Glaucoma A Silent Cause of Vision Loss

Introduction:-

Glaucoma is a group of eye disease which is characterized by increase intraocular pressure. Increase IOP damages the Optic nerve and nerve fiber layer. A glaucoma is a group of ocular conditions characterized by optic nerve damage. The optic nerve damage is related to the intraocular pressure (IOP) caused by congestion of aqueous humor in the eye. There is a range of pressures that have been considered “normal” but that may be associated with vision loss in some patients. Glaucoma is one of the leading causes of irreversible blindness in the world and is the leading cause of blindness among adults in the United States. It is estimated that at least 2 million Americans have glaucoma and that 5 to 10 million more are at risk (Margolis et al.,2002). Glaucoma is more prevalent among people older than 40 years of age, and the incidence increases with age. It is also more prevalent among men than women and in the African American and Asian populations.

Glaucoma

Glaucoma Causes:-

  • Genetic factors:- Family history of glaucoma.
  • Old age:- age for more than 45 years.
  • Hypertension.
  • Diabetes.
  • Myopia ( nearsightedness ).
  • Eye trauma.
  • Prolong use of topical or systemic corticosteroids.
  • Cardiovascular disease.

Types of Glaucoma:-

There are several types of glaucoma. Whether glaucoma is known as open-angle or angle-closure glaucoma depends on which mechanisms cause impaired aqueous outflow. Glaucoma can be primary or secondary, depending on whether associated factors contribute to the rise in intraocular pressure (IOP).

Glaucoma is divided into two type:-

  1. Primary Glaucoma:- Primary glaucoma are two types. those are Primary Open-angle Glaucoma and Primary Angle Closer (Pupillary block) Glaucoma.
  2. Secondary Glaucoma.

Primary Glaucoma:-

Open angle Glaucoma:-

It is the most common type of glaucoma. It is usually bilateral and slowly progressive occur without discomfort and pain. In this type of glaucoma, the trabecular meshwork is obstructed so the aqueous humor outflow is further obstructed and the Intraocular pressure (IOP) increases.

In open-angle glaucoma the outflow of aqueous humor is obstructed at trabecular meshwork.

Clinical Manifestation:-

Sign and symptoms or clinical manifestations of open-angle glaucoma are different according to different subtypes. those symptoms of subtypes are:-

  • Chronic open-angle glaucoma (COAG):- Optic nerve damage, visual field defects, Intraocular pressure (IOP) >21 mm Hg. May have fluctuating IOPs. Usually no symptoms but possible ocular pain, headache, and halos.
  • Normal-tension glaucoma:- Intraocular pressure (IOP) ≤ 21 mm Hg. Optic nerve damage, visual field defects.
  • Ocular Hypertension:- Elevated intraocular pressure (IOP). Possible ocular pain or headache.
  • Other Sign and symptoms are:-
    • Gradual onset.
    • Painless.
    • Mild Headache.
    • Frequent visual changes.
    • Mild itching.
    • Loss of peripheral vision (Tunnel vision).
    • Increase Intraocular Pressure.

Angle closer Glaucoma:-

The primary close angle glaucoma occurs to the anatomically narrow-angle between the iris and cornea, so the aqueous humor outflow is inhibited and the intraocular pressure is increase. Obstruction in aqueous humor outflow due to the complete or partial closure of the angle from the forward shift of the peripheral iris to the trabecula. The obstruction results in an increased IOP.

Clinical Manifestation:-

SIgn and symptoms of angle closer glaucoma are different according different subtypes. those symptoms are:-

  • Acute angle closer Glaucoma (AACG):-
    • Rapidly progressive visual impairment, periocular pain, conjunctival hyperemia, and congestion.
    • Pain may be associated with nausea, vomiting, bradycardia, and profuse sweating.
    • Reduced central visual acuity, severely elevated IOP, corneal edema.
    • The pupil is vertically oval, fixed in a semi dilated position, and unreactive to light and accommodation.
  • Subacute angle closer glaucoma:-
    • The transient blurring of vision, halos around lights; temporal headaches, and/or ocular pain; pupil may be semi-dilated.
  • Chronic Angle closer Glaucoma:-
    • Progression of glaucomatous cupping and significant visual field loss; IOP may be normal or elevated; ocular pain and headache.
  • Other Symptoms are:-
    • Rapid Onset.
    • Halos around Light.
    • Blurred vision.
    • Severe pain and redness in the eye.
    • Nausea and vomiting were due to an increase in intraocular pressure.
    • Headache.

