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Sensory

Glaucoma

High-yield Verified · Sep 2026

Glaucoma is a group of optic neuropathies in which retinal ganglion cells die and the visual field is lost — usually but not always with raised intraocular pressure — either because the drainage meshwork resists outflow with the angle open, or because the iris physically closes the angle.

The disorder behind the 10-to-21 pressure range that proves nothing on its own, the mid-dilated fixed pupil, the headache that gets sent for a CT scan, punctal occlusion, and the reason myopia and hyperopia point at opposite diagnoses.

What’s going wrong in the body

The normal physiology, where it fails, and why the body’s compensation backfires.

01 One fluid, two ways to block it

Everything on this page starts with a circuit. "Aqueous humor is produced in the ciliary body, passes through the pupil, and drains through the trabecular meshwork (TM) and Schlemm’s canal at the anterior chamber angle." Pressure is set by three variables: "the ciliary body’s production rate of aqueous humor, the resistance to aqueous outflow through the trabecular meshwork and Schlemm’s canal, and the episcleral venous pressure." Most drainage goes through the meshwork, "and a minority of aqueous outflow is drained through the uveoscleral pathway" — those two routes are the two places the drugs act. "The angle" itself is simply "the space between the iris and the cornea in the anterior chamber, which can become structurally obstructed."

In open-angle glaucoma the angle is open and the filter is clogged. The commonest type is "characterized by increased resistance to drainage IN the trabecular meshwork. However, the drainage angle between the cornea and iris remains OPEN. Due to this blockage, the pressure in the eye gradually increases." What clogs it, when a cause is identifiable, is a list of particles: lens proteins after phacolysis, red blood cells after trauma, pigment granules from the iris epithelium, pseudoexfoliation material described as "white dandruff-like material on the anterior lens surface," tumour debris — and corticosteroids, since "steroid therapy of any kind can contribute to elevated IOP; however, topical eye and periocular steroids are most likely to increase IOP."

In angle closure the iris physically covers the filter, and it does so in a loop that cannot open itself. The "most common cause of primary AAC is PUPILLARY BLOCK": increased lens–iris apposition disrupts aqueous flow, so "fluid forces are built behind the iris, pushing and bulging the peripheral iris. This bulging causes the iris to contact the TM, leading to acute closure of the angle between the iris and the cornea." That positive feedback is why the source calls it "a sudden and NON–SELF-RESOLVING increase in IOP," and why the definitive treatment is a hole rather than a drug. It also explains every drug warning on this page: in an eye with a shallow chamber, "mydriasis… can disrupt the normal movement of aqueous humor from the posterior chamber."

The same fluid, two failures. Open-angle disease clogs the filter while the angle stays open and the pressure creeps up silently; angle closure is a self-reinforcing loop in which the bowed iris covers the filter and the pressure rises in hours.

02 Where the damage actually happens — and why the peripheral field goes first

Pressure is the risk factor; the disease is the death of nerve cells. "The exact cause of glaucoma is not fully known, but the underlying pathology lies in the APOPTOSIS OF RETINAL GANGLION CELLS… Regardless of whether IOP is elevated, normal, or decreased, the death of RGCs underlies glaucoma pathology." The experimental link is axonal transport: induced ocular hypertension in animals "has shown blockade of orthograde and retrograde axonal transport, integral in transporting growth factors such as brain-derived neurotrophic factors." The practical consequence is stated by the USPSTF: "The initial aim of primary treatment of POAG is reduction of IOP, even in persons without elevated IOP." A number above 21 is neither necessary for the disease nor sufficient to define it.

The anatomy decides which vision is lost first, and it is not a coincidence. "The lamina cribrosa is a sieve-like fenestration at the back of the sclera that allows for a conglomeration of retinal axons and blood vessels to exit… The superior and inferior channels of the lamina cribrosa contain LARGER PORES and THINNER connective tissue support for the passage of nerve-fiber bundles than the nasal and temporal parts of the lamina. The most common pattern of glaucomatous optic nerve thinning occurs at the inferior and superior portions of the optic nerve… the superior and inferior laminar zones of the lamina cribrosa are where the arcuate area ganglion cell axons travel, and these axons are the most susceptible to glaucomatous damage." The structurally weakest pores carry the axons that serve the arcuate peripheral field — so the peripheral field is what goes, in that order: "a sequential loss of PERIPHERAL vision followed by a loss of CENTRAL vision."

Cupping is the same process seen from the front. "In more advanced glaucomatous optic nerve atrophy, cupping of the optic nerve and atrophy of the ganglion cell and nerve fiber layers is prevalent. As the ganglion cells deteriorate, the structural integrity of the nerve is compromised. Increased IOP can push into the optic nerve and cause the visible phenomenon of cupping." And pressure is not the only route in. In normal-tension glaucoma the proposed mechanisms are "vascular insufficiency at the optic nerve head, metabolic and neurodegenerative disorders, oxidative stress, and abnormal biomechanics of the lamina cribrosa." And lowering pressure still helps: "Once progression has been demonstrated, CNTGS showed an aggressive IOP lowering of 30%, leading to a slower visual field loss rate."

Why glaucoma is silent. The weakest pores of the lamina cribrosa carry the arcuate axons, so the peripheral field goes first while central acuity is preserved — and the patient notices nothing until roughly 40 percent of nerve fibres are already lost.

03 Two diseases, two patients — and the refractive error that tells them apart

Open-angle glaucoma is the common one and it is silent. It accounts for 74% of glaucoma worldwide and nearly 80% in the United States, affecting "about 70 million people worldwide" and being "the second leading cause of blindness globally." The clinical description is unforgiving: "OAG is often asymptomatic in its early stages… Early changes in OAG involve a loss of peripheral vision that the patient is usually UNAWARE of until 40% of their nerve fibers are compromised; only then do they start to notice having tunnel vision." And crucially, "patients do not avert glaucomatous signs and symptoms, unlike maculopathies and cataracts that lead to decreased visual acuity." Reading the chart perfectly tells you nothing.

Acute angle closure is the rare one, and it is louder and more destructive. It is "an ophthalmologic emergency with elevated IOP, posing a risk of irreversible damage and potential blindness if not treated promptly," with an incidence of "approximately 2 to 4 cases per 100,000 people" in white populations and "6 to 12 cases per 100,000" in Singapore and other Asian countries. Yet "Meta-analyses have consistently demonstrated that PACG is MORE likely to lead to blindness than primary open-angle glaucoma." And it is not always acute: there is a subacute or intermittent form of "recurrent, self-limiting symptomatic episodes," and a chronic form producing "elevated IOP WITHOUT symptoms" through prolonged iris-meshwork contact and synechial closure.

The demographics split cleanly, and one item is the single best discriminator on the page. Open-angle risk rises with older age, African, Afro-Caribbean and West African ancestry (a four-fold increased risk, with glaucoma "the leading cause of blindness in African Americans"), family history (9.2 times higher with an affected first-degree relative), thin central cornea, disc haemorrhage, diabetes — and MYOPIA, "up to 20% for each diopter increase." Angle-closure risk rises with age 55 to 65, female sex (a "2–4 times higher incidence"), Southeast Asian, Chinese and Inuit ancestry while "remaining relatively uncommon in Black populations" — and HYPEROPIA, because far-sightedness "is often associated with… a shallow anterior chamber depth or a more anterior lens position." Opposite refractive errors, opposite mechanisms, opposite populations. Learn the pair together.

