Risk factors for self-reported visual symptoms with Intacs inserts for myopia

Intrastromal Corneal Ring Segments in Children with Keratoconus

Purpose

To evaluate the long-term follow-up of Ferrara intrastromal corneal ring segments (ICRSs) (Ferrara Ophthalmics, Belo Horizonte, Brazil) implantation for the management of keratoconus in children.

Study design

Paulo Ferrara Eye Clinic, Belo Horizonte, Minas Gerais, Brazil.

Materials and methods

A total of 58 eyes of 37 children with keratoconus were included. One or two ring segments were inserted into the cornea, embracing the keratoconus area. Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), asphericity, pachymetry, and keratometry.

Results

Ferrara ICRS implantation significantly improved the mean UDVA and CDVA. Corneal tomography (Pentacam®) showed corneal flattening in all eyes implanted with the Ferrara ring. The mean K decreased, and the corneal asphericity and pachymetry increased in all cases.

Conclusion

The Ferrara ICRS improved all parameters after 2 years of implantation in children with keratoconus. There was significant corneal flattening after ring implantation with improvement of the UDVA and the CDVA. All studied parameters remained stable over time.

How to cite this article

Ferrara G, Ferrara P, Torquetti L. Intrastromal Corneal Ring Segments in Children with Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):45-48.

Intrastromal corneal ring segments to correct low myopia in eyes with irregular or abnormal topography including forme fruste keratoconus: 4-year follow-up

PURPOSE

To report the 4-year outcomes after Intacs intrastromal corneal ring segment (ICRS) implantation to correct low myopia in patients with abnormal topography.

SETTING

Instituto de Microcirugia Ocular, Barcelona, Spain.

METHODS

This retrospective consecutive interventional case series included eyes with myopia lower than -4.50 diopters (D) and abnormal topography that excluded excimer laser surgery. Evaluation was performed preoperatively and at yearly intervals up to 4 years postoperatively. The 4-year outcomes measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, predictability and stability of refractive correction, the efficacy and safety indices, and complications.

RESULTS

After ICRS implantation, 82.05% of 39 eyes (21 patients) were within +/-1.00 diopter (D) of emmetropia and 46.15% were within +/-0.50 D. Refractive correction improved during the first 6 months and remained stable up to 4 years. The UDVA was 20/40 or better in all eyes and 20/20 or better in 38.46% of eyes. Seven eyes (17.95%) lost 1 line of CDVA, and no eye lost 2 or more lines. No intraoperative complications occurred. The ICRS were exchanged for thicker ICRS in 7 eyes (17.9%) because of undercorrection. One patient requested ICRS removal due to unsatisfactory refractive results.

CONCLUSIONS

The 4-year results indicate that ICRS implantation is effective and safe in the correction of low myopia in patients for whom excimer laser surgery is contraindicated because of abnormal topography, including forme fruste keratoconus. The achieved refractive correction remained stable throughout the follow-up.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Long-term follow-up of intrastromal corneal ring segments in keratoconus

PURPOSE

To report the long-term follow-up of Ferrara intrastromal corneal ring segment (ICRS) implantation for the management of keratoconus.

SETTING

Private clinic, Belo Horizonte, Brazil.

METHODS

This study comprised patients with keratoconus who completed at least 5 years of follow-up. One or 2 ICRS were inserted in the cornea, embracing the keratoconus area. Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and keratometry (K) values.

RESULTS

Thirty-five eyes of 28 patients were evaluated. The mean UDVA improved from 0.15 preoperatively to 0.31 postoperatively and the mean CDVA, from 0.41 to 0.62, respectively; the increases were statistically significant (P = .003 and P = .002, respectively). Corneal topography showed corneal flattening in all eyes. The mean minimum K value decreased from 48.99 D preoperatively to 44.45 D postoperatively and the mean maximum K value, from 54.07 D to 48.09 D, respectively; the decreases were statistically significant (both P = .000).

CONCLUSIONS

Five years after ICRS implantation, the UDVA and CDVA were improved in eyes with keratoconus. There was significant postoperative corneal flattening that remained stable over the follow-up period.

Modified Intracorneal Ring Segment Implantations (INTACS) for the Management of Moderate to Advanced Keratoconus

PURPOSE

To evaluate the safety and efficacy of modified intracorneal ring segment implantation (INTACS) in the management of moderate and advanced keratoconus (KCN).

METHODS

A modified procedure of intracorneal ring segment (INTACS) implantation was performed in eyes with moderate to advanced keratoconus that were intolerant to contact lens or spectacle correction. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), refraction, and keratometry. The preoperative values were compared with the values 6 and 12 months postoperatively.

RESULTS

Implantation was performed on 20 eyes of 15 patients; 9 were female and 6 were male. The mean age was 30.2 years (SD +/- 5.44; range, 23-40). At the 6-month follow-up, UCVA improved from 20/154 (SD +/- 0.11) preoperatively to 20/28 (SD +/- 0.21) postoperatively (P < 0.05); BCSVA improved from 20/37 (SD +/- 0.21) preoperatively to 20/22 (SD +/- 0.13) postoperatively (P < 0.05). Spherical refractive error improved from -3.38 D (SD +/- 3.12) to -1.15 D (SD +/- 1.84); cylindrical refractive error improved from -3.75 (SD +/- 2.04) preoperatively to -1.21 (SD +/- 0.84) postoperatively (P < 0.05); average keratometry decreased from 49.50 D (SD +/- 1.64) preoperatively to 46.35 D (SD +/- 1.50) postoperatively. The changes remained stable to the 12-month follow-up. There was 1 case of anterior chamber perforation. There were 6 eyes that had ring exposure secondary to corneal thinning over the implants 3-6 months postoperatively, and a dense corneal infiltrate developed in 1 patient at 7 months postoperatively.

CONCLUSIONS

The procedure appears to be effective in improving UCVA and BSCVA of patients with clinical keratoconus. In our small study group, however, there were significant (6/20) postoperative problems with regards to thinning and ring exposure.