Eye Dictionary: K
K
Keflex. This is an oral antibiotic that is good for skin and sinus infections. Also known as cephalexin, it is relatively inexpensive and fairly effective. This medication is on the $4 list at Walmart and free at Publix supermarket.
Kenalog. This is a steroid that is used to decrease inflammation in the eye. Unlike other steroids we use in ophthalmology, this drug is delivered as an injection. We occasionally inject Kenalog into chalazion eyelid lesions to speed their resolution. For patients with resistant ocular inflammation (uveitis), Kenalog can be injected in the skin next to the eye or even behind the eye for continuous release. With macular edema, Kenalog is injected directly into the vitreous of the eye itself.
keratitis sicca. This is a fancy and erudite way of saying dry eye. Only pompous academics use this term.
keratoconus. This is an abnormal curvature of the cornea (the clear window that makes up the front of the eye). Normally, the cornea is spherical with a surface shape like a basketball. People with astigmatism have a cornea that is shaped like an American football. These shapes are easy to "fix" with glasses. Keratoconus is a whole different game. With this condition, the cornea weakens over time and takes on an irregular shape ... like that of a "beer belly" or a "pointy cone." This irregular surface creates optical aberrations that are impossible to correct using glasses. Hard contacts can be helpful, as they create a rounder 'surface' on the eye, but are difficult to fit. If bad enough, keratoconus eyes may require a corneal transplant to regain useful vision. The cause of keratoconus is believed to be from a defect in the collagen tissue that makes up the eye. Diagnosis is usually made with microscopic examination of the eye and by corneal topography (a machine that maps out the surface shape of the eye like a topographical map). People with keratoconus are poor candidates for LASIK as the laser procedure makes the cornea thinner and further weakens it.
keratometry. This is the technique used to measure the steepness of the cornea (the clear window that makes up the front of the eye.) Everyone has a different corneal steepness, and this variation has a large effect on the eye's overall focusing prescription. Normally, the cornea is perfectly round like the surface of a basketball. With astigmatism, however, the corneal surface is more like a football, and steeper along one axis while flatter along the other. Keratometry can measure this astigmatism. Keratometry measurements are important when fitting for contact lenses as contacts come with different "steepnesses" and they need to fit properly. Keratometry readings are also needed before cataract surgery in order to calculate the intraocular lens implants to use. Keratometry measurements can be performed manually or via automated machines (for example, the IOL-master machine used before cataractsurgery).
ketotifen. This is a second generation antihistamine medication found in several of the better over-the-counter allergy eye drops. This medicine can be found at the store under the trade names Zaditor and Alaway. There are generic drops as well ... but not much cheaper than the brand names. Allergy medications like this are good for treating itchy eyes and ocular swelling. The half-life is about 12 hours, so this drop is commonly dosed twice a day.
Kenalog. This is a steroid that is used to decrease inflammation in the eye. Unlike other steroids we use in ophthalmology, this drug is delivered as an injection. We occasionally inject Kenalog into chalazion eyelid lesions to speed their resolution. For patients with resistant ocular inflammation (uveitis), Kenalog can be injected in the skin next to the eye or even behind the eye for continuous release. With macular edema, Kenalog is injected directly into the vitreous of the eye itself.
keratitis sicca. This is a fancy and erudite way of saying dry eye. Only pompous academics use this term.
keratoconus. This is an abnormal curvature of the cornea (the clear window that makes up the front of the eye). Normally, the cornea is spherical with a surface shape like a basketball. People with astigmatism have a cornea that is shaped like an American football. These shapes are easy to "fix" with glasses. Keratoconus is a whole different game. With this condition, the cornea weakens over time and takes on an irregular shape ... like that of a "beer belly" or a "pointy cone." This irregular surface creates optical aberrations that are impossible to correct using glasses. Hard contacts can be helpful, as they create a rounder 'surface' on the eye, but are difficult to fit. If bad enough, keratoconus eyes may require a corneal transplant to regain useful vision. The cause of keratoconus is believed to be from a defect in the collagen tissue that makes up the eye. Diagnosis is usually made with microscopic examination of the eye and by corneal topography (a machine that maps out the surface shape of the eye like a topographical map). People with keratoconus are poor candidates for LASIK as the laser procedure makes the cornea thinner and further weakens it.
keratometry. This is the technique used to measure the steepness of the cornea (the clear window that makes up the front of the eye.) Everyone has a different corneal steepness, and this variation has a large effect on the eye's overall focusing prescription. Normally, the cornea is perfectly round like the surface of a basketball. With astigmatism, however, the corneal surface is more like a football, and steeper along one axis while flatter along the other. Keratometry can measure this astigmatism. Keratometry measurements are important when fitting for contact lenses as contacts come with different "steepnesses" and they need to fit properly. Keratometry readings are also needed before cataract surgery in order to calculate the intraocular lens implants to use. Keratometry measurements can be performed manually or via automated machines (for example, the IOL-master machine used before cataractsurgery).
ketotifen. This is a second generation antihistamine medication found in several of the better over-the-counter allergy eye drops. This medicine can be found at the store under the trade names Zaditor and Alaway. There are generic drops as well ... but not much cheaper than the brand names. Allergy medications like this are good for treating itchy eyes and ocular swelling. The half-life is about 12 hours, so this drop is commonly dosed twice a day.