) had to wear "coke bottle" glasses just to see normally after their cataracts were removed. Modern implants are made of a flexible acrylic plastic that allows them to fold up very small like a burrito. This allows them to be injected into the eye through a very small incision through the cornea. Once inside the eye, the intraocular lens opens up like a blossoming flower into its normal shape. Newer implant technology has improved refractive outcomes. For example, the Toric lens can now fix astigmatism and the Restor lens has a fresnel lens bifocal, which can help with near vision and decrease the need for reading glasses.
injections. Several medicines are best delivered to the eye by injecting them directly into the vitreous cavity. The most common are the anti-VEGF medications like Avastin and Lucentis used for treating macular degeneration. Steroids such as Kenalog can also be injected into the eye for severe cases of uveitis and for decreasing inflammatory macular edema. Finally, with cases of internal eye infection (endophthalmitis), powerful antibiotics like vancomycin are typically injected directly into the eye to better target any infections.
Intralase. This is an advance in LASIK surgery where the corneal flap is created using a laser. The older method of flap creation was using a microkeratome blade. Laser flap construction may decrease the chance of human errors in flap construction and makes LASIK surgery slightly safer. See LASIK and femtosecond laser for more information about this surgery.
intraocular pressure. Also known as "IOP," this is the pressure inside the eye. We call this intraocular pressure to differentiate it from other kinds of pressure such as BP (blood pressure) and ICP (intracranial pressure) inside the skull. Normal eye pressure is 10-21. High pressure can cause glaucoma damage to the eye. See the entry on pressure for more information on this topic.
intraocular lens (IOL). Also called an "IOL," this is the plastic lens placed into the eye during a cataract surgery. See implant for more information.
IOL-Master. This is a machine used prior to cataract surgery to help determine the implant to use during surgery. With cataract surgery, the cloudy cataract lens inside the eye is removed and must be replaced by a new lens implant. These implants come in different prescriptions, just like glasses or contact lenses. To help determine the proper implant prescription, the IOL-Master measures the length of the eye and the curvature of the cornea. This technology has removed much of the operator error with implant calculations (these used to be done by hand and were thus prone to mathematical or transcription errors). The IOLMaster has some limitations with cloudy cataracts and can't always measure through dense opacities in the lens. If this machine is unable to obtain a good eye measurement, a different (more involved) technique called immersion ultrasound (A-scan) can be used to measure the length of the eye prior to surgery.
ION. An ischemic optic neuropathy is a damaging event that happens in the optic nerve behind the eye when the blood supply to the nerve is temporarily blocked or interrupted. Without nutrition the nerve tissue swells and becomes damaged. Sudden and severe vision darkening occurs, often affecting either the upper or lower half of the vision. IONs tend to occur in middle age. While it is impossible to predict who will have an ION, some people have a "disk at risk" ... this is tight nerve insertion in the back of the eye seen during an eye exam. Something about this anatomy puts certain people at higher risk for an ION. While not a perfect metaphor, you can imagine that people who wear tight watch bands around their wrist will have more nerve damage if their arm ever swells up. There is no treatment for an ION, other than ruling out more serious conditions like temporal arteritis. The vision loss may improve with time. A new ION will often prompt a workup to look for vasculopathic risk factors like hypertension and diabetes. If the history warrants, we may also start an embolic workup to make sure the heart is beating normally (arrhythmias can cause clot formation) and a carotid ultrasound (to look for cholesterol emboli).
iris. The iris is the "colored" muscle inside the eye that controls pupil size. Some people have brown irises and others have blue. The color of the eye is determined by the amount of pigment in the iris, with dark brown eyes having more pigment than lighter eyes. The iris has rings of muscle fiber that contract and changes the pupil shape in response to light entering the eye. When inflamed, a condition called iritis, the iris can cause pain and sensitivity to light (photophobia). The iris is thin, like a drumhead, and very mobile. If the iris bows forward, the trabecular meshwork (the drain of the eye) may become blocked, leading to angle closure and acute glaucoma. Floppy iris syndrome (usually caused by urinary medications like Flomax) can cause difficulties during cataract surgery. Pupil abnormalities can occur from nerve blockage to the iris muscle from many sources including Horner's syndrome, Adie's pupil, third nerve palsy, or pharmacologic dilation.
iris synechiae. This is an oddly shaped pupil that forms after inflammation inside the eye. The iris is the flat muscle inside our eye that controls pupil size and gives our eyes "color." When the iris is inflamed, such as after trauma or uveitis, it tends to become "sticky" and wants to scar to nearby structures. The pupil overlies the lens itself and if the edge of the pupil adheres to the lens underneath, the pupil will look abnormal. This adhesion is called a synechiae, and makes the pupil look like a cat's eye or a keyhole. If the adhesions are bad enough, the pupil can scar and create an acute glaucoma. In cases of ocular inflammation, we typically treat the eye with steroids to cool the eye down as quickly as possible. In addition, we may prescribe dilating drops to force the pupil to dilate and keep these adhesions from forming.
