Open angle glaucoma

Mechanism of outflow obstruction: degenerative changes in the trabecular meshwork, canal of Schlemm, or the venules draining the area; increased IOP causes optic nerve fibers to die through apoptosis-like process

Onset: slowly progressive (gradual)

Prevalence in general population: 2.2 million, 90% of adult glaucoma cases (MOST COMMON)

Sequence of vision loss: affecting both eyes (though to varying degrees), first effect is peripheral visual field loss (often goes unrecognized), then blindness

Signs and Symptoms: NO EARLY SIGNS OR SYMPTOMS; intraocular pressure > 21 mm Hg; cup-to-disk ratio > 50%; cup-to-disk ratio in one eye > 20% greater than that in the other eye

Acute angle closure glaucoma (narrow angle)

Mechanism of outflow obstruction: mechanical blockage of the aqueous outflow channel in the angle bet. the iris and the canal of Schlemm; pupilary dilation

Onset: sudden onset (visual deterioration)

Prevalence in general population: 5% of all cases of glaucoma

Sequence of vision loss: affecting one eye, rapid onset of blurred vision, foggy vision, then visual deterioration, then blindness

Signs and Symptoms (sudden onset): 

• excrutiating unilateral orbital pain pain can be perceived as headache in the brow or temple

• nausea, and vomitting

• blurry vision, foggy vision, and seeing colored halos around lights

• paralysis of the pupillary sphincter muscle due to reduced blood flow from the increased intraocular pressure;

-non-reactive (fixed) and mid-dilated pupil

• ciliary flush (congestion of the deep conjunctival and episcleal vessels) -> red eye

• papilledema (optic disk swelling) from edema of the optic nerve

• blindness (if uncontrolled)

• photophobia

Danger signs of red eye (PHASIC BASH)

1. Blurred vision that doesn't disappear with blinking

2. Pain

3. Photophobia (Aversion to light)

4. Halos or rainbows around a light source

5. Ciliary flush

6. Corneal opacity (Haziness)

7. Abnormalities of pupil size and/or pupillary reaction to light

8. Presence of a Shallow anterior chamber

9. Increased intraocular pressure

10. Sudden proptosis (anterior dispacelemt of the globe)

History (Causes of Red eye based on diagnosis)

Acute Glaucoma: severe blurred vision, moderate-severe pain, mild photophobia, moderate halo

Acute Iridocyclitis: mild-severe blurred vision, moderate pain, severe photophobia;

Keratitis: severe blurred vision, moderate pain, severe photophobia, none-severe exudation

Bacterial conjunctivitis: severe exudation

Viral conjunctivitis: moderate exudation; none-moderate head, cold, and fever

allergic conjunctivitis: mild exudation, moderate itching

Physical exam findings

Acute glaucoma: mild ciliary flush, moderate conjunctival injection, severe corneal haze, mid-dilated nonreactive pupil, shallow anterior chamber depth, high intraocular pressure

Acute iridocyclitis: moderate ciliary flush, moderate conjunctival injection, small +/- irregular, normal anterior chamber depth, low intraocular pressure

Keratitis: severe ciliary flush, moderate conjunctival injection, mild-severe corneal haze, normal or small pupil, normal anterior chamber depth, normal intraocular pressure; +/- discharge

Bacterial conjunctivitis: severe conjunctival injection, normal pupil, normal anterior chamber depth, normal intraocular pressure, moderate to severe discharge

Viral conjunctivitis: moderate conjunctival injection, none-mild corneal haze, normal pupil, normal anterior chamber depth, normal intraocular pressure, moderate discharge, mild preauricular nodes

Allergic conjunctivitis: mild conjunctival injection, normal pupil, normal anterior chamber depth, normal intraocular pressure, mild discharge

ciliary flush: pressure induced congestion of the deep conjunctival and episcleral vessels causes a "red eye";

ciliary flush has a perilimbal distribution

conjunctival infection (conjunctivitis): inflammation pushing down on the conjunctival vasculature

Open angle glaucoma

due to outflow obstruction due to degernative changes in the trabecular meshwork, canal of Schlemm, or venules draining the area

A 60 y/o female presents in the emergency room with a unilateral, sudden onset visual loss, with severe pain in the affected orbit, nausea and vomitting. She reported cases of blurred vision and seeing colored halos around lights.

Pt PMH: Patient is far sighted. Paitnet has a history of Ciliary flush. On applanation tonomety, intraocular pressure measured 50 mm Hg. On fundoscopic exam, papilledema was reported.

What does this patient have? What should you avoid doing/giving to her?

Acute angle closure (narrow angle) glaucoma

due to mechanical blockage of the aqueous outflow channel between the iris and the canal of Schlemm.

Avoid giving her anything that will cause the pupil to dilate including: darkness, acute stress, and drugs