[Intrastromal corneal ring segments (ICRS, KeraVision Ring, Intacs): clinical outcome after 2 years].

BACKGROUND

Since 1996 Intrastromal Corneal Ring Segments (Intacs, KeraVision, Inc., Fremont, CA, USA) have been used for the correction of mild to moderate myopia at the Salzburg Eye Clinic. Aim of this study was to evaluate the stability, reversibility and adjustability of this new method.

PATIENTS AND METHODS

Our experiences and final results of 54 surgeries--30 eyes with a minimum follow-up of 2 years--, as well as the potential reversibility (3 explanations, 2 of them followed by PRK) and adjustability (3 exchanges) are reported in detail.

RESULTS

None of the eyes lost more than one line in BSCVA (in 14 of 30 eyes the BSCVA improved, "Safety-Index": 1.13). 73% (22/30) reached an UCVA of 1.0 or better, 47% (14/30) of 1.25 or better ("Efficacy-Index": 0.79). After two years 47% (14/30) were within +/- 0.5 D of the attempted correction. We observed no significant intra- or postoperative complications. After ICRS removal the refractive data returned to within +/- 0.75 D (MRSE) and +/- 0.5 D (mean keratometry) of preoperative values, respectively. Patients with an ICRS exchange obtained an improved UCVA between 0.8 and 1.0, gaining between 2 to 4 lines.

CONCLUSIONS

Within the follow-up period of 2 years the ICRS seem to provide a very stable correction of low to moderate myopia. The procedure is reversible to a large extent, potentially adjustable (within certain limits) and carries a minimal risk only. After explantation PRK can be performed with good visual results.