Single Intra-Stromal Ring Segment (intacs) Implanted for Keratoconus Correction Using Femtosecond Laser: 30 Cases

Abstract

Purpose: : to evaluate the safety and the efficacy of a single intra-stromal ring Intacs implantation for keratoconus correction using the IntraLase femtosecond laser.

Methods: : This prospective study comprised 30 eyes from 30 patients with keratoconus treated by one Intacs implantation. Intra-stromal channel's dissection was performed with the Intralase FS 60 kHz. Channel's size was 6.6 mm X 7.6 mm. Dissection's depth was 80% of the central corneal thickness. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent and keratometry values measured with the Orbscan and Pentacam elevations maps were assessed and analysed before the procedure and 1 month, 3 months and 6 months after the procedure. Corneas implanted were scanned with a ConfoScan 4 confocal microscope.

Results: : Intacs implantation was performed with no intraoperative complications and no loss of vision. Post operatively, UCVA and BCVA improved for 90% and 70% of eyes respectively. Mean UCVA increased from 1.06 LogMAR (L) to 0.37 L (p<0.001). Mean BCVA increased from 0.47 L to 0.22 L(p<0.001). Mean spherical equivalent decreased from -5.92 dioptries (D) to -4.23 D. Mean keratometry decreased from 50.45 D to 48.21 D. No stromal inflammation reaction was observed on ConfoScan 4 images. 2 Intacs were removed from 2 eyes because of partial extrusion.

Conclusions: : Intacs implantation using IntraLase FS 2 was safe . Only one Intacs implantation was effective to reduce keratoconus induced ametropia within 6 months in our patients.

Keywords: cornea: clinical science • keratoconus • laser