Secondary Glaucoma:-

When the Intraocular Pressure is increased due to the trauma, diabetes, corticosteroid use, congenital abnormalities, sepsis, tumor then this type of glaucoma called Secondary glaucoma.

Glaucoma Diagnostic Evaluation:-

  1. Patient ocular and medical history collection.
  2. Tonometry by the tonometry to increase the Intraocular pressure.
  3. Ophthalmoscopy to inspect the optic nerve.
  4. Gonioscopy to asses irido corneal angle.
  5. Slit-lamp examination.
  6. Central visual field testing.

Glaucoma Management:-

Glaucoma Medical management:-

  • Cholinergic agent:- These agents increase aqueous fluid outflow by contracting the ciliary muscle and constrict the pupil.
  • Carbonic Anhydrase inhibitor:- These agent decreases aqueous humor production.
  • Steroidal eye drops to reduce the inflammation.
  • Osmatic Diuretics:- Use to treat an acute form of glaucoma.

Glaucoma Surgical Management:-

  1. Laser Peripheral Iridotomy. In peripheral for pupillary block glaucoma, an opening is made in the iris to eliminate the pupillary blockage and to allow fluid to drain.
  2. Surgical Iridectomy. In this procedure, the iris is surgically removed for the proper flow of the aqueous humor. It is an invasive procedure.
  3. Laser Trabeculoplasty. In this procedure laser burns are applied to the inner surface of the trabecular meshwork to open the intertrabecular space and widen the canal of scheming, therapy promoting outflow of aqueous humor and decrease intraocular pressure.
  4. Trabeculectomy. In this procedure, the part of iris and trabecular meshwork is totally removed by surgery.

Glaucoma Nursing management:-

  • Instruct the client for the uses of medication life long.
  • Instruct the client any changes in the vision and eye pain then the immediate report.
  • If the patient has any surgery of the eye then time to time dressing with the strict aseptic technique should be applied.
  • Asses the Intraocular pressure and de[th of the anterior chamber.
  • Record the vital sign in every 2 hours until the effect of anesthesia.
  • Instruc the patient mot to touch the eye to decrease the chance of infection.
  • Position the patient on the unoperated site with the head of the bed is 30 degrees elevated.
  • Check the eye for any leakage from the surgical site if occur then immediately inform the doctor.
  • Encourage the patient to wear an eye shield at night to protect the operated eye from injury.
  • Encourage the patient to wear dark glasses after eye dressing is removed.
  • Administer the medication as prescribed by the doctor.

Glaucoma Patient Education for Home care:-

Know your intraocular pressure (IOP) measurement and the desired range. • Be educated almost the degree of your vision loss and optic nerve damage. • Keep a record of your eye pressure estimations and visual field test results to screen your claim progress. • Review all your medications (including over-the-counter and herbal drugs) together with your ophthalmologist, and mention any side effects each time you visit. • Ask about potential side impacts and drug interactions of your eye medications. • Inquire whether non-specific or less expensive shapes of your eye medications are available. • Survey the dosing plan together with your ophthalmologist and inform him or her in case you have got inconvenience complying with the schedule. • Participate in the decision-making process. Let your doctor know what dosing plan works for you and other inclinations with respect to your eye care. Have the Nurse watch you instilling eye medication to decide whether you are administering it properly. Be mindful that glaucoma drugs can cause unfavorable effects if utilized improperly. Eyedrops are to be administered as prescribed, not when eyes feel irritated. • Ask your ophthalmologist to send a report to your primary care doctor after each appointment. • Keep all follow-up appointments.

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