A cataract is due to the progressive opacification of the crystalline lens, and is generally due to age. Diabetes, myopia and long-term cortico-steroid use are also risk factors.
The crystalline lens (the lens) is located inside the eye, behind the iris that facilitates clarification, which means the focusing of light beams at the center of the retina. At around the age of 45, the lens begins to lose its elasticity, close-range vision is blurry or hazed: This is presbyopia.
Normally, the lens is transparent. When transparency is lost, and opacification occurs, light can no longer normally go through. Vision is impaired and becomes unfocused: There is a cataract.
A cataract is generally associated with the natural aging of the lens after the age of 65, but it can also be related to diabetes or ocular trauma; in rare cases, it may be congenital.
A loss of vision affecting the (far or near) view appears, as does bedazzlement or doubling of images.
It is surgical. The objective of the operation is to remove the the opaque lens and to have it replaced by an artificial lens. A cataract operation is generally ambulatory and takes place under local anesthesia.
Video presentation of a cataract operation (attention, these are surgery images!).
Glaucoma is a severe ocular disease. Most often, it is associated with ocular hypertension leading to irreversible loss of vision through degeneration of the optical fibers.
It is a frequent disease, representing the second worldwide cause of blindness; it affects 1 to 3% of persons over 50 years of age.
Different types of glaucoma are commonly distinguished:
- chronic open-angle glaucoma, the most frequent form, it is painless;
- acute or sub-acute angle closure glaucoma, a less frequent form, it is painful; ,
- congenital, infantile, juvenile glaucoma (highly rare).
Risk factors are:
- ocular hypertonia;
- age: Glaucoma is often characterized as an age-related disease, even though it can actually occur at any age;
- family history: Family factors represent a risk factor for glaucoma occurrence, necessitating sensitization and oriented supervision of patients reporting cases of glaucoma in their families;
- medication taken: cortico-steroids;
- vascular diathesis: In cases of glaucoma, vascular risk factors may be suspected.
It is an insidious disease, without pain or loss of central vision. Only examination by an ophthalmologist can ensure its being screened. Glaucoma screening is carried out by intraocular pressure measurement and a number of examinations: field of vision, fiber optic analysis (optical coherence tomography/OCT).
Treatment consists in lowering eye pressure so as to prevent the disease from progressing. At present, treatment is built around:
- hypertonic eye-drops;
- SLT or YAG laser (iridotomy),
- filtration surgery (sclerectomy or trabeculectomy),
- cyclodestruction by cryotherapy of the ciliary bodies by a new high-intensity focused ultrasound technology .
Vidéo d’une sclérectomie (attention, ce sont des images de chirurgie !)
Vidéo d’une pose d’istent après une opération d’un glaucome (attention, ce sont des images de chirurgie !)
The cornea is the first transparent lens of the eye. It covers the anterior part of the eye in front of the iris and the pupil. It needs to remain transparent.
Corneal diseases can have multiple sources: traumatic, infections, genetic, inflammatory, allergic or toxic.
Following physical or chemical traumas, or in the course of hereditary pathologies (corneal dystrophies), infections or inflammations, the cornea can lose its transparency, and the resulting opacity can have variable repercussions on the visual functioning of the affected eye.
When the opacities are too thick, or when all the layers of the cornea are involved, a corneal graft is likely to be necessary. A major surgical breakthrough over recent years consists in replacing the diseased parts of the cornea while respecting the healthy parts: lamellar grafts. However, when the entire cornea is diseased, full thickness grafts are called for: transfixing grafts.
Video report on a corneal graft (attention, these are images of surgery!).