EctasiaEctasia is an umbrella term for a group of conditions affecting the cornea. In these conditions the cornea becomes distorted creating aberrations resulting in complex astigmatism prescriptions and visual disturbance. This all means that the sufferer sees a very distorted image a little like looking through decorative bulls eye glass.
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Anatomy of EctasiaThe cornea is the clear window of the eye that arches over the iris (the coloured part of the eye). It provides 80% of the refractive power (the focusing power) of the eye which means that if there are any irregularities in it's shape then the eyes image focus can be greatly affected.
The shape should ideally be spherical i.e. dome-like, although some people have rugby ball shaped corneas, where it is steeper in one meridian than another this results in astigmatism. Astigmatism is very common, as long as the shape of the cornea is symmetrical it is easily corrected with glasses or standard contact lenses. As the corneal shape becomes less symmetrical then the refraction is much much difficult to deal with. There are several different forms of ectasia all of which result is subtle differences in the shape an the cornea and ultimately how it is corrected. I have outlined the three most common conditiond here plus the iatrogenc (surgically induced) catagory. |
Topographic AnalysisFor more information on how to interpret your topographic maps please click on this link.
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