Cataract The Leading Cause Of Blindness

4 min readNov 23, 2022

Cataract is the one of the leading cause of avoidable blindness. Our eye is just like the camera. There is a clear crystalline lens in our eye which focuses the light coming from the pupil on to the retina. There are photoreceptors in the retina that send signals to brain through optic nerves.Brain processes image and sensation of vision is perceived by us. For clear image crystalline lens must be clear for the passage of light. When there is cloudiness and opacification of lens vision is diminished and blurred. This condition or opacification of lens is called cataract.

Epidemiology of cataract

v Around 95 million people are affected globally by cataract.

v Prevelance of cataract increases with age 3–9% at age 55–64 years to 92.6% at age 80 and above. Around 48% of blindness is due to cataract.

Types of cataract according to age

1. Congenital and developmental cataracts (approx 1%)

2. Acquired cataract (approx 99%)

Signs and symptoms

v Photosensitivity

v Cloudiness of vision

v Blurriness

v Coloured halos, Glare

v In dim light and night time difficult to visualize objects

Causes of cataract

v Age

v Diabetes

v Glaucoma

v Trauma to eye

v Surgical induced cataract

v Eye inflammation(uveitis)

v Uv light exposure

v Smoking

v Excessive radiaton exposure

v Long term use of steroid medication

Management of Cataract

Medication: Currently World is at advanced level of technology but still there is no such medication which removes cataract.

Cataract surgery: The only treatment to remove cataract is cataract surgery which is carried out by replacing the opaque crystalline lens by clear artifical lens.Currently 3 types of cataract surgeries are performed.

v Phacoemulsification

v Femtosecond laser

v Extracapsular cataract extraction

In surgery mostly posterior chamber intraocular lens implantation is carried out but in some cases where posterior chamber IOL is not possible anterior chamber IOL is performed.

Is it necessary to implant artificial lens?

A condition in which natural lens of eye Is replaced by artificial lens is called pseudophakia. In pseudophakia vision of patient is 6/6 in most cases depending upon how much vision is before cataract. Exact IOL measurement of patient results in emmetropia if patient is emmetropic before cataract. A very small even 0.25D measurement error result in myopic or hypermetropric patient.

If during cataract surgery after removal of cataract artificial lens is not implanted patient becomes aphakic. In aphakic patient high degree of hypermetropia +10D to +12D is induced resulting in very poor vision. Loss of accommodation also occurs due to absence of lens.Patient must have to wear high plus prescription which causes lots of problem and also cosmetically unacceptable. So it is necessary to implant artifical lens after cataract removal for clear vision and also to avoid such problems.

Does cataract again develops after catract surgery?

No once surgery is performed there is no chance to develop catract. Yes posterior capsular opacification develops with the passage of time but no need to worry. Yag capsulotomy is performed to treat PCO. This is a very easy procedure performed in maximum 1–2 minutes and also it is painless.

Complications of cataract surgery

Nearly 98% had no serious complications yet there are 1–2% people in which serious complications are noticed including

v Inflammation

v Infection

v Bleeding

v Ptosis

v Dislocated lens

v Retinal detachment

v Glaucoma

v Loss of vision

Preventive measures for cataract

v Controlling risk factors like controlling blood sugar level for diabetic patient.

v When you are going outside wear sunglasses .Sunglasses protect us from harmful UV rays.

v Smoking should be avoided completely.

v Healthy diet

v Self medication should be avoided especially corticosteroids.

v Regular eye examination.

v Quit alcohol intake.

Conclusion

According to WHO cataract cases increases upto 78% by 2050. Although cataract is the leading cause of blindness yet interesting thing is that it is avoidable.We have to take some instant steps to decrease ratio of blindness resulting from cataract in the community.To eliminate cataract from community we have to perform lot of cataract surgeries, raising awareness in community about cataract , and proper education and counselling of eye health care professionals and public. Free eye camps should be organized as they play vital role in treating cataract and other eye problems especially for people who can’t afford expenses of cataract surgery.