Dr Ben Wild
Overview |
For vision to be in clear and in focus, light must pass through the cornea, the clear tissue at the front of the eye, the pupil, the black hole in the center of the colored iris, and the lens, the clear tissue inside the eye, to the tissue responsible for detecting light, the retina. The lens sits inside a bag (capsule) attached to strings (zonules) that are controlled by muscles (ciliary body).
Cataracts refer to the fogging/clouding of the lens and lead to decreased vision, poor night vision, and glare. A cataract, or the fogged lens, is treated with cataract surgery. In this surgery, a hole is created in the capsule at the front of the lens, the lens is then emulsified and vacuumed away, and an implant lens is inserted into the capsule.
A healthy eye with an implanted lens after cataract surgery.
Posterior capsular opacification (PCO), also known as 'after-cataract', occurs in about 20-25% of patients after cataract surgery. It can occur as little as 1 week after cataract surgery but often occurs a year or a few years after cataract surgery. It occurs when some of the biological cells from the natural lens (the cataract) are left in the capsule before the implant lens is placed. These cells attach to the implanted lens and start growing and multiplying. Interestingly, research shows that the design of the implanted lens has more impact on PCO development than the material of the lens.
An eye with an implanted lens after cataract surgery with PCO.
Signs and Symptoms |
Signs
Clear pearls of swollen natural lens cells or a fibrous layer of cells, on the back surface of the implant lens.
Symptoms
Slowly worsening vision, increasing glare, double vision coming from one eye, reducing contrast sensitivity.
Causes and Risk Factors |
Causes
Growth and multiplication of cells from the natural lens on the implanted lens.
Risk Factors
The design of the implanted lens, and to a lesser extent, the material of the implanted lens.
Prevention, Treatment, and Complications |
Prevention
There are no known preventative measures.
Treatments
Laser (Nd:YAG laser) capsulotomy where the surgeon dilates the pupils with eye drops, focusses a laser on the cells creating the PCO, and creates a hole in the back of the capsule so that there is no meshwork for the cells to adhere.
Complications
Complications of the laser capsulotomy are usually very rare but can include lens pitting (if the laser hits the implanted lens instead of the capsule) which rarely causes any issues, new floaters which dissipate over 4-6 weeks, mild/temporary increase in eye pressure, retinal tears or retinal detachments in highly myopic/nearsighted eyes, and swelling of the macula if attempted within 6 months of cataract surgery.
Prognosis |
PCO is easily treated with a simple 30 second to 1 minute laser treatment. If treated correctly, it should never return.