1. 1. CORNEAL RINGS Intrastromal corneal ring segments
2. 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. 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. 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. 5. How does it work? ICRS shorten the corneal cord length, produce flattening across the entire cornea
6. 6. The Procedure
7. 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. 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. 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.
10. 10. Cont. Late postoperative observations: segment migration, segment extrusion, persistent incisional gaping, night halos, chronic pain, focal edema, infectious keratitis & corneal neovascularization.
11. 11. References http://eyewiki.aao.org/Intrastromal_Corneal_Ri ng_Segments_(ICRS) http://emedicine.medscape.com/article/122144 1-overview http://www.ncbi.nlm.nih.gov/pmc/articles/PMC 3959038/
12. 12. Thanks for listening Done By: Doha Hamdy Abish (609) Supervised By: Dr. Amr ElKamshoushy