04 The emergency, and the reason it gets missed

The acute attack has a symptom cluster that belongs to the eye and a presentation that sends patients to neurology. The sourced symptoms are "eye pain or headache · blurred vision and reduced visual acuity · rainbow-colored halos · nausea and vomiting," or in the fuller version, "unilateral intense periocular pain, redness in the eye, rapid vision loss, systemic symptoms, nausea, headache, multicolored halos around light sources, and vomiting." The warning is explicit: "nonophthalmologic practitioners may MISINTERPRET these symptoms as NEUROLOGICAL conditions, leading to unnecessary cranial imaging and neurologic consultations before ophthalmologic examinations are conducted." Migraine and cluster headache are on the differential alongside conjunctivitis, keratitis, scleritis and corneal ulcer.

The examination settles it in minutes without any imaging at all. Look for a fixed mid-dilated pupil, a hazy or cloudy cornea, conjunctival injection around the limbus — ciliary flush, engorged conjunctival vessels, a shallow anterior chamber, and 360-degree closure on gonioscopy. The pressure is "typically 50 to 80 mm Hg" against a normal range of 10 to 21. And the counterweight to the imaging trap is stated directly: "In the acute phase of AAC, imaging studies are generally unnecessary for diagnosis. The clinical signs and symptoms, along with findings from slit-lamp examination and IOP measurement, are usually sufficient."

Treatment is layered by mechanism, and one drug waits. Acetazolamide 500 mg orally or intravenously cuts production; intravenous mannitol 1 to 2 g/kg "draws fluid out of the eye"; topical timolol 0.5% and apraclonidine 1% cut production further; and pilocarpine 1% to 2%, one drop every 15 minutes for two doses, constricts the pupil to widen the angle — given "once the intraocular pressure is below 40 mm Hg." Then the definitive step, which is anatomical rather than pharmacological: laser peripheral iridotomy, in both eyes, because the untreated fellow eye "has a 40% to 80% chance of developing an AAC glaucoma within 5 to 10 years."

The acute angle-closure pathway. The presentation invites a neurological work-up, the diagnosis needs only a slit lamp and a tonometer, the medical treatment attacks production, volume and outflow in turn — and the definitive fix is a hole in both irides.

Causes & risk factors

Modifiable factors are teaching targets — the patient can act on them.

Older age — open-angle screening from 40 in African American patients and 65 in Caucasian patients; angle closure typically manifests between 55 and 65, because of "age-related increases in lens thickness and decreases in anterior chamber depth" African, Afro-Caribbean and West African ancestry — a 4-fold increased risk of open-angle disease, the highest US prevalence, and "the leading cause of blindness in African Americans"; NEI names people who "Are African American and over age 40" and those who "Are over age 60, especially if you’re Hispanic/Latino" as higher risk Southeast Asian, Chinese and Inuit ancestry, and female sex — the angle-closure pattern, with a 2 to 4 times higher incidence in women, and angle closure "relatively uncommon in Black populations" Family history — a 9.2 times higher risk if a first-degree relative has glaucoma, with a sibling specifically flagged as a referral trigger Myopia — the open-angle refractive error, with an increased risk "of up to 20% for each diopter increase in myopia" Hyperopia — the angle-closure refractive error, because far-sightedness is "often associated with… a shallow anterior chamber depth or a more anterior lens position" Elevated intraocular pressure — a risk factor and the target for therapy, but not the diagnosis by itself modifiable Corticosteroids by any route — "steroid therapy of any kind can contribute to elevated IOP; however, topical eye and periocular steroids are most likely to increase IOP," and chronic topical or systemic steroid use is a named referral trigger modifiable Over 60 drugs associated with acute angle closure — named are the topical mydriatics atropine and cyclopentolate, and systemic topiramate, sulfonamides, duloxetine and phenothiazines, "particularly for individuals with ocular predispositions" modifiable Thin central cornea, optic disc haemorrhage and an increased cup-to-disc ratio — thin central corneal thickness and disc haemorrhage are on the StatPearls normal-tension glaucoma risk lists, and a systematic review found risk "highest when an examination revealed an increased cup-disk ratio (CDR)"; nocturnal hypotension "is hypothesized" to reduce optic-nerve perfusion pressure Type 2 diabetes mellitus, and migraine or vasospasm; low systolic and diastolic blood pressure appear on both risk lists modifiable Smoking, obesity, alcohol, anxiety, stress and sleep apnea — the named lifestyle risk factors for open-angle disease modifiable Secondary causes — uveitis, ocular trauma, cataract surgery, intraocular tumour and pseudoexfoliation, each supplying particulate matter that clogs the trabecular meshwork

Signs & symptoms

Each finding tied to the mechanism that produces it — and the triage it calls for.

Nothing at all — open-angle glaucoma is silent early Expected
Why: "OAG is often asymptomatic in its early stages… Early changes in OAG involve a loss of peripheral vision that the patient is usually UNAWARE of until 40% of their nerve fibers are compromised," and only then do they notice tunnel vision. The patient-facing version is blunter still: "The symptoms can start so slowly that you may not notice them." This is why screening, not symptom review, finds it.
Normal visual acuity in a patient with established glaucoma early Expected
Why: Not reassurance, and not a reason to defer referral. "Visual field defects typically occur AFTER asymptomatic retinal nerve fiber layer thinning and optic nerve cupping… Patients do not avert glaucomatous signs and symptoms, unlike maculopathies and cataracts that lead to decreased visual acuity." Reading the chart is the wrong test for this disease.
Difficulty driving, or bumping into things around the home Hold & notify
Why: The sourced screening question, and it is functional rather than clinical. "Older patients might give clues about their history of losing peripheral vision by admitting to difficulties driving or running into objects around the home more frequently." The field loss runs in a fixed order — "a sequential loss of peripheral vision followed by a loss of central vision" — so the first complaints are about space, not about sharpness.
Tunnel vision late Hold & notify
Why: The stage at which patients finally notice, and it means roughly 40% of nerve fibres are already lost. The anatomy explains the shape: the arcuate axons run through the superior and inferior lamina cribrosa pores, which have "larger pores and thinner connective tissue support," so they are "the most susceptible to glaucomatous damage."
Sudden severe unilateral eye pain with headache, nausea and vomiting Report immediately
Why: Acute angle closure. The full sourced cluster is "unilateral intense periocular pain, redness in the eye, rapid vision loss, systemic symptoms, nausea, headache, multicolored halos around light sources, and vomiting." The systemic symptoms are the trap: "nonophthalmologic practitioners may misinterpret these symptoms as neurological conditions, leading to unnecessary cranial imaging and neurologic consultations before ophthalmologic examinations are conducted."
Rainbow-coloured halos around lights Report immediately
Why: A specific and highly suggestive symptom, produced by corneal oedema at high pressure — the patient may also describe "steamy" or cloudy vision. It appears on both the clinical and patient-facing symptom lists, and it is the one symptom that points at the eye rather than the head.
A fixed mid-dilated pupil with a hazy cornea and ciliary flush Report immediately
Why: The examination signature of an acute attack, alongside "Engorged conjunctival vessels… Marked conjunctival injection… Mild aqueous flare and cells," angle closure on gonioscopy — "Gonioscopy will reveal angle closure for 360 degrees" — and a swollen optic nerve. Note that the pupil is mid-dilated and does not react — not pinpoint, not fully blown.
Recurrent self-limiting episodes of eye ache and halos, especially in the evening Hold & notify
Why: The subacute or intermittent form of primary angle closure, characterised by "Recurrent, self-limiting symptomatic episodes." It matters because it is a warning that the anatomy is there — and because dim light dilates the pupil, which is exactly the trigger the mechanism predicts.
Raised pressure with no symptoms at all in an eye with a narrow angle Hold & notify
Why: The chronic form of angle closure, which "involves recurrent episodes of angle closure, resulting in elevated IOP WITHOUT symptoms and causing structural damage to the angle due to prolonged contact between the trabecular meshwork and the peripheral iris," leading to "synechial closure and both structural and functional impairment." Angle closure is not always dramatic, and that is the trap.
Glaucomflecken — grey-white opacities on the anterior lens capsule late Hold & notify
Why: Evidence that an attack has already happened: they are "grey-white opacities that may be visible on the anterior lens capsule, typically following previous episodes of angle-closure glaucoma." Finding them in a patient presenting with something else means the angle has closed before and will close again.
Rising pressure after a technically successful iridotomy Report immediately
Why: Malignant glaucoma, the complication of the complication: "a significant increase in IOP characterizes malignant glaucoma DESPITE A PATENT IRIDOTOMY. In this condition, the eye’s anterior chamber becomes FLAT due to a fluid imbalance, leading to further elevation of IOP." Also called aqueous misdirection syndrome or ciliary block glaucoma, it "is challenging to treat and progressively leads to blindness."
In an infant — cloudy cornea, an enlarged eye, tearing, light sensitivity and redness Report immediately
Why: Congenital glaucoma presents in infancy with a cloudy, enlarged eye. These are not normal newborn findings, and the enlargement happens because an infant eye is distensible in a way an adult eye is not.

