Glaucoma Flashcards
What is Glaucoma?
Glaucoma is a group of eye diseases associated with acute or chronic destruction of the optic nerve with or without concomitant increased intraocular pressure (IOP).
What is the Epidemiology of Glaucoma?
- Second leading cause of blindness in adults in the US following age-related macular degeneration (AMD) ∼ 2.3 million cases of glaucoma in the US
- Vision impairment in ∼ 10% of patients
- Blindness in ∼ 5% of patients
- Open-angle glaucoma is more common than angle-closure glaucoma
List 10 Risk Factors for Glaucoma?
What is the pathophysiology of gluacoma?
Anatomy & Physiology
- IOP is regulated by aqueous production and outflow
- Normal range = 10-21mmHg
- Aqueous production does not vary much but outflow can be wuite variable
- Any increase in resistance to outflow will lead to a rise in IOP (usually at the level of the trabecular meshwork)
Describe the 2 routes of Aqueous outflow?
How is Glaucoma classified?
What is involved in the assessment of someone with suspected glaucoma?
- Hx?
- Exam? (3)
- Ixs? (2)
Exam
What is the Glaucoma triad? Do you need to have all three criteria for diagnosis?
History Taking For Glaucoma?
- Symptoms?
- POH?
- PMH?
- FM?
- Meds?
- Steroids?
What is involved in the examination of a patient with suspected glaucoma?
What is Gonioscopy? What 4 things can you see?
In ophthalmology, gonioscopy is a routine procedure that measures the angle between the iris and the cornea, using a goniolens together with a slit lamp or operating microscope.
What are 4 pathologies that you might see in the iris in a patient with glaucoma?
List 4 Slit lamp tests to perform for investigation of glaucoma?
Retinoschisis = splitting of the retina
Describe the appearance of a healthy optic disc. How can you tell if its a left or right eye?
- Orange-pink colour
- Distinct contours
- In the centre of the disc is the cup which should be relatively small in comparison
2 images on the left = the patients right eye and the 2 images on the right are the patients left eye - large vessels point temporally.
What is the vertical cup: disc ratio (VCDR)? What is its significance in glaucoma?
Optic cup = no neural tissue right in the centre of the optic disc
Lighter circle around = where the optic nerves enter.
Glaucoma = gradual destruction of optic nerves = less of them = bigger cup
Normal disc size = 1.5-2mm
What is the ISNT rule of the optic disc?
What are 6 optic disc changes you may see in glaucoma?
What is the diagnosis?
= VCDR assymmetry - suspicious for glaucoma in the right eye
What are neuroretinal rim notches/thinning?
= Focal loss of neurons in the eye in glaucoma
What is vessel bayoneting?
Vessels displaced nasally as neurons are lost - need several images over time to visualise
What is the lamina dot sign?
More severe cases
List 5 Optic disc features of glaucoma seen in this image?
How can visual fields be assessed?
List 6 types of visual field defects? (seen more commonly in glaucoma but can be in many ocular pathology)
What is the role of imaging in glaucoma?
Describe an approach to the treatment of POAG?
- What 8 things do you need to counsel that patient on?
Describe the Medical treatment for POAG?
List 5 classes of drugs that can be used as topical drops in glaucoma treatment? (BAPCC)
- Prostaglandin analogues are the drug of 1st choice because of their efficacy and once-daily dosing.
- Beta-blockers are second choice
- Cholinergics are rarely used.
Describe the role of laser in glaucoma?
Describe how laser trabeculoplasty works to treat glaucoma? 2 types?
What surgeries are available to treat glaucoma? 2 classes? Which is most effective?
Penetrating = more effective
What is a Trabeculectomy?
How can a tube shunt be used to treat glaucoma?
What are MIGS devices? Name a few.
What is an iStent inject?
List 4 classes of drugs used to treat glaucoma that reduce the synthesis of aqueous humor?
List 2 classes of drugs used to treat glaucoma that increase aqueous humor outflow?
Open-angle glaucoma
- Definition?
- 7 