RETAINED LENS FRAGMENTS

Following cataract surgery, sometimes patients have retained lens fragments that can cause problems with inflammation and high intraocular pressure.

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Modern cataract surgery involves breaking up the lens into small pieces (phacoemulsification) and removing those pieces using suction. One of the downsides to breaking up the cataractous lens during removal is that sometimes, a piece of lens material falls into the back of the eye during cataract surgery. The instruments used to remove lens fragments from the back of the eye are different from the instruments used for cataract surgery.  Therefore, it is usually unsafe for the cataract surgeon to remove lens pieces that fall posteriorly into the eye. A retina surgeon can remove those pieces of lens if necessary.

Lens fragments in the eye cause inflammation and increased intraocular pressure.  This is because you natural cataractous lens is immunopriviledged. That means that your immune system never sees the inside of your lens.  Since your immune system has not make contact with the nucleus of the lens, once a lens piece falls into the eye, your immune system mounts an inflammatory response to the lens piece just like it would to a foreign body or infection. This inflammatory response usually causes vision loss, eye pain and increased intraocular pressure.

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About one percent of cataract surgeries result in retained lens fragments. Some lens fragments absorb and cause no trouble and others do not absorb and cause trouble. It is difficult to tell from an eye examination which fragments are good and which are bad. They all cause the patient to see floaters. In general, if the lens fragments are not inciting an inflammatory response, macular edema or an increase in intraocular pressure, they can be safely observed. If, on the other hand, the lens fragments are causing inflammation, elevated intraocular pressure or macular edema, they need to be removed or permanent vision loss is likely to occur.

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The retina surgeon is comfortable doing surgery in the vitreous cavity where lens fragments settle. Vitrectomy involves removing the vitreous. At the same time, the lens fragments can be broken up and removed from the back of the eye. Once the lens fragments have been removed, the intraocular pressure usually normalizes right away and other problems, like inflammation, cystoid macular edema, and corneal edema, begin to resolve. Usually the vision begins to improve within a week or two.

This 73 year old woman had cataract surgery 2 days ago. Lens fragments dropped into the back of the eye during surgery. The cataract surgeon placed a sulcus IOL. The video shows removal of the lens fragments using a 23 gauge vitrectomy cutter. Scleral depression is essential to identify and remove all fragments from the eye. The patient’s vision was 20/40 uncorrected one week after this procedure.

This video shows how scleral depression is essential to removing all of the lens fragments from an eye, especially when there is time between the cataract surgery and the vitrectomy. This 77 year old man had high intraocular pressures. The posterior lens material looked like just cortex (which is usually tolerated). Examination of the peripheral retina – especially the inferior retina, showed nuclear fragments.

This video shows the removal of lens fragments from an eye with iris fixation of the intraocular lens. The patient regained normal vision within about 1 month of the surgery with no complications. Lens fragment surgery is sometimes necessary following cataract surgery if lens material enters the posterior pole – vitreous – of the eye during cataract extraction.