Glaucoma refers to a group of diseases characterized by
-specific pattern of visual field defect
-raised intraocular pressure
• Damage to optic nerve is irreversible process
• Normal IOP is 10-21mmHg.
Glaucoma is the name given to a group of diseases where the optic nerve is being damaged. The nerve fibres progressively die taking away the peripheral or side vision first. Therefore visual loss goes undetected until it is quite advanced. The increased pressure, called intraocular pressure, can damage the optic nerve, which transmits images to your brain. If the damaged is continue, glaucoma can lead to permanent vision loss. Without treatment, glaucoma can cause total permanent blindness within a few years.
Types of glaucoma: There are two types of glaucoma.
1.Acute closed-angle glaucoma
2.Chronic open-angle glaucoma
In chronic open-angle glaucoma,obstruction to outflow of aqueous humor through the trabecular meshwork inyo schlemm s canal leads to increased IOP.It usually is bilateral.Increased IOP eventually destroys optic nerve function causing blindness.
In acute closed-angle glaucoma,results in increased IOP because of obstructed outflow of aqueous humor.However,acute closed-angle glaucoma typically involves sudden,complete,unilateral closure with pupil dilation stimulated by a dark environment,emotional stress,or mydriatic drugs.
Anatomy & Physiology:
• IOP is determined by a balance between production and removal of aqueous humor.
• Aqueous is actively secreted into the posterior chamber by the ciliary processes.
• It then passes through the pupil into the anterior chamber and leaves the eye.
• Aqueous drains through two pathways.
Symptoms and Signs:
-Corneal edema,corneal enlargement more than 13mm diameter.
-Sclera become thin and appears blue
-Iris may show iridodonesis and atrophic patches in late stage
-Optic disc shows increased cup/disc ratio and atrophy specially after third year
-IOP is invariably high.
? With early detection, the outlook is improved.
? The prognosis for the patient depends upon the type of tumor, the amount of involvement within the eye, as well as the treatment received.
? The primary goal for treatment is to control the tumor first and then control the IOP.
? Management of any intraocular tumor must be done concurrently with an oncologist to account for systemic disease.