Know more about Cataract
Cataract is the clouding of the normally clear lens of the eye. Cataract is the the most common cause of decrease in vision in people older than 50 years .It usually presents with foggy or cloudy vision. In the early stages the vision can be corrected with adjustment of glass power. Cataracts may develop slowly over a period of years and cause impaired vision which will ultimately require cataract surgery and an intraocular lens.
Causes
Most cataracts develop due to aging, the natural crystalline lens becomes less flexible, starts to thicken and opacifies. The proteins inside the lens gets denatured and clump together, causing small cloudy areas within the lens.
As the cloudiness increases to involve a larger area, the vision starts to get affected due to obstruction to light or scatter of light.
Other causes may be injury or disease in the eye, use of steroids both systemic and topical, some metabolic diseases most common being diabetes, thyroid disease. Rarely they may be present at birth called congenital or developmental cataract.
Symptoms
Both eyes develop cataract simultaneously, but not evenly. The cataract in one eye may be more advanced than the other.
1] Blurred or cloudy vision
2]Glare, difficulty in vision at night.
3]Need for a brighter light for reading.
4]Halo’s around light.
5]Frequent change of glasses
6]washed out colours
7]Double vision
Types of Cataract
1]Nuclear Cataract: this type of cataract starts in the centre of the lens. It may cause more nearsightedness or sometimes improvement in reading vision called as second sight. Once advanced leads to cloudy vision
2]Cortical Cataract: this type of cataract affects the edges of the lens. It usually begins as a wedge shaped opacity looking like spokes on a wheel. Once advanced the streaks may extend till the centre and cause cloudy vision.
3]Posterior Subcapsular cataract: this type of cataract affects the last layer of the lens. This type of cataract interferes with vision early on as it lies right in the centre of the visual axis. It may cause glare, difficulty in reading and other disturbances. These progress faster and may require early intervention.
4]Congenital Cataract: the cataract which is present at birth or develop in early childhood. These may be genetic or associated with intrauterine infections or trauma. If they are interfering with vision these should be removed early.
Diagnosis
Examination by your ophthalmologist will help you do get a clear picture of the stage of cataract
Visual acuity test – uses the snellen chart to measure vision
Slit lamp examination- allows the structures of the eye to be seen under magnification
Retinal exam- to rule out any retinal problem
Non contact tonometry- to assess the IOP
A scan biometry- this is done to determine the required power of the IOL, to be used .
Treatment
Early stages glasses may help, if the day to day life starts to get affected e.g problems while reading or driving you may be advised to go ahead with cataract surgery.
Cataract surgery can be planned in most cases as there is no rush to remove the cataract. Cataracts will progress over time and in advanced cataracts it may require immediate surgery.
Even if you do not choose surgery at a given point,do go ahead with a periodic follow up to see how the cataract is progressing.
Cataract surgery
During Cataract surgery the cloudy lens is removed and replaced by an artificial lens . It is called the intraocular lens, once implanted it remains in the eye permanently. It is done as an out patient surgery and you can go home after surgery. If your doctor feels that you are comfortable many times the surgery can be done using only eyedrops for anaesthesia.
Phacoemulsification [ phaco ]
It is a technique used to remove cataracts with the help of an ultrasonic device. The hard cataracts are softened and then aspirated out of the eye with the help of a hand piece. All this is done through a very small incision that is the reason it is called Micro incisional cataract surgery [MICS]
After the removal of the cataract the desired intraocular lens is placed in the same position as the cataract using the same incision. The back membrane of the cataract is left to help position the IOL.
The wound is very small and does not require stitches in most cases. Most patients experience clearer vision and can resume normal activities fairly rapidly.
Laser assisted cataract surgery
Like Phacoemulsification, in laser cataract surgeries the laser assists in making a few cuts in the lens and can make the process smoother and more predictable. However ultrasound phacoemulsification is used to remove the actual cataract. Recovery time in Laser assisted surgeries is similar to Phacoemulsification cataract surgery.
About the writer :--
Dr Smriti Jain is an Cataract and Glaucoma Surgeon with over 18 years of experience based at Dehradun. She can be contacted at Dr Smriti Eye Centre, Dehradun and on phone at 8077248489 / drsmritijain@outlook.com
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