By Dr Neeraj Jain, MD(ophthalmology), DNB, MNAMS
Whenever a patient comes to know that he has got ‘another cataract’ after a surgery for cataract, he often feels that the surgery wasn’t done properly or the surgeon has left some cataract in the eye which is causing him trouble. To clear the confusion originating from similar looking words like ‘cataract’ and ‘after cataract,’ I will discuss about the condition called ‘after cataract’ or ‘posterior capsular opacification.’
What is cataract?
A cataract is clouding of the lens in the eye that affects the vision. The lens is made up of a bag filled with protein and protein-like material and is suspended in the eye with the help of tiny spokes (zonules). When a person gets a cataract the material in the bag gets cloudy and causes blurring of the vision. This can be treated by surgery (phacoemulsification) and once the opaque material (cataract) is removed from the bag, the same bag is used to hold an artificial clear lens.
What is an intra-ocular lens?
An IOL (intra-ocular lens) is the substitute for the natural lens to maintain the vision without thick glasses. After a cataract surgery an IOL implant is a routine step. Most common implants are placed ‘in the bag’ which is considered the safest implant site. There are other sites for the lens implant but they are chosen only if an ‘in the bag’ implant is not possible.
What is an
after cataract?
A posterior capsular opacity is an opacity that can form behind an intra-ocular lens implant after cataract surgery. The opacity develops in the posterior capsule (posterior part of the clear membranous bag) that supports the lens implant after cataract surgery.
After a successful cataract surgery, it may take several weeks to several years to develop an after cataract. It is not necessarily the case that all will have an after cataract. Other names for this condition include secondary cataract, posterior capsular membrane, or posterior capsular fibrosis.
Why does an after cataract develop?
The natural lens is made up of the bag and the fluid material inside it. The bag is coated with the cells which keep secreting the material inside. When a person develops the cataract, this material gets opaque and a cataract surgery can remove it. Even though a meticulous removal of proteinaceous material is done some cells are always left behind; which later start growing and forming an opacity.
What are the symptoms of after cataract?
* Slow, progressive blurring of vision
* Colours seem faded
* Glare − headlights, lamps, or sunlight may appear too bright. A halo may appear around lights.
* Poor night vision
* Double vision or multiple images in one eye
How is after cataract treated?
The most common and most effective method is YAG laser capsulotomy. The final objective is to make a small opening in the post wall of the bag so that a window can be created from the partially opaque capsule. When the capsule is too thick, some surgical methods can be employed to cut the central opaque part of the bag.
What is a YAG laser?
A YAG laser is a type of laser which is used to cut or make a hole in the bag. Because of the precise nature of lasers, this process involves making a small window in the bag.
What is the procedure?
This after cataract condition is treated by the YAG laser capsulotomy, performed as a minor in-office or outpatient procedure. The pupil is generally dilated prior to the procedure. A laser is then used to cut through the hazy capsule behind the IOL implant. Entirely painless, it takes just a few minutes and results in no post-operative discomfort.
An anti-inflammatory eye drop medication is usually recommended after the procedure. Patients may resume normal activities immediately. Some ‘floaters’ can be expected, which will generally disappear within a few weeks. YAG laser capsulotomy almost always enables vision to be restored or improved.
Is there any
risk involved?
After the laser a very few patients may feel some pain, and a few may develop inflammation and high intra-ocular pressure.
Will I get any other opacity after the
‘after cataract’?
No. Once the after cataract is treated, there should be no opacity for life.
