Cataract: symptoms and treatment

Diagnosis

Once cataract is diagnosed during a consultation, surgery must be planned. Preoperative tests are required, including at least an OCT (optical coherence tomography) to analyze the macula and optic nerve, ensuring there are no other diseases responsible for the visual decline. Biometry, a measurement of the eye, is also performed to calculate the power of the artificial lens to be implanted.

Secondary cataract

Secondary cataract is caused by opacification of the posterior part of the capsule that holds the implant (the capsular bag that previously contained the cataractous lens). It can occur at varying intervals after surgery, ranging from a few weeks to several years, and leads to progressive vision loss in the operated eye, with symptoms similar to primary cataract.

The treatment is YAG laser capsulotomy, performed in the office during a simple consultation. This is a painless and quick procedure.

Epidemiology of cataract

Cataract is the leading cause of blindness (visual acuity less than 1/10) and the second leading cause of visual impairment (visual acuity between 1/10 and 3/10) worldwide. Cataract surgery is the most commonly performed surgical procedure globally, across all surgical specialties, with 30 million operations per year. In France, over 800,000 cataract surgeries are performed annually.

Cataract: treatment and surgery

Vision progressively worsens as the lens becomes more opaque and rigid. There is no medical treatment to slow its progression, nor any lifestyle modifications that can reduce cataract development.

The treatment for cataract is surgical. The principle of the operation is to remove the lens and replace it with an implant. Without an implant, vision is not possible; the patient would be highly hyperopic (+14 diopters). Therefore, an implant is systematically placed after lens removal. This implant is intended to last a lifetime and, except in rare cases, does not need to be replaced. Long-term experience shows that these implants are well tolerated throughout life. There is no contraindication to undergoing MRI or other scans with this implant.

Yag laser capsulotomy procedure

Once secondary cataract is diagnosed, an appointment is scheduled for YAG laser treatment, and you will be prescribed eye drops to use before and after the session. An information sheet about the procedure, prepared by the French Society of Ophthalmology, will be provided.

The laser session is performed during a consultation and involves making a circular opening in the posterior part of the capsular bag, behind the implant, to clear the visual axis. The released fragment will fall into the vitreous and gradually degrade. In the days following the laser, you may notice a floater corresponding to the released fragment, but it will disappear over time.

This procedure lasts only a few seconds and is completely painless. Vision gradually returns in the hours following the laser session.

What is secondary cataract?

The lens is contained in a capsule called the “lens capsule.” During cataract surgery, this capsule is opened to access the opacified lens, which is then broken up using ultrasound before the fragments are removed. An implant tailored to the patient’s needs is then placed, resting on the posterior part of the preserved capsule.

Within five years after surgery, 30–50% of patients may develop cell proliferation on the posterior surface of the capsule, leading to “secondary cataract,” also called posterior capsular opacification (PCO) or capsular fibrosis. This condition is painless but causes progressive visual loss, both at distance and near. Patients may also experience diminished color perception and sometimes double vision. Glare in bright light, especially at night while driving, is also common. The treatment is a relatively minor procedure using a specific laser (YAG laser).

Why does the lens become more opaque with age?

The main components of the lens are water and proteins. For the lens to remain transparent and allow light to pass through to the retina, these proteins must be precisely arranged. Most often due to aging, structural changes occur, resulting in the formation of opaque “amyloid bodies.” The lens has different parts: a central nucleus surrounded by the cortex, all enclosed in a capsule. Depending on the patient, opacities can develop in different regions of the lens. Thus, “nuclear cataract” occurs when the nucleus is affected, often seen in myopic patients and as part of age-related cataracts. Other forms include “corticonuclear cataracts” (when both the nucleus and cortex are affected), anterior or posterior subcapsular cataracts (often related to diabetes, excessive sun exposure, smoking, nutritional deficiencies, or corticosteroid use), and “fern leaf” cataracts following trauma.