Four-year Follow-up of Intrastraomal Corneal Ring Segments in Patients with Keratoconus

Several surgical strategies have been proposed to improve visual function in patients with keratoconus who become contact lens intolerant1,2. In mild-tomoderate keratoconus, when the central cornea remains clear, intrastromal corneal ring segments (ICRS), and phakic intraocular lenses (PIOLs) may provide enough BSCVA, and sometimes uncorrected visual acuity (UCVA), to postpone and sometimes avoid the need for corneal transplantation. To stop the progression of the disease, these refractive procedures may be combined with collagen cross-linking (CCL) in cases of progressive keratoconus, which may grant a more sustained result3-6. ICRS improve quality of vision and visual acuity through a dual effect. Not only do they correct myopic spherical equivalent, but they also improve topographic abnormalities by recentering the corneal optical zone7-13. However, their role on ectasia stabilization remains unclear. Long-term follow-up is specially important in the case of keratoconus because if ectasia were to progress,