Intrastromal corneal ring segments and posterior chamber phakic intraocular lens implantation for keratoconus correction

J Cataract Refract Surg. 2011 Apr;37(4):706-13. doi: 10.1016/j.jcrs.2010.10.060.


Purpose: To evaluate the efficacy, safety, and predictability of sequential implantation of Keraring intrastromal corneal ring segments (ICRS) and an Implantable Collamer Lens phakic intraocular lens (pIOL) with corneal relaxing incisions for refractive correction of keratoconus.

Setting: Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

Design: Cohort study.

Methods: This study comprised patients with keratoconus who had ICRS implantation followed 6 months later by pIOL implantation with corneal relaxing incisions. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors, analyzed using vector analysis, were recorded preoperatively, 6 months after ICRS implantation, and 6 months after pIOL implantation.

Results: The study enrolled 40 eyes (31 patients). The mean UDVA (decimal) was 0.11 Snellen ± 0.05 (SD) preoperatively, 0.18 ± 0.14 Snellen 6 months after ICRS implantation (P=.001), and 0.50 ± 0.27 Snellen 6 months after pIOL implantation (P<.0001). The mean CDVA was 0.56 ± 0.23 Snellen, 0.68 ± 0.25 Snellen, and 0.73 ± 0.20 Snellen, respectively (all P<.0001). Six months after pIOL implantation, the efficacy index was 0.88 and the safety index, 1.28. At 6 months, 65% of eyes were within ±1.00 diopter (D) of the desired refraction and 45% were within ±0.50 D. The mean spherical equivalent after pIOL implantation was -1.19 ± 1.33 D.

Conclusion: Sequential ICRS and pIOL implantation plus corneal relaxing incisions provided good visual and refractive outcomes, indicating that it is a predictable procedure for refractive correction of keratoconus.

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

MeSH terms

  • Adult
  • Cohort Studies
  • Corneal Stroma / surgery*
  • Female
  • Humans
  • Keratoconus / physiopathology
  • Keratoconus / surgery*
  • Lens Implantation, Intraocular*
  • Male
  • Middle Aged
  • Phakic Intraocular Lenses*
  • Polymethyl Methacrylate
  • Prognosis
  • Prospective Studies
  • Prostheses and Implants*
  • Prosthesis Implantation*
  • Refraction, Ocular / physiology
  • Visual Acuity / physiology


  • Polymethyl Methacrylate