Secondary cataract: causes, symptoms and laser treatment
Secondary cataracts are benign clouding of the capsule surrounding the corrective lens implant (placed during cataract surgery). They affect 10 to 30% of patients who have undergone cataract surgery and most often occur within 2 to 3 years of the procedure. They reproduce the symptoms of cataracts: decreased vision, blurred vision, glare, etc. Fortunately, treatment does not require further surgery, but a simple in-office laser procedure: YAG laser capsulotomy. Visual recovery is almost immediate.
What is secondary cataracts?
Secondary cataract, also called posterior capsule opacification or capsulosis, is a common consequence of cataract surgery.
It occurs in 3 to 30% of cases five years after cataract surgery.
It corresponds to an opacification of the capsular sac that formerly contained the cataract.
It is caused by migration and proliferation of epithelial cells in the capsule.
Capsulosis leads to a decrease in visual acuity, similar to that experienced with previously operated cataract surgery.
Its treatment is done with laser and fortunately does not require further surgery.
Diagnosis
The diagnosis of secondary cataract is clinical. On examination with a slit lamp (tabletop microscope), the ophthalmologist notices a thin opaque layer on the posterior surface of the implant.
He will complete his assessment with a dilated fundus examination and an OCT (scan) to confirm that the only cause of decreased vision is indeed cataracts.
Causes of secondary cataracts
Cataract surgery involves removing the clouded lens, leaving the capsule that contains it empty, and replacing it with an intraocular lens called an implant.
The lens capsule is the thin, transparent membrane that surrounds it.
To remove the cataract, a window is made in the anterior part of the capsule, leaving the posterior capsule intact. The implant is then slid against the posterior capsule.
This capsule can become opaque months or years after cataract surgery, resulting in a secondary cataract.
Prevention
Advances in surgical techniques and implants have greatly reduced the occurrence of capsulosis. The two main preventive factors are:
Careful polishing of residues present on the capsule at the end of cataract surgery.
The use of so-called hydrophobic implants, with square edges, helps to limit cell regrowth.
Evolution and complications
Secondary cataracts are usually slow-developing. Vision will become blurred over a few months, or even a few years.
However, it is not uncommon for some patients to be surprised by a fairly rapid onset, suddenly realizing the decrease in vision when closing the healthy eye.
Differential diagnoses
Concluding that a decrease in vision is linked to cataracts requires having eliminated all other causes of decreased visual acuity.
Therefore, the diagnosis should only be made after a meticulous clinical examination ruling out damage to the cornea, retina, macula and optic nerve.
For greater diagnostic accuracy, it is advisable to supplement the clinical examination with an OCT of the retina and optic nerve.
Evolution and prognosis
Secondary cataracts are usually slow-developing. Vision will become blurred over a few months, or even a few years.
However, it is not uncommon for some patients to be surprised by a fairly rapid onset, suddenly realizing the decrease in vision when closing the healthy eye.
Frequently Asked Questions
Is it possible to have a secondary cataract more than once?
No! Secondary cataracts cannot grow back because the capsule on which the cells proliferate is destroyed during capsulotomy.
How to treat and cure secondary cataracts?
Secondary cataract treatment is performed in the office. This involves laser capsulotomy. The treatment does not require surgery. It carries no risk of infection and does not require time off work.
When is surgery necessary for a secondary cataract?
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Secondary cataracts are treated with laser as soon as they become bothersome for the patient.