Alloplastic Material Addition Techniques
The shape of the cornea can be altered by adding alloplastic material such as hydrogel on the surface or into the corneal stroma to modify the anterior shape or refractive index of the cornea. For example, the 2 arc segments of an intrastromal corneal ring can be placed in 2 pockets of the stroma to directly reshape the surface contour according to the profile and location of the individual rings (Fig 1-18). In addition to altering the shape or curvature of the cornea, new inlay materials and designs have been developed that alter the optical function of the cornea—specifically the KAMRA corneal inlay (AcuFocus Inc, Irvine, CA), for presbyopia, approved in 2015, and the Raindrop (ReVision Optics, Inc, Lake Forest, CA), approved in 2016. For further discussion, see Chapter 4.
Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.