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Ophthalmology > INTRAOCULAR PRESSURE
Glaucoma, Phacomorphic
Article Last Updated: Jan 7, 2008
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Harpreet Gill, MD, Staff Physician, Henry Ford Ophthalmology
Harpreet Gill is a member of the following medical societies: Alpha Omega Alpha and American Academy of Ophthalmology
Coauthor(s):
Mark S Juzych, MD, MHSA, Chief, Department of Ophthalmology, Harper Hospital; Associate Chair and Program Director, Associate Professor, Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine;
Anju Gupta Goyal, MD, Assistant Professor of Ophthalmology, Kresge Eye Institute, Wayne State University; Director of Resident's Clinic, Kresge Eye Institute
Editors: Richard W Allinson, MD, Associate Professor, Department of Ophthalmology, Texas A&M University Health Science Center, Scott and White Clinic; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Martin B Wax, MD, Clinical Professor, Department of Ophthalmology, University of Texas Southwestern Medical School; Vice President, Ophthalmology Research and Development, Head, Ophthalmology Discovery Research, Alcon Labs, Inc; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
phacomorphic glaucoma, lens intumescence, lens-induced angle-closure glaucoma, cataract, pupillary block glaucoma, senile cataracts
Background
Phacomorphic glaucoma is the term used for secondary angle-closure glaucoma due to lens intumescence. The increase in lens thickness from an advanced cataract, a rapidly intumescent lens, or a traumatic cataract can lead to pupillary block and angle closure.
Pathophysiology
In an eye with advanced cataract formation, the lens is swollen or intumescent. Progressive reduction occurs in the iridocorneal angle. In such eyes, pupillary block glaucoma is caused by changes in the size of the lens and the position of the anterior lens surface. Angle closure may be secondary to an enhanced pupillary block mechanism, or it may be due to forward displacement of the lens-iris diaphragm.
Frequency
International
Although no formal epidemiologic statistics are available, angle closure from hypermature cataracts is more common in countries where cataracts are common and surgery is not readily available.
Race
Phacomorphic glaucoma can occur in any race.
Sex
Phacomorphic glaucoma occurs equally in men and women.
Age
Generally, phacomorphic glaucoma is observed in older patients with senile cataracts, but it can occur in younger patients after a traumatic cataract or a rapidly developing intumescent cataract.
History
- Patients with phacomorphic glaucoma complain of acute pain, blurred vision, rainbow-colored halos around lights, nausea, and vomiting.
- Patients generally have decreased vision before the acute episode because of a history of a cataract.
Physical
Signs of phacomorphic glaucoma include the following:
- High intraocular pressure (IOP) - Greater than 35 mm Hg
- Middilated, sluggish, irregular pupil
- Corneal edema
- Injection of conjunctival and episcleral vessels
- Shallow central anterior chamber (AC)
- Lens enlargement and forward displacement
- Unequal cataract formation between the 2 eyes
Causes
- Certain factors predispose a patient to phacomorphic glaucoma, as follows:
- Intumescent cataract
- Traumatic cataract
- Rapidly developing senile cataract
- Phacomorphic glaucoma is more common in smaller hyperopic eyes with a larger lens and a shallower AC.
- An angle-closure attack can be precipitated by pupillary dilation in dim light. The dilation to midposition relaxes the peripheral iris so that it may bow forward, coming into contact with the trabecular meshwork, setting the stage for pupillary block. Angle closure also is facilitated by the pressure originating posterior to the lens and the enlargement of the lens itself.
- Zonular weakness secondary to exfoliation, trauma, or age can play a part in causing phacomorphic glaucoma.
Glaucoma, Angle Closure, Acute
Glaucoma, Intraocular Tumors
Glaucoma, Lens-Particle
Glaucoma, Phacolytic
Glaucoma, Plateau Iris
Glaucoma, Uveitic
Imaging Studies
Optical coherence tomography (OCT) is useful in the visualization of the AC angle. See Medical Care.
Other Tests
Gonioscopy shows a closed AC angle. See Medical Care.
Medical Care
Medical treatment of phacomorphic glaucoma is aimed at rapidly reducing the IOP to prevent further damage to the optic nerve, to clear the cornea, and to prevent synechiae formation. The reduction of IOP is necessary to prepare the patient for laser iridotomy, which relieves the pupillary block that is causing the glaucoma. - Initial management should address the acute nature of the angle closure and include beta-blockers, alpha 2-adrenergic agonists, and carbonic anhydrase inhibitors. Miotics can worsen the secondary angle closure attack by increasing iridolenticular contact.
- Secondary management begins with laser iridotomy to relieve the pupillary block.
