Continuous intracorneal ring implantation for keratoconus using a femtosecond laser

To assess the clinical outcomes after continuous intracorneal ring (ICR) implantation for the management of keratoconus using femtosecond laser technology.

Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Prospective nonrandomized consecutive case series.

All patients presented with reduced visual acuity, contact lens intolerance, and a central corneal thickness of more than 360 μm. A Myoring ICR was inserted in an intrastromal pocket created by a femtosecond laser. The visual, refractive, aberrometric, and corneal biomechanical outcomes were measured preoperatively as well as 1, 3, and 6 months and 1 year postoperatively.

The study comprised 98 keratoconic eyes of 98 patients with a mean age of 30.7 years ± 9.01 (SD). Fifteen eyes (15.3%) had grade I keratoconus, 37 eyes (37.7%) had grade II keratoconus, 24 eyes (24.5%) had grade III keratoconus, and 22 eyes (22.4%) had grade IV keratoconus. The uncorrected and corrected distance visual acuities and spherical and cylindrical errors improved 1 month after surgery (P<.001); however, no changes were detected thereafter (P>.05). The mean keratometry and corneal astigmatism decreased 1 month after surgery (P<.001); however, no significant change was observed at the 3-month or 1-year visits compared with the 1-month values (P>.05). Primary coma decreased significantly (P=.03), and spherical aberrations increased significantly (P<.001) postoperatively.

Continuous ICR implantation in keratoconus appears to be an acceptable substitute for keratoplasty in advanced keratoconus.

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