INTACS inserts for treating keratoconus - One-year results

Objective: To evaluate the use of INTACS micro-thin prescription inserts (Kera Vision, Inc., Fremont, CA) for the treatment of keratoconus. Design: Prospective, nonrandomized (self-control led) comparative trial. Participants/Intervention: Ten patients from our prospective clinical study who had completed 12 months of follow-up were evaluated. All patients had keratoconus with clear central corneas and were contact lens intolerant. After reviewing corneal pachymetry and topography of individual patients, INTACS inserts of 0.45-mm thickness were placed in the inferior cornea to lift the cone and INTACS of 0.25-mm thickness were inserted superiorly to counterbalance and flatten the overall anterior corneal surface. Main Outcome Measures: Differences between preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, and keratometry values were statistically assessed. Changes in corneal ectasia were evaluated by reviewing cornectopographic maps. Results: No intraoperative complications occurred in this series of patients. Spherical equivalent error and refractive astigmatism were reduced with INTACS inserts treatment. Postoperative month 12 uncorrected visual acuity (logarithm of the minimum angle of resolution [logMAR] mean, 0.35, standard deviation [SD], 0.16 [similar to 20/50, similar to2 lines]) was significantly better than preoperative (logMAR mean, 1.05; SD, 0.33 [similar to 20/200, similar to3 lines]; P less than or equal to0.05). Average best spectacle-corrected visual acuity at postoperative month 12 was improved by approximately two lines compared with baseline (logMAR mean, 0.22; SD, 0.12 [similar to 20/32, similar to1 line]; logMAR mean, 0.38; SD, 0.13 [similar to 20/50, similar to1 line], respectively). Topographic corneal shape (size and height of the cone) was improved for all subjects after insert placement. Conclusions: INTACS micro-thin prescription inserts seem to provide a viable method for treating clear corneal keratoconus for patients who are contact lens intolerant. The corneal steepening and astigmatism associated with keratoconus were reduced, and visual acuity was improved with treatment in almost all eyes. Ophthalmology 2001;108:1409-1414 (C) 2001 by the American Academy of Ophthalmology.