- This procedure provides an alternate route for aqueous trapped in the posterior chamber to enter the AC, allowing the iris to recede from occluding the trabecular meshwork. Both the argon laser and the Nd:YAG laser can be used.
- Laser iridectomy sometimes relieves the acute angle-closure attack, but the AC remains shallow. These eyes are susceptible to repeated attacks of angle closure; therefore, cataract extraction should be performed if the AC does not deepen after laser iridectomy.
- Gonioscopy is useful after an iridectomy for retrospective assessment of the angle. If the angle is markedly widened, the pupillary block was the likely main mechanism causing the elevated IOP, and laser iridectomy is sufficient in that case. If the angle does not deepen significantly, lens intumescence or forward displacement of the lens is the causative factor, and the patient needs cataract extraction. If the angle closure is not relieved by a laser iridotomy, plateau iris syndrome also is a differential diagnosis.
- OCT may serve as an additional aid in establishing a diagnosis prelaser and postlaser.
Surgical Care
- Laser iridotomy can temporarily stop an attack of acute pupillary block, but, in most patients with phacomorphic glaucoma, cataract extraction is needed. Laser iridotomy should be performed first as mydriasis because surgery can exacerbate the condition. An extracapsular approach typically is used for cataract extraction. A trabeculectomy often is combined with cataract extraction.
- Surgery in the nanophthalmic eye is not the procedure of choice; laser peripheral iridectomy and iridoplasty with medical therapy are recommended. The nanophthalmic eye is small with a shallow chamber and moderate-to-high hyperopia. In these patients, cataract extraction has a high rate of exudative detachment of the choroid and ciliary body with rhegmatogenous retinal detachment.
- On initial puncture of the capsule on an intumescent lens, an increased risk of a tear extending to the equator exists due to increased pressure forces as the liquefied cortex egresses. One method for dealing with this possibility is using a 30-gauge needle on a syringe to aspirate the liquefied cortex as the capsule is punctured. This provides for a controlled lens decompression.
- Because of the increased risk of complications during cataract extraction, deepening of the AC with pars plana vitreous tap or small-gauge vitrectomy has been suggested.1
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.
Drug Category: Carbonic anhydrase inhibitors
Carbonic anhydrase is an enzyme found in many tissues of the body, including the eye. Catalyzes a reversible reaction where carbon dioxide becomes hydrated and carbonic acid becomes dehydrated. By slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport, it may inhibit carbonic anhydrase in the ciliary processes of the eye. This effect decreases aqueous humor secretion, reducing IOP.
| Drug Name | Acetazolamide (Diamox, Diamox Sequels) |
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| Description | Inhibits enzyme carbonic anhydrase, reducing the rate of aqueous humor formation, which, in turn, reduces IOP. |
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| Adult Dose | 250-500 mg IV/IM; may repeat in 2-4 h to maximum 1 g/d |
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| Pediatric Dose | 8-30 mg/kg/d or 300-900 mg/m2/d IV/IM divided q8h |
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| Contraindications | Documented hypersensitivity; hepatic disease; severe renal disease; adrenocortical insufficiency; severe pulmonary obstruction |
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| Interactions | Can decrease therapeutic levels of lithium and alter excretion of drugs (eg, amphetamines, quinidine, phenobarbital, salicylates) by alkalinizing urine |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Patients with impaired hepatic function may go into coma; may cause substantial increase in blood glucose in some diabetic patients |
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| Drug Name | Dorzolamide (Trusopt) |
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| Description | Used concomitantly with other topical ophthalmic drug products to lower IOP. If more than one ophthalmic drug is being used, administer the drugs at least 10 min apart. Reversibly inhibits carbonic anhydrase, reducing hydrogen ion secretion at renal tubule and increasing renal excretion of sodium, potassium bicarbonate, and water to decrease production of aqueous humor. |
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| Adult Dose | 1 gtt in affected eye(s) tid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity |
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| Interactions | Coadministration with high-dose salicylate therapy may increase toxicity; may have additive systemic effects if patient is already on oral carbonic anhydrase inhibitors |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Local ocular adverse effects, primarily conjunctivitis and lid reactions, may occur with long-term administration of dorzolamide (discontinue therapy and evaluate patient before restarting therapy) |
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Drug Category: Alpha-adrenergic agonists
Decrease IOP, possibly by reducing aqueous humor production.
