Blindness means complete loss of vision. In France, 207,000 people would be blind. Lighting with Dr. Laurence Desjardins, ophthalmologist.
Definition of blindness
France counts 1.7 million visually impaired people including 207,000 blind, thus suffering from blindness. According to French Federation of the Blind, blindness means total or very severe loss of vision. Not to be confused with disability. There are thus five stages in the loss of sight:
► The absolute blindness;
► The severe blindness or almost total deficiency which corresponds to a visual acuity of less than 1/50 with a perception of light or a visual field of less than 5 degrees;
► The profound impairment which corresponds to a visual acuity of less than 1/20 and greater than 1/50 or a visual field between 5 and 10 degrees;
► The severe impairment which corresponds to a visual acuity of less than 1/10 and greater than 1/20;
► The medium impairment which corresponds to a visual acuity of less than 3/10 and greater than 1/10 or a visual field of at least 20 degrees.
What are the causes of blindness?
Diabetic retinopathy is the leading cause of blindness before the age of 65 in France. THE glaucoma may also progress to blindness. “There cataract is also one of the main causes of blindness, but mainly in developing countries due to the lack of surgeons who can perform the operation“, explains Dr. Laurence Desjardins, ophthalmologist at the Institut Curie and director of the French Society of Ophthalmology. age-related macular degeneration (AMD), “the disease is a cause of visual impairment but no blindness. If the macula is affected by the disease, the peripheral visual field remains intact. It’s the opposite of glaucoma“, specifies the ophthalmologist.
What are the symptoms at the onset of blindness?
“There are no rules about symptoms. It depends on the cause.“
► Diabetic retinopathy: leading cause of blindness before the age of 65, diabetic retinopathy causes an alteration of the visual field and a decrease in visual acuity thus making reading, movement and orientation difficult.
► Glaucoma: in the case of glaucoma, the narrowing of the visual field is slow and gradual. “Since the disease is most often asymptomatic for open-angle glaucoma, regular monitoring of ocular pressure from the age of 50 is recommended.
► Cataract: cataract is characterized by progressive loss of vision. The patient then sees blurry and becomes sensitive to light. follows loss of color vision. Reading, seeing faces becomes difficult but peripheral vision remains intact, allowing the person to live independently. In France, cataracts do not cause blindness thanks to the 600,000 operations that take place each year. In some developing countries, however, a subject affected by the cataract can become blind.
How long does it take to lose sight?
“There is no no speed rules of disease progression. It depends on each pathology. The progression of cataracts, for example, can be very slow.”
Are there treatments to slow down blindness?
The treatment depends on the pathology.
► Diabetic retinopathy: the most appropriate treatment is to control diabetes. Laser or intravitreal injections can allow the patient to protect their eyesight;
► Glaucoma: Glaucoma can be treated with drops, laser and surgery in order to limit its progression;
► Cataract: an operation to replace the lens with an artificial lens prevents disease progression to blindness.
Thanks to Dr. Laurence Desjardins, ophthalmologist at the Institut Curie and director of the French Society of Ophthalmology.