Diagnostics

Test In this disorder Normal
Intraocular pressure by tonometry Read 10 to 21 as a population reference, not as a diagnostic boundary. Normal-tension glaucoma "is open-angle with a presenting IOP in the normal range," and equally that a raised reading is not a diagnosis, since "IOP levels greater than 21 mm Hg do not necessarily cause glaucoma." Do not use 40 mm Hg as a diagnostic figure for an acute attack either; 40 is the separate threshold below which pilocarpine becomes useful. Normal is 10 to 21 mm Hg. In acute angle closure it is "typically 50 to 80 mm Hg," and can "reach levels of 60–80 mm Hg" on examination. A pressure below the normal range — hypotony — suggests "uveitis, ocular traumas, retinal detachment, and post-surgery complications, especially after filtering surgery" Population reference range, as reported by StatPearls 10 to 21 mm Hg
The open-angle diagnostic triad Two errors this triad prevents, and they point in opposite directions. A normal pressure does not exclude glaucoma — normal-tension glaucoma is open-angle disease with an IOP in the normal range, and "Once progression has been demonstrated, CNTGS showed an aggressive IOP lowering of 30%, leading to a slower visual field loss rate." And a high pressure is not a diagnosis — "IOP levels greater than 21 mm Hg do not necessarily cause glaucoma… studies have shown asymptomatic individuals with OCULAR HYPERTENSION who maintain normal visual fields and healthy optic nerves" Optic disc or retinal nerve fiber layer changes · visual field changes · elevated IOP — all three, not pressure alone. StatPearls —
Optic disc examination and the ISNT rule "The optic cup should be determined by its contour and not color." A systematic review found "the risk of glaucoma was highest when an examination revealed an increased cup-disk ratio (CDR), CDR asymmetry, disc hemorrhage, or elevated IOP" — note that three of those four are disc findings, not pressure Examine with a slit lamp and a 90D or 78D lens. The ISNT rule: the Inferior neuroretinal rim is thickest, then Superior, Nasal, Temporal. In open-angle glaucoma "the superior and inferior NRR are thinned, BREAKING the ISNT rule." Typical findings: notching or shelving of the rim superiorly or inferiorly · cup-to-disc ratio greater than 0.5 · increased VERTICAL cup-to-disc ratio · asymmetry of 0.2 or more between eyes · disc haemorrhage · peripapillary atrophy —
Gonioscopy — including of the unaffected eye That second sentence is the basis of the fellow-eye rule. The untreated opposite eye "shares the same anatomic predisposing factors as the first eye" and "has a 40% to 80% chance of developing an AAC glaucoma within 5 to 10 years. Therefore, it is recommended to perform LPI in BOTH eyes to reduce the risk of such an attack." Distinguishes an open angle from a closed one, and in an acute attack shows 360-degree closure. "Gonioscopy of the unaffected eye may reveal a narrow, almost occluded angle" StatPearls —
Visual field testing and optical coherence tomography These are the instruments that follow the disease rather than diagnose it. Anterior segment OCT and ultrasound biomicroscopy are used in patients with angle-closure risk factors. The complete examination also includes dilated fundoscopy, slit lamp, pupillary reflex response, visual acuity and visual field measurement — and dilation is itself the step that must be reconsidered in an eye with a narrow angle Automated static perimetry measures "the patient’s ability to perceive visual stimuli at different locations," and serial testing over time gives "valuable information about the condition’s progression and the treatment’s effectiveness." OCT assesses retinal nerve fibre layer thickness, with serial scans "Serial OCT scans enable monitoring of changes over time" —
What is NOT needed in the acute attack This is the direct counterweight to the commonest error on this page — the headache-plus-vomiting presentation that gets a CT scan and a neurology consult while the eye goes untreated. The differential the source names includes migraine and cluster headache alongside conjunctivitis, keratitis, scleritis, corneal ulcer, trauma and chemical injury Imaging. "In the acute phase of AAC, imaging studies are generally unnecessary for diagnosis. The clinical signs and symptoms, along with findings from slit-lamp examination and IOP measurement, are usually sufficient" —
Basic metabolic panel — one specific indication The other monitoring requirement during an attack is the pressure itself: "it is advisable to measure IOP AT LEAST HOURLY after the initial onset of symptoms until it stabilizes" "If osmotic agents, such as mannitol or glycerin, are used as part of the treatment regimen, a basic metabolic panel can help monitor electrolyte levels and renal function due to their potential systemic effects" —
Screening — two answers to two different questions An I statement is not a recommendation against screening. The Task Force’s own implementation wording is "insufficient evidence to recommend for or against… clinicians should use their clinical judgement." It applies to primary care and explicitly not to symptomatic adults or to angle-closure and secondary glaucoma. Its reasoning: screening tests "are not commonly administered in the primary care setting," progression "cannot be precisely predicted," and there is "limited evidence about whether or not these changes lead to improvements in visual impairment, vision-related function, and quality of life." The eye-examination advice comes from the AOA and NEI — not from the Task Force’s own recommendation USPSTF, 24 May 2022 — an I statement: "the current evidence is insufficient to assess the balance of benefits and harms of screening for primary open-angle glaucoma in [asymptomatic] adults [40 years or older]." The American Optometric Association (with a second, excluded body; as reported by the USPSTF) recommends a baseline comprehensive eye evaluation at age 40, and NEI advises that "If you’re at higher risk, you need to get a comprehensive dilated eye exam every 1 to 2 years." USPSTF 2022 (primary); AOA baseline exam as reported by the USPSTF; NEI —

