The lens capsule is the thin, elastic-like bag that holds the intraocular lens (IOL) in position after cataract surgery.During the operation, the front (anterior) portion of the lens capsule is carefully opened and the cataract is removed.The IOL is inserted into the remaining (posterior) portion of the capsule. The remaining portion of the capsule becomes clouded in about 25% of cataract surgery patients.When this occurs, patients experience symptoms similar to those from the original cataract.
The eye care practitioner can diagnose posterior capsule opacification during a routine eye examination using a slit lamp microscope. It is more easily detected if the pupils are dilated. Potential acuity testing is often performed to determine the expected improvement of vision.
A simple procedure called a YAG posterior capsulotomy is performed to restore vision lost from the clouded capsule. The YAG is a type of "cold" laser used to create a small opening in the center of the capsule, allowing a clear area for light to enter the eye. The procedure is painless, requires no anaesthesia, and has very little risk since no incision is required.
After the dilating drops wear off from the procedure, most patients notice an immediate improvement in vision. The improvement each person experiences is dependent on the extent of the capsular clouding and the overall eye health.
Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.