Cataract
Cataracts: At a Glance
Early Symptoms: None
Later symptoms: Blurred vision, dull colors, sensitivity to light, night blindness (trouble seeing in the dark), double or multiple images
Diagnosis: Dilated eye exam
Treatment: Surgery
Simple Definition Of Cataract:
The crystalline lens is a structure that is transparent. When lens fibers opacify due to
degenerative process, its transparency may be compromised. It occurs when an opacity
forms in the lens.
CONGENITAL AND DEVELOPMENTAL CATARACTS
These arise from a disruption in the lens’s regular growth. Children who experience this disruption
prior to birth are born with a congenital cataract.
Etiology:
• Genetics: About 25% of congenital cataracts are caused by genetics. Most often, autosomal
dominant genetic mutations are the cause. One of the maternal causes is malnutrition,
which can result in zonular cataracts.
• Viral infection of the mother, such as rubella during the first 30 days of pregnancy.
• Placenta praevia is one example of a severe placental hemorrhage that results in inadequate
oxygenation.
• Idiopathic
• There is noticeable visual impairment if the opacity is large and centered.
• Leucocoria means “white pupil.”
• There may be abnormal eye movements brought on by nystagmus or squint.
Signs
• The pupillary region exhibits the white reflex.
• Ophthalmoscopic examination: A red background with black opacity
Treatment
• No treatment If the vision is good, no treatment is necessary.
• Mydriasis with atropine: If the cataract is small, central, and the vision is good, it is
recommended to continue at least until puberty. Once a week, an atropine drop is
administered.
• If the opacity is small, central, and stationary, an optical iridectomy may be performed.
• Lens aspiration: Since the fixation reflex takes two to four months to develop, the child
should have surgery sooner. In order to establish binocular vision, an intraocular lens (IOL)
implant comes next. Since children’s lens material is soft, aspiration of the lens matter is
possible. The implantation of an IOL comes next.
• Lensectomy: This procedure involves removing the lens, anterior vitreous, and anterior and
posterior capsules.
Snile Cataract
This is the commonest type of acquired cataract. It is also known as ‘age related cataract
Etiology:
• Heredity
• The onset age is typically around ten years earlier in tropical nations like Pakistan. This
could be brought on by exposure to UV-A and UV-B radiation from the sun.
• Growing older, diabetes, atopic dermatitis, myotonic dystrophy, trauma, etc. are risk
factors.
TYPES OF SNILE
SENILE CORTICAL:
It is the most common type of senile cataract
Etiology
It happens as a result of the already-formed lens fibers degenerating. Lens opacification is
caused by any physical or chemical factor that throws off the intracellular and extracellular
balance of water and electrolytes.
Incidence
• Age: It typically occurs after the age of fifty.
• Sex: The effects are the same for both sexes. Usually bilateral, it first appears in one
eye.
Symptoms
• Frequent changes of glasses
• Diminished visual acuity
• Glare
• Coloured halos around light are seen due to presence of irregular refractive index in
different parts of the lens.
STAGES OF SENILE CORTICAL CATARACT
1. Stage of lamellar separation
• There is demarcation of cortical fibers due to their parting by fluid
• Grey appearance of the pupil: This is caused by increased light reflection and
scattering as well as an increase in the cortex’s refractive index.
2. Incipient
• Lens striae
• Polyopia [The meaning of polyopia is perception of more than one image of a
single object, especially with one eye] may be present due to irregular refraction.
• Vision is impaired
3. Immature
• In this stage, opacification improvements further.
• Deeper layers of the cortex become cloudy and opaque
• As the lens swells due to progressive hydration, the anterior chamber becomes
shallow. It could result in secondary glaucoma of the phacomorphic type. At this
point, some patients may experience lens swelling as a result of their continued
hydration. “Intumescent cataract” is the term for this condition.
• Because the lens is hydrated, colored halos may be visible.
4. Mature senile cataract (MSC)
At this stage, opacification is complete, meaning that the entire cortex is involved. The lens
turns a brilliant white. Another name for it is “ripe cataract.”
• Iris shadow test: There is no iris shadow. The iris casts a semilunar
shadow on the deeper lens opacity when there is clear lens substance between the
pupillary margin and the opacity.
5. Hyper mature senile cataract (HMSC).
The stage of hypermaturity begins when the mature cataract is left in place.