Complications

Warning: Irreversible blindness Report immediately
Open-angle glaucoma is "chronic, progressive, and IRREVERSIBLE," and nearly 10% of all patients with glaucoma are blind bilaterally. Glaucoma is "the second-leading cause of irreversible blindness in the US and the leading cause of blindness in Black and Hispanic/Latino persons," and the second leading cause of blindness globally.
The heralding cue in open-angle disease is that there isn’t one — nothing is felt until roughly 40% of nerve fibres are gone, so the cue is the examination itself. In angle closure, "If AAC goes undetected and untreated in its early stages, it can result in temporary vision loss or blindness," and primary angle-closure glaucoma is "more likely to lead to blindness than primary open-angle glaucoma" despite being far rarer. The one genuinely hopeful sentence is also sourced: "there’s no cure for glaucoma, but early treatment can often stop the damage and protect your vision."
Warning: An attack in the other eye Hold & notify
After one acute angle-closure attack, "the untreated opposite eye shares the same anatomic predisposing factors as the first eye. The untreated eye has a 40% to 80% chance of developing an AAC glaucoma within 5 to 10 years."
The conclusion the source draws is unambiguous: "it is recommended to perform LPI in BOTH eyes,". Gonioscopy of the unaffected eye typically confirms the anatomy — "a narrow, almost occluded angle." Say it out loud so the second procedure does not look like overtreatment: the laser is "to reduce the risk of such an attack" in an eye that has never had one.
Warning: Malignant glaucoma after iridotomy Report immediately
"A significant increase in IOP characterizes malignant glaucoma despite a patent iridotomy. In this condition, the eye’s anterior chamber becomes flat due to a fluid imbalance, leading to further elevation of IOP."
Also named aqueous misdirection syndrome or ciliary block glaucoma, it "is challenging to treat and progressively leads to blindness." The heralding cue is a pressure that rises after a procedure that technically worked — which is exactly when a team is most likely to attribute the symptoms to normal postoperative discomfort.
Caution: Non-adherence — the preventable route to the preventable blindness
"Glaucoma is a PREVENTABLE cause of blindness, making patient education crucial… However, patient adherence and compliance with medical therapy are notoriously difficult. Treatment regimens require DAILY treatment to control IOP, and this can be a challenging task for patients FOR THE REST OF THEIR LIVES." The reasons patients gave: forgetfulness 30%, other priorities 11%, lack of information 9%, emotional factors 7%, with 27% giving no reason.
Two findings shape what a nurse should actually do. First, "studies have confirmed an INVERSE relationship between the number and frequency of dosage and patient adherence" — which is the disorder-side argument for a once-daily agent. Second, the evidence on teaching is honest and uncomfortable: education makes patients "consistently more likely to adhere," but a 2018 study found "physician-centric multifaceted informational and educational mailings were ineffective," and "the best way to provide such education is still unknown." Notably, other studies found no link between adherence and side effects — so the drug is usually not the reason.
Caution: The cost of the field loss itself
"An impaired visual field leading to the LOSS OF A DRIVER’S LICENSE can significantly impact quality of life. Adverse effects and costs of medical and surgical treatments should be weighed against the risk of visual loss."
This is why the functional screening question is about driving. The loss is peripheral first, so it takes the field a person needs to change lanes, notice a child at a kerb, or walk through a doorway — long before it takes the acuity needed to read. In normal-tension glaucoma, where the disease "can range from non-progressive, asymptomatic disease to bilateral blindness," that trade-off between treatment burden and risk has to be made without a high pressure to justify it.

Medications for this condition

Why each class is prescribed here — every card links to its full pharmacology page.

Glaucoma / Ophthalmic Agents First-line
Sensory / Ophthalmic

The goal is a number the team sets for this patient, not a universal target. Treatment aims at "preventing the progression of optic nerve head changes" and "preventing deterioration of the visual field," through the concept of target IOP — "below a certain upper limit of IOP, it is estimated that the visual field, the optic nerve head, and RNFL parameters will not deteriorate." That target is individual, set "depending on the severity of structural and functional damage, baseline IOP, age, race, family history, corneal thickness, hysteresis, and other risk factors," and revised as the disease behaves. When to start is genuinely debated, with "some clinicians initiating treatment of IOP when it reaches above only 21 mm Hg and others reserving treatment either until evidence of optic nerve or RNFL damage or if the patient is at high risk" — the sourced trigger being evidence of damage, or symptoms with an IOP consistently above 28 to 30 mm Hg. PROSTAGLANDIN ANALOGUES ARE FIRST-LINE, and the reasons are both pharmacologic and behavioural: each "reduces IOP 25% to 33% by increasing the UVEOSCLERAL OUTFLOW," the dose is daily, and the class "is preferred as initial therapy", and laser therapy and surgery are the other treatment families. The disorder-side counselling point is cosmetic and it costs adherence if unmentioned: lengthening of eyelashes and pigmentation of the lids or iris, plus possible exacerbation of uveitis or herpetic infection and cystoid macular oedema. The other four classes, by mechanism: alpha-2 agonists (brimonidine, apraclonidine) reduce IOP 20–25% by both decreasing production and increasing uveoscleral outflow — and cause apnoea, lethargy or bradycardia in children; beta-blockers (timolol and relatives) reduce IOP 20–25% by decreasing production, and non-selective agents must be avoided in COPD and asthma, with heart block, hypotension and bradycardia as further contraindications (betaxolol is the selective option with a "better safety profile about respiratory symptoms"); carbonic anhydrase inhibitors (dorzolamide, brinzolamide) reduce IOP 15–20% by decreasing production; and cholinergics (pilocarpine) reduce IOP 20–25% by increasing outflow but "are poorly tolerated and normally not considered first-line." THE ADMINISTRATION TEACHING IS THE NURSING HEART OF THIS CLASS: "closing eyelids after administration of drops with NASOLACRIMAL DUCT OCCLUSION may prevent SYSTEMIC ABSORPTION of the topical medication" — a drop drains into a highly vascular nasal mucosa, which is how a "topical" beta-blocker produces systemic beta-blockade. And when the disease worsens on therapy, check the patient before changing the drug: "if IOP, visual field, or optic nerve inflammation worsens while the patient is on medical therapy, COMPLIANCE TO TREATMENT MUST BE CHECKED. Systemic factors, including diabetes, smoking, and nocturnal hypotension, should be controlled." The class page owns each agent’s systemic adverse-effect profile.
Anticholinergics (Atropine)
Autonomic · atropine

On this page as a precipitant, and the scope of the warning is as important as the warning itself. "Over 60 drugs have been reported to be associated with AAC and are considered risk factors, particularly for individuals with OCULAR PREDISPOSITIONS. These drugs include topical anticholinergic pupil dilators, such as ATROPINE and CYCLOPENTOLATE, and systemic medication, including TOPIRAMATE, SULFONAMIDES, DULOXETINE, and PHENOTHIAZINES." The mechanism is already on the page: mydriasis increases iris-lens apposition and can tip a narrow angle into pupillary block. The scope limit is what makes this teachable rather than ignorable. The sourced risk is specifically about angle-closure-predisposed eyes, and no fetched source states a contraindication in open-angle glaucoma — which is 74% to 80% of all glaucoma. So the rule is: ask about a known narrow angle or a prior angle-closure attack before any pupil-dilating or anticholinergic drug, and say which type of glaucoma the caution applies to every single time. The undifferentiated warning — "avoid anticholinergics in glaucoma" — is both wrong and, because it is wrong, routinely ignored. The follow-up instruction is sourced too: "patients taking these medications should undergo regular ophthalmic examinations, particularly if they have [angle-closure] risk factors." The class page owns the anticholinergic pharmacology.
Corticosteroids
Endocrine · prednisone

Here as a cause of glaucoma, not a treatment for it. "Steroid therapy of any kind can contribute to elevated IOP; however, topical eye and periocular steroids are most likely to increase IOP," and corticosteroids are named among the causes of secondary glaucoma alongside uveitis, diabetes and eye injury. Chronic use of topical or systemic corticosteroids is on the sourced referral list — a patient on long-term steroids needs ophthalmologic monitoring, not reassurance. The mechanistic link is hiding in the genetics of the disease, and it is worth teaching because it makes the association memorable: the gene most associated with inherited open-angle glaucoma is MYOC, which encodes myocilin — a protein "expressed in the trabecular meshwork and is also known as trabecular meshwork glucocorticoid-inducible response protein." The drainage tissue that fails in glaucoma is running a protein that steroids switch on. The nursing consequence is a medication reconciliation that includes topical and inhaled products and over-the-counter preparations, since "steroid therapy of any kind" is the sourced phrase. The class page owns systemic corticosteroid pharmacology.

