Glaucoma Flashcards
What is glaucoma?
A group of chronic diseases causing progressive optic neuropathy with characteristic visual field defects due to optic nerve damage
What is the only modifiable risk factor for glaucoma?
Raised intraocular pressure (IOP)
Name three risk factors for glaucoma
Increasing age
Myopia
Afro-Caribbean ethnicity
How is aqueous humour normally drained?
Through the trabecular meshwork and Canal of Schlemm
What causes the optic nerve damage in glaucoma?
Increased intraocular pressure leading to damage at the optic disc and nerve
What is the key difference in drainage between open and closed-angle glaucoma?
- Open angle - poor drainage through the trabecular meshwork
- Closed angle: blockage at the iris/lens interface causes the iris to bow forward and block the trabecular meshwork
What is rubeotic glaucoma and when does it occur?
Glaucoma due to neovascularisation (new vessels obstruct the angle)
= seen in late diabetic eye disease
What is the clinical presentation of acute closed-angle glaucoma?
- Sudden onset red eye 1/3 present as an emergency
- Visual loss
- Headache
- Nausea and vomiting
- Dilated pupil
- Cloudy cornea
Signs
1. Red eye, cloudy cornea,dilated pupil
2. Can lose sight very quickly
3. Hyperopia (farsightedness)
Which ethnic group and refractive error increase the risk of closed-angle glaucoma?
Asian ethnicity and hyperopia (farsightedness)
How does open-angle glaucoma typically present?
Usually asymptomatic and detected during routine screening; signs include peripheral vision loss and a cupped optic disc
What is the significance of a cupped optic disc?
Indicates loss of retinal ganglion cells and neuro-retinal tissue due to glaucoma
What does a pale optic disc suggest in the context of glaucoma?
Optic atrophy due to advanced disease
Is high intraocular pressure alone diagnostic of glaucoma?
No – it’s called ocular hypertension without visual field or optic nerve changes
What is the 1st line treatment for primary open-angle glaucoma?
Prostaglandin analogues e.g. latanoprost
What is the 2nd treatment for primary open-angle glaucoma?
β blockers, carbonic anhydrase inhibitors e.g. acetazolamide
How is acute closed-angle glaucoma managed?
- Emergency reduction of IOP with pilocarpine 4% eye drops ± oral meds;
- The definitive treatment is laser peripheral iridotomy
Name three systemic conditions or drug classes that are risk factors for primary open-angled glaucoma
Hypertension, diabetes mellitus, and corticosteroid use
Describe the typical progression of visual field loss in POAG
Starts as nasal scotomas and progresses to ‘tunnel vision’
What additional optic disc features may be seen in POAG besides cupping and pallor?
Cup notching (especially inferiorly) and disc haemorrhages
What investigation assesses the configuration of the peripheral anterior chamber?
Gonioscopy
A 74-year-old male presents to his ophthalmologist for review - his sister has been diagnosed with primary open-angle glaucoma and he is concerned that this may also be the cause of his worsening eyesight. He has a past medical history of hypertension, diabetes mellitus, and prostate cancer.
What potential finding would support a diagnosis of this condition?
Myopia
A 71-year-old man is under the ophthalmology clinic for bilateral primary open-angle glaucoma.
He has been using latanoprost eye drops but despite this, his intraocular pressures remain elevated.
The ophthalmologist has to add in a second topical agent to try to reduce intraocular pressure further by decreasing the rate of aqueous humour production.
Which class of drug should be offered next?
Beta blocker
“ocular pain, decreased visual acuity, worse with mydriasis, haloes around lights” This suggests what?
Acute angle closure glaucoma
A 62-year-old woman presents to the clinic for a routine eye examination. She reports occasional blurriness in her vision and has noticed increasing difficulty with her peripheral vision. On examination, her intraocular pressure (IOP) is measured at 26 mmHg in both eyes. Her visual field test reveals peripheral loss. She has a background of well-controlled hypertension. She has no other significant medical issues, and her family history is notable for glaucoma in her mother.
What is the most appropriate next step?
