Sunday, October 9, 2016


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Problems in a mature cataract


    What is a mature cataract?
Photo of a mature cataract





    Mature Cataract


    As the natural lens ages, it undergoes a process whereby the normal transparent lens fibers become opaque. This is a gradual process that can take months or years to complete. During the time taken to complete this process the lens is called an immature cataract. As all the lens fibers opacify the lens gradually becomes a mature cataract. The time taken for this process varies from person to person ranging from a few months to a few years.

    What happens after the cataract matures?    
Photo of a Morgagnian cataract





    Morgagnian Cataract

Once the cataract matures it can follow one of two different processes.
  • Liquefaction: Here the mature lens fibers undergo a process where the individual fibers disintegrate and form a liquid. This remains in the capsule of the lens. The lens is transformed into a bag containing milky fluid. This is called a Morgagnian cataract. This type is very dangerous as this can burst inside the eye, giving rise to a severe reaction, which needs immediate treatment. Even if the cataract does not burst, surgery in this stage has increased risk of complications such as vitreous loss, etc.
  • Desiccation: Here as the name suggests the lens fibers undergo a drying process where the lens dries up a progressively becomes thinner and harder. This lens can at any stage abruptly undergo liquefaction. Surgery in this lens is also fraught with danger, as the hard lens is very difficult to phacoemulsify.

    Is there an association between cataract and glaucoma?
As the lens matures it increases the risk of development of a variety of glaucoma.
There are three types of glaucoma associated with a developing cataract.
Optic Nerve showing glaucomatous damage





    Glaucomatous optic nerve

  • Phacolytic glaucoma: This is caused presumably by lens proteins leaking from the thinned-out capsule. These proteins cause a severe reaction in the eye causing rise in the intraocular pressure causing glaucoma. If not treated vigorously it can cause permanent blindness. Surgery in these carries an increased risk of vitreous loss.
  • Phacomorphic glaucoma: As the lens matures it increases in size. This decreases the space available for the outflow of aqueous (the fluid in the eye). This obstruction to the outflow causes a rapid rise in intra-ocular pressure causing redness and pain in the eye. The visual outcome is very poor in untreated cases.

    Is it advisable to wait for the lens to mature?
Photo of an immature cataract





Immature cataract
As is evident from the discussion above a mature cataract causes more problems. In the past patient's were advised to wait for the cataract to mature. This was done because the surgery in those days was intra-capsular. Here the emphasis was on removing the entire lens along with the capsule, which was easier done if all of the lens fibers were opaque.
But with the advances in the operating microscope even clear transparent fibers are easily visible and can be easily removed. Moreover phacoemulsification is easier done in an immature cataract than in a mature one. Hence today there is no rationale to wait for the cataract to mature.
However this does not mean that the lens has to be removed at the earliest sign of cataract. Cataract surgery though much safer than before still has it's attendant risk's. This has to be taken into account before the decision for surgery is made. So the ideal time, unless otherwise advised by the doctor is when the diminished vision causes hindrance in the day to day activities of the patient.


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