1. CORNEAL RINGS Intrastromal corneal ring segments
2. Intrastromal corneal ring (ICR) a device designed to correct
mild-to-moderate myopia by flattening the anterior corneal
curvature. an open-ended PMMA transparent ring. It is inserted
through a peripheral radial incision.
3. Intrastromal corneal ring segments a more recent design
modification of the ICR INTACS and KeraRings The ring segments
split the ring into two 150 arcs.
4. Ring segments can be placed away from the radial incision,
thereby minimizing the potential for incision-related complications
The degree of correction (greater-thicker) is determined by the
thickness of the Intacs inserted
5. How does it work? ICRS shorten the corneal cord length,
produce flattening across the entire cornea
6. The Procedure
7. Indications Mild myopia (-1.00 to -3.00 D) in patients who
are aged 21 years or older & documented stability of refraction
Patients with Astigmatic component is +1.00 D or less. Keratoconus
: for patients who are no longer able to achieve adequate vision by
contact lenses or glasses and for whom corneal transplantation is
the only remaining option. Post LASIK ectasia.
8. Contraindications High degrees of myopia or astigmatism. Age
younger than 21 y/o with stable refractive error Existing collagen
vascular, autoimmune, or immunodeficiency disease Patients with
previous anterior segment trauma Presence of existing ocular
conditions; any (recurrent) corneal pathology that may predispose
the patient to future complications Thin Cornea (corneal thickness
of less than 450 m at the proposed incision site) Using meds that
affect corneal healing or vision: isotretinoin (Accutane),
amiodarone (Cordarone), and/or sumatriptan (Imitrex)
9. Complications Complications are rare... [as it is
reversible, no corneal tissue is removed, and the central optical
zone is left untouched] Immediate postoperative observations:
epithelial defects, undercorrection and overcorrection,
incision-healing responses, extension of the incision towards the
central visual axis or towards the limbus.