Treatment strategies for corneal ectasia

Abstract

Purpose of Review The aim of this article is to review the most recent management strategies for corneal ectasia after keratorefractive surgery. Recent Findings Management options for postoperative ectasia include conservative management with various types of contact lenses such as rigid gas permeable lenses, custom wavefront-guided soft contact lenses, hybrid lenses and tandem soft contact lens-rigid gas permeable lenses. Minimally invasive surgical options include corneal ring segment implantation with Intacs, KeraRings or Ferrara rings have shown to have good results in the initial time period after insertion. However there appears to be some evidence that this initial effect may regress with time. Collagen cross-linking is also minimally invasive and has been documented to stop the progression of ectasia and in some cases may cause regression. Recently, techniques combining collagen cross-linking with intracorneal ring segments or with topography-guided excimer laser treatments have shown to have promising results. Summary Early management of ectasia is essential to prevent its progression and to preserve visual potential. There are several management options that are available that may be used to reduce the need for corneal transplantation for these patients.

Refractive Lenticule Re-Implantation after Myopic ReLEx: A Feasibility Study of Stromal Restoration after Refractive Surgery in a Rabbit Model

“…23 These techniques are technically and surgically demanding, time consuming, and are usually performed by corneal transplant surgeons, necessarily limiting their applicability to specific indications. In addition, use of donor corneal tissue involves some risk of graft rejection.…”

Complications of Refractive Surgery

“…(21) In the majority of patients, this is of no clinical consequence. (16) However, in a small subset of patients, this results in significant loss of biomechanical integrity. Most of these patients have predisposing pre-operative factors making them more likely to develop ectasia; a small percentage have had either corneas that are overly thinned or a low residual stromal bed (RSB) thickness from a deep ablation or a thicker flap, resulting in a loss of ability to maintain the integrity of the cornea.…”

“…In the native cornea, the anterior 40% of the cornea has a higher cohesive tensile strength than the posterior 60% perhaps due to the higher keratocyte density in the anterior 10% of the stroma. (16, 21, 22) Roberts and Dupps suggest that biomechanical modification after LASIK is focal in nature. (23) Work by Scarcelli et.…”

Evolution in the use of intrastromal corneal ring segments for corneal ectasia

“…Post-LASIK corneal ectasia is a rare but serious complication of LASIK, occurring in 0.04-0.6% of patients receiving treatment [38,39]. The exact pathophysiology of the disorder remains unclear, but risk factors for its occurrence include thin corneas, high myopia, thin residual stromal bed, and subclinical keratoconus [40].…”