Fine-Tuning IOLs After Surgery

The Light Adjustable Lens (LAL, RxSight) is the first and only intraocular lens (IOL) on the market offering post-implantation sphere and cylinder error adjustment, allowing precise refraction revisions following cataract surgery. But other IOL adjustment technologies are not far off, according to Mark A Kontos MD.

Initially developed by Nobel Prize-winning chemist Professor Robert H Grubbs PhD and Professor Dan Schwartz MD in 1997, LAL technology employs directed UV light to selectively polymerise macromers in the lens, changing lens curvature and refractive power. Once optimal power is reached after surgery, the light polymerises all remaining macromers to prevent further changes. Typically, three follow-up sessions over approximately five weeks are required to adjust and lock in treatment.

Adjustment today

Calhoun Vision was founded in 2000 to develop the LAL, which entered FDA trials in 2007. The company and technology were re-invented and re-branded as RxSight in 2017, and the LAL gained FDA approval. As of 2024, more than 200,000 LALs had been implanted by more than 1,700 surgeons, said Dr Kontos, who is a consultant for RxSight.

The LAL is particularly useful for post-refractive surgery patients, Dr Kontos said. “There are many millions of patients who have had refractive surgery, and [they] are among the more challenging groups [for] cataract surgery.” These patients expect excellent visual outcomes, but such outcomes are more challenging due to difficulty in accurately predicting lens power.

In a recently published study, 74% of 76 post-corneal refractive surgery eyes implanted with the LAL achieved 20/20 or better uncorrected vision, with 88% corrected to 20/25 or better and 93% correctable to 20/20 or better. Two-thirds were within 0.25 D of target, and 86% within 0.50 D.¹ “For that group of patients, those are pretty amazing results,” Dr Kontos said. “I would take these results in my general cataract surgery group—let alone in those who have had refractive surgery.”

Adjustment tomorrow

The LAL is specially designed to allow for adjustments. In the near future, femtosecond lasers may make it possible to adjust the power of many standard lenses, Dr Kontos said. The laser can be used to change the hydrophilicity of targeted areas in an IOL, altering its refractive index. This can change defocus power, toricity, and asphericity, extending depth of focus. It can even create or reverse multifocality.

Further in the future, it may be possible to adjust the effective position of lenses after surgery. Dr Kontos said a nitinol-based adjustable IOL allowing up to +1.50 D anterior change in lens position, as well as radial movement, has been tested in rabbits.²

“It will be interesting to see where all these things go. In my mind, lens adjustability is something that is here now, and it is rapidly being accepted by patients,” Dr Kontos said. “The future is bright.”

Dr Kontos spoke at the 2025 ASCRS annual meeting in Los Angeles.

Mark A Kontos MD is a former US Navy flight surgeon and an ophthalmologist currently practising at Empire Eye Physicians in Spokane Valley, Washington, and Coeur d’Alene, Idaho, US.

1. Jones M, et al. J Cataract Refract Surg, 2024 Sep 1; 50(9): 936–941.

2. Lapid-Gortzak R, et al. J Refract Surg, 2023 Oct; 39(10): 662–667.