Corneal topography provides doctors or ophthalmologists with the most detailed possible information about the curvature of the cornea (the transparent part in the front of the eye), potential eyesight issues, and eye diseases.
- The greatest advantage of corneal topography is its ability to detect conditions that cannot be identified using most conventional testing.
- Identification of deep or superficial corneal disorders/distortions causing visual disturbances and impairment, such as keratoconus (a disorder in which there is progressive thinning of the cornea making it bulge outwards like a cone resulting in blurry vision, double vision, and nearsightedness).
- Contact lens fitting and complex contact lens prescriptions.
- If a patient is to undergo refractive surgery with an excimer laser. In refractive surgery, the corneal topography is an exam of primary importance before and after the surgery.
- In ocular surface disorders, such as pterygium (pinkish, triangular tissue growth on the cornea), corneal topography is used to monitor progression.
- Dry eye evaluation
- Corneal transplants
- Corneal scars or opacities
- Irregular astigmatism (error in the shape of the cornea) following corneal transplantation
- Postoperative cataract extraction with acquired astigmatism
- In patients who may be interested in Ortho K (overnight wear) lenses
What is a cornea?
The cornea is the transparent dome-shaped covering the front of the eye and protecting the pupil, iris, and eye chamber. The cornea plays a key role in a patient’s vision quality and optical health. The cornea works with the lens and anterior chamber to focus light to help you see clearly.
Why is corneal topography important?
Corneal topography, computer-assisted videokeratography (CAVK), or corneal mapping is a computer-assisted diagnostic imaging technique that helps in creating visuals of the corneal surface so that the doctor can view the visuals and analyze the entire shape of the cornea for diagnosis and treatment. It is a noninvasive medical imaging technique used for mapping the surface curvature of the cornea. Since the cornea is normally responsible for approximately 70% of the eye’s refractive power, its topography is of critical importance in determining the quality of vision. Therefore, corneal topography is an important diagnostic test.
How corneal topography is performed?
This corneal topography creates a map of the cornea that allows the physician to formulate a 3D perspective of the cornea’s shape.
- The corneal topography usually has a computer linked to a lighted bowl, which has a pattern of concentric rings.
- The patient is usually asked to sit in front of the bowl with their head pressed against a bar.
- Multiple light concentric rings are then projected on the cornea and the reflected image is captured on a charge-coupled device (CCD) camera.
- The computer software then digitizes these data points and prints out the corneal shape using different color representations to identify different elevations.
- The cool shades of blue and green are usually used to indicate flatter areas of the cornea.
- Warmer shades of orange and red may indicate steeper areas.
Are corneal topography and corneal tomography the same imaging techniques?
No, both are different diagnostic techniques. However, both are very useful in the diagnosis of keratoconus.
- Corneal topography usually provides a map of the front surface of the cornea that is used to evaluate its curvature.
- Corneal tomography also provides a map of the front surface, as well as additional information about the curvature of the back surface of the cornea (inside of the eye). It may also be used to create a map showing the thickness of different areas of the cornea.
QUESTION
What causes dry eyes? See AnswerHealth Solutions From Our Sponsors
Medically Reviewed on 9/28/2022
References
Corneal Imaging: An Introduction:
(https://webeye.ophth.uiowa.edu/eyeforum/tutorials/Corneal-Imaging/Index.htm)
Complete List
Top What is Corneal Topography Used for? Related Articles
Corneal Disease
The cornea is the clear outer layer of the eye. If it is damaged by disease, infection, or injury, vision problems may occur. Corneal problems can be detected by having an eye exam. Corneal problems can be prevented by protecting the eyes from injury and avoiding contact with people who have eye infections.
Corneal Ulcer
A corneal ulcer is an open sore on the cornea. Infection is a common cause of corneal ulcer. Symptoms and signs of corneal ulcer include redness, eye pain and discharge, blurred vision, photophobia, and a gray or white spot on the cornea. Treatment depends upon the cause of the corneal ulcer.
Dry Eye Quiz
What causes dry eye? Take this quiz to learn about dry eye syndrome and what can be done about it.
Dry Eyes
Dry eyes are caused by an imbalance in the tear-flow system of the eye, but also can be caused by the drying out of the tear film. This can be due to dry air created by air conditioning, heat, or other environmental conditions. Treatment may involve self-care measures, medications, or rarely, surgery.
What Are the Types of Eye Care?
Many common eye disorders resolve without treatment and some may be managed with over-the-counter (OTC) products. It's important to visit a physician or ophthalmologist is the problem involves the eyeball itself or the condition hasn't improved after 72 hours of use of an OTC eye care product.
Common Eye Problems
Eye diseases can cause damage and blindness if not treated soon enough. Learn the warning signs and symptoms of common eye conditions such as glaucoma, cataracts, pink eye, macular degeneration and more.
Eye Picture
The eye has a number of components which include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous. See a picture of the Eye and learn more about the health topic.
Eye Strain
Eye strain is a symptom caused by looking at something for a long time. Symptoms and signs include redness, light sensitivity, headaches, and blurred vision. Symptoms may be treated by closing the eyes and taking a break from the visual task.
Eye Conditions Quiz
What do you know about your eyes? Take this quick quiz to learn about a range of eye diseases and conditions.
Maxidex (dexamethasone) Suspension
Maxidex (dexamethasone) ophthalmic suspension 0.1% is an adrenocortical steroid used to treat steroid responsive inflammatory conditions of the palpebral and bulbar conjunctiva, cornea, and anterior segment of the globe such as allergic conjunctivitis; acne rosacea, superficial punctate keratitis, herpes zoster keratitis, iritis, and other conditions. Common side effects of Maxidex include glaucoma with optic nerve damage, vision problems, cataracts, secondary eye infection following suppression of host response, and perforation of the outer membranes of the eye.sodium chloride hypertonic
Sodium chloride hypertonic ophthalmic is a medication topically administered in the eye to reduce swelling caused by corneal edema. Common side effects of sodium chloride hypertonic ophthalmic include temporary burning, redness, and/or irritation of the eyes; and transient changes in vision. Check with your physician before using sodium chloride hypertonic ophthalmic if you are pregnant or breastfeeding.
Sty (Stye)
A sty is a bump that forms on the eyelid as a result of a blocked gland. Styes may be caused by infections, burns, or trauma to the eyelid. Most styes resolve on their own. The application of warm compresses can speed healing. In some cases, steroid injection or incision and drainage may be necessary. Keeping the area clean and consuming a diet high in omega-3-fatty acids may help prevent the formation of styes.
What Does An Eye Infection Look Like?
An eye infection may bring about the following changes in the eye: A pink tint in the whites of the eye, swollen red or purple eyelids, crusty lashes or lids, and/or discharge of fluids which may be yellow, green or clear.What Is Corneal Disease?
The term "corneal disease" refers to any ailment that affects the cornea. The cornea is the transparent outer layer that covers the front of the eye. It is a barrier to keep out foreign items, enhances vision by focusing light, and blocks UV rays from entering the eye. Eye injuries, dry eyes, corneal dystrophies and degenerations, corneal infections that cause keratitis (inflammation), scarring, and keratitis are common disorders that damage the cornea.