How to Prevent Posterior Capsular Opacification
Understand the key considerations in modern cataract surgery that minimize the risk of posterior capsular opacification for lasting, clear vision.
A common follow-up issue after cataract surgery is Posterior Capsular Opacification (PCO), which can cause vision to become cloudy again. Often called a “secondary cataract,” PCO is not a return of the original cataract but a clouding of a membrane inside the eye. This condition can develop months or years after the initial surgery, but preventative measures related to surgical tools and techniques can reduce its likelihood.
Understanding PCO and the Lens Capsule
The eye’s natural lens sits inside a thin, clear membrane called the lens capsule, which acts like a tiny bag. During cataract surgery, the surgeon removes the clouded natural lens but intentionally leaves the posterior, or back part, of this capsule in place. This intact posterior capsule serves as a platform to securely hold the new artificial lens, known as an intraocular lens (IOL).
The clouding of PCO occurs on this remaining posterior capsule. It is caused by the eye’s natural healing process, where some of the original lens’s epithelial cells (LECs) remain after surgery. Over time, these residual cells can multiply and move onto the posterior capsule, causing the membrane to thicken and become hazy. This process obstructs light from reaching the retina, leading to symptoms like blurry vision, glare, and halos around lights.
Intraocular Lens Selection for PCO Prevention
The type of intraocular lens (IOL) implanted during surgery has a substantial impact on the chances of developing PCO. While several materials are used, including silicone and PMMA, studies suggest hydrophobic acrylic IOLs are associated with lower rates of PCO. The tacky surface of this material allows it to adhere tightly to the lens capsule, which is thought to reduce the ability of lens epithelial cells to multiply and migrate.
A primary factor in IOL-related prevention is the design of the lens edge. An IOL with a sharp, squared posterior edge is effective at lowering PCO rates because it creates a physical barrier, blocking migrating LECs from reaching the central part of the posterior capsule. For this barrier to be most effective, the sharp edge should extend a full 360 degrees around the lens optic.
Surgical Techniques to Reduce PCO
The surgeon’s technique during the operation is another line of defense against PCO. A primary goal is the removal of as many lens epithelial cells (LECs) as possible from the capsular bag. One technique is hydrodissection, which uses a fluid to separate the lens from the capsule, allowing for a cleaner removal of the lens material and attached cells.
Surgeons may also perform capsular polishing, which uses a specialized instrument to polish the inner surfaces of the capsule and physically remove lingering LECs. Another technique is the creation of the capsulorhexis, the circular opening in the front of the lens capsule. Crafting a capsulorhexis that is slightly smaller than the IOL optic allows the capsule to overlap the lens, creating a “shrink-wrap” effect that seals the IOL and impedes cell migration.
Treating PCO if it Occurs
Even with advanced preventative methods, PCO can still develop. When it begins to interfere with vision, a straightforward and effective treatment called a YAG laser capsulotomy is available. This procedure is the standard method for correcting the condition.
The YAG laser capsulotomy is a non-invasive outpatient procedure that takes only a few minutes. A surgeon uses a specialized laser to create a small opening in the clouded posterior capsule, allowing light to pass unimpeded to the retina and restoring clear vision. The procedure is safe, and because an opening is created in the capsule, the cloudiness cannot return.