iritis. This is inflammation of the iris, the "colored" part of the eye. The iris is a muscle that controls the size of the pupil. When inflamed, the iris muscle can "spasm" and cause intense eye pain. Most people with an iritis complain of extreme sensitivity to light (photophobia). Iris inflammation can occur from many sources such as trauma or after intraocular surgery. Another cause is uveitis. Uveitis is a similar (but more encompassing) term used to describe internal ocular inflammation, usually from pro-inflammatory systemic problems like sarcoidosis, rheumatoid arthritis, inflammatory bowel disease, and infection. Treatment for iritis involves topical steroids to "cool" the eye down. Cycloplegia dilating drops can help with iris pain by "paralyzing" the iris muscle so that it stops "spasming." Dilation drops are also helpful because they keep the pupil dilated and help avoid the formation of iris synechiae (this is when the iris inflammation causes it to 'stick' to nearby structures like the lens underneath).
ischemic optic neuropathy. This is damage to the optic nerve behind the eye that can occur in middle age. See ION for more information on this topic.
Istalol. This is the trade name for the glaucoma eye drop timolol. Timolol is a beta-blocker similar to the beta-blocker medicine used to control blood pressure. As this medicine has been around for a long time, it is also available as an inexpensive generic. Istalol comes in a thicker consistency, so the medicine lasts longer and is usually dosed once a day (as opposed to the twice a day dosing of the generic equivalent).
ICG angiography. This is a type of angiography used by a retina specialist to look for problems in the retina. With this test, indocyanine green dye is injected into a blood vessel in the arm. As the dye travels through the circulatory system, it will eventually reach the eye's circulation. Photographs are then taken every few seconds to track how the dye flows and illuminates structures inside the eye. ICG is particularly good for examining deep structures in the retina, especially in cases of retinal bleeding where the view is otherwise obscured. Fluorescein angiography is a similar test, and more commonly performed. It looks for problems in the more superficial layers of the retina.
Ilevro. This is a new formulation of the anti-inflammatory eye drop Nevanac. This formulation contains three times the concentration of the drug nepafenac, allowing the medication to be dosed once a day. These NSAID eye drops are useful after cataract surgery to decrease the chance of retina swelling.
implant. This is a plastic lens that is placed inside the eye during cataract surgery and is sometimes called an IOL (intraocular lens). With cataract surgery, the natural lens inside the eye has become cloudy and needs to be removed. If a new lens is not put back in the eye, the vision will remain blurry and be completely out of focus. Before the invention of modern intraocular lenses, patients with no lenses (aphakia) had to wear "coke bottle" glasses just to see normally after their cataracts were removed. Modern implants are made of a flexible acrylic plastic that allows them to fold up very small like a burrito. This allows them to be injected into the eye through a very small incision through the cornea. Once inside the eye, the intraocular lens opens up like a blossoming flower into its normal shape. Newer implant technology has improved refractive outcomes. For example, the Toric lens can now fix astigmatism and the Restor lens has a fresnel lens bifocal, which can help with near vision and decrease the need for reading glasses.
injections. Several medicines are best delivered to the eye by injecting them directly into the vitreous cavity. The most common are the anti-VEGF medications like Avastin and Lucentis used for treating macular degeneration. Steroids such as Kenalog can also be injected into the eye for severe cases of uveitis and for decreasing inflammatory macular edema. Finally, with cases of internal eye infection (endophthalmitis), powerful antibiotics like vancomycin are typically injected directly into the eye to better target any infections.
Intralase. This is an advance in LASIK surgery where the corneal flap is created using a laser. The older method of flap creation was using a microkeratome blade. Laser flap construction may decrease the chance of human errors in flap construction and makes LASIK surgery slightly safer. See LASIK and femtosecond laser for more information about this surgery.
intraocular pressure. Also known as "IOP," this is the pressure inside the eye. We call this intraocular pressure to differentiate it from other kinds of pressure such as BP (blood pressure) and ICP (intracranial pressure) inside the skull. Normal eye pressure is 10-21. High pressure can cause glaucoma damage to the eye. See the entry on pressure for more information on this topic.
intraocular lens (IOL). Also called an "IOL," this is the plastic lens placed into the eye during a cataract surgery. See implant for more information.
