QuestionSBA
QuestionChoice
This is a beta-blocker that would be contraindicated in patients with asthma, COPD, heart block and severe heart failure, to name a few conditions. It may cause bronchoconstriction in a patient with asthma
32125
c
Timolol
QuestionChoice
This is a cycloplegic that dilates the pupil and is used in anterior uveitis to prevent the formation of posterior synechiae. It would worsen glaucoma as it exacerbates angle closure
32127
e
Cyclopentolate
QuestionChoice
This patient is presenting with acute angle closure. The immediate management of this includes pilocarpine eye drops, acetazolamide (contraindicated in this case), analgesia and an anti-emetic if needed.
32123
a
Pilocarpine
QuestionChoice
This is an alpha agonist that reduces aqueous secretion and increases outflow through the trabecular meshwork. It is contraindicated in patients taking monoamine oxidase inhibitors (selegiline in this case) due to the risk of hypertensive crisis
32126
d
Brimonidine
QuestionChoice
This is a carbonic anhydrase inhibitor, which is contraindicated in those with sickle cell disease, as it may precipitate a vaso-occlusive crisis by exacerbating sickling of cells. In the absence of contraindications, IV acetazolamide may be given in acute glaucoma to lower intraocular pressure
32124
b
Brinzolamide
QuestionComment
I'm flabbergasted 
38039
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JAK Gastro
QuestionComment
This case sounds like acute angle closure in which case they use pilocarpine first line. 
I’m pretty sure they sure latanoprost for open angle closure glaucoma instead. 
54684
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Lo
QuestionComment
why would acetazolamide be contraindicated in this case ??
60235
QuestionComment
Acetazolamide is not advised for patients with sickle cell disease as it can cause metabolic acidosis, increasing the likelihood of red blood cell sickling and may trigger a vaso-occlusive crisis. Additionally, its diuretic effect can lead to dehydration, further heightening the risk of sickling episodes.
60535
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administrator
Digital Teaching Fellow @ Quesmed
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Fungal Metabolism
Concept
Chapter
# Summary

Primary angle closure glaucoma (PACG) is a severe ocular condition primarily affecting older individuals, particularly those of Asian ethnicity or with hypermetropia. Key signs and symptoms include systemic discomfort, nausea, headaches, ocular pain, blurred vision, and a fixed-dilated pupil. Immediate referral to ophthalmology is necessary to prevent progression of visual loss. Key investigations include intraocular pressure measurement and ophthalmological examination. Management includes the prompt reduction of intraocular pressure via a combination of pharmaceutical interventions, and potentially a peripheral iridectomy.

# Definition

Primary Angle Closure Glaucoma (PACG) is a type of glaucoma characterized by the blockage or narrowing of the drainage angle formed by the cornea and the iris, resulting in a sudden increase in intraocular pressure. 

# Pathophysiology

In health, aqueous humour, which is produced by the ciliary body, flows through the pupil and leaves the eye via the trabecular meshwork.

The trabecular meshwork is a circular structure that lies in the anterior chamber angle, which is where the cornea meets the iris.

Pprimary angle-closure glaucoma occurs when the iris blocks the drainage angle, which causes a rise in IOP and subsequent damage to the optic nerve. **Primary angle closure** is the term used to describe when the iris blocks the drainage angle but there is no evidence of optic nerve damage.

# Epidemiology

PACG predominantly affects older individuals, with an incidence rate of approximately 0.4% in individuals over 40 years of age in the UK.

# Risk Factors

* Hyperopia (long-sightedness) and short axial length of the eyeball
* Age – the lens grows with age and can push the iris forwards into the angle
* Ethnicity – Asian or Inuit populations
* Pupillary dilatation – either iatrogenically (eg. topical mydriatics or systemic alpha-adrenergic agonists) or owing to the patient being in a dimly lit environment (eg. watching television in a dark room) 


# Signs and Symptoms

## Symptoms

- **Pain** – an extremely painful eye that develops rapidly, with pain spreading throughout the orbit
- **Blurred vision** – can progress to vision loss
- **Haloes** – patients will often describe coloured haloes around lights
- **Systemically unwell** – nausea and vomiting are very common presenting symptoms


## Signs

- **Red eye** – ciliary flush with a hazy cornea
- **Mid-dilated or fixed pupil** 
- **Closed iridocorneal angles** on gonioscopy
- **Corneal oedema**
- **Raised IOP** (defined as >21 mmHg) – the globe may feel hard on palpation


# Differential Diagnosis

The main differential diagnoses for PACG include other types of glaucoma, such as open-angle glaucoma, as well as other ocular emergencies like acute anterior uveitis and retinal detachment. The key presenting signs and symptoms of these conditions are:

- Open-angle glaucoma: Gradual loss of peripheral vision, usually in both eyes, and tunnel vision in the advanced stages.
- Acute anterior uveitis: Red, painful eye, blurred vision, photophobia, and a small, irregular pupil.
- Retinal detachment: Sudden appearance of floaters, flashes of light in the periphery, and a shadow or curtain over a portion of the visual field.

# Investigations

In cases of suspected PACG, the following investigations are typically performed:

- Gonioscopy - assessing angle between iris and cornea 
- Tonometry - measurement of intraocular pressure
- Ophthalmological examination

# Management

Acute angle-closure glaucoma is an emergency and requires urgent admission and referral to ophthalmology.

## Medical management

The intra-ocular pressure (IOP) must be reduced as soon as possible to prevent further damage to the optic nerve and preserve vision. Medical management consists of:

- IOP-lowering agents e.g. a combination of beta blockers, pilocarpine, and IV acetazolamide.
- Rarely intravenous hyperosmotics (eg. mannitol) may be added if there is no improvement in IOP
- Analgesia and antiemetics

The aim of medical management is to stabilise or reduce the IOP while awaiting formal ophthalmological assessment and definitive surgical intervention.

## **Surgical management**

- **Peripheral iridotomy** – a laser is used to make a hole in the peripheral iris to allow free flow of aqueous – the contralateral eye is treated prophylactically as it is predisposed to PACG
- **Surgical iridectomy** – rarely used nowadays, but still carried out when a laser iridectomy is not possible


# NICE Guidelines

[Click here for NICE CKS on glaucoma](https://cks.nice.org.uk/topics/glaucoma/)




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1001
Acute closed angle glaucoma
Topic
16
Ophthalmology
6425
Latanoprost is a prostaglandin analog used to treat glaucoma and ocular hypertension by increasing the outflow of aqueous humor, which lowers intraocular pressure (IOP).
A 50-year-old woman presents to the Emergency Department with sudden onset severe pain in her right eye. Her past medical history includes severe asthma, sickle cell disease and depression. She only takes selegiline. She has nausea and vomited once on the way to the hospital. On inspection, she has right conjunctival redness, and her right pupil reacts poorly to light.

Which of the following medications should be started?
a