Refractive and topographic stability of Intacs in eyes with progressive keratoconus: five-year follow-up

To evaluate the long-term rate of progression of keratoconus in eyes implanted with Intacs (Addition Technology Inc) at 5-year follow-up.

Data of 105 eyes from 85 patients who had undergone consecutive Intacs implantation between January 2001 and December 2005 were studied retrospectively for progression of keratoconus. Progression of keratoconus was defined as an increase in steep keratometry (K) of ≥ 1.00 diopter (D) over 4 years between 1- and 5-year follow-up. All eyes were categorized into three subgroups: eyes with documented preoperative progression (change in steep K ≥ 1.00 D over 12 months preoperatively), eyes with documented absence of preoperative progression, and eyes with no record of preoperative progression.

Ninety-two eyes were available for analysis. Overall, 91.3% (84/92) of eyes demonstrated no progression between 1- and 5-year follow-up. In the sub-group analysis, 92.9% (52/56) of eyes with documented preoperative progression demonstrated no progression. Additionally, no statistically significant differences were noted in mean steep, flat, and average keratometry; manifest refraction spherical equivalent; and uncorrected and corrected distance visual acuity (P>.05) between 1- and 5-year follow-up.

Results of our study demonstrate the long-term stability of refractive and topographic outcomes following Intacs implantation in eyes with keratoconus. The finding that 92.9% of eyes with progressive keratoconus did not progress postoperatively indicates that Intacs implantation may be a potential therapeutic option to halt progressive keratoconus.