Abstract
Purpose: :
To evaluate the safety, efficacy and stability of sequential corneal collagen cross-linking by UVA/riboflavin procedure and Ferrara intraestromal corneal rings segments (Ferrara ring) implantation in selected cases of keratoconus.
Methods: :
This prospective study involved 10 eyes with keratoconus diagnoses between June 2007 to October 2008. The inclusion criteria were keratoconus diagnoses (Amsler-Krumeich grades I, II y III), no corneal opacities, corneas thicker than 450 um, contact lens intolerance, no other treatment for keratoconus except contact lens. Each patient underwent crosslinking procedure in the keratoconus eye. Refraction 6 months after crosslinking procedure showed residual myopia greater than 5.0 D. Thus, Ferrara rings were inserted. The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, and topographic profiles were taken 1, 3, 6 months after the second surgery.
Results: :
All eyes achieved UCVA of 20/30 or better. The final spherical error ranged from -0.5 to -1.5 D and the cylindrical error, from -0.5 to -1.00 D. No eye lost lines of preoperative BCVA. Statistically significant reductions in the mean maximum (2.66D, p=0.04) and minimum (1.61 D, p=0.03) keratometry values were present at 6 months postoperatively. None of the segments were removed at any time of the follow up.
Conclusions: :
Sequential corneal collagen crosslinking and Ferrara rings implantation is a safe and efficacious treatment option in the management of selected cases of keratoconus. Instead it is necessary a longer follow-up.
Keywords: keratoconus • cornea: epithelium • refractive surgery: other technologies