2020–2021 BCSC Basic and Clinical Science Course™
13 Refractive Surgery
Chapter 8: Intraocular Refractive Surgery
Light-Adjustable Intraocular Lenses
The light-adjustable IOL is a 3-piece silicone-optic posterior chamber IOL that can be irradiated with ultraviolet light through a slit-lamp delivery system 1–2 weeks after implantation to induce a change in the shape, and thus the power, of the IOL (Fig 8-5). This lens received FDA approval in November 2017 but is not yet available in the United States. Specific irradiation patterns can be applied to the lens to induce myopic, hyperopic, and astigmatic shifts. In initial work, results indicate that up to 5.00 D of spherical and up to 2.00 D of astigmatic change can be induced. Once final irradiation is performed, the effect is “locked in” and no further adjustments can be made.
Figure 8-5 Schematic representation of the light-adjustable IOL. A, When the IOL is treated with UV light in the center, polymerization occurs and macromers move to the center, increasing the IOL power. B, When the IOL is treated with light in the periphery, macromers move to the periphery, decreasing the IOL power.
(Courtesy of Calhoun Vision.)
Prior to postoperative irradiation, the lens must be protected from sunlight exposure. Further, it seems possible that an error in the irradiation treatment related to centration or improper data entry could cause irreversible changes in the IOL’s visual properties and require IOL exchange surgery. Despite the refractive alterations available initially, after irradiation, the lens is functionally a monofocal IOL with all the limitations that come from that implantation strategy. See also Chapter 9.
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.