Contrast sensitivity key consideration for IOL selection in glaucoma patients

An aspheric IOL may be considered the implant design of choice for most patients withglaucoma who require cataract surgery, said Richard L. Lindstrom, MD.

"Providing the best quality vision is paramount in the visually compromised, glaucoma patient,"said Dr. Lindstrom, founder and attending surgeon, Minnesota Eye Consultants, Minneapolis."These individuals are known to have reduced contrast sensitivity that is related to areduction in retinal ganglion cells.

"Given this neuronal influence, it is rational to do whatever we can to maximize contrastsensitivity on the basis of optics, and that is accomplished best with the use of an asphericIOL," he added.

Dr. Lindstrom noted there is good evidence that aspheric IOLs enhance contrast sensitivity byreducing total spherical aberration in the eye. The only situation where a spherical IOL wouldbe preferred over an aspheric implant would be in the rare instance of a patient with glaucomawho has negative corneal spherical aberration related to previous LASIK for hyperopia.

In general, presbyopia-correcting IOLs-and particularly, current-generation multifocaldesigns-should be avoided in patients with glaucoma because of a potential to compromisecontrast sensitivity. Laboratory measurements of modulation transfer function, however, showthat an investigational, next-generation design of a proprietary accommodating IOL (crystalensHD-100, eyeonics) outperformed a previous model of the accommodating IOL, as well as multifocalpresbyopia-correcting implants.

"For now, multifocality might be considered only if visual loss [from glaucoma] is mild andexpected to stay that way," Dr. Lindstrom said. "When available, the new accommodating IOL maybecome a reasonable compromise for select glaucoma patients who want to reduce their dependenceupon glasses."