Any opacity in the lens or its capsule is called a cataract. However cataract is the opacity in lens preventing clear image formation on retina. The WHO/NPCB (National Programme for Control of Blindness) survey has shown that there is a backlog of over 22 million blind eyes (12 million blind people) in India, and 80.1% of these are blind due to cataract. The annual incidence of cataract blindness is about 3.8 million.
ETIOLOGY OF CATARACT
Senile
Congenital
Systemic diseases: Diabetes Mellitus, Galactosaemia, Hypoparathyroidism etc
Trauma
Drug: Steroid
Toxic agents: Copper, Cigarette smoking etc
Complicated cataract: (Cataract due other ocular disease ) Iridocyclitis, Retinitis pigmentosa etc
Radiation
Electric shock
SYMPTOMS
Blurring of vision/ diminution of vision
White or grayish opacity
Frequent changes of glass
Difficulty in bright light
Difficulty in night vision
Coloured haloes
Glare
Loss of contrast sensitivity
Myopic shift( increase of minus power in aged person)
TREATMENT
There is no medical treatment for cataract. Though, surgery (Cataract extraction & Intraocular lens implantation) is the only treatment, but in initial stages, refraction and adjustment of illumination helps.
TYPES OF SURGERY
TYPES OF SURGERY
Phacoemulsification with foldable IOL ( Intra Ocular Lens) implantation is the choice of surgery. Manual small incision cataract surgery is also very popular surgery in India .
Laser Cataract Surgery: Femtosecond Laser is used to perform few steps of surgery in phacoemulsification.