Sight loss: Treatment, symptoms, advice and help
About sight loss
Sight loss is loss (corrected vision poorer than 6\60) of previously existing vision which may occur acutely or chronically.
Sight loss: Incidence, age and sex
According to WHO estimates there are 27-33 million blind with about 65 per cent residing in Asia and 20 per cent in Africa.
Signs and symptoms of sight loss: Diagnosis
Features may vary with the cause, mode of onset, severity of the deficit. Gradual loss may be undetected. Clumsiness, timidity may be the only symptoms. Prompt and thorough ophthalmic evaluation is necessary when the cause is not obvious. In addition, neurological evaluation, CT scans MRI studies; metabolic toxic screening and genetic studies may be required.
Causes and prevention of sight loss
Alterations in function of any of the structures along the visual pathway may cause vision loss.
There are three major anatomic categories.
- Visual media problems - disorders of the cornea, anterior chamber, lens, and vitreous
- Retinal problems - vascular occlusion, retinal detachment, and retinal tumors
- Neuro-visual pathway problems - optic nerve, chiasmal, and retrochiasmal pathology)
Conjunctivitis:Acute vision loss occurs rarely in children with infectious conjunctivitis, except for newborns with gonococcal conjunctivitis in older children and adult’s trachoma is a common cause.
Keratitis:Inflammation of cornea is most commonly caused by bacteria (especially Staphylococcus aureus and Pseudomonas aeruginosa), Herpes simplex virus, and adenovirus (epidemic keratoconjunctivitis or EKC) Bacterial infections are seen more in lens wearers.
Open globe:Rupture or laceration of the globe from direct trauma is a common cause of acute vision loss that requires immediate ophthalmologic consultation. Paintball guns, BB guns, projectile toys, scissors, and recreational sharp objects are major culprit
Chemical burn:Eye contact with acids or alkalis
Iritis:Iritis is an inflammation of iris that causes pain, photophobia, and sometimes vision loss. Traumatic iritis following blunt trauma is very common in children. Other causes, such as rheumatologic conditions, tend to present sub acutely or chronically
Glaucoma:is a condition where the pressure inside the eyeball is elevated. Mostly occurs in adults. A rare form occurs in children called congenital glaucoma.
Cataract:One of the leading causes of blindness in developing countries. Occurs mostly in adults. Congenital cataracts can occur in infants.
Vitreous hemorrhage:It occurs mostly due to trauma. It can rarely occur in adults with poorly controlled diabetes.
Retinal detachment can occur due to trauma, or spontaneous.Central retinal artery and central retinal vein occlusion
Macular degeneration:This may occur due to diabetes, metabolic disorders etc.
Diseases involving the nerve pathway to the brain:This can occur in stroke, tumors infections of the brain. Infections or tumors of the orbit can also cause blindness. Transient visual loss can occur in migraine, temporary block of blood circulation to the eye or brain
Functional sight loss: or convertion disorder is when a person perceives loss of vision even though no disease is present.
Sight loss: Complications
Sight loss would result in loss of the visual sense and all the attendant consequences – mental, physical, physiological and psychological.
Sight loss: Treatment
A person with acute vision loss must undergo a rapid evaluation to determine the most likely etiology. Treatment would depend on the cause. Patients with intraocular trauma, chemical burns, orbital infection, central retinal artery occlusion, and endophthalmitis warrant emergent ophthalmologic consultation in order to provide the best chance for preservation of vision. Thorough irrigation of the eye is required for chemical burns. Trauma to the eye should be carefully dealt with the eye should not be forcefully opened. Eye should be shielded until ophthalmologist can evaluate.