Why may YAG laser treatment be needed after cataract surgery?
Cataract surgery is the removal and replacement of the aged, cloudy natural lens of the eye with a new, artificial lens implant. If an intraocular lens implant (IOL) were not used, you would have to wear super thick glasses to get the eye to focus properly.
When the cloudy lens material is broken up and removed during the cataract procedure, the transparent, cellophane-like outermost "wrapping" that held the natural lens in place is left intact. The IOL is inserted into and held in place within this "envelope" which contracts and sticks tightly to the IOL holding it securely in place. But as this happens, the "cellophane" envelope (called the capsule) can lose its crystalline transparency and become foggy. When this occurs (which can be a few months or even many years later) a pupil-sized opening can be made in this cloudy "cellophane" just behind the IOL. This provides a permanent clear pathway for light to be focused by the IOL. The peripheral capsule is left intact and so continues to secure the IOL in place.
reason this is not done at the time of the original cataract procedure is that
putting an opening in the capsule before it has begun to stick to the IOL could
cause instability in or dislocation of the lens implant's position.
_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic