![]() ![]() ![]() The malleable nature of silicone makes it chemically stable as well as imparts diverse mechanical properties. Since 1950s, silicone has been used in a variety of medical device applications including contact and intraocular lenses. This made way for the flexible and foldable breed of IOLs. However, the incision still had to be extended for implantation of the rigid IOL. The obligation of downsized incision was still amateur. This “glistening” phenomenon is rarely seen with PMMA.Īfter the advent of phacoemulsification in 1967, by Charles Kelman, the size of the incision did decrease significantly. Penetration by aqueous humor has been noted to cause small vacuoles within the lens optic. It is said to be three piece when the optics and the haptics are made from different materials and are attached together ( Figure 3). One piece variant of PMMA lens means that optics and haptics are made from a single mold of the same material. Hence PMMA is seldom used today except in developing countries due to economic reasons. Large sized incisions are associated with delayed healing and astigmatic refractive errors. An incision size of about 5.5–6 mm or a large corneoscleral tunnel is required for its implantation. They are usually single piece and have low memory haptics.ĭue to their property of rigidity, a large incision is required for its implantation. The refractive index is 1.49 and the usual optic diameter is 5–7 mm. Hydrophobic nature of PMMA lenses makes them more likely to adhere to corneal endothelial cells during insertion, thus causing potential endothelial loss. One of the first materials to be used for the purpose of intraocular lenses, polymethyl methacrylate (PMMA) is a rigid, non-foldable, hydrophobic material ( Figure 2). ![]()
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