Intrastromal Corneal Ring Segments have been offered by Dr. Alan N. Carlson and his colleagues at the Duke Eye Center for the past 8 years and now with the addition of the Femtosecond Laser, they we have been able to offer this improvement to patients with more complex problems including previous refractive surgery and corneal transplantation.  The abstract below is from a recent article demonstrating it’s use in patients with residual corneal astigmatism after corneal transplantation procedures:

Intrastromal Corneal Ring Segment Implantation by
Femtosecond Laser for the Correction of Residual
Astigmatism After Penetrating Keratoplasty
Tatiana Moura Bastos Prazeres, MD,* Allan Cezar da Luz Souza, MD,* Nicolas Cesa´rio Pereira, MD,*
Fa´bio Ursulino, MD,† Leon Grupenmacher, MD,* and Luciene Barbosa de Souza, MD*
Purpose: To evaluate the safety and efficacy of intracorneal ring
segments (ICRSs) aided by femtosecond (FS) laser for the correction of
residual astigmatism after penetrating keratoplasty (PKP).
Methods: This retrospective noncomparative study comprised
14 eyes of 14 patients with high astigmatism after PKP who had
ICRS implantation by femtosecond laser. The study evaluated
uncorrected distance visual acuity (UDVA), corrected distance visual

Intacs Corneal Rings

acuity (CDVA), refractive astigmatism, and corneal maximum
Results: The CDVA postoperatively improved after 3 months
(P , 0.001) and 6 months (P , 0.001) compared with CDVA
preoperatively. The CDVA at 3 months was similar to that at 6 months
(P . 0.999) as well as the UDVA (P = 0.276). The preoperative
astigmatism was higher than that after surgery (P = 0.001). The
preoperative maximum curvature was higher than that of the postoperative
maximum curvature (P , 0.001).
Conclusions: The implantation of ICRSs using the femtosecond
laser for residual astigmatism post-PKP was safe and showed
satisfactory results. It reduced refractive astigmatism and maximum
corneal curvature and improved UDVA and CDVA.
Key Words: intracorneal ring segment, penetrating keratoplasty,
femtosecond laser, keratoconus
(Cornea 2011;30:1293–1297)