The ability to fine-tune and customize patients' refractive outcome after cataract surgery could shift the need for physicians to do counseling and decision-making preoperatively more to postoperatively.
This article was reviewed by David Chang, MD
A light-adjustable IOL (LAL, RxSight) can improve patient satisfaction by allowing ophthalmologists to fine-tune and customize the patient’s refractive outcome after cataract surgery, according to David Chang, MD.
“It shifts the need to do all of our counseling and decision-making preoperatively more to postoperatively,” said Dr. Chang, clinical professor of ophthalmology at the University of California, San Francisco.“You can let the patient preview different refractive outcomes while they are pseudophakic.”
The LAL is a three-piece silicone lens with diffusible monomers in the optic. Following a standard phacoemulsification procedure, the ophthalmologist uses a slit lamp equipped with a near-UV light to alter the IOL shape to adjust the patient’s refraction.
As the light hits the lens, it initiates polymerization, causing micron-level changes in the structure of the lens. This allows the surgeon to adjust both the sphere and cylinder, Dr. Chang said.
An LAL precludes the need to perform intraoperative aberrometry or to mark the astigmatism axis prior to surgery, because the refraction will be adjusted to correct any astigmatism postoperatively, he said. Unlike with conventional toric IOLs, the LAL will not rotate, Dr. Chang added.
A surgeon can adjust up to 2 D of sphere in either direction using a single treatment, along with up to 3D of astigmatism, and up to 4.5D of astigmatism can be corrected with 2 treatments, he said. Light-adjustable IOLs offer a number of advantages over traditional cataract surgery.
“We still have to estimate the effective lens position, posterior corneal astigmatism, or surgically induced astigmatism (SIA),” he said. “In addition, many eyes are at higher risk for IOL power surprise, such as those with prior keratorefractive surgery or unusual keratometry or axial lengths.”
In a 2018 EUREQUO study of 280,000 patients cited by Dr. Chang, 27% of cataract surgeries failed to achieve within in a half diopter of the target refraction.
Dr. Chang predicted, that for eyes with astigmatism, an ophthalmologist fresh out of residency should be able to achieve better results with the LAL than the most experienced surgeons now get with the most advanced pre- and intraoperative technologies.
While refractive outcomes can be changed or enhanced with LASIK, many ophthalmologists do not perform keratorefractive surgery, requiring a patient who needs an enhancement to see a second surgeon.
Even then, the patient must wait a few months until the refraction is stable before undergoing LASIK or PRK.