Supraciliary contraction segments: A new method for the treatment of presbyopia.

Background and Objective: To evaluate the safety and effectiveness of supraciliary contraction segment implants (SCSIs) for the treatment of presbyopia. Materials and Methods: This prospective, noncomparative study comprised 10 eyes from five phakic and emmetropic 50-year-old subjects. Preoperative and postoperative near and distance visual acuity, topography, axial length, pachymetry, and intraocular pressure were analyzed. A 5.32-mm long and 0.85-mm thick piece of polymethyl methacrylat (PMMA) and a 5.32-mm long or 0.55-mm thick dried hydrophilic SCSI were placed within the scleral tunnels that were created 2 mm away from the limbus. The 500–550 μm deep tunnels were parallel to the limbus and four segments were implanted per eye. The SCSIs were entirely placed at a depth of approximately 85% in the sclera. Results: The uncorrected distance visual acuity was similar before and after the surgery (0.00 logMAR). The monocular mean uncorrected near visual acuity (UNVA) was 0.5 ± 0.0 before surgery, 0.12 ± 0.10 logMAR at 1 month after surgery, 0.16 ± 0.18 logMAR at 3 months after surgery, and 0.29 ± 0.16 logMAR at the 18-month follow-up. Conclusion: Despite obtaining satisfactory results at 6 months after the surgery, a follow-up of the SCSI intervention at 18 months revealed a regression of the early post-op UNVA improvement caused by a progressive outward movement of SCSIs.

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

Purpose: To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS) implantation in patients with keratoconus using a mechanical implantation technique. Materials and Methods: Thirty eyes of 17 patients with keratoconus were enrolled. ICRSs (Keraring) 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 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 1.36 ± 0.64 logMAR. At 12 months, the mean UDVA was 0.51 ± 0.28 logMAR (P = 0.001), and the mean preoperative CDVA was 0.57 ± 0.29 logMAR, which improved to 0.23 ± 0.18 (P = 0.001) at 1 year. There was a significant reduction in spherical equivalent refractive error from –6.42 ± 4.69 diopters (D) preoperatively to –1.26 ± 1.45 D (P = 0.001) at 1 year. In the same period, the mean K-readings improved from 49.38 ± 3.72 D to 44.43 ± 3.13 D (P = 0.001), and the mean ISAI improved from 7.92 ± 3.12 to 4.21 ± 1.96 (P = 0.003). No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during and or after surgery. Conclusion: ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for keratoconus. All parameters improved by the 1-year follow-up.

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

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.