| Drug Name | Apraclonidine (Trusopt) |
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| Description | Reduces elevated and normal IOP whether or not accompanied by glaucoma. Apraclonidine is a relatively selective alpha-adrenergic agonist that does not have significant local anesthetic activity. Has minimal cardiovascular effects. |
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| Adult Dose | 1-2 gtt in affected eye(s) tid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; patients on MAOIs or have taken them in the past 14 d |
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| Interactions | Monitor pulse and BP frequently when giving cardiovascular drugs; not for use concurrently with MAOIs |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | May exacerbate or precipitate ocular irritation, topical sensitivity, vasovagal attack, and optic nerve ischemia in patients with advanced glaucomatous optic neuropathy |
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Drug Category: Hyperosmotic agents
Lower IOP by creating an osmotic gradient between ocular fluids and plasma. They are not for long-term use.
| Drug Name | Isosorbide (Ismotic) |
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| Description | May be used to abort an acute attack of glaucoma. In the eyes, may create an osmotic gradient between plasma and ocular fluids and induce diuresis by elevating osmolarity of glomerular filtrate. These effects may inhibit tubular reabsorption of water. Treatment preferred when less risk of nausea and vomiting than that posed by other oral hyperosmotic agents is desired. |
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| Adult Dose | Initial dose: 1.5 g/kg PO
Dose range: 1-3 g/kg PO 2-4 times/d, as indicated |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; anuria; severe dehydration; frank or impending acute pulmonary edema; severe cardiac decompensation |
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| Interactions | None reported |
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| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
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| Precautions | Use repetitive doses with caution, particularly in patients with diseases associated with salt retention |
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| Drug Name | Mannitol (Osmitrol, Resectisol) |
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| Description | Reduces elevated IOP when the pressure cannot be lowered by other means. Initially assess for adequate renal function in adults by administering a test dose of 200 mg/kg, given IV over 3-5 min. Should produce a urine flow of at least 30-50 mL/h over 2-3 h. In children, assess for adequate renal function by administering a test dose of 200 mg/kg, given IV over 3-5 min. Should produce a urine flow of at least 1 mL/h over 1-3 h. |
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| Adult Dose | 1.5-2 g/kg IV as 20% solution (7.5-10 mL/kg) or as 15% solution (10-13 mL/kg) over a period as short as 30 min |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; anuria; severe pulmonary congestion; progressive renal damage; severe dehydration; active intracranial bleeding; progressive heart failure |
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| Interactions | May decrease serum lithium levels |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Carefully evaluate cardiovascular status before rapid administration of mannitol since a sudden increase in extracellular fluid may lead to fulminating CHF; avoid pseudoagglutination, when blood given simultaneously, add at least 20 mEq of sodium chloride to each liter of mannitol solution; do not give electrolyte-free mannitol solutions with blood |
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Drug Category: Prostaglandins
Decrease IOP, possibly by increasing outflow of aqueous humor.
| Drug Name | Bimatoprost ophthalmic solution (Lumigan) |
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| Description | Prostaglandin agonist that selectively mimics effects of naturally occurring substances, prostamides. Exact mechanism of action unknown but believed to reduce IOP by increasing outflow of aqueous humor through trabecular meshwork and uveoscleral routes. |
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| Adult Dose | 1 gtt of 0.03% solution in affected eye(s) hs; not to exceed 1 dose/d |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity |
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| Interactions | None reported |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Hyperemia is relatively common; may cause permanent increase in pigment to iris (ie, increases brown pigment) and eyelid; may increase eyelash growth; may cause bacterial keratitis; caution in uveitis or macular edema; do not instill if wearing contact lenses |
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| Drug Name | Travoprost ophthalmic solution (Travatan) |
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| Description | Prostaglandin F2-alpha analog and selective FP prostanoid receptor agonist. Exact mechanism of action unknown but believed to reduce IOP by increasing uveoscleral outflow. |
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| Adult Dose | 1 gtt in affected eye(s) hs; not to exceed 1 dose/d |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; pregnancy; signs of inflammation |
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| Interactions | None reported |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Commonly causes ocular hyperemia; may cause permanent increase in pigment to iris (ie, increases brown pigment) and eyelid; may increase eyelash growth; may cause bacterial keratitis; caution in uveitis or macular edema; do not instill if wearing contact lenses |
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| Drug Name | Unoprostone ophthalmic solution (Rescula) |
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| Description | Prostaglandin F2-alpha analog and selective FP prostanoid receptor agonist. Exact mechanism of action unknown but believed to reduce IOP by increasing uveoscleral outflow. |
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| Adult Dose | 1 gtt in affected eye(s) bid |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; signs of inflammation |
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| Interactions | None reported |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
|
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| Precautions | Well tolerated ocularly but may cause permanent increase in pigment to iris (ie, increases brown pigment) and eyelid; may increase eyelash growth; may cause bacterial keratitis; caution in uveitis or macular edema; do not instill if wearing contact lenses |
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| Drug Name | Latanoprost (Xalatan) |
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| Description | May decrease IOP by increasing outflow of aqueous humor. |
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| Adult Dose | 1 gtt (1.5 mcg) in affected eye(s) qd in evening; higher frequency administrations may decrease effectiveness |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; signs of inflammation |
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| Interactions | Coadministration with eye drops containing the preservative thimerosal may reduce effects (administer at intervals of 5 min between applications) |
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| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
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| Precautions | Do not administer while wearing contact lenses; may increase brown pigment in iris and may change eye color gradually (unknown effect); may reactivate herpetic eye disease |
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Drug Category: Beta-blockers
Decrease aqueous humor production.
