Corneal Ring

An annular surface ulcer of the corneal limbus, which corresponds to coalesced ulcers, in a background of marginal keratitis
Etiology Infections—e.g., dysentery, brucellosis, dengue, gonorrhea, hookworms, influenza, TB; connective tissue disease—e.g., SLE—periarteritis nodosa, rheumatoid arthritis, scleroderma, Sjögren syndrome; others—e.g., gold intoxication, ischemia, lethal midline granuloma, leukemia, porphyria, ulcerative colitis, Wegener’s granulomatosis
References in periodicals archive ?
Intacs, also known as intrastromal corneal ring segments (ICRS) is used to manage patients with keratoconus, as an alternative to contact lenses or transplant surgery.
It differs from excimer laser procedures such as Photorefractive Keratectomy (PRK), Laser-Assisted Instrastromal In Situ Keratomileusis (LASIK), and traditional incisional surgeries such as Radial Keratotomy (RK) because no incisions or laser ablations are used to cut or irretrievably remove corneal tissue; and from Intra Corneal Ring (ICR) and Intraocular Lens (IOL) procedures because nothing is inserted into the eye.
For persons who fear poor results from excimer laser surgery or who don't want to risk wound-healing complications, an alternative is the intrastomal corneal ring (ICR).
The Intrastromal Corneal Ring, 7 millimeters in diameter, is inserted into the cornea's periphery, around the lens.
On day 112, both corneas developed inferior deep neovascularization up to where the outer corneal ring was.
Contributors explain the needs and future potential of retinal prosthetic devices, then get specific with information on retina implants (including noninvasive models), visual prostheses that improve reading, subretinal micro-implants for retinitis pigmentosa, electrode architecture for retinal interfaces, circuit designs that model the properties of the outer and inner retina, retinal stimulation with surface electrode arrays, Glaucoma drainage, corneal regeneration, toric lenses in correction of postkeratoplasty, artificial lenses for the treatment of high myopia, a telescoping prosthetic device and internal corneal ring segments for keratoconus.
This can range from simple interventions such as spectacles and contact lenses in the early stages, to more complex treatments such as corneal ring segments and CXL.
It is called a corneal arcus rather than a corneal ring as it initially presents as arcs in the inferior and superior poles of the perilimbal cornea before spreading to form a complete ring.