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Chapter 2: History of Vectorial Analysis of Astigmatism

Practical Astigmatism: Planning and Analysis book order -

The surgical correction of astigmatism over the years, Arcuate keratotomies, Transverse keratotomies, Definition of a Vector, Surgically induced asitgmatism, The Alpins Method - Concepts and Terms What got you first interested in the subject of astigmatism? Astigmatism became obvious to us when implantology commenced. I spent a lot of time dividing sutures and doing what I call a dynamic vector analysis to divide sutures to try and minimise and orientate the astigmatism better. Lans in the late 1890’s was the first to demonstrate that incisions could actually change the astigmatism status of the eye Then Naylor in the 1960s discussed the obliquely crossed cylinders, the addition of them for lenses, but then Jaffe and Clayman in 1975 took that one step further rather than talking about lenses they started talking about corneas and incisions and sutures. What is the basic difference between a vector and astigmatism? Is this a vector or is this an astigmatism, is based on can you measure it? If you can measure it, it is an astigmatism but if you can’t measure it you can only calculate it then it is a vector. So when performing astigmatic analysis many are done looking at the magnitude alone. What more does the axis of the astigmatism tell us about how well a procedure corrected astigmatism? It is important to know whether the astigmatism increases or decreases and so certainly magnitude comparisons have a usefulness but if you want to understand the process of how the operation is performed success wise over/under correction then you really need to look at the axis as well or the meridian