For all corneal conditions considered, including keratoconus, the larger the button used the less the resultant myopia. Residual astigmatism was not affected by graft button size in any condition. In cases of keratoconus, a running button size in any condition. In cases of keratoconus, a running suture resulted in less myopic spherical equivalent than did interrupted sutures. Residual astigmatism was not affected by suturing technique in any condition. Contact lens use was required for acuity of 20/40 or better in 11% of these keratoplasties. There appears to be no practical solution for the problem of high astigmatism following keratoplasty as of this time. Keratometry readings at the end of the operative procedure might allow readjustment of the tension in the sutures and thus reduce the final astigmatic error. However, the mires will certainly be distorted at the end of the operative procedure; in addition, it is well known that the refractive error following cataract surgery changes considerably during the first postoperative month when 10-0 nylon suture is used. This readjustment is probably due to the sutures cutting into the tissue. It therefore seems reasonable that the 10-0 suture material will migrate through corneal tissue to some degree after keratoplasty and this in turn will alter the astigmatic error. The use of larger grafts (8 mm buttons) may reduce residual myopia in keratoconus. However, this slight improvement has to be evaluated against the increased possibility of an allograft reaction. In most instances, a severe allograft reaction is much more devastating to a corneal graft than is astigmatism.
|Original language||English (US)|
|Number of pages||9|
|Journal||Transactions of the American Ophthalmological Society|
|State||Published - Jan 1 1974|
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