Last updated: 02/17/2009

Approximately 20% of patients who undergo cataract extraction with placement of an intraocular lens into the posterior lens capsule will eventually undergo a laser capsulotomy, although a PCO may appear in up to 50% of patients who have undergone cataract...

surgery. The average time after cataract extraction for this procedure to be performed is two years, but it may be performed as early as three months after cataract removal, or as late as five years afterward.

Patients who fall into groups with an increased incidence of a secondary cataract formation have an increased rate of YAG capsulotomy. Patients who are younger when undergoing cataract removal are more likely to develop a PCO than are geriatric patients. This is particularly true of pediatric patients who are experiencing ocular growth. The incidence of PCO is higher in women than in men. Fifty percent of patients who experience papillary, or iris capture, of the IOL, which occurs if the IOL moves through the pupil (a hole in the iris) from its position in the posterior chamber of the eye to the anterior chamber, will form a PCO and benefit from laser capsulotomy.

The degree and incidence of capsule opacification also varies with the type of implant used in the initial cataract operation. Larger implants are associated with decreased opacification, and round-edged silicone implants are associated with a greater incidence of opacification than are acrylic implants, which have a square-edged design. These two types of IOLs are called foldable implants because they unfold after being placed in the eye, allowing for a smaller incision on the front of the eye during cataract surgery. Also, the incidence of PCO is less with a silicone IOL than with a rigid IOL. The greater the amount of remaining lens material after extraction, especially in the area of Soemmering's ring, the greater the probability of PCO formation and laser capsulotomy. Also, diabetic patients are more likely to require a YAG capsulotomy than are non-diabetic patients. This is especially true for YAG capsulotomies performed on diabetics 18 months or later after cataract removal. The extent of diabetic retinopathy does not correlate with incidence of PCO or laser capsulotomy. Finally, insufficient dilation of the pupil during cataract surgery and inexperience of the surgeon doing cataract removal contribute to an increased risk of secondary cataract formation.