RN Elisa Urruchi ORBIS International GLAUCOMA

GLAUCOMA What is it? involving: A disease of progressive optic neuropathy involving: Structural changes in the optic nerve head Visual field loss Resulting in blindness if left untreated. And you thought glaucoma was a disease in which there was too much pressure in the eye! So did most ophthalmologists until several years ago. 2

GLAUCOMA What causes it? There is a dose-response relationship between intraocular pressure and the risk of damage to the visual field. But pressure certainly plays a role. Glaucoma is just too complicated to fit a nice simple definition. Elevated IOP is sometimes called ocular hypertension. If your doctor diagnoses ocular hypertension, it does not mean you have glaucoma, but it does mean you are at a higher risk for developing the condition, and you should see an ophthalmologist Normal (or low) tension glaucoma is an unusual and poorly understood form of the disease. In this type of glaucoma, the optic nerve is damaged even though the IOP is consistently within a range usually considered normal. Secreted by ciliary body •Flows into posterior chamber •Flows through pupil into anterior chamber• Leaves eye through the trabecular meshwork Into the bloodstream. Elevated IOP Glaucoma Normal IOP Glaucoma 3

GLAUCOMA Intraocular Pressure Pressure within the eye is maintained by a balance between aqueous production and aqueous drainage Normal Range 12 -21 mm Hg •Average 16 mm Hg •Glaucoma Suspect over 21 mm Hg 4

DIAGNOSING GLAUCOMA How do we measure IOP? Goldman applanation tonometry Tono - pen Schiotz tonometer No contact tonometer Non-contact These techniques illustrate the most common means of measuring intra-ocular pressures. Applanation is probably the most accurate method but requires a slit lamp to use it. Remove your corrective lens, such as contact lens Topic anesthesia Goldmann applanation --a small amount of an orange dye called fluorescein will be placed in the eye The numbing drops wear off in about 20 minutes and the dye washes out in a few minutes. It is important not to rub your eye while it is numb. Possible complications or side effects of tonometry are corneal abrasion or an allergic reaction to the anesthetic drops, but this would be extremely rare 5

DIAGNOSING GLAUCOMA Incorrect IOP reading can be caused by: Cornea being thicker or thinner than normal A history of eye surgery, such as LASIK

DIAGNOSING GLAUCOMA VISUAL FIELD Goldmann perimeter Humphrey automated perimetry 7

Visual fields in glaucoma DIAGNOSING GLAUCOMA Visual fields in glaucoma Vision loss is slow, progressive, & irreversible Early 8

DIAGNOSING GLAUCOMA Cup-to-disk ratio Normal Glaucoma No two disks are alike. Signs suggesting glaucoma as seen in the right photo include a large cup, nasalization of vessels, and pallor of the cup. Note the peripapilary depigmentation on the right which can make the true cup:disk ratio difficult to estimate. In glaucoma of all types, if not controlled. There is progressive enlargement of the cup, increased pallor of the base of the cup, and nasalization of the disk vessels. Whie there is lots of variation in glaucomatous disks, three common characteristics stand out: large cups, pale color and nasalization of the vessels. 9

GLAUCOMA CLASIFICATION The classification of glaucoma depends on the following factors: 1.According to the appearance of the drainage angel (open or closed). 2.Presence of any other factors that may contribute to the rise in IOP. 3. Primary glaucoma has no other ocular disorders associated with a rise in IOP. 4.Secondary glaucoma is associated with another condition such as inflammation, neovascular disease, et. And accounts for one-third of all glaucoma cases. Is caued for some other ocular or systemic disease. •steroid induced •inflammation •ocular disease •due to trauma/surgery: Hyphema, blunt, no penetrating trauma to globe and orbit This lecture covers only congenital and adult varieties of glaucoma but it is important to realize there are many other causes

GLAUCOMA 2. Open angle 1. Closed angle Poor access to the drainage system Problems in the drainage system aqueous suppressants (timoptic, betagan, trusopt) •miotic (pilocarpine alone may be sufficient in mild attacks) •intravenous or oral carbonic anhydrase inhibitors •intravenous or oral hyperosmotic agents Secreted by ciliary body•Flows into posterior chamber•Flows through pupil into anterior chamber•Leaves eye through the trabecular meshwork•Flows into Canal of Schlemm & into episcleral veins

Primary Open Angle Glaucoma Most common form Also know as Chronic Open Angle Glaucoma Gradually increased resistance to outflow of aqueous through the trabecular meshwork Pressure slowly increases

Primary Open Angle Glaucoma Risk factors Elevated IOP Increases with age Positive family history African American background 13

Primary Open Angle Glaucoma Onset: 50+ years of age Signs Elevated IOP Visual field loss Glaucomatous disk changes Symptoms Usually none May have loss of central and peripheral vision Remember: most patients with open angle glaucoma have no symptoms. This is the best reason to have periodic eye examinations with pressure checks and optic nerve evaluations. Painless until pressure is very high •May not notice any vision loss until severe damage has occurred •Peripheral vision is affected 1st •Central vision spared initially •Tunnel vision: only a few surviving fibres from macula •Disc Changes: nerve fibres atrophy with sustained pressure 14

Goal TREATMENT To preserve vision by reducing IOP to a level thought to be safe for the optic nerve. Medical Laser Surgical Colateral effects: Allergy, Hypotension n children, cardiac failure, heart block, bronchospasm, renal insufficiency, stroke,hypertension, hipotension, headaches, macular edema, iris colour change, lash growth so this patients might have a strict follow up. No treatment works all the time! Reduces aqueous production by destruction of the ciliary body Used in severe glaucoma when conventional treatment fails to control IOP Medical Decrease aqueous fluid production in the ciliary body Improve aqueous outflow via the trabecular meshwork Laser Argon laser trabeculoplasty Cyclolaser ablation Iridotomy Surgical Trabeculectomy Filtering procedure Drainage procedures Cyclocryotherapy

Medical Medications TREATMENT Decrease aqueous fluid production in the ciliary epithelium. Improve aqueous outflow via the trabecular meshwork or uveoscleral route or both

Colateral effects: Allergy, Hypotension n children, cardiac failure, heart block, bronchospasm, renal insufficiency, stroke,hypertension, hipotension, headaches, macular edema, iris colour change, lash growth so this patients might have a strict follow up. No treatment works all the time!

Laser treatment of glaucoma Argon laser trabeculoplasty These are the two most common surgical procedures for open angle glaucoma with success rates of 80+%. it stimulates the trabecular meshwork to perform its function efficiently by creating evenly spaced minute burns onto the area. Creates a small hole in the peripheral iris 18

Trabeculectomy TREATMENT Creating a path for the aqueous to escape into the sub-conjunctival space is the aim of filtration surgery. Creates a new drainage system within the eye to under the conjunctiva 19

Valve Implant TREATMENT The device works by bypassing the trabecular meshwork and redirecting the outflow of aqueous humor through a small tube into an outlet chamber or bleb. The IOP generally decreases from around 33 to 10 mmHg

Postoperative Care Glaucoma medications are usually discontinued to improve aqueous humor flow to the bleb. Topical medications consist typically of antibiotic drops 4 times per day and anti-inflammatory therapy e.g. with prednisolone drops every 2 hours. A shield is applied to cover the eye until anesthesia has worn off (that also anesthetizes the optic nerve) and vision resumes. Patients are instructed to call immediately for pain that cannot be controlled with over the counter pain medication or if vision decreases do not rub the eye and to wear the shield at night for several days after surgery.

Laser Cyclophotocoagulation TREATMENT Laser Cyclophotocoagulation Reduces aqueous production by destruction of the ciliary body Used in severe glaucoma when conventional treatment fails to control IOP Cyclophotocoagulation is generally used to treat advanced or aggressive open-angle glaucoma. It is usually used after other treatments have proven unsuccessful. In open-angle glaucoma, the eye's aqueous humor (the clear liquid that circulates inside the front portion of the eye) does not drain properly. This causes pressure to build up within the eye. The medical term for this pressure is intraocular pressure. Such pressure inside the eye may damage the optic nerve and lead to vision loss. Medications, laser surgery, or other glaucoma surgeries may be used to lower and control the eye pressure.

Medical Emergency Acute/Primary Angle Closure Glaucoma Flow of aqueous is prevented from the posterior chamber to the anterior chamber Aqueous collects behind the iris & pushes it forward to block the trabecular meshwork Drainage of aqueous from the eye is prevented

Acute/Primary Angle Closure Glaucoma Risk factors Hyperopia Elderly Woman Family history African American background 24

Acute/Primary Angle Closure Glaucoma Onset: 50+ years of age Symptoms Severe eye/headache Pain Blurred vision Nausea and vomiting Halos around lights Intermittent eye ache at night Signs Red, teary eye Elevated IOP (usually over 40 mm Hg) Corneal edema Shallow AC Mid-dilated, fixed pupil Eye feels hard Closed angle seen With gonioscopy The classical signs and symptoms of narrow angle glaucoma. 25

Acute/Primary Angle Closure Glaucoma Mid-dilated, fixed pupil, cloudy cornea Mid-dilated, fixed pupils and cloudy corneas during an angle closure attack. 26

Treatment Acute/Primary Angle Closure Glaucoma Aqueous suppressants (timoptic, betagan, trusopt) Miotic (pilocarpine alone may be sufficient in mild attacks) Intravenous or oral carbonic anhydrase inhibitors Intravenous or oral hyperosmotic agents Acetazolamide is an inhibitor of carbonic anhydrase. It is used for glaucoma Common agents include glycerin (glycerol), isosorbide, mannitol and urea

Narrow Angle Glaucoma Treatment: Peripheral Laser Iridotomy Goal To preserve vision by reducing IOP to a level thought to be safe for the optic nerve Creates a small hole in the peripheral iris

Key Points Once peripheral or central vision is lost from glaucoma, it can never be restored by any form of treatment. Early detection of glaucoma is critical. Progression of the disease & permanent blindness can be prevented by appropriate treatment. Glaucoma is an increasingly important public health concern due to our aging population demographics

Glaucoma Quiz Glaucoma is more common in Blacks than in Whites Glaucoma tends to run in families A person can have glaucoma and not know It People over age 60 are more likely to get glaucoma Eye pain is often a symptom of glaucoma Glaucoma can be controlled Glaucoma is caused by increased eye pressure Vision lost from glaucoma can be restored A complete glaucoma exam consists only of measuring eye pressure

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