Posterior capsule opacification
Posterior capsule opacification (PCO), often referred to as "after cataract", is the most common complication of cataract surgery.In a small percentage of patients, posterior chamber intraocular lenses may form PCOs a few months after implantation. They are easily treatable, and typically only require a one-time capsulotomy procedure (using a Nd:YAG laser) to clarify. Materials
The materials that have been used to manufacture intraocular lens implants include polymethylmethacrylate (PMMA), silicone, hydrophobic acrylate, hydrophilic acrylate and collamer. Polymethylmethacrylate (PMMA) was the first material to be used successfully in intraocular lenses. British ophthalmologist Sir Harold Ridley observed that Royal Air Force pilots who sustained eye injuries during World War II involving PMMA windshield material did not show any rejection or foreign body reaction. Deducing that the transparent material was inert and useful for implantation in the eye, Ridley designed and implanted the first intraocular lens in a human eye. Advances in technology have brought about the use of silicone and acrylic glass, both of which are soft foldable inert materials. This allows the lens to be folded and inserted into the eye through a smaller incision. Specifically, acrylic lenses are a better choice in people who have a history of uveitis or are likely to have to undergo retinal surgery requiring vitrectomy with replacement by silicone oil, such as persons with proliferative diabetic retinopathy or who are at high risk of retinal detachment, such as persons with high myopia.
They are notorious for their negative impact on the corneal endothelial lining, which is vital for maintaining a healthy clear cornea. Iris-fixated PIOLs, attached by claws to the mid-peripheral iris by a technique called enclavation. It is believed to have a lesser effect on corneal endothelium. The main complication with this type is their tendency to cause endothelial cell reduction. Sulcus-supported PIOLs, placed in the posterior chamber in front of the natural crystalline lens. This type of PIOLs is gaining more and more popularity. They have special vaulting so as not to be in contact with the normal lens. The main complication with older versions was a small possibility of cataract formation. Blue-light filtering IOLs
Blue light filtering IOLs filter the UV and high-energy blue light present in natural and artificial light, both of which can cause vision problems; however too much filtering of blue light can increase depression, especially in the winter months (SAD). The trademarked "Natural Yellow" material is available in three hydrophilic IOLs. Dr. Patrick H. Benz of Benz Research and Development created the first IOL material to incorporate the same UV-A blocking and violet light filtering chromophore thats present in the human crystalline lens in order to attempt to protect the retina after cataract extraction of the natural crystalline lens. A Cochrane Review found little evidence of important differences between blue‐light filtering and non‐blue‐light filtering lenses for protecting the macula (back of the eye) after cataract surgery. This was due to studies being too small and too short‐term to provide reliable results.