CATARACT-SURGERY AND ASTIGMATIC KERATOTOMY

The clinical results with this approach are reasonable. It must be emphasized, however, that the most common problems involve the unpredictability of overcorrection or undercorrection of the astigmatism. Although there are medical and surgical options for the management of these outcomes, thorough preoperative discussion pertaining to expectations and outcomes is essential. What are the surgical alternatives to our approach as outlined? With respect to naturally occurring astigmatism, adequate results can be obtained using straight or arcuate keratotomies. We believe that larger corrections can be obtained with arcuate incisions, and this is borne out in the literature [17, 19]. A single incision or a pair of symmetrical incisions is adequate; we do not advocate more than two incisions. A clear zone of 6 or 7 mm is reasonable; incisions any closer to the center of the entrance pupil are not justified and may be fraught with more significant problems involving glare. We do not use arcuate incisions more than 90 degrees long, but others have reported success with incisions of up to 120 degrees [19]. As stated earlier, we have abandoned the trapezoidal astigmatic keratotomy or Ruiz procedure owing to extreme variability in the results [24]. Owing to the inherent variability of results of keratotomy, it is reasonable in older post-cataract surgery patients to use a single incision, as we have observed large shifts, often unexpectedly, with this approach. An additional incision can be made later if necessary. In patients with astigmatism incited by cataract extraction, an alternative method is revision of the wound. Because wound revision often involves tissue excision, a long healing process, and a greater possibility of entering the anterior chamber, we usually favor refractive keratotomy. One exception to this is early postoperative astigmatism associated with wound dehiscence with or without a filtering bleb or iris prolapse. In these cases, the wound may be resutured under keratometric control. When significant astigmatism is present preoperatively in patients with cataracts, we favor performing the cataract incision in the steep axis, because cataract wounds tend to result in against-the-wound astigmatism with time. Intraoperative keratometry can aid in reducing preoperative astigmatism by titrating suture tension to a level of approximately 2 D of with-the-rule astigmatism. We believe that concurrent astigmatic surgery rarely is indicated and that this should be performed at a later time if necessary.