2024-08-20 11:40:00
As ophthalmologists who have performed thousands of these surgeries, we know that many patients have misconceptions about this surgery and the causes of cataracts (for example, some patients believe they are growths on the surface of the eye).
Let’s evaluate this very common pathology, but in most cases its treatment does not present any special difficulties.
What are cataracts?
To understand what this situation actually is, you have to imagine a window with a frosted surface: light is still transmitted, but detail is lost. Another image we can use is that of the transparent surface of a tropical ocean, which finds itself disturbed by storm turbulence. Likewise, when the lens (lens) The eye’s “natural” converging lens), which was previously transparent, becomes opaque.
This condition is not uncommon, as it is estimated that more than half of Americans over the age of 80 have cataracts (in France, cataracts affect more than half of Americans) Editor’s note: 20% of people over 65 years old, more than 60% of people over 85 years old). Nearly 4 million cataract surgeries are performed in the United States each year (Editor’s note, 830,000 surgeries were performed in France in 2017).
After surgery, more than 90% of patients regain 10/10 vision with glasses. However, this is not the case for people with other eye conditions, including glaucoma (a progressive disease characterized by high intraocular pressure), diabetic retinopathy (which can cause damage to retinal tissue), or age-related Macular degeneration. Finally, the infection rate after endophthalmitis surgery is less than 0.1%.
What does cataract surgery involve?
During cataract surgery, the defective lens is removed and replaced with a synthetic lens to restore vision. Most patients report that the procedure is painless.
The surgery is usually performed on an outpatient basis. It’s usually done under local anesthesia, using sedation similar to that used for dental surgery (we like to tell our patients they’ll be receiving the equivalent of three margaritas intravenously…). However, some surgical candidates must undergo surgery under general anesthesia. This is the case, for example, in patients with claustrophobia or in patients with movement disorders such as those caused by Parkinson’s disease.
Before surgery, the patient will be given drops to dilate the pupil to make it as wide as possible. Anesthetic is used on both the surface and inside of the eye. The surgeon then makes an incision between the clear and white parts of the eye, usually using the tip of a small, sharp scalpel. This allows it to enter the lens capsule, a membrane similar in thickness to the walls of a plastic bag.
The crystal capsule is Suspended by small fibers called zonulesarranged like springs suspending a trampoline from the frame. To gain access to the lens, the surgeon performs a capsulotomy: an incision in the capsule. In order to be able to remove it through the small hole thus created, ultrasound is then used to break the crystal into pieces. These emulsify the lens, and the resulting debris is removed by suction. It may sound scary to describe it this way, but the process is painless.
Note that results obtained with laser-assisted cataract surgery are similar to those obtained with traditional surgery.
rare complications
Serious postoperative complications, such as infection, eye bleeding, or retinal detachment, are rare. They occur in about 1 in 1,000 cases, and even when they do occur, appropriate treatment can preserve vision in a large number of cases.
However, there is one complication that deserves attention. These are capsular complications. This occurs when a tear occurs on the posterior surface of the sac during surgery. In this case, the clear gel-like substance (lentus) behind the lens that fills the cavity of the eye Vitreous body) can be found at the front of the eye. According to some studies, such complications occur in up to 2% of cases.
If this happens, the offending gel must be removed during surgery (called a vitrectomy). By doing this, the likelihood of postoperative complications is reduced. On the other hand, patients who undergo vitrectomy are at increased risk for certain complications, including postoperative swelling (edema).
after surgery
Patients usually go home immediately after surgery. Most hospitals and clinics require an escort, but this precaution has more to do with the potential consequences of anesthesia than with the procedure itself.
Postoperative treatment begins the same day. It involves applying eye drops and wearing an eye patch without touching the eyes. This protective case is not needed during the day, but must be installed while sleeping.
Patients should keep their eyes clean and avoid contact with dust, debris, and water. For at least the first week after surgery, they should try not to bend over and avoid any exertion or heavy lifting. If this instruction is not followed, there is a risk of choroidal hemorrhage, in other words, bleeding of the eye wall, which can seriously impair vision. The problem is that straining and lifting heavy objects can cause a sudden increase in blood pressure in the face and eyes.
Activities that only moderately increase your heart rate, such as walking, are allowed. Routine post-op checkups are usually done the day after surgery, then about a week after surgery, and finally a month after surgery.
Which new lens to choose?
For best results, the size of the plastic lens (also called an intraocular lens) used to replace the cataract must be precise. The first intraocular lenses developed were monofocal: they provided a single focusing distance, and the person undergoing the surgery had to choose whether they preferred to see clearly from a distance or up close. Most of the time, distant vision is favored, and people who have the surgery use glasses for near tasks, such as reading. This approach remains relevant as it is still relevant to approximately 90% of patients today.
However, recent advances have led to the development of multifocal intraocular lenses, which offer the possibility of seeing near as well as distance, thus eliminating the need for glasses. Some of these lenses are even trifocal: they allow you to see near, far, and at intermediate distances, which is important due to the democratization of screen use.
Most patients who have multifocal lenses implanted are satisfied with them. However, a small percentage of them report suffering from a variety of visual disturbances, including nighttime glare and halos that form around light sources in dim light. Some patients who are troubled by these disturbances sometimes require removal of the multifocal lens to replace it with a standard intraocular lens. When the discomfort is too great, this approach helps alleviate discomfort for most everyone involved.
Research is currently underway to determine for whom multifocal lenses are best suited and for whom they are not. Most clinicians would not recommend such lenses to those who are detail-oriented, as these individuals may focus on the shortcomings of such lenses rather than the benefits they provide.
Like most technologies, intraocular lenses have continued to improve over the years. Those currently available are much better than those that came before, and their successors may further improve vision in patients who receive them while further limiting side effects, such as the aforementioned halo.
But it’s worth noting that new lenses are often not reimbursed in full, often resulting in significant costs for patients.
Deciding which type of lens is best can be complicated. Fortunately, except in certain cases (such as cataracts following eye trauma), emergency surgery is usually not required when a diagnosis is made. Therefore, you can make your choice with complete confidence.
*Alan Stegmanassociate professor of ophthalmology, University of Florida wait Elizabeth M. Hofmeisterassociate professor of surgery, Uniform Services University of Health Sciences
This article is reproduced from dialogue sous licensed under Creative Commons. liraOriginal article.
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