| Drug Name | Levobunolol (AKBeta, Betagan) |
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| Description | Nonselective beta-adrenergic blocking agent that lowers IOP by reducing aqueous humor production. |
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| Adult Dose | 0.5% solution: 1-2 gtt in affected eye(s) qd
0.25% solution: 1-2 gtt in affected eye(s) bid
Severe or uncontrolled glaucoma: 0.5% solution bid; closely monitor patient; > 1 gtt (0.5% levobunolol) bid not shown to be more effective; if IOP not at satisfactory level on this regimen, concomitant therapy can be instituted; do not administer 2 or more topical ophthalmic beta-adrenergic blocking agents simultaneously |
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| Pediatric Dose | Not established |
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| Contraindications | Documented hypersensitivity; bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second- and third-degree AV block; overt cardiac failure; cardiogenic shock |
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| Interactions | May cause bradycardia and asystole when used in combination with systemic beta-blockers (may cause additive effects) |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
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| Precautions | Beta-blockade may potentiate muscle weakness that is consistent with certain myasthenic symptoms (eg, diplopia, ptosis, generalized weakness); product may have sulfites, which may cause allergic-type reactions in certain susceptible persons |
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| Drug Name | Timolol (Timoptic, Timoptic XE) |
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| Description | May reduce elevated and normal IOP, with or without glaucoma, by reducing production of aqueous humor or by outflow. |
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| Adult Dose | 1 gtt of 0.25% or 0.5% in affected eye(s) bid; if IOP is maintained at satisfactory levels, change dosage to 1 gtt in affected eye(s) qd; if clinical response not adequate, change dosage to 1 gtt of 0.5% solution in affected eye(s) bid; if IOP is still not at satisfactory level, consider concomitant therapy |
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| Pediatric Dose | Administer as in adults |
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| Contraindications | Documented hypersensitivity; bronchial asthma; sinus bradycardia; second- and third-degree AV block; severe chronic obstructive pulmonary disease; overt cardiac failure; cardiogenic shock |
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| Interactions | May cause bradycardia and asystole when used in combination with systemic beta-blockers (may cause additive effects) |
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| Pregnancy | C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
|
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| Precautions | Product may have sulfites, which may cause allergic-type reactions in susceptible patients; may exacerbate or precipitate heart block, asthma, chronic obstructive pulmonary disease, and mental changes (especially in the elderly) |
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Patient Education
Medical/Legal Pitfalls
- Recognizing phacomorphic glaucoma is important. After medical therapy to control glaucoma, the pupillary block needs to be relieved. Most patients require cataract extraction for phacomorphic glaucoma.
- Dada T, Kumar S, Gadia R, Aggarwal A, Gupta V, Sihota R. Sutureless single-port transconjunctival pars plana limited vitrectomy combined with phacoemulsification for management of phacomorphic glaucoma. J Cataract Refract Surg. Jun 2007;33(6):951-4. [Medline].
- Albert DM, Jakobiec FA. Principles and Practice of Ophthalmology. Vol 3. 1994.
- Duane TD, Jaeger EA. Clinical Ophthalmology. Vol 3. 1986.
- Leung CK, Chan WM, Ko CY, Chui SI, Woo J, Tsang MK, et al. Visualization of anterior chamber angle dynamics using optical coherence tomography. Ophthalmology. Jun 2005;112(6):980-4. [Medline].
- McKibbin M, Gupta A, Atkins AD. Cataract extraction and intraocular lens implantation in eyes with phacomorphic or phacolytic glaucoma. J Cataract Refract Surg. Jun 1996;22(5):633-6. [Medline].
- Rao SK, Padmanabhan P. Capsulorhexis in white cataracts. J Cataract Refract Surg. Apr 2000;26(4):477-8. [Medline].
- Ritch R, Shields MB, Krupin T. The Glaucomas. Vol 2. 1996.
- Shields MB. Textbook of Glaucoma. 1998.
- Vander JF, Gault JA. Ophthalmology Secrets. 1998.
Glaucoma, Phacomorphic excerpt Article Last Updated: Jan 7, 2008
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