360° selective laser trabeculoplasty (SLT) is first-line if the IOP is ≥ 24 mmHg
A patient is undergoing medical management for primary open-angle glaucoma. The class of medication prescribed acts to reduce intraocular pressure. After a few weeks of treatment, the patient reports increased eyelash length, and iris and periocular pigmentation.
What class of medication has caused these side effects?
Prostaglandin analogues
A 62-year-old woman presents to her GP with a painful right eye associated with blurred vision, nausea and vomiting.
On examination, the patient’s right eye is red with a fixed dilated pupil. When her left eye is covered she is unable to read a poster on the wall, even with her glasses on. Her left eye appears normal.
The GP refers the patient for immediate ophthalmology assessment.
What is the definitive treatment for the most likely diagnosis?
Laser peripheral iridotomy is the definitive treatment for acute angle-closure glaucoma
What best describes the action of latanoprost in the management of primary open-angle glaucoma?
Increases uveoscleral outflow
A 63-year-old gentleman is diagnosed with primary open-angle glaucoma. He asks how untreated glaucoma is most likely to affect vision?
Impairs peripheral visual fields
A 68-year-old retired biomedical scientist is diagnosed with primary open-angle glaucoma after visual field testing revealed peripheral sight loss. She is commenced on Timolol.
What is the mechanism of action of this drug?
Reduces aqueous secretion by the ciliary body
A 74-year-old man presents for surgery after seeing his optician. They have noticed raised intra-ocular pressure and decreased peripheral vision. His past medical history includes asthma and type 2 diabetes mellitus. You refer him to ophthalmology. What treatment is the most likely to be started on given the likely diagnosis?
Latanoprost
A 40-year-old man presents to their emergency department with sudden unilateral left eye pain and nausea. The patient said they were sitting at home watching TV when the eye pain came on suddenly.
The patient reports reduced vision in the affected eye. The left pupil is dilated on examination and unreactive to light.
There is no significant past medical history. The patient mentions he wears glasses to read.
Tonometry is carried out.
What other investigation is required to confirm the diagnosis?
Both tonometry and gonioscopy should be performed in patients with suspected acute angle-closure glaucoma
An 83-year-old man is brought to the emergency department by his daughter. He is complaining of a 2-hour history of a severe headache around his left eye, significant nausea and a few episodes of vomiting. He also reports that his vision is blurred and that he is seeing halos with bright lights.
Examination reveals his left pupil is semi-dilated and non-reactive. There is no evidence of papilloedema.
Based on the most likely diagnosis, what is the most definitive treatment once this patient’s condition is stable?
Laser iridotomy
A 67-year-old man who is known to have raised intraocular pressure is prescribed dorzolamide eye drops. What is the mechanism of action of this drug?
Carbonic anhydrase inhibitor
A 72-year-old man presents with a painful, red eye to the Emergency Department. Due to the severity of his symptoms and reduced visual acuity, he is referred to ophthalmology who makes a diagnosis of acute glaucoma.
What should be the aims of treatment?
- Reducing aqueous secretion
- Inducing pupillary constriction
A 25-year-old man is visiting his GP for a new patient check-up. He is fit and well, with no concerns. On enquiry about illnesses that run in the family, he reveals that both his mother and grandfather suffer from glaucoma
What advice should you give him regarding glaucoma?
Those with a positive family history of glaucoma should be screened annually from aged 40 years
A 60-year-old man presents to the emergency department with severe deep pain in the right eye over the last hour. During this time, he has felt severe nausea. He has no past medical history and wears glasses for hypermetropia. He does not wear contact lenses.
His pulse is 111 bpm, his blood pressure is 134/75 mmHg, and he is afebrile. Visual acuity is reduced in the right eye and the right pupil is semi-dilated and non-reactive. His right eye is red. Tonometry reveals a raised intraocular pressure in the right eye. The left eye is unaffected.
What investigation is likely to confirm the underlying diagnosis?
Gonioscopy
= patient has suspected acute angle-closure glaucoma
‘Adverse effects include brown pigmentation of the iris’
This suggests what?
Latanoprost
‘Causes pupillary constriction, blurred vision and headaches’
This suggests what?
Pilocarpine
