[Minimizing induction of astigmatism in preoperative spherical cornea a. by mini-incision surgery with foldable IOL and b. by corneal tunnel incision with limbal relaxing incision].
BACKGROUND
In case of a spheric cornea preoperatively the refractive effect of a clear corneal cataract incision is undesirable. We studied two actual techniques to minimize the surgically induced astigmatism.


METHODS
Temporal clear corneal incision was performed in 77 patients with practically spherical cornea (0.2 +/- 0.1 D). 27 patients with 4.1-mm clear corneal stretch incision and 5 mm PMMA lens implantation served as control. 25 further patients were operated on with the same technique, but 2 additional limbal relaxing incisions (LRI) of 0.55-mm depth and 8 mm length at 6 and 12 o'clock were performed. In 25 patients a foldable acrylic lens (Acrysof) was implanted through a 3.2-mm temporal clear corneal incision. Corneal topography results were evaluated in all patients by the Jaffe and the Holladay analysis.


RESULTS
The surgically induced astigmatism of 0.8 +/- 0.5 dpt in the control group was reduced to 0.4 +/- 0.3 dpt by LRI and by reduction of the incision size as well in the treatment groups. With-the-wound-change (WTW) in the Holladay analysis was 0.6 +/- 0.7 dpt in the control group and around 0 in the groups with astigmatism reducing techniques.


CONCLUSIONS
To preserve a spherical cornea in clear corneal-tunnel incision, compensating limbal relaxing incisions (LRI) or ultra-small incisions with foldable lens implantation should be performed.
Müller-Jensen
K
K
Augenklinik des Städtischen Klinikums Karlsruhe.
Fischer
P
P
D001251:Astigmatism / Q000209:etiology / Q000517:prevention & control*; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D007910:Lenses, Intraocular; D016850:Limbus Corneae / Q000601:surgery*; D008866:Microsurgery; D011183:Postoperative Complications / Q000517:prevention & control*; D011474:Prosthesis Design; D012029:Refraction, Ocular; D016639:Scleroplasty