IOL-Master. This is a machine used prior to cataract surgery to help determine the implant to use during surgery. With cataract surgery, the cloudy cataract lens inside the eye is removed and must be replaced by a new lens implant. These implants come in different prescriptions, just like glasses or contact lenses. To help determine the proper implant prescription, the IOL-Master measures the length of the eye and the curvature of the cornea. This technology has removed much of the operator error with implant calculations (these used to be done by hand and were thus prone to mathematical or transcription errors). The IOLMaster has some limitations with cloudy cataracts and can't always measure through dense opacities in the lens. If this machine is unable to obtain a good eye measurement, a different (more involved) technique called immersion ultrasound (A-scan) can be used to measure the length of the eye prior to surgery.
ION. An ischemic optic neuropathy is a damaging event that happens in the optic nerve behind the eye when the blood supply to the nerve is temporarily blocked or interrupted. Without nutrition the nerve tissue swells and becomes damaged. Sudden and severe vision darkening occurs, often affecting either the upper or lower half of the vision. IONs tend to occur in middle age. While it is impossible to predict who will have an ION, some people have a "disk at risk" ... this is tight nerve insertion in the back of the eye seen during an eye exam. Something about this anatomy puts certain people at higher risk for an ION. While not a perfect metaphor, you can imagine that people who wear tight watch bands around their wrist will have more nerve damage if their arm ever swells up. There is no treatment for an ION, other than ruling out more serious conditions like temporal arteritis. The vision loss may improve with time. A new ION will often prompt a workup to look for vasculopathic risk factors like hypertension and diabetes. If the history warrants, we may also start an embolic workup to make sure the heart is beating normally (arrhythmias can cause clot formation) and a carotid ultrasound (to look for cholesterol emboli).
iris. The iris is the "colored" muscle inside the eye that controls pupil size. Some people have brown irises and others have blue. The color of the eye is determined by the amount of pigment in the iris, with dark brown eyes having more pigment than lighter eyes. The iris has rings of muscle fiber that contract and changes the pupil shape in response to light entering the eye. When inflamed, a condition called iritis, the iris can cause pain and sensitivity to light (photophobia). The iris is thin, like a drumhead, and very mobile. If the iris bows forward, the trabecular meshwork (the drain of the eye) may become blocked, leading to angle closure and acute glaucoma. Floppy iris syndrome (usually caused by urinary medications like Flomax) can cause difficulties during cataract surgery. Pupil abnormalities can occur from nerve blockage to the iris muscle from many sources including Horner's syndrome, Adie's pupil, third nerve palsy, or pharmacologic dilation.
iris synechiae. This is an oddly shaped pupil that forms after inflammation inside the eye. The iris is the flat muscle inside our eye that controls pupil size and gives our eyes "color." When the iris is inflamed, such as after trauma or uveitis, it tends to become "sticky" and wants to scar to nearby structures. The pupil overlies the lens itself and if the edge of the pupil adheres to the lens underneath, the pupil will look abnormal. This adhesion is called a synechiae, and makes the pupil look like a cat's eye or a keyhole. If the adhesions are bad enough, the pupil can scar and create an acute glaucoma. In cases of ocular inflammation, we typically treat the eye with steroids to cool the eye down as quickly as possible. In addition, we may prescribe dilating drops to force the pupil to dilate and keep these adhesions from forming.
iritis. This is inflammation of the iris, the "colored" part of the eye. The iris is a muscle that controls the size of the pupil. When inflamed, the iris muscle can "spasm" and cause intense eye pain. Most people with an iritis complain of extreme sensitivity to light (photophobia). Iris inflammation can occur from many sources such as trauma or after intraocular surgery. Another cause is uveitis. Uveitis is a similar (but more encompassing) term used to describe internal ocular inflammation, usually from pro-inflammatory systemic problems like sarcoidosis, rheumatoid arthritis, inflammatory bowel disease, and infection. Treatment for iritis involves topical steroids to "cool" the eye down. Cycloplegia dilating drops can help with iris pain by "paralyzing" the iris muscle so that it stops "spasming." Dilation drops are also helpful because they keep the pupil dilated and help avoid the formation of iris synechiae (this is when the iris inflammation causes it to 'stick' to nearby structures like the lens underneath).
ischemic optic neuropathy. This is damage to the optic nerve behind the eye that can occur in middle age. See ION for more information on this topic.
Istalol. This is the trade name for the glaucoma eye drop timolol. Timolol is a beta-blocker similar to the beta-blocker medicine used to control blood pressure. As this medicine has been around for a long time, it is also available as an inexpensive generic. Istalol comes in a thicker consistency, so the medicine lasts longer and is usually dosed once a day (as opposed to the twice a day dosing of the generic equivalent).