Prepared byAizuddin Hidrus

Mohd Zakariyya Bin Kamil

It means opacification of the lens secondary to local(ocular) or systemic disease

Ocular disease- disturbance of the nutrition of the lens and accumulation of toxins in the aqueous.

The opacity usually starts in the posterior part of the cortex in the axial region(posterior cortical) as the capsule here is very thin and the subcapsular epithelium is absent allowing easy passage of toxins inside the lens.

Examples: 1)perforated central corneal ulcer 2)chronic glaucoma 3)iridocyclitis 4)chorio-retinitis 5)retinal –deatchment 6)intraocular tumors 7)high myopia 8)Retinitis pigmentosa 9)Subluxation or dislocation of the lens  

1)Diabetic cataract a)Snow flakes cataract(true diabetic cataract): -It occurs typically in young type 1 diabetics(insulin

dependent) -It starts as “fluid vacuoles” then a cloud of opacities

resembling “snow-flakes” appear all over the lens and finally becomes totally milky white.

b)Pre-Senile cataract: -It stimulates senile cataract but it develops at an earlier

age 2)Hypo-paratyrodism 3)Severe anemia 4)Toxic(Naphthalene,didnitrophenol,ergot,thalium, and

systemic cortisone) 5)Radiation(infra red in glass blowr cataract,x ray ,electric

cataract and ultrasonic radiation) 6)Other systemic diseases:atopic dermatitis,myotonia

dystrophica,sclerodermia,mongolism, and cretinism.)

-Positive history of ocular or systemic diseases.

-The age may be suggestive (young age). -The opacity starts in the posterior subcapsular

area,shows polychromatic luster )characteristic rainbow display of colors) seen on slit lamp examination .

-The opacity may progress to total opacity with chalky white appearance (excessive calcium deposition).

-The eye shows sign of the original disease e.gKPs of iridocyclitis,High intraocular pressure or bad projection of light in retinal detachment.

 

-retinal function should be good -If the opacity is total,retina cannot be

seen ,so Ultrasonography is mandatory -Cataract extraction is done by extra

capsular cataract extraction .