What is posterior capsule opacification?
During cataract surgery, the natural clouded lens is removed and an artificial lens is implanted inside a thin membrane called the posterior capsule. In some patients, cells on this membrane gradually grow and become cloudy over the months or years following surgery — a process called posterior capsule opacification (PCO), sometimes referred to as a "secondary cataract."
PCO is not uncommon, is not a complication of the original surgery, and does not mean the artificial lens has failed. However, it can cause symptoms that closely resemble those of the original cataract.
Symptoms of posterior capsule opacification
Symptoms typically develop gradually after a period of good vision following cataract surgery.
- blurred or hazy vision that progressively worsens
- increased glare from lights or sunlight
- difficulty reading or with fine detail tasks
- reduced contrast sensitivity
- halos around lights at night
Any new visual change after cataract surgery should be assessed to determine the cause. PCO is one possibility, but other conditions including retinal changes or dry eye may also contribute to post-operative symptoms.
What is YAG laser capsulotomy?
YAG laser capsulotomy uses a precisely focused laser beam to create a small opening in the cloudy posterior capsule, restoring a clear visual pathway through the eye. The artificial lens is not touched or affected by the procedure.
The procedure is performed in the consulting room without any surgical incision. It typically takes only a few minutes once the pupil has been dilated with drops.
What to expect at the appointment
The assessment and treatment typically take place in one visit. Dilating drops are applied to the eye in advance, which may take 20–30 minutes to work. During the laser treatment, a small contact lens is placed on the eye to help focus the beam. Most patients notice a series of brief clicking sounds and flashes of light but experience no significant discomfort.
The procedure itself usually takes only a few minutes. Patients can generally return home shortly afterwards, though driving is not recommended until the dilating drops have fully worn off.
After the procedure
Many patients notice an improvement in visual clarity within one to two days. Some experience new floaters in the days following treatment as the treated capsule tissue disperses within the vitreous — these typically settle over a few weeks.
A follow-up appointment is arranged to check eye pressure, which can temporarily rise after YAG laser treatment, and to confirm that recovery is progressing well. Eye drops may be prescribed for a short period after the procedure.
Who needs YAG laser capsulotomy?
Not all patients who develop posterior capsule changes require treatment. YAG capsulotomy is recommended when PCO is causing visually significant symptoms that affect daily activities such as reading, driving, or general visual comfort.
The decision is based on both the clinical examination findings and the patient's reported symptoms, ensuring that treatment is appropriate and timely rather than automatic. Patients with a history of retinal conditions, high myopia, or other ocular factors are assessed carefully before treatment.