Intracorneal Ring Segments for Iatrogenic Keratectasia After Laser in situ Keratomileusis or Photorefractive Keratectomy

Abstract

PURPOSE: Intrastromal corneal ring segments (Intacs) were inserted in four eyes with iatrogenic keratectasia, 12 to 44 months after laser in situ keratomileusis (LASEK) in two patients and photorefractive keratectomy (PRK) in two patients, in order to avoid penetrating keratoplasty and to improve quality of vision. METHODS: A modified asymmetrical Intacs micro-thin prescription inserts implantation technique was used in three eyes where a 1.0-mm temporal incision and a superior-inferior dissection were performed A thicker segment was implanted in the lower stromal channel and a thinner one was placed in the superior channel. In the fourth eye, because of the severity of the corneal bulging after PRK, two 5.0-mm optical zone symmetrical Ferrara Ring segments were implanted. RESULTS: len months after surgery, all eyes experienced a significant improvement of uncorrected and best spectacle-corrected visual acuity. The topographical indices showed an overall surface régularisation with increased corneal uniformity and potential corneal visual acuity. No intraoperative or postoperative complications occurred. CONCLUSIONS: Asymmetrical or symmetrical corneal ring segment implantation in eyes with keratectasia after LASIK or PRK resulted in safe, fairly predictable corneal regularization, with significant improvement of aided and unaided vision. In the short term, these techniques seem to be helpful in reducing the progression of corneal ectasia after excimer laser surgery, delaying or avoiding the need of penetrating keratoplasty. [J Refract Surg 2002;18:535-541]

Chronic pain after Intacs implantation

“…[1][2][3][4][5][6] In this case, the patient had a significant improvement in both BSCVA and BCVA and positive topographic changes after implantation, yet required segment explanation for chronic pain.…”

“…[1][2][3][4][5][6][7] Most patients tolerate the Intacs segments well; however, there are reports of segment explantation for a variety of reasons, [5][6][7][8][9][10] including chronic discomfort and foreign-body sensation. 6, 10 We report a case of Intacs segment explantation for chronic pain and propose a mechanism for this discomfort elucidated by confocal microscopic evaluation.…”

European clinical evaluation: Use of Intacs for the treatment of keratoconus

“…[20][21][22] Treatment with Intacs will not eliminate the progression of keratoconus, but it may delay a corneal transplant procedure and may slow the progression of the corneal thinning associated with the disease. Results from preliminary studies indicate that Intacs seem to allow better quality of vision in patients with advanced keratoconus, may permit refitting these patients with contact lenses, and may delay or eliminate the need for a corneal transplant procedure.…”

Corneal ectasia after photorefractive keratectomy

“…However, isolated cases of corneal ectasia after PRK have been recently reported [7][8][9][10][11][12], even after low myopic corrections [10], raising the suspicion that surface ablation may induce ectasia in predisposed corneas, in spite of a thick residual stroma. The real incidence of corneal ectasia after PRK has not yet been assessed.…”