by
Mamisoa Andriantafika
Cataract is a clouding of the natural lens usually related to age. It can be congenital, meaning presents since birth, but also secondary to another condition e.g. ocular traumatism or inflammation.
Sometime there is no symptom. On the other hand, it can cause amblyopia, meaning an anomaly of development of the visual function if not detected early during childhood.
A loss of contrast vision can be perceived. Patient can also be bothered with more glare more often. Those two phenomena get evident while driving at night. Vision is much lower and other car headlights are blinding.
A change of optical correction, most often short-sightedness induce worsening of the distance vision, but paradoxically a better close vision for patient with no correction for far. Unfortunately, situation changes and opacification of the lens makes the vision not suitable enough at any distance.
Cataract can increase short-sightedness and paradoxically enhance close vision.
The eye doctor notices under the microscope a loss of transparency of the lens. Clouding is usually homogenous and brownish, it is called a nuclear cataract. It can also be peripheral, it is then called a cortical cataract. A sub-capsular posterior cataract occurs when the clouding is axial and on the very back of the lens, inducing a faster decrease in vision. This situation is usually secondary to corticoid intake or diabetes, and is therefore more common with patients under 60yo. Cataract can be congenital, meaning present since birth.
Cataract surgery is not usually urgent. It occurs when the patient is symptomatic enough.
When the diagnosis is made, a follow-up is done until the loss of vision is symptomatic enough. There are no medical treatment preventive or therapeutic that show sufficient efficiency.
Cataract surgery occurs when the vision loss affect the patient in his everyday life. The doctor will also exclude that no other underlaying disease is present. At this age, age related macular degenerecence or ARMD can also impair the vision and if possible, should be treated first. The most common surgical technique is to emulsify the clouded lens with ultrasounds, sometime assisted with femtosecond laser, through micro-incisions, and then replace with a customized artificial lens.
Surgical treatment can be urgent during very young childhood when it can induce a profound amblyopia, which happens when the screening is late and visual development did not occurs correctly. It is usually the case when it is unilateral. Most often, emergency is very relative and surgery occurs when it becomes symptomatic.