Intrastromal ring improves distance vision, refractive error in eyes with post-LASIK ectasia
An intrastromal ring improved uncorrected and corrected distance visual acuity and reduced refractive error in eyes with post-LASIK corneal ectasia, according to a study.
The prospective study included 15 eyes of 14 patients with post-LASIK ectasia who underwent implantation of a MyoRing (Dioptex). Researchers evaluated logMAR uncorrected and corrected distance visual acuity (UDVA/CDVA), refraction, keratometry, central corneal thickness, corneal biomechanics and corneal aberrometry preoperatively and at 1, 3, 6 and 12 months postoperatively.
UDVA improved significantly from 1.02 preoperatively to 0.30 at 1 month, according to the researchers. Maximum keratometry also improved significantly, from 50.14 preoperatively to 43.80 at 1 month. Sphere decreased significantly from –4.4 D to +1.5 D. Further improvements from 1 month to 12 months were insignificant in all three areas, the researchers found.
CDVA improved insignificantly at 1 month; however, significant improvement occurred from 1 month to 3 months (0.3 to 0.17), with no further improvement at later follow-up visits.
Central corneal thickness increased from 439.4 µm to 452.2 µm at 1 month, which approach significance, according to the researchers.
Primary coma, higher-order aberrations and trefoil decreased insignificantly at 1 month and subsequent time points.
Spherical aberration increased significantly from –0.64 before surgery to 1.18 at 1 month. Changes in corneal hysteresis and corneal resistance factor were insignificant at all follow-up points, according to the researchers.
Disclosure: The study authors report no relevant financial disclosures.