Beyond medications

  • LASER PERIPHERAL IRIDOTOMY — the definitive treatment for angle closure, and it is anatomical rather than pharmacological. "Laser peripheral iridotomy (LPI) is the TREATMENT OF CHOICE. LPI involves using a laser to create a small hole in the peripheral iris, allowing aqueous humor to flow from the posterior chamber to the anterior chamber, BYPASSING the blocked angle. LPI helps to relieve pupillary block and prevent future angle-closure episodes. LPI is a minimally invasive procedure performed on an outpatient basis." It is also preventive: "LPI is a recommended preventative measure in individuals with [acute angle-closure] risk factors." And it is done in both eyes, because the fellow eye carries a 40% to 80% risk over 5 to 10 years.
  • Surgical iridectomy, and a placement rule with a memorable reason. "Surgical iridectomy is indicated when laser iridectomy cannot be performed or is insufficient… Iridectomy or iridotomy relieves the pupillary block as the pressure between the posterior and anterior chambers approaches zero… Iridectomy/iridotomy should be as PERIPHERAL as possible and COVERED BY THE EYELID to avoid MONOCULAR DIPLOPIA through this second hole in the pupil." A hole in the iris that the eyelid does not cover gives the patient a second, blurred image from the same eye.
  • Lens extraction as a first-line option where anatomy dominates. "Lens extraction can be considered when significant anatomical risk factors are present. In these cases, lens extraction may be considered as a FIRST-LINE treatment… This approach is often beneficial in eyes with advanced [acute angle closure]."
  • The acute medical regimen, layered by mechanism. Medical therapy comes first and aims to bring the pressure down as fast as possible — systemic agents (a carbonic anhydrase inhibitor and a hyperosmotic agent) lead, with pressure-lowering drops alongside — so that the corneal edema clears and the definitive laser iridotomy can follow. Read each drug below by what it does to aqueous humor: most cut production (apraclonidine also enhances outflow), mannitol reduces volume, and pilocarpine increases outflow. Acetazolamide 500 mg orally or IV inhibits "the enzyme that generates bicarbonate ions," cutting production. IV mannitol 1 to 2 g/kg "draws fluid out of the eye" — and because of its systemic effects, a basic metabolic panel monitors electrolytes and renal function. Topical timolol 0.5% blocks "beta-adrenergic receptors in the ciliary body," and topical apraclonidine 1% reduces production and enhances trabecular outflow. Topical pilocarpine 1% to 2%, one drop every 15 minutes for two doses, once IOP is below 40 mm Hg, works "by constricting the pupil and increasing iris tension, thereby WIDENING THE ANGLE between the iris and the cornea and facilitating drainage." Recheck the pressure at least hourly until it stabilises.
  • Open-angle procedures. "Treatments include medication, laser therapy, and surgery," and "Surgery is usually reserved for patients with SEVERE VISUAL FIELD LOSS AT BASELINE or patients with ADVANCED POAG WHO DO NOT RESPOND to medications or laser trabeculoplasty." Laser trabeculoplasty and medical therapy "were associated with similar effects on IOP, visual acuity, visual fields" in the largest trial, which matters for a patient who cannot manage daily drops.
  • After an acute attack, the disease often becomes a chronic one. "If elevated IOP persists after the acute phase of AAC, treatment strategies similar to those used in open-angle glaucoma can be employed. These include topical medical therapy, laser treatment, and surgical interventions. Routine ophthalmologic examinations, visual field testing, and OCT should be considered for patients at risk of developing elevated IOP and future glaucomatous damage."
  • ❗ AVOID DIM LIGHTING — a patient instruction that follows straight from the mechanism. "Patients with a history of acute angle-closure glaucoma should be advised to AVOID DIM LIGHTING CONDITIONS. Dim light can cause PUPIL DILATION, thereby further narrowing the iridocorneal angle." The same physiology that makes a dilating drop dangerous makes a dark cinema or a dimly lit restaurant a risk, and telling the patient why is what makes the instruction stick.
  • Systemic factors are part of glaucoma management. When the disease progresses on therapy, "compliance to treatment must be checked" and "systemic factors, including diabetes, smoking, and nocturnal hypotension, should be controlled" — which lines up with the modifiable half of the risk list: smoking, obesity, alcohol, sleep apnoea, blood pressure and diabetes control. Low blood pressure appears as a risk factor on the StatPearls list, so aggressive overnight blood-pressure lowering is not a neutral act in a patient with glaucoma.

Nursing considerations

The RN-specific layer — each action paired with the reason it matters.

