With newer technology,clear vision becomes accessible to the masses
Cataract is the leading cause of preventable blindness worldwide,accounting for more than 20 million cases. In India too,cataract contributes to 60-65 per cent of all cases of preventable and treatable blindness.
Gone are the days,when patients had to be hospitalized for a week or more,or had to wear thick glasses after surgery. Today,surgery aims at achieving super vision or spectacle-free vision at all times. Nowadays cataract surgery is done with a very small incision which does not require stitches,doctors say. The natural cloudy lens is replaced with an artificial implant lens made of a special type of plastic – polymethylmethaacrylate or acrylic or silicon. The acrylic or silicon lens folds up like a taco and is placed thorough an incision as small as 3 mm. Once inside,the lens opens up in the eye like a flower. This surgery is done with foldable lens using high speed ultrasound energy called phacoemulsification,Dr Shilpa Joshi,Consultant,H.V.Desai Eye Hospital said. Usually a monofocal lens is placed in the eye,which gives a clear distance vision. For reading or any work that requires near sight however,the patient has to wear a reading glass. To eliminate the need of glasses totally after surgery,a new type of lens is being used,called multifocal lens which enables the patient to have good near,intermediate and distance vision. The flip side to these lenses however is shadowing or ghost images while reading and halos of light,making night driving a little difficult. However these problems reduce over a period of two to three months,as the brain adapts to the new optics.
Another ingenious modification in the lens design is aspheric lens which eliminates the rainbow of colours in the peripheral vision which used to be associated with multifocal lens. For patients who have pre-existing astigmatism,there are special lenses called Toric lenses. These help patients to regain quality of vision without any annoying aberrations or distortions. Another breakthrough in modern cataract surgery,are the accommodative lenses,which move inside the eye as the focusing muscles of the eye contract,mimicking the eyes natural ability to focus. To put it simply,it makes a seventy-year-old eye function like a twenty-year-old one. Recently,with the use of Femtosecond lasers in cataract surgery,ophthalmologists have taken another step towards perfection. New developments in instrumentation and phaco machines have also shown some promising results.
Of course all these technologies come with a price,which may be well beyond the capacity of an average Indian. Does that mean good vision is the prerogative of only rich people? Not anymore,with some fine touches to the existing affordable technology,results can be equally precise,Joshi added. The manual Small Incision Cataract Surgery (SICS),even though touted as the poor cousin of phaco,does give good vision post-operatively. It remains the technique of choice in very high volume set ups because of its safety and affordability. Today,cataract surgery has moved from being a technique primarily concerned with safe removal of cloudy lens to refractive cataract surgery,a procedure refined to yield the best possible visual outcome.