Evaluation of intrastromal corneal ring segments for treatment of post-LASIK ectasia patients with a mechanical implantation technique

Abstract

Aim:To evaluate the clinical outcomes of Keraring segment implantation in patients with post- laser-assisted in situ keratomileusis (LASIK) ectasia, using a mechanical implantation technique.Materials and Methods:Twelve eyes of 10 patients with post-LASIK ectasia were enrolled. Intracorneal ring segments (ICRS) were implanted after dissection of the tunnel using Tunc's specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent, keratometric (K) readings, inferosuperior asymmetry index (ISAI), and ultrasound pachymetry. All 3, 6, and 12-month follow-ups were completed, and statistical analysis was performed.Results:The mean preoperative UDVA for all eyes was 1.28 ± 0.59 logMAR. At 12 months, the mean UDVA was 0.36 ± 0.19 logarithm of the Minimum Angle of Resolution (logMAR) (P=0.002), and the mean preoperative CDVA was 0.58 ± 0.3 logMAR, which improved to 0.15 ± 0.12 (P=0.002) at 1 year. There was a significant reduction in cylindrical refractive and spherical equivalent refractive error from –5.29 ± 2.47 diopters (D) and –5.54 ± 5.04 D preoperatively to –1.47 ± 0.71 D and –0.74 ± 1.07 D (P=0.001, P=0.002), respectively, at 1 year. In the same period, the mean K- readings improved from 47.93 ± 4.84 D to 40.87 ± 2.36 D (P=0.002), and the mean ISAI improved from 5.34 ± 3.05 to 2.37 ± 1.68 (P=0.003). No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during or after surgery.Conclusion:ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for post-LASIK ectasia. All parameters showed improvement at 1-year follow-up.

Evaluation of intrastromal corneal ring segments for treatment of keratoconus with a mechanical implantation technique

“…The technique was also successfully used in the treatment of patients with post-LASIK ectasia. [29] As previously described for the post-LASIK ectasia, Tunc's dissector for the preparation of the tunnel facilitates the procedure and adds to the safety of the surgery in patients with keratoconus. Further follow-up and additional cases are needed to draw final conclusions about the efficacy of this surgical technique.…”

Ultrastructural and three‐dimensional study of post‐LASIK ectasia cornea

“…Corneal ectasia (also called "kerectasia" or "keratectasia") after laser‐assisted in situ keratomileusis (LASIK) surgery is a rare but devastating complication that was first described by Seiler et al () Keratectasia is defined as a progressive steepening of the corneal curvature, with or without associated central and paracentral corneal thinning. Clinically, it presents as the initial appearance of low myopia that progresses over time to high myopia and irregular astigmatism, resulting in loss of uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) (Randleman et al, ; Tunc et al, ). Two major risk factors are thought to be responsible for this complication: operating on corneas with preexisting disposition to corneal ectasia, and removing too much corneal tissue (Flanagan and Binder, ).…”

Femtosecond Laser-Assisted MyoRing Implantation in Postoperative LASIK Ectasia

“…2,23 In patients with corneal ectatic disorders, corneal hysteresis and corneal resistance factor were reported to be lower than in those with normal corneas. 1,17,24 AUTHOR CONTRIBUTIONS…”

“…We recruited patients with ectasia after LASIK. According to previous studies, 10,17 patients were characterized by existence of all five criteria: progressive steepening and myopia; loss of corrected distance visual acuity (CDVA); inferior superior asymmetry index greater than 1.2 (according to corneal topography map); highest elevation value of greater than 0.042 and 0.071 mm for anterior and posterior bestfit spheres, respectively (according to Orbscan elevation map); and progressive corneal thinning.…”