Cataract surgery is one of the most prevalent surgeries around the world, with approximately 4.2 million procedures performed on US patients in 2017.*
But in the seventy years since Harold Ridley conducted the first intraocular lens implant, one frustration for cataract patients and their doctors has remained.
Cataracts prevent patients from seeing exactly what their refractive correction options are, but the decisions regarding lens power prescription must be made before the surgery.
For providers, aspects of predicting the needed correction have been based on calculated estimates and the patient’s best guess based on their cloudy, pre-operative preferences. Furthermore, as incisions heal, the new intraocular lens may shift, altering the patient’s corrected vision. Patients may be disappointed to learn they still require glasses after surgery.
Vance Thompson Vision is pleased to offer to our cataract patients the first FDA approved IOL that eliminates the need for pre-operative estimates for refractive correction, gives patients a clear vision of what their results will be.
The Light Adjustable Lens (LAL) is a three-piece foldable lens that is implanted like any monofocal lens implant. But unlike other lenses, its prescription can be adjusted and reshaped after implantation.
The lens, which is made of photoreactive silicone, can be reshaped by applying a special UV light, or Light Delivery Device (LDD), to the LAL while it is inside the healed eye. Adjustments to the lens are made three weeks after surgery when the eye has healed. Therefore, the lens is extremely stable when it is being reshaped.
To increase the power of the implanted lens, the surgeon treats the center of the lens with the LDD to increase the curvature. To decrease the power of the lens, the outer edges are treated, and a flattening effect occurs in the center of the LAL. Over a period of two days, the lens will change shape.
When the patient’s desired correction is achieved, the surgeon will use the LDD to “lock in” the prescription. In clinical trials, patients had the LAL adjusted three weeks after surgery, and the device was locked in three days after that adjustment. Before the prescription is locked in, however, patients must wear UV-blocking glasses to keep the new lens from incidental UV exposure.
Optometrists are perfectly suited to advise their patients regarding the desired power of correction offered by the LAL. Our own Dr. Vance Thompson, who became one of the first surgeons to perform the surgery since its FDA approval explains.
Postoperatively, the optometrist will send the patient back to the surgeon for an adjustment based on the targeted refraction the patient has selected. The surgeon will double-check the prescription and show the patient various options, such as both eyes corrected for distance or some monovision. Then, the patient will decide what sort of vision he or she would like.*
Risk factors are the same as for any IOL implantation. But surgeons observed an additional challenge in some patients at the time of the UV adjustment. To make adjustments, the entire surface of the 6mm LAL device must be visible to the surgeon. The patient’s eye had to be dilated to at least 6.5 or 7 mm. In some patients, pupils would not dilate enough. In subsequent dilations for additional adjustment or the “lock-in” procedure, the pupils in these patients seemed to show some dilation fatigue. In these cases, surgeons used additional dilation drops to achieve the desired diameter.
Most cataract patients are ideal candidates for the LAL. Though the LAL is not yet indicated for post-refractive surgery correction, it could be used for such patients in the future.* Results for patients have been remarkable with 92% of the eyes with the LAL device being within 0.5 D of the target.*
The Light Adjustable Lens is a breakthrough technology that will positively impact the results patients experience after cataract surgery. Vance Thompson Vision is committed to offering our cataract patients the best technology available, and our use of the LAL is the latest step toward that commitment.
1. Roy Freeman and Alex Haung, 2017, FDA Approves RxSight’s Light Adjustable Lens, First IOL to enable Refractive Correction After Cataract Surgery [Press Release] https://www.rxsight.com/media/1002/pr_2017_nov_22_rxsight.pdf
2. Bryn Mawr Communications, (2018, March/April). The RxSight Light Adjustable Lens: Insights from an investigator of the technology. An Interview with Vance Thompson, MD, FACS. Retrieved from http://glaucomatoday.com/2018/04/the-rxsight-light-adjustable-lens/ (accessed 7/23/19)
3. Bethke, W. (2018 January) RxLAL: Say Goodbye to Postop Surprise? Review of Ophthalmology, p. 12, 15, 66 https://www.reviewofophthalmology.com/CMSDocuments/2018/01/rp0118i.pdf
4. Stodola, E. (2018, September). What to know about the Light Adjustable Lens. Retrieved from https://www.eyeworld.org/what-know-about-light-adjustable-lens (accessed 7/26/19)