Secondary Cataracts
What is it?
Cataract surgery involves removing the cloudy lens using ultrasound, leaving the capsular “sack” that contains it almost completely transparent and introducing an intraocular lens inside. To do so we make a small window in the front of the “sack” (anterior capsule), a clear membrane, leaving intact the posterior capsule lens and the intraocular lens implant within. Said posterior capsule may become cloudy, months or years after cataract surgery, leading to decreased vision. This is called “secondary cataract”. This is due to the migration and proliferation of lens epithelial cells from the equatorial and anterior capsule to posterior capsule.
Symptoms
The most prominent symptoms include decreased visual acuity, months or years after cataract surgery, that hinders both distant and near vision, plus the glare of the sun or the lights of the cars at night.
Treatment
To restore lost vision, an opening or window is made in the center of the posterior capsule (capsulotomy), by applying a laser (Nd:YAG). The Nd:YAG capsulotomy is a simple, painless procedure, and on an outpatient basis. It is performed a few minutes after dilating the pupil, under the effect of a few anesthetic drops, and the patient can return home immediately with a treatment in beads.
The visual recovery is full (if no other retinal eye disorders, optic nerve or corneal disorders are present) and fast, with noticeable improvement within a few hours. A few days later we conduct a visual inspection to check the evolution and a review to assess the need, if any, to change the glasses. In any case, the capsulotomy improves vision as much as possible.
Despite being a very safe procedure, some patients report seeing”floaters” a few days later, possibly due to small residual fragments of the capsule which are normally reabsorbed and disappear within a few days, although in isolated cases this feeling may persist a longer time.
It is a definitive treatment in a single session, although in very exceptional cases the opacity comes back, making it necessary to repeat the process.
Prevention
It is complicated to prevent or delay opacification of the posterior capsule, although this does not occur in all patients. There are several factors that could delay it, such as a comprehensive polishing of the capsular epithelial cells during cataract surgery, although some authors suggest the opposite. Moreover, certain intraocular lenses, due to their large footprint on the equator of the capsular bag, provide a “bridge” of growth of the epithelial cells into the posterior capsule. The most important thing is to know the symptoms, identify them, and treat it if possible.