Implant shows positive results for all stages of keratoconus, study finds

Intacs segments implantation using a femtosecond laser may be considered a beneficial treatment for patients with moderate to severe keratoconus, a retrospective study found. However, patients with more severe manifestations of the disorder may experience less improvement in uncorrected visual acuity and cylindrical refraction.

Aylin Ertan, MD, and Günhal Kamburoglu, MD, reviewed visual and anatomical results for 306 keratoconic eyes of 255 patients who had Intacs segment (Addition Technology) implantation. For analysis, patients were divided into three groups based on the Amsler-Krumeich keratoconus classification of disease stage. Specifically, 155 eyes had stage 2 keratoconus, 83 eyes had stage 3 keratoconus and 68 eyes had stage 4 keratoconus.

After a mean 10.39 months of follow-up, best corrected visual acuity had improved in 71.6% of eyes and uncorrected visual acuity had improved in 75.7% of eyes, the authors noted.

The investigators found that mean keratometry values had decreased from 50.7 D to 47.9 D, mean manifest spherical refraction had improved from –6.04 D to –3.09 D and mean manifest cylindrical refraction had improved from –4.11 D to –3.82 D.

There were no statistically significant changes in BCVA and manifest spherical and cylindrical refraction between the three groups.

After Intacs implantation, patients with stage 4 keratoconus experienced a smaller change in UCVA and more improvement in mean keratometry value than patients with stage 2 and 3 keratoconus, according to the study, published in the September issue of Journal of Cataract & Refractive Surgery.