INTRASTROMAL CORNEAL RING SEGMENTS (ICRS, KERAVISION RING, INTACSTM): CLINICAL RESULTS AFTER 2 YEARS

Abstract

Background. Since 1996 Intrastromal Corneal Ring Segments (IntacsTM, 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 for this new method.Patients and methods. Our experience and final results of 54 surgeries – 30 eyes with a minimum follow-up of 2 years – as well as the potential reversibility (3 explantations, 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). 73% (22/30) eyes reached an UCVA of 1.0 or better, 47% (14/30) eyes of 1.25 or better. After 2 years 47% (14/30) eyes were within ± 0.5 Dsph of the attempted correction. We observed no significant intraor postoperative complications. After ICRS removal the refractive data returned within ± 0.75 Dsph (MRSE) and ± 0.5 Dsph (mean keratometry) of preoperative values, respectively. Patients with an ICRS exchange obtained an improved visual acuity between 0.8 and 1.0, gaining between 2 to 4 lines.Conclusions. With 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.

Keywords

• intrastromal corneal ring segments
• ICRS
• KeraVision ring
• IntacsTM
• myopia
• stability-reversibility-adjustability