Acute angle-closure glaucoma Flashcards
(12 cards)
Describe the pathophysiology of acute angle-closure glaucoma
The primary mechanism underlying AACG is pupillary block: lens and iris come into close apposition, obstructing the flow of aqueous humour from the posterior to the anterior chamber
- This causes a pressure gradient, pushing the peripheral iris against the trabecular meshwork and closing the angle.
Describe the clinical features of acute angle closure glaucoma:
- severe pain: may be ocular or headache
- decreased visual acuity
- symptoms worse with mydriasis (e.g. watching TV in a dark room)
- hard, red-eye
- haloes around lights
- semi-dilated non-reacting pupil
- corneal oedema results in dull or hazy cornea
- systemic upset may be seen, such as nausea and vomiting and even abdominal pain
What would signs on a exam show for acute angle glaucoma? [5]
- Red eye
- Hazy cornea
- Decreased visual acuity
- Mid-dilated pupil
- Fixed-size pupil
- Hard eyeball on gentle palpation
What are the risk factors for AACG? [4]
60+ year old,
Female
Chinese
South East Asians, Hypermetropic (eye
size)
What are the symptoms of AACG? [4]
Pain ++
Red eye
Blurred vision
Haloes around eyes
NV
Headache
Lecture
What are the signs of AACG? [4]
- Red eye
- fixed mid-dilated pupil
- shallow AC
- hazy cornea
- high IOP
Mx of AACG? [4]
− Urgent ophthalmology referral
− Oral/IV Acetazolamide
− IOP lowering drops: timolol, Apraclonidine, Prednisolone, Pilocarpine - reduce the pupil size and create space at iridocorneal angle)
Once IOP managed:
– Peripheral iridotomy
– Clear lens extraction
Describe how pilocarpine acts to treat AACG? [2]
Pilocarpine acts on the muscarinic receptors in the sphincter muscles in the iris and causes pupil constriction (it is a miotic agent).
- It also causes ciliary muscle contraction. These two effects open up the pathway for the flow of aqueous humour from the ciliary body, around the iris and into the trabecular meshwork.
[] is usually required as a definitive treatment.
Laser iridotomy is usually required as a definitive treatment.
How do you differentiate between AACG and anterior uveitis? [3]
While both AACG and anterior uveitis can present with a red, painful eye, the pain in anterior uveitis is usually described as dull or throbbing rather than the severe pain often associated with AACG.
The vision loss in anterior uveitis tends to be less sudden than in AACG. It may also be accompanied by photophobia which is typically absent in AACG.
Ciliary flush (circumcorneal injection) is often seen in anterior uveitis but not typically observed in AACG.
How do you ddx AACG and keratitis? [3]
Keratitis presents with a red, painful eye similar to AACG. However, the pain is usually described as sharp or stabbing and may be associated with foreign body sensation which is not typical of AACG.
Visual acuity may be reduced but this change tends to occur more gradually than the rapid onset of visual loss seen in AACG.
A key distinguishing feature is the presence of corneal epithelial defects or infiltrates on slit lamp examination which are not characteristic of AACG.
acute angle closure glaucoma
