What is it?
Cataracts are eye diseases that lead to partial or total opacity of the crystalline lens. It leads to a progressive and irreversible loss of vision.
The crystalline lens, located between the iris and the vitreous, is a converging lens. It consists of a nucleus at the center of a cortex surrounded by a capsule (crystalloid). The zonule, which joins it to the ciliary body, holds the lens in place.
This vision disease most often appears after the age of 60. But it is not uncommon in people over 50, and can even occur as early as age 40.
Causes and risk factors
Senile or presenile cataracts are the most common, beginning around the age of 55. The proteins making up the crystalline lens change and make it opaque. But the exact cause is unknown.
Congenital cataracts are often hereditary (dominant transmission). They are sometimes the consequence of fetal diseases (rubella, syphilis, toxoplasmosis, metabolic disease: galactosemia).
Some cataracts are the result of a general illness:
- Diabetes ;
- Chronic generalized eczema ;
- Steinert’s myopathy ;
- Trisomy 21 ;
- Prolonged corticosteroid therapy…
Signs of the disease
The most important sign is a progressive decline in visual acuity. This decline is accompanied by the development of myopia linked to the crystalline lens, which in everyday practice means that presbyopes can do without glasses when reading.
Light glare is a frequent source of discomfort at night, especially when driving.
- Daylight examination may reveal a whitish or grayish pupil, indicating a complete cataract;
- Slit-lamp examination pinpoints the location of lens opacities;
- Fundus examination for retinal or optic nerve pathology.
Treatment
In the early stages, glasses can be adjusted to improve visual comfort. However, cataract treatment is exclusively surgical. In fact, only surgery can restore correct vision. Senile cataracts are operated on when useful vision is lost. The average age for surgery is 72, but the procedure can be performed earlier, as soon as functional discomfort appears.