Topical Phaco with Toric IOL скачать в хорошем качестве

Topical Phaco with Toric IOL

Toric IOLs are premium intraocular lenses that correct pre existing astigmatism. Toric IOLs can correct astigmatism because they have different powers in different meridians of the lens. They also have alignment markings on the peripheral part of the lens that enable the surgeon to adjust the orientation of the IOL inside the eye for optimal astigmatism correction. Just prior to cataract surgery, the surgeon places temporary markings on the patient's cornea that identify the location of the most curved meridian of the front of the eye. Then, when the toric IOL is implanted during the cataract procedure, the surgeon rotates the IOL so the markings on the IOL are aligned with the markings on the cornea to insure proper astigmatism correction. Prior to the development of toric IOLs, cataract surgeons had to perform a procedure call limbal relaxing incisions (LRI) to correct astigmatism during or after cataract surgery. In LRI, small incisions are made at opposite ends of the cornea, very near the junction between the cornea and the surrounding white sclera. (This junction is called the limbus.) When these incisions heal, the cornea becomes more spherical in shape, reducing or eliminating astigmatism. In some cases — even when a toric IOL is used — limbal relaxing incisions may be needed after cataract surgery to fully correct astigmatism. But typically in such cases, the amount of astigmatism remaining after implantation of a toric IOL is far less, making a better LRI outcome more likely. LASIK, PRK and a procedure called astigmatic keratotomy (AK) also can be performed after cataract surgery to correct residual astigmatism, but toric IOLs decrease the likelihood of needing these additional surgical procedures.