Assessment & monitoring
Ask the functional question, not the acuity question: any new difficulty driving, or bumping into things at home?
Why: The sourced clue is exactly that — older patients "might give clues about their history of losing peripheral vision by admitting to difficulties driving or running into objects around the home more frequently." Visual acuity is preserved until late, so a patient who reads the chart perfectly can still be losing their field. The loss runs "peripheral vision followed by… central vision," and nothing is noticed until about 40% of nerve fibres are gone.
In any patient with unilateral eye pain, headache, halos, nausea and vomiting, look at the eye before ordering a head scan.
Why: The sourced warning: "nonophthalmologic practitioners may misinterpret these symptoms as neurological conditions, leading to unnecessary cranial imaging and neurologic consultations before ophthalmologic examinations are conducted." And the counterweight: "in the acute phase of AAC, imaging studies are generally unnecessary for diagnosis. The clinical signs and symptoms, along with findings from slit-lamp examination and IOP measurement, are usually sufficient."
Take a medication history that includes topical, inhaled and over-the-counter products, and ask specifically about a prior angle-closure attack.
Why: "Over 60 drugs" are associated with acute angle closure, including atropine and cyclopentolate drops and systemic topiramate, sulfonamides, duloxetine and phenothiazines, and "patients taking these medications should undergo regular ophthalmic examinations, particularly if they have [angle-closure] risk factors." Separately, "steroid therapy of any kind can contribute to elevated IOP," with ocular and periocular routes the highest risk — so an eye drop the patient does not think of as medication belongs on the list.
Do not let a normal pressure close the question, or a high one settle it.
Why: Both errors are sourced against. Normal-tension glaucoma is open-angle disease with a pressure in the normal range, and the USPSTF confirms that treatment aims at "reduction of IOP, even in persons without elevated IOP." Conversely, "IOP levels greater than 21 mm Hg do not necessarily cause glaucoma… studies have shown asymptomatic individuals with ocular hypertension who maintain normal visual fields and healthy optic nerves." The diagnosis needs disc, field and pressure together.
During an acute attack, recheck the intraocular pressure at least hourly, and draw a basic metabolic panel if mannitol is used.
Why: "It is advisable to measure IOP at least hourly after the initial onset of symptoms until it stabilizes," because the response to treatment is what determines whether the next step is needed. And osmotic agents such as mannitol or glycerin require a metabolic panel "can help monitor electrolyte levels and renal function due to their potential systemic effects."
At every visit, confirm which drops the patient actually uses and how often — before anyone escalates the regimen.
Why: The sourced sequence is explicit: "if IOP, visual field, or optic nerve inflammation worsens while the patient is on medical therapy, COMPLIANCE TO TREATMENT MUST BE CHECKED," and only then are systemic factors controlled. Given that 30% of non-adherence is simple forgetfulness, assuming treatment failure before asking about the bottle wastes a drug line.
Interventions & safety
Teach and supervise punctal occlusion — close the eyes and press at the inner corner after the drop — and teach why.
Why: "Closing eyelids after administration of drops with nasolacrimal duct occlusion may prevent SYSTEMIC ABSORPTION of the topical medication." The eye drains into a highly vascular nasal mucosa, so a drop is not confined to the eye. That is how a "topical" non-selective beta-blocker reaches a patient with asthma or heart block — and those conditions are themselves the sourced contraindications that decide whether the drop can be used at all.
Screen for COPD, asthma, heart block, hypotension and bradycardia before a beta-blocker drop, and know the paediatric problem with brimonidine.
Why: "Non-selective beta-blockers should be avoided in chronic obstructive pulmonary disease and asthma. Other contraindications include heart block, hypotension, and bradycardia," with betaxolol the selective alternative with a "better safety profile about respiratory symptoms." And brimonidine "may cause allergic blepharoconjunctivitis and APNEA, LETHARGY, OR BRADYCARDIA IN CHILDREN."
Before giving any pupil-dilating or anticholinergic drug, ask whether the patient has a narrow angle or a previous angle-closure attack — and name the glaucoma type when you document the caution.
Why: The sourced risk is specifically for eyes with "ocular predispositions," and no fetched source contraindicates anticholinergics in open-angle glaucoma, which is the large majority of cases. An undifferentiated "contraindicated in glaucoma" alert is inaccurate and gets overridden; a precise "known narrow angle" question changes practice.
In the acute attack, give the agents in the order the pressure allows, and understand that pilocarpine waits.
Why: The regimen is layered by mechanism — acetazolamide, timolol and apraclonidine cut production, mannitol reduces volume, and pilocarpine increases outflow by constricting the pupil and widening the angle. The sourced rule is that pilocarpine "is usually administered once the intraocular pressure is below 40 mm Hg." Give the rule as the source gives it; the sources do not supply a physiological explanation for the threshold, so none is invented here.
Ensure the fellow eye is treated, and explain to the patient why a healthy-feeling eye is having a procedure.
Why: The untreated opposite eye "has a 40% to 80% chance of developing an AAC glaucoma within 5 to 10 years. Therefore, it is recommended to perform LPI in BOTH eyes," Without the explanation, the second procedure looks like overtreatment of an eye that has never hurt.
After an iridotomy, treat rising pressure as a new problem, not as expected postoperative discomfort.
Why: Malignant glaucoma is defined by a significant IOP increase "despite a patent iridotomy," with a flat anterior chamber, and it "is challenging to treat and progressively leads to blindness." The cue is precisely the situation in which a team is least likely to escalate — after a procedure that technically worked.
Patient teaching
Teach that feeling fine is not evidence the drops are unnecessary — and say why.
Why: "One of the tricky aspects of glaucoma is that patients often do not experience any symptoms until it is too late." Treatment "require daily treatment to control IOP, and this can be a challenging task for patients for the rest of their lives," against a disease that gives no feedback. Naming that gap is the honest version of adherence counselling, and the evidence supports teaching even while conceding that "the best way to provide such education is still unknown."
Warn the patient starting a prostaglandin that their lashes may darken and lengthen and their iris colour may change.
Why: The sourced adverse effects are "lengthening of eyelashes, pigmentation of lids or iris," plus possible exacerbation of uveitis or herpetic infection and cystoid macular oedema. These are cosmetic rather than dangerous, but discovered unexpectedly they are a reason to stop — and the dosing advantage that makes prostaglandins first-line is once daily, which matters because adherence has "an inverse relationship between the number and frequency of dosage and patient adherence."
After an angle-closure attack, teach avoiding dim lighting and explain the mechanism.
Why: "Patients with a history of acute angle-closure glaucoma should be advised to avoid dim lighting conditions. Dim light can cause PUPIL DILATION, thereby further narrowing the iridocorneal angle." Told as a bare instruction it sounds arbitrary; told with the mechanism, it connects to every other warning on the page — dilating drops, anticholinergics, topiramate.
Teach the patient to tell every prescriber, dentist and pharmacist about the angle closure before any new medicine.
Why: Over 60 drugs are implicated, and the systemic ones — topiramate, sulfonamides, duloxetine, phenothiazines — are prescribed by clinicians who are not thinking about eyes. The sourced follow-up is that "patients taking these medications should undergo regular ophthalmic examinations, particularly if they have [angle-closure] risk factors."
Give the eye-examination schedule with its owner named, and do not present the USPSTF statement as advice against screening.
Why: The American Optometric Association recommends a baseline comprehensive eye evaluation at age 40 (as reported by the USPSTF), and people at higher risk need "a comprehensive dilated eye exam every 1 to 2 years." The USPSTF issued an I statement — insufficient evidence in the primary care setting, which is "not a recommendation for or against" and which explicitly does not apply to symptomatic adults or to angle-closure glaucoma. The patient-facing message is NEI’s: "The only way to find out if you have glaucoma is to get a comprehensive dilated eye exam."
Teach higher-risk patients why their schedule is different, using their own risk factors.
Why: The sourced risks are specific enough to be personal: a four-fold increase with African ancestry, with screening from age 40; 9.2 times higher risk with an affected first-degree relative, and a sibling flagged specifically; and up to 20% more risk per dioptre of myopia. For angle closure the list is different — age 55 to 65, female sex, Southeast Asian, Chinese or Inuit ancestry, and hyperopia.
Reinforce the systemic factors as part of eye care, not general advice.
Why: "Systemic factors, including diabetes, smoking, and nocturnal hypotension, should be controlled," and the risk list adds obesity, alcohol and sleep apnea. Low blood pressure is a risk factor on the StatPearls list, which is the counter-intuitive one: a patient whose overnight pressures run very low is not automatically better off.

How a real nurse thinks

The clinical-judgment loop, worked for a typical presentation — reasoning, not reference.

  1. 1
    Recognize cues

    The cluster is ocular, not neurological, and every element is on the sourced list. Unilateral severe periocular pain, a red eye, blurred vision, rainbow halos, and vomiting are the acute angle-closure symptom set. The examination settles it: a fixed mid-dilated pupil, a hazy cornea, ciliary flush, a shallow chamber, and 360-degree closure on gonioscopy, with a pressure of 62 mm Hg against a normal range of 10 to 21. Three background cues explain why this eye and why tonight. She is of Southeast Asian ancestry, one of the named higher-risk groups; she is hyperopic, which is the angle-closure refractive error because far-sightedness carries "a shallow anterior chamber depth or a more anterior lens position"; and she started topiramate two weeks ago, one of the systemic drugs named among the "over 60" associated with acute angle closure. And the fourth cue is on the triage note, not the patient: she has been flagged as a headache with vomiting, which is the exact misreading the source warns about.

  2. 2
    Analyze cues

    The first analytic step is to resist the imaging pathway. "Nonophthalmologic practitioners may misinterpret these symptoms as neurological conditions, leading to unnecessary cranial imaging and neurologic consultations before ophthalmologic examinations are conducted" — and the counterweight is equally explicit: "In the acute phase of AAC, imaging studies are generally unnecessary for diagnosis. The clinical signs and symptoms, along with findings from slit-lamp examination and IOP measurement, are usually sufficient." A slit lamp and a tonometer have already answered the question that a CT scanner would delay. The second step is to understand why this will not settle on its own. Acute angle closure is "a sudden and non–self-resolving increase in IOP," because pupillary block bows the iris forward, which narrows the angle further, which raises the pressure further. The third step is the pressure number itself. At 62 mm Hg she is within the sourced typical range of 50 to 80 — and above the 40 mm Hg threshold at which pilocarpine becomes useful, which sets the order of the drugs. The fourth is the right eye. A narrow, almost occluded angle in the asymptomatic eye means the anatomy is bilateral, and the untreated fellow eye carries a 40% to 80% risk of its own attack within 5 to 10 years.

