Clinical outcomes after implantation of a new intrastromal corneal ring with a 210-degree arc length.
OBJECTIVE
To report the clinical outcomes of implantation of a new Ferrara intrastromal corneal ring segment (ICRS) with a 210-degree arc length in eyes with keratoconus.


METHODS
Private eye clinic, Belo Horizonte, Brazil


METHODS
Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction, and keratometry.


RESULTS
Eighty eyes (76 patients) were evaluated. The UDVA improved from 20/350 preoperatively to 20/136 postoperatively and the CDVA, from 20/125 to 20/50; the differences were statistically significant (P = .001 and P = .0001, respectively). Corneal tomography (Pentacam) showed corneal flattening in all eyes. The mean preoperative spherical equivalent decreased from -5.22 diopters (D) preoperatively to -2.26 D postoperatively (P = .050); the mean keratometry (K) 1 value, from 51.49 D to 47.40 D (P = .00014); and the mean K2 value, from 54.33 D to 49.14 D (P = .00022). Two patients required penetrating keratoplasty despite ICRS implantation.


CONCLUSIONS
A new ICRS with 210 degrees of arc was effective in treating keratoconus. It improved visual acuity and reduced corneal steepening in selected patients.
Ferrara
Paulo
P
pferrara@ferrararing.com.br
Torquetti
Leonardo
L
D003319:Corneal Stroma / Q000503:physiopathology / Q000601:surgery*; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000601:surgery*; D019904:Polymethyl Methacrylate; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
D019904:Polymethyl Methacrylate