Toric lens

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In optics, a toric lens is a type of lens whose surface is a combination of a sphere and a cylinder. One surface of the lens is spherical, the other toroidal.


TICL Toric Implantable Contact Lens is a phakic lens and an alternative for laser vision correction. The TICL is distributed by Staar Surgical, Switzerland. 1999 first successful implantations were performed by Neuhann, Munich Germany. The TICL function similar to a contact lens, except the lens is implanted into the eye, not placed over it. Because of the similarities between the phakic intraocular lens and contact lenses, many replace the word "Collamer" in the ICL acronym and call the lenses "implantable contact lenses." (This term is widely accepted in international markets.)The TICL is an intraocular implant manufactured from a proprietary, hydroxyethyl methacrylate (HEMA)/porcine-collagen based biocompatible polymer material. The TICL contains a UV absorber made from a UV absorbing material. The Visian TICL features a plate-haptic design with a central convex/concave optical zone and incorporates a forward vault to minimize contact of the Visian TICL with the central anterior capsule. The TICL features an optic diameter with an overall diameter that varies with the dioptric power: the smallest optic/overall diameter being 5 mm/12.1 mmn and the largest 5.8 mm/13.7 mmn. All descriptions of optic diameter-, overall diameter or TICL power refer measuremrents in BSS unless otherwise noted. The lenses are capable of being, folded and inserted into the posterior chamber through an incision of 2.5 mm or less. The Visian TICL is intended to be placed entirely within the posterior chamber.


[1][2]

[edit] References

  1. ^ E. Ahmed (2004). A Textbook of Ophthalmology. Prentice Hall of India, 107. ISBN 8120319168. 
  2. ^ James Thewlis (1961). Encyclopaedic Dictionary of Physics. Pergamon Press, 268. 
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