Cataract: an artificial lens to correct all vision

Cataract surgery is the most frequently performed operation in France with nearly 1 million interventions in 2022. This age-related pathology results from the opacification of the lens following the formation of clusters of particles at the inside the organ. The lens is a transparent natural lens behind the iris, which allows light rays to converge inside the eye to focus on the retina. Opacification blocks this transmission and ultimately threatens blindness.

Around 5% of individuals are affected over the age of 65, and more than a quarter after the age of 80. Simply annoying at first in the form of a feeling of “dirty glasses”, halos and glare, cataracts gradually become very disabling. The progressive loss of vision limits daily activities with difficulty reading, watching television, driving, etc. Surgery is then the only therapeutic option and can be carried out at any age, including very advanced ones. Currently the average is 72-73.

The operation takes place on an outpatient basis and usually lasts fifteen to thirty minutes. It involves removing the lens to place an artificial lens, also called an “intraocular implant”. The operation takes place under local anesthesia obtained by instilling drops or gel into the eye and it is held open by an eyelid retractor.

The surgeon makes a small 2.2 millimeter incision, then inserts an ultrasound probe into the lens sac to break up the contents and suction them out. He then places the implant which will have been carefully chosen according to the patient. Indeed, this operation not only treats cataracts, but also corrects vision in general, presbyopia, myopia, hyperopia or even astigmatism.

“Cataract surgery, which compensates for vision defects, makes it possible in many cases to remove glasses postoperatively. We are talking about refractive surgery,” explains Professor Béatrice Cochener, ophthalmic surgeon at Brest University Hospital and president of the National Professional Council of Ophthalmology.

“Monofocal” implants correct distance or near vision. “Multifocals” divide the light into several foci for focusing at different distances. Implants, called “Edof” for extended depth of field, improve distance and intermediate vision, avoiding the formation of halos and a reduction in contrast which sometimes result from multifocal corrections. All of these products can also be “toric” to additionally correct astigmatism… “There have been significant technical advances, now offering many possibilities depending on each individual situation,” summarizes Béatrice Cochener.

After surgery, vision generally improves the next day. The operation goes well in the vast majority of cases, however the risk of complications is not zero; rupture of the lens sac, infection, edema… “These events are extremely rare,” recalls Dr. Barbara Ameline, ophthalmic surgeon in Paris and vice-president of the French Ophthalmological Society. And we achieve the expected result in visual correction in more than 90% of cases.” However, this operation raises some concern among a large number of patients because the eyes are a precious organ. The initial consultation is generally much longer than the operation itself to reassure them!