Cataract
Cataract is the commonest cause of blindness and visual impairment in India. It happens mostly among elderly people. Rarely children can be born with cataract or develop cataract while growing. Individuals with Diabetes or under steroid therapy may develop diabetes earlier in life. Cataract can develop due to injuries also.
What is Cataract?
Cataract is a Greek word meaning waterfall; because of the similarity in colour the name is coined. The condition is called Cataract when there is presence of any opacity in the natural lens leading to reduced quality of vision.
Symptoms of cataract
Commonest symptom is dimness of vision. There can be difficulty in tolerating light in day time or driving at night. Sometimes one can see multiple images like seeing three four moons in the sky. In certain varieties of cataract distance vision drops but near vision improves and an aged persons regains spectacle free near vision.
Treatment of cataract
The treatment of cataract is primarily surgery. Whether to plan for surgery depends upon the quality of vision the patient is experiencing. In early stage spectacle correction can improve sight for a period of time. Beyond that surgery is the only treatment. Till date there is no anti cataract drug available.
Cataract surgery is considered if the visual disturbance felt by the individual can be explained by the presence of cataract and removal of cataract is likely to improve the quality of sight.
Cataract surgery is the commonest surgery in Ophthalmology. A cloudy lens is removed and is replaced by a clear artificial lens which is popularly known as IOL (Intra Ocular Lens). Except for very young children and certain limited ocular conditions IOL implantation remains the method of choice. Continued medical research has resulted in marked improvement in techniques of surgery and optical quality of lenses that offer comfortable sight after surgery.
Phacoemulsification is popularly known as “PHACO’’. It is a method of crushing (emulsifying) the opaque lens (phacos) inside the eye using ultrasonic energy. This technique enables the surgeon to perform surgery through a small opening (<3mm).
There is another popular method called Manual Small Incision Cataract Surgery (MSICS). This is an effective and safe method of cataract surgery. When PHACO is not possible for clinical reason MSICS is a good alternative.
Small incision surgeries have the advantage of reduced period of restrictions after operation.
Tests usually done before cataract surgery
What is Cataract?
Cataract is a Greek word meaning waterfall; because of the similarity in colour the name is coined. The condition is called Cataract when there is presence of any opacity in the natural lens leading to reduced quality of vision.
Symptoms of cataract
Commonest symptom is dimness of vision. There can be difficulty in tolerating light in day time or driving at night. Sometimes one can see multiple images like seeing three four moons in the sky. In certain varieties of cataract distance vision drops but near vision improves and an aged persons regains spectacle free near vision.
Treatment of cataract
The treatment of cataract is primarily surgery. Whether to plan for surgery depends upon the quality of vision the patient is experiencing. In early stage spectacle correction can improve sight for a period of time. Beyond that surgery is the only treatment. Till date there is no anti cataract drug available.
Cataract surgery is considered if the visual disturbance felt by the individual can be explained by the presence of cataract and removal of cataract is likely to improve the quality of sight.
Cataract surgery is the commonest surgery in Ophthalmology. A cloudy lens is removed and is replaced by a clear artificial lens which is popularly known as IOL (Intra Ocular Lens). Except for very young children and certain limited ocular conditions IOL implantation remains the method of choice. Continued medical research has resulted in marked improvement in techniques of surgery and optical quality of lenses that offer comfortable sight after surgery.
Phacoemulsification is popularly known as “PHACO’’. It is a method of crushing (emulsifying) the opaque lens (phacos) inside the eye using ultrasonic energy. This technique enables the surgeon to perform surgery through a small opening (<3mm).
There is another popular method called Manual Small Incision Cataract Surgery (MSICS). This is an effective and safe method of cataract surgery. When PHACO is not possible for clinical reason MSICS is a good alternative.
Small incision surgeries have the advantage of reduced period of restrictions after operation.
Tests usually done before cataract surgery
- Measurement of Intra Ocular Pressure
- Assessment of patency of the channel that connects eye with the nose (naso-lacrimal duct). If any block is detected that problem should be treated first to prevent infection.
- Blood sugar level
- Blood pressure
- Biometry – Ultrasonic or Optical
- Opinion of treating physician for systemic diseases
- Specular Microscopy – when indicated
- OCT of retina – when there is any doubt about retinal function
- USG B Scan - when retina cannot be seen due to hazy media doctor may ask for ultrasonography
- Patients who require general anesthesia need to undergo pre-anasthetic check up
Selection of lens
Broadly the IOLs are of two varieties, Rigid and Soft (foldable). Rigid lenses are being used for more than five decades all over the world. Most of the newer technological developments have taken place in soft lenses. TORIC lenses can correct preexisting cylinder power. MULTIFOCAL/TRIFOCAL lenses can reduce spectacle dependency for distance and near, BUT it is very much individual specific.
Lenses can be classified according to physical property as Hydrophilic and Hydrophobic. Hydrophobic materials are more compatible to the eye according to present research.
Need for LASER
During cataract surgery the artificial lenses are placed over a very thin transparent capsule. Some patients, specially the younger individuals may develop thickening of that capsule leading to loss of transparency known as PCO (posterior capsular opacification). Gradually the vision goes down. This can be easily treated by a single sitting of YAG LASER application.
