The most commonly performed surgery is cataract surgery, with over 1.5 million of these surgeries performed each year. Cataract surgery is required when a cloud forms in the lens of the eye, resulting in double and blurred vision and sensitivity to glare and light, as well as other symptoms.
This standard cataract surgery consists of removing a disc from the capsule surrounding the eye’s lens, a procedure known as capsulorhexis, which entails making an incision in the eye controlled by tearing and pulling the capsular tissue freehand. The lens is then broken up by using an ultrasound probe and after that suctioned out. An artificial lens is then inserted into the empty pocket made in the capsule as snugly as possible.
Femtosecond laser cataract surgery, called a capsulotomy, cuts circles in lens capsules that are 12 times more precise than those achieved by the traditional method, as well as leaving edges that are twice as strong in the remaining capsule, which serves as a pocket in which the plastic replacement lens is placed.
Without the eye being opened, the hole in the capsule can be cut and the lens and cataract sliced by the laser which can go through the outer tissue, all of which takes place prior to the patient entering the operating room. An incision through the cornea that stops just beneath the outermost surface is also created by the laser, meaning less cutting needs to be performed once the operation starts, with a decreased risk of infection. Once the operation has started, removing the sliced-up lens and the cut part of the capsule can be done quite easily, with a lot less ultrasound energy needed.
Femtosecond lasers can deliver quadrillionths of second pulses of energy, and were already being successfully and widely made use of for cornea reshaping and the correcting of astigmatisms, farsightedness and nearsightedness. The laser would however have to cut tissue deep within the eye for use in cataract surgery. While the laser will have to reach an intensity level sufficiently powerful enough to ionize tissue at a chosen focal point, it’ll also need to have average power and pulse energy low enough for avoiding collateral damage to the retina and surrounding tissue.
Femtosecond laser cataract surgery offers other benefits besides the capsulotomy. Because the laser has already spliced the lens, there’s less need to make use of the ultrasound probe, which can in some cases create too much heat, damaging the corneal endothelium and other surrounding tissue. A multi-planar zigzag pattern for the cornea incision can also be created by the laser, allowing the incision to self-seal and decreasing infection risk as well as risk of other complications.