| Abstract: | Background and objective. Since May 1998, small incision instruments for the implantation of intrastromal corneal ring segments (ICRS) are available enabling incisions only 1.2 mm in width instead of 1.8 mm to be made. After a follow-up period of 22 months in the conventional group and 8 months in the small incision group, the results of both groups were compared. Patients and methods. Since April 1997, 73 intrastromal corneal ring segments have been implanted, the first 43 ICRS implantations in 29 patients were performed using the conventional technique, the next 30 ICRS implantations in 22 patients were performed with the small incision technique. The average preoperative myopia was ?3.5 D. Results. After 6 months, 66.7% of the patients of both groups achieved the refraction target ±0.5 D. Even on the first postoperative day, the final refraction is achieved and shows stability for 1 year without regression. After 6 months, 80% of the conventionally operated patients and 77.8% of the patients operated on with the small incision technique showed an uncorrected visual acuity of 1.0 or better. With the small incision technique the preparation of the corneal dissection channel in 2/3 corneal stromal depth is significantly easier and can be carried out more safely.. Perforations towards the inner or outer surface of the cornea can be practically excluded. Due to the smaller superficial wound in contrast to the conventional technique, a corneal suture is not necessary. Stromal depth of implantation was more than 50% and in both groups no decentration of 1.0 mm or more occurred. Conclusions. The small incision technique increases the intraoperative safety in the dissection of the stromal lamellae in the correct level. Both techniques are comparable with regards to visual acuity and refraction. The smaller corneal wound does not need a corneal suture. Because of these advantages we have completely switched our technique to the small incisions. |
