Glaucoma definition, Types of Glaucoma and Management

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:

  • 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:

  • 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.

  • Surgical management:

- Argon laser trabeculoplasty (ALT).

- Trabeculoplasty with or without filtering implant.

- Cyclotherapy destruction of the ciliary body.

- Laser iridotomy.

- Surgical iridotomy.

  • 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.