دانلود کتاب جراحی استرابیسم – رویکردهای نوآورانه و کلاسیک

Strabismus surgical techniques developed in the 20th century were based upon anatomical knowledge and assumptions of that time. Most procedures involved recessions, which weaken muscles by moving their insertions posteriorlyon the sclera, or resections, which strengthen muscles byshortening them.Over the years, variations of those basic procedures were added to the mix, until our current complex collection of procedures was developed. Strabismus surgery can be frustrating, especially in adults and reoperation cases, in which results can be unpredictable. One patient may respond beautifully, while another with the same measurements has almost no effect, and a third has a large overcorrection, all from the same procedure. What can explain this variability? Some like to blame it on the patient’s “brain,” which is an easy scapegoat, but maybe we have been lumping many different disorders with the same measurements into a “one size fits all” approach. If we methodically approach diagnosis to correctly identify the mechanism of the problem, can we improve results? I remember sitting in the audience at an Association for Research in Vision and Ophthalmology (ARVO) meeting as a newly minted ophthalmologist. During a discussion about motility, David Robinson, PhD, stood up and told the audience that when he was first trying to develop a computer model of the eye muscles, he plugged in the then-known anatomical data. The model predicted that the globe would flip backward with the cornea facing the orbital apex. Needless to say, this bizarre result was so false that it led to questioning of old assumptions. This trail of questioning led to a prodigious body of detailed and elegant research into the anatomy and function of the eye muscles and orbital connective tissue. It has revolutionized our understanding of normal motility and strabismus, which has only recently begun to be applied to the development of new surgical techniques. The facts we now have at our disposal include a large body of elegant anatomical and radiologic studies, which prove the critical importance of the orbital collagen scaffolding system or “pulleys” to the function of the extraocular muscles (EOMs). There are also many new facts emanating from other research in other fields of medicine regarding collagen, wound healing, inflammation, and other factors. Pioneering work by Alan Scott into the physiology of the muscles, showing how they gain and lose sarcomeres in response to position and tension, as well as the forces they exert in normal and pathologic states, also added more important data to the mix. Abnormalities of the pulleys have been shown to cause strabismus, but this knowledge has yet to be translated into substantive changes in strabismus surgical techniques. Most of our standard EOM surgery was developed empirically, without knowledge of these facts. Although our standard techniques are often successful, sometimes they are not, or don’t produce lasting results. As we begin to examine these new facts without bias, and apply them to strabismus problems, we are finding ourselves on the brink of an exciting revolution in the treatment of strabismus. If we approach strabismus correction mechanistically, we will think about the conditions with a completely different approach. For example, rather than presenting A and V patterns as a unified group, we can separate them into different groups based upon etiology. Orbital rotations and pulley displacements, oblique dysfunctions, and issues with the vertical rectus muscles can all cause A and V patterns but are very different problems. Specifically correcting the cause rather than just the pattern gives a more precise and lasting result.