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What is it? |
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Corneal topography also known as videokeratography or corneal mapping is a method of computer assisted examination of the cornea, the clear front portion of the eye that transmits and focuses light into the eye. |
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What is it done for? |
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Corneal topography is performed by projecting illuminated rings on to the corneal surface which are reflected back and measure by the instrument. The test results in the generation of a topographical map of the cornea. |
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How is it done? |
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Corneal topography is performed by projecting illuminated rings on to the corneal surface which are reflected back and measure by the instrument. The test results in the generation of a topographical map of the cornea. |
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What are the benefits? |
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a.It is used in estimating the degree of astigmatism in patient’s eye.
b.It is used as an aid in fitting of contact lenses.
c. It is used in evaluation of patients undergoing lasik and other surgeries to estimate the regular surface of the cornea.
d.It is used to detect the Keratoconus (irregular distortions in the corneal surface) |
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What are the limitations? |
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Limited with the errors in placido’s based system,focussing alignment and fixation error with induced astigmatism. Early keratoconus, penetrating keratoplasty and complicated refractive surgeries. Mucus tear debris and poor tearfilm status affects interpretation |
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How much time is taken? |
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For normal tests 10 to 15 minutes are required. |
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When is to be repeated? |
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As per doctors advise. |
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What are other alternative tests? |
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Videokeratography, orbscan and corneal mapping test. |
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What is the expense? |
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The cost may vary from one hospital to the other. |