  3. 3
    Prioritize

    First, get the ophthalmologist, and get the drops going — this is an ophthalmic emergency and the outcome depends on how long the angle stays shut. Second, lower the pressure by every available mechanism at once: cut production, reduce volume, and then — when the pressure allows — open the outflow. Third, analgesia and antiemesis, both because she is in 9/10 pain and because vomiting raises pressure and makes drop administration impossible. Fourth, the monitoring that tells you whether it is working: hourly pressures, and a basic metabolic panel because mannitol is being used. Fifth, the definitive plan — laser peripheral iridotomy — and the conversation about doing the other eye too. Sixth, and easy to drop in the rush: the topiramate. It is a named precipitant, and the prescriber who started it needs to know.

  4. 4
    Generate solutions

    Anticipate the layered medical regimen exactly as sourced: acetazolamide 500 mg orally or intravenously to cut production by inhibiting the enzyme that generates bicarbonate; intravenous mannitol 1 to 2 g/kg to draw fluid out of the eye; topical timolol 0.5% and apraclonidine 1%, one drop each, to cut production further; and pilocarpine 1% to 2%, one drop every 15 minutes for two doses — held until the pressure falls below 40 mm Hg, because that is the sourced rule. Anticipate a basic metabolic panel alongside the mannitol. Anticipate hourly tonometry. Anticipate laser peripheral iridotomy as the definitive treatment — "a small hole in the peripheral iris, allowing aqueous humor to flow from the posterior chamber to the anterior chamber, bypassing the blocked angle" — with surgical iridectomy if laser is not feasible, and lens extraction as a first-line option where the anatomy dominates. And plan the fellow eye from the outset, because the recommendation is to perform iridotomy in both.

  5. 5
    Take action

    Escalate immediately with an SBAR that names the diagnosis rather than the symptom: "68-year-old woman, four hours of severe left eye pain with a red eye, rainbow halos and vomiting. She is hyperopic, of Southeast Asian ancestry, and started topiramate two weeks ago. Left eye has a fixed mid-dilated pupil, hazy cornea and ciliary flush, with an IOP of 62 against 18 on the right, and 360-degree closure on gonioscopy. This is acute angle closure, an ophthalmic emergency. The right eye has a narrow, almost occluded angle. Requesting ophthalmology now, and the acute pressure-lowering regimen. She has had no eye examination in over a decade." Give the drops as ordered, in the order the pressure allows, and recheck the pressure at least hourly. Treat the pain and the vomiting. Three traps to avoid. Sending her for cranial imaging first — the diagnosis is already made at the bedside. Giving pilocarpine at 62 mm Hg rather than waiting for the pressure to come below 40. And discharging her after the attack settles without arranging bilateral iridotomy.

  6. 6
    Evaluate

    Success in the next hours: pressure falling on serial measurement, pain and vomiting controlled, cornea clearing, and iridotomy arranged. The prognostic point to hold onto: a study of 116 cases found that "the timing of presentation and the duration of the acute episode were crucial determinants of patient outcomes. High IOP was found to have LESS impact on the long-term prognosis." How long the angle stayed shut matters more than how high the number went. Discharge teaching: avoid dim lighting, because dim light dilates the pupil and narrows the angle further; tell every prescriber, dentist and pharmacist about the angle closure before any new medicine; expect and attend the second iridotomy; and understand that persisting pressure after the attack is managed like open-angle disease, with drops, laser or surgery. And then the second half of her story, six months later at a routine dilated examination: a cup-to-disc ratio of 0.7 in the right eye with inferior rim thinning that breaks the ISNT rule, and an IOP of 24 mm Hg — early open-angle glaucoma she has had no symptoms from, because nothing is noticed until about 40% of nerve fibres are gone. She starts a once-daily prostaglandin analogue, is taught punctal occlusion and why it matters, and is warned that her lashes may darken and lengthen and her iris colour may change. One patient, both diseases — which is exactly why "glaucoma" is a word that needs a qualifier.

Scenario — you’re the nurse

Work each question before revealing the answer. Rationales explain the wrong options too.

Emergency department · 2100, then the eye clinic six months later

A 68-year-old woman of Southeast Asian ancestry, who wears glasses for far-sightedness, arrives with four hours of severe left-sided eye pain, a red eye, blurred vision with rainbow halos around lights, and vomiting. She was started on topiramate for migraine prophylaxis two weeks ago. Triage has flagged her as a headache with vomiting.

2100 vitals — HR 96 · BP 162/88 · RR 18 · T 36.9 °C · pain 9/10, left periocular
Left eye — fixed mid-dilated pupil · hazy cornea · ciliary flush around the limbus · shallow anterior chamber
Tonometry — left 62 mm Hg · right 18 mm Hg (normal range 10 to 21)
Gonioscopy — left 360-degree closure · right eye: a narrow, almost occluded angle
Medications — topiramate started 2 weeks ago · no eye drops · no prior eye examination since her fifties
Q1 Select all that apply
Which findings indicate acute angle-closure glaucoma rather than a primary headache? Select all that apply.
  1. A. Fixed mid-dilated pupil with a hazy cornea
  2. B. Rainbow-coloured halos around lights
  3. C. Intraocular pressure of 62 mm Hg in the affected eye
  4. D. Ciliary flush around the limbus
  5. E. Nausea and vomiting
Reveal answer & rationale
Answer: A, B, C, D
The fixed mid-dilated pupil with corneal haze (A), rainbow halos (B), a pressure far above the normal range of 10 to 21 (C), and ciliary flush (D) are all sourced findings of an acute attack — S2 lists a "Fixed midpoint dilated pupil," a "Hazy or cloudy cornea" and "Marked conjunctival injection." Nausea and vomiting (E) is the tempting distractor: it is part of the sourced symptom cluster, but it is precisely the systemic symptom that causes the misdiagnosis, since "nonophthalmologic practitioners may misinterpret these symptoms as neurological conditions." It does not by itself distinguish the eye from the head — the eye examination does.
Q2 Multiple choice
The patient’s intraocular pressure is 62 mm Hg. Pilocarpine is ordered but not yet given. The nurse should understand that:
  1. A. Pilocarpine should be given immediately because it is the most effective agent
  2. B. Pilocarpine is usually administered once the intraocular pressure is below 40 mm Hg
  3. C. Pilocarpine is contraindicated in angle-closure glaucoma because it constricts the pupil
  4. D. Pilocarpine replaces the need for laser peripheral iridotomy
Reveal answer & rationale
Answer: B
The sourced rule is exactly that: pilocarpine "is usually administered once the intraocular pressure is below 40 mm Hg" (B), so the production-lowering and volume-reducing agents come first. Giving it immediately (A) ignores the sequencing the source specifies. Option C inverts the pharmacology — pupillary constriction is the point, because pilocarpine works "by constricting the pupil and increasing iris tension, thereby widening the angle between the iris and the cornea and facilitating drainage." Option D confuses medical with definitive treatment: laser peripheral iridotomy is the treatment of choice, creating a hole that bypasses the blocked angle, and no drop substitutes for it.
Q3 Put in order
Put the nurse’s actions in order:
  1. A. Arrange laser peripheral iridotomy for both eyes
  2. B. Escalate immediately to ophthalmology and begin the ordered pressure-lowering regimen
  3. C. Recheck intraocular pressure hourly and draw a basic metabolic panel with the mannitol
  4. D. Teach avoidance of dim lighting and reporting the angle closure to every prescriber
Reveal answer & rationale
Correct order: B → C → A → D
Ophthalmology and the pressure-lowering drugs come first (B): this is "an ophthalmologic emergency… posing a risk of irreversible damage and potential blindness if not treated promptly," and the duration of the episode is a crucial determinant of outcome. Monitoring follows (C) because "it is advisable to measure IOP at least hourly after the initial onset of symptoms until it stabilizes," and osmotic agents require a metabolic panel for electrolytes and renal function. Definitive iridotomy (A) comes next, in both eyes, since the untreated fellow eye carries a 40% to 80% risk within 5 to 10 years. Teaching (D) is essential to preventing the next attack but belongs to the recovery phase, not the acute one.
Q4 Multiple choice
A 55-year-old man is found to have an intraocular pressure of 17 mm Hg, a cup-to-disc ratio of 0.7, inferior rim thinning and an arcuate visual field defect. Which statement is correct?
  1. A. Glaucoma is excluded because the intraocular pressure is within the normal range
  2. B. This may be normal-tension glaucoma, and lowering the intraocular pressure is still beneficial
  3. C. The findings indicate ocular hypertension rather than glaucoma
  4. D. Treatment should be withheld until the pressure rises above 21 mm Hg
Reveal answer & rationale
Answer: B
Normal-tension glaucoma is "open-angle with a presenting IOP in the NORMAL range," and once progression is shown "CNTGS showed an aggressive IOP lowering of 30%, leading to a slower visual field loss rate" (B). Excluding glaucoma on the pressure alone (A) is the exact error to avoid, since those patients benefit from having the pressure lowered anyway. Ocular hypertension (C) is the opposite picture: a raised pressure with normal fields and a healthy optic nerve, which is not this patient. Waiting for the pressure to rise (D) ignores that the diagnostic triad — disc change, field change, pressure — is already two-thirds met with documented damage.
Q5 Multiple choice
Which statement by a patient starting a prostaglandin analogue eye drop indicates correct understanding?
  1. A. "I will stop the drops once my vision feels normal again."
  2. B. "After the drop I will close my eyes and press at the inner corner, because otherwise some of it goes into my bloodstream."
  3. C. "If my eyelashes get longer or my eye colour changes, I should stop the drops immediately."
  4. D. "I can skip the drops on days when my eye pressure feels low."
Reveal answer & rationale
Answer: B
Punctal occlusion is the sourced technique and the reason is systemic: "closing eyelids after administration of drops with nasolacrimal duct occlusion may prevent systemic absorption of the topical medication" (B). Stopping when vision feels normal (A) misunderstands the disease — "patients often do not experience any symptoms until it is too late," and treatment is daily "for the rest of their lives." Stopping for cosmetic change (C) is unnecessary: lengthening of eyelashes and pigmentation of the lids or iris are known prostaglandin effects, which is why they are taught in advance rather than discovered. Option D is not possible — intraocular pressure cannot be felt, which is the entire reason glaucoma is managed by measurement and by disc and field assessment rather than by sensation.

Common questions

What causes glaucoma?
Common causes and risk factors include older age — open-angle screening from 40 in african american patients and 65 in caucasian patients; angle closure typically manifests between 55 and 65, because of "age-related increases in lens thickness and decreases in anterior chamber depth", african, afro-caribbean and west african ancestry — a 4-fold increased risk of open-angle disease, the highest us prevalence, and "the leading cause of blindness in african americans"; nei names people who "are african american and over age 40" and those who "are over age 60, especially if you’re hispanic/latino" as higher risk, southeast asian, chinese and inuit ancestry, and female sex — the angle-closure pattern, with a 2 to 4 times higher incidence in women, and angle closure "relatively uncommon in black populations", family history — a 9.2 times higher risk if a first-degree relative has glaucoma, with a sibling specifically flagged as a referral trigger, myopia — the open-angle refractive error, with an increased risk "of up to 20% for each diopter increase in myopia", and others.
What are the early signs of glaucoma?
Early findings include Nothing at all — open-angle glaucoma is silent, Normal visual acuity in a patient with established glaucoma.
Which findings should a nurse report immediately in glaucoma?
Report immediately: Sudden severe unilateral eye pain with headache, nausea and vomiting, Rainbow-coloured halos around lights, A fixed mid-dilated pupil with a hazy cornea and ciliary flush, Rising pressure after a technically successful iridotomy, In an infant — cloudy cornea, an enlarged eye, tearing, light sensitivity and redness, and others. These signal deterioration that needs rapid intervention.
Can you have glaucoma with a normal eye pressure?
Yes, and it has a name. Normal-tension glaucoma is "open-angle with a presenting IOP in the normal range," and treatment still aims at "reduction of IOP, even in persons without elevated IOP." The reason the definition cannot rest on the number is mechanical: the death of retinal ganglion cells underlies glaucoma pathology regardless of whether IOP is elevated, normal, or decreased. The mirror error is just as common: a pressure above 21 is not a diagnosis either, since "IOP levels greater than 21 mm Hg do not necessarily cause glaucoma," and asymptomatic people with ocular hypertension can keep normal fields and healthy optic nerves indefinitely. The diagnosis rests on the triad — disc or nerve fibre layer change, visual field change, and pressure — and a single reading is the least informative of the three.
Why does myopia point at one type of glaucoma and hyperopia at the other?
Because the two refractive errors come with opposite eye anatomy, and the two glaucomas are failures of opposite kinds. Myopia is a risk factor for OPEN-ANGLE glaucoma, with an increased risk "of up to 20% for each diopter increase in myopia," Open-angle disease is a drainage-resistance problem — the angle stays open and the meshwork clogs. Hyperopia is a risk factor for ANGLE-CLOSURE glaucoma, because far-sightedness "is often associated with specific anatomical predispositions… such as a shallow anterior chamber depth or a more anterior lens position." Angle closure is a mechanical problem — a shallow chamber lets the iris and lens sit in close contact, pupillary block builds pressure behind the iris, the iris bows forward, and it covers the meshwork. The rest of the demographics split the same way: open-angle risk is highest in people of African ancestry, where glaucoma is the leading cause of blindness; angle closure is commonest in Southeast Asian, Chinese and Inuit populations and "relatively uncommon in Black populations," with a 2 to 4 times higher incidence in women.
Are anticholinergics really contraindicated in glaucoma?
Not in glaucoma generally — and the imprecision is why the warning gets ignored. The sourced risk is precipitation of acute angle closure in an eye with an anatomic predisposition: "over 60 drugs have been reported to be associated with AAC and are considered risk factors, particularly for individuals with ocular predispositions." The named agents are the topical mydriatics atropine and cyclopentolate, plus systemic topiramate, sulfonamides, duloxetine and phenothiazines. No fetched source states a contraindication in open-angle glaucoma, which is 74% to 80% of all glaucoma. The mechanism makes the distinction obvious: mydriasis increases iris-lens apposition and can tip a narrow angle into pupillary block — which requires a narrow angle to begin with. So the practical rule is to ask about a known narrow angle or a previous angle-closure attack before any pupil-dilating drug, and to name the glaucoma type whenever the caution is documented. The same physiology gives the patient instruction that follows an attack: avoid dim lighting, because "dim light can cause pupil dilation, thereby further narrowing the iridocorneal angle." And note that antihistamines are not named by any source behind this page, so they are not listed among the precipitants here.

Sources

Reviewed by Hae Suk Lee, RN

Educational summary for nursing students. Scenarios are fictional teaching cases. Always verify against current guidelines and your institution's protocols before acting in practice. Not medical advice.

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