Abstract
Purpose: :
Many procedures can improve and perfect visual acuity. However, high levels of astigmatism are still difficult to correct. There are studies looking at toric contact lenses, toric intraocular lens implants, LASIK, PRK, limbal relaxing incisions (LRIs) and astigmatic keratotomies (AKs) to reduce levels of astigmatism. However, few techniques can correct high astigmatism, and the corrections are modest. By combining AK and compression sutures with management of the body’s natural healing response, we have corrected astigmatisms ranging from -4.2D to -18.7D. First described by Dr. R Troutman, compression sutures create tension on the corneal surface allowing for the incisions to remain open, filling in by secondary intention. This maintains the cornea in a flatter configuration, thereby decreasing astigmatism. Prior to this study there has been no data on this methods efficacy.
Methods: :
This is a prospective study involving 20 eyes of 18 patients with cylinder ranging from -4.2D to -18.7D. The treatment consisted of 2 arcuate incisions at a steep meridian and 2 compression sutures 90 degrees away at the flat meridian. Using an intraoperative placido ring, slip knot sutures was titrated to induce about half of the patient’s original astigmatism in a perpendicular meridian. Once the corneal incisions from the AK or LRI healed sufficiently, measured by lack of fluorescence staining or pooling, sutures were removed. Patients were followed with serial corneal topography (Orbscans) to quantify astigmatism and annotate axis at 1 week prior to, and 1 day, 1 month and 3 months post surgical intervention.
Results: :
Of our 19 patients, 5 were male, 14 female. 19 of the 21 eyes previously had a PK. Currently, 17 eyes are status post removal of sutures. Average astigmatism in this group, preoperatively was -9.4D ± 4.0, while immediate postoperatively was -6.2D ± 3.5, with a final average astigmatism of -3.8. A 60% decrease in astigmatism was achieved. BCVA improved by 2.4 lines. In 2 eyes visual acuity worsened by 1 line.
Conclusions: :
The addition of compression sutures to incisional correction of astigmatism can broaden the range of correctable astigmatism. The removal of sutures after sufficient healing of the incisions allows for high degree of astigmatism correction. With a significant decrease in the astigmatism, these patients are no longer functionally blind and now can be corrected with glasses and contact lenses.
Keywords: astigmatism • refractive surgery: other technologies • wound healing