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[PMMA lens implantation in sutureless corneal cataract surgery]
1Augenklinik des Städtischen Klinikums Karlsruhe.
Background:
Self-sealing corneal cataract procedures have been known since 1992 and are recommended for foldable silicon lenses. Our goal was a technical modification without refractive disadvantages, which would also allow for the implantation of more rigid, but less expensive PMMA lenses of high optical quality.
Methods:
The "scleral stretch incision" by Freeman (1991) was applied to the corneal situation by widening the inner wound lip up to 6.5 mm; this makes it possible to implant a 5 mm optic through an outer wound opening of 4-4.2 mm. This method has been used since October 1992 on 980 patients, whereby the lamellar corneal incision was placed 1.5-1.8 mm deep to compensate for the astigmatism, if possible in the steeper meridian.
Results:
The first 107 cases were followed up for longer than 6 months; they showed a surgically induced astigmatism of 1.18 +/- 0.79 D and a postoperative astigmatism of 0.86 +/- 0.70 D. Neither postoperative infection nor hypotony was observed in any of the cases.
Conclusion:
The modified corneal tunnel incision is recommended for 5 mm PMMA lenses; this is especially suited for cases of low to midgrade preoperative astigmatism that can be optimally improved by this procedure. In cases of pure spheric refraction, a 3 to 3.5 mm incision with foldable lens implantation is preferred.