Glaucoma: Topic covers the following details,
- Glaucoma definition,
- Types of glaucoma,
- Aetiology,
- Clinical manifestations,
- Pathophysiology,
- Clinical manifestations,
- Assessment and diagnostic studies,
- Glaucoma Management
GLAUCOMA
Glaucoma Definition:
It is the group of eye disorders characterized by
- An increase in intra ocular pressure and the complications of the high IOP,
- Optic nerve atrophy,
- Loss of vision.
Aetiology:
- An elevated intra ocular pressure (IOP)
- Imbalance between the aqueous humour production and its reabsorption.
Glaucoma Types:
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Open- angle glaucoma:
It is usually bilateral. It is of three types. They are as follows,
- Chronic open- angle glaucoma (COAG):
It is a chronic condition caused as a result of trabecular meshwork obstruction. Has fluctuating IOP, visual defects and damage of the optic nerve.
- Normal tension glaucoma :
IOP<= 21 mm hg, damage of the optic nerve, vision problems
- Ocular hypertension:
Increased IOP, eye pain, headache.
-
Angle-closure glaucoma:
It occurs because of the obstruction in the outflow of the aqueous humour.
- Acute-angle closure glaucoma(AACG):
Visual impairment, eye pain, hyperemia of the conjunctiva, nausea, vomiting, decreased heart rate, edema of the cornea.
- Subacute angle- closure glaucoma:
Transient vision blurring, halos around lights, headaches.
- Chronic angle-closure glaucoma:
Glaucomatous cupping, loss of visual field, high or normal IOP, eye pain, headache.
-
Congenital glaucoma:
It is an abnormal development of the angle of filtration which occurs secondary to other disorders.
Pathophysiology:
Obstruction in the outflow of the aqueous humour
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Improper balance between production and reabsorption of the aqueous humour
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Accumulation of aqueous humour
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Increase IOP
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If not controlled
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Optic nerve damage
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Vision impairment.
Clinical manifestations:
- IOP more than 24 mm Hg.
- Gradual loss of vision.
- Loss of peripheral vision before central visual loss.
- Tunnel vision.
- Dull eye pain – severe eye pain.
- Difficulty in dark adaptation.
- Inability to detect colour changes.
- Enlarged pupils.
- Red eye.
- Coloured lights around the halos.
- Nausea and vomiting.
- Permanent blindness if elevated IOP for more than 24 – 48 hours.
- Enlarged eye.
- Lacrimation.
- Photophobia.
- Blepharospasm.
Assessment and diagnostic studies:
- History collection.
- Physical examination.
- Measuring visual acuity.
- Tonomery.
- Tonography.
- Ophthalmoscopy.
- Gonioscopy
- Fundus photography.
Related: Cataract definition, Types of cataract and Management
Glaucoma Management:
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Medical management:
- Miotics : to constrict the pupils. Eg , cholinergics, pilocarpine HCL.
- Cholinesterase inhibitors: it constricts the ciliary muscle and the sphincter of the iris. Eg, physiostigmine.
- Adrenergic antagonists: it helps to reduce the production of the aqueous humour.Eg, betaxolol.
- Carbonic anhydrase inhibitor: it’s used to reduce the aqueous humour production. Eg, diamox.
- Osmotic agents: it helps to remove the water from the intraocular structures. Eg, glycerine.
- Prostaglandin agonists: it increases the outflow of the aqueous humour. Eg, latanoprost.
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Surgical management:
- Argon laser trabeculoplasty (ALT).
- Trabeculoplasty with or without filtering implant.
- Cyclotherapy destruction of the ciliary body.
- Laser iridotomy.
- Surgical iridotomy.
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Nursing management:
- The nurse protects the patient’s eye with eye shield or patch.
- Promote comfort of the patient’s eye.
- Assessment of the IOP.
- Administration of cycloplegics, mydriate and a combination of antibiotic and steroids.
- Supports selfcare of the patient.
- Education to the family and to the patient.