ST. PAUL UNIVERSITY PHILIPPINESSCHOOL OF MEDICINE

MANAGEMENT OF GLAUCOMA

By: John Henry Binarao

Management of Glaucoma• Treatment Reduction of IOP

and when possible, Correcting the underlying cause

• Medical and Surgical Treatments

 

Medical TreatmentRaised IOP

A. Suppression of Aqueous Production Topical beta-adrenergic blocking agents:

used alone or in combination with other drugs o Timolol maleateo Betaxolol o Levobunolol

A2-adrenergic agonist o Apraclonidineo aqueous humor formation without effect on

outflowo Useful for preventing rise of IOP after

anterior segment laser treatment and used on a short-term basis in refractory cases

 

A. Suppression of Aqueous Production• A-adrenergic agonist

o Brimonidine o 1° inhibits aqueous production and 2 ° aqueous outflow

• Systemic Carbonic Anhydrase Inhibitorso Acetazolamide is the most widely used (dichlorphenamide

and methazolamide)o Chronic glaucoma when topical therapy is insufficient o Acute glaucoma when very high IOP needs to be controlled

quicklyo Suppressing aqueous production by 40–60%.

• Topical Carbonic Anhydrase Inhibitors o Dorzolamide hydrochloride and brinzolamide that are

especially effective when employed adjunctively 

B. Facilitation of Aqueous Outflow

• Prostaglandin analogueso Bimatoprosto Latanoprost o Travoprost o uveoscleral outflow of aqueous. o Highly effective first-line or adjunctive agentso All the prostaglandin analogues conjunctival

hyperemia, hyperpigmentation of periorbital skin, eyelash growth, and permanent darkening of the iris

 

• Parasympathomimetic agents (Cholinergics)o Pilocarpine eg. Carbachol o aqueous outflow by action on the trabecular

meshwork through contraction of the ciliary muscle

• Epinephrine o aqueous outflow with some decrease in aqueous

production. o Dipivefrin is a prodrug of epinephrine that is

metabolized intraocularly to its active state

B. Facilitation of Aqueous Outflow

C. Reduction of Vitreous Volume• Hyperosmotic agents

o Blood hypertonic, thus drawing water out of the vitreous and causing it to shrink

o In addition to aqueous productiono Oral glycerin (glycerol)\

o MC- 1 mL/kg of body weight in a cold 50% solution mixed with lemon juice but it should be used with care in diabetics.

o Alternatives are oral Isosorbide and Intravenous Urea or Mannitol

 

D. Miotics, Mydriatics, and Cycloplegics

• Constriction of the pupil Primary angle-closure glaucoma and Angle crowding of plateau iris

• Pupillary dilation Angle closure secondary to iris bombé due to posterior synechiae

• Cycloplegics (cyclopentolate and atropine)When angle closure is secondary to anterior lens displacemento used to relax the ciliary muscle and thus tighten the

zonular apparatus in an attempt to draw the lens backward

 

Surgical & Laser TreatmentPeripheral Iridotomy, Iridectomy, and

Iridoplasty• Pupillary block in angle-closure

glaucoma Forming a direct communication between the anterior and posterior chambers that removes the pressure difference between them

• Laser Peripheral Iridotomy neodymium:YAG o Laser creates a hole on the outer edge,

or rim, of the iris, the colored part of the eye.

o This opening allows fluid to flow  

Peripheral Iridotomy, Iridectomy, and Iridoplasty

• Surgical Peripheral Iridectomy - if YAG laser iridotomy is ineffective

• Argon Laser Peripheral Iridoplasty (ALPI)o when it is not possible to control the IOP

medically or YAG laser iridotomy cannot be performed

o A ring of laser burns on the peripheral iris contracts the iris stroma, mechanically pulling open the anterior chamber angle

Surgical & Laser TreatmentLaser Trabeculoplasty• Application of laser (usually argon)

burns via a goniolens to the trabecular meshwork facilitates aqueous outflow by virtue of its effects on the trabecular meshwork and Schlemm's canal or cellular events that enhance the function of the meshwork.

• Laser trabeculoplasty may be used in the initial treatment of primary open-angle glaucoma

 

Glaucoma Drainage Surgery• Trabeculectomy

o MC used to bypass the normal drainage channels, allowing direct access from the anterior chamber to the subconjunctival and orbital tissues

• The major complication is fibrosis in the episcleral tissues, leading to closure of the new drainage pathway

 

Surgical & Laser Treatment

Aqueous Shunt Surgey • Implantation of a silicone

tube to form a permanent conduit for aqueous flow out of the eye (alternative procedure for eyes that are unlikely to respond to trabeculectomy)

• Indications: secondary glaucoma—particularly neovascular glaucoma—and glaucoma following corneal graft surgery

Cyclodestructive Procedures• Failure of medical and surgical

treatment in advanced glaucoma may lead to consideration of laser or surgical destruction of the ciliary body to control IOP

• Cryotherapy, diathermy, thermal mode neodymium:YAG laser, or diode laser

• Treatment is usually applied externally through the sclera

 

Surgical & Laser Treatment

Acute Angle Closure- Ophthalmic Emergency!• Treatment is initially directed at reducing

IOP• Intravenous and oral acetazolamide—along

with topical agents, such as beta-blockers and apraclonidine, and, if necessary, hyperosmotic agents—will usually reduce the intraocular pressure.

• Topical steroids may also be used to reduce secondary intraocular inflammation

• Once the intraocular pressure is under control, laser peripheral iridotomy should be undertaken to form a permanent connection between the anterior and posterior chambers, thus preventing recurrence of iris bombé.

 

Subacute Angle Closure • Treatment consists of laser peripheral iridotomy

Chronic Angle-Closure Glaucoma• Laser peripheral iridotomy should always be undertaken as the

first step in the management of these patients.• Intraocular pressure is then controlled medically if possible

Plateau Iris• Long-term miotic therapy or laser iridoplasty is required

Congenital Glaucoma• Treatment is always surgical, and either a goniotomy or

trabeculectomy can be undertaken

Secondary Glaucoma• Treatment involves controlling IOP by medical and surgical

means but also dealing with the underlying disease if possible

Pigmentary Glaucomao Both miotic therapy and laser peripheral iridotomy o Laser trabeculoplasty is frequently used in this condition but is

unlikely to obviate the need for drainage surgery.

Glaucoma Secondary to Changes in the Lens• Lens Dislocation 

o In anterior dislocation, the definitive treatment is lens extraction once the intraocular pressure has been controlled medically

o In posterior dislocation, the lens is usually left alone and the glaucoma treated as primary open-angle glaucoma

• Intumescence of the Lenso Treatment consists of lens extraction once the intraocular

pressure has been controlled medically.

Glaucoma Secondary to Changes in the Uveal TractUveitis• Treatment is directed chiefly at controlling the uveitis with

concomitant medical glaucoma therapy as necessary• Long-term therapy, including surgery, is often required

because of irreversible damage to the trabecular meshwork 

Glaucoma Secondary to Trauma• Treatment is initially medical, but surgery may be required

if the pressure remains elevated

Ciliary Block Glaucoma (Malignant Glaucoma)• Treatment consists of cycloplegics, mydriatics, aqueous

suppressants, and hyperosmotic agents.  Neovascular Glaucoma• Treatment of established neovascular glaucoma is difficult and often

unsatisfactory• Topical atropine 1% and intensive topical steroids should be given to

reduce inflammation and improve comfort. • In many cases, vision is lost and cyclodestructive procedures are

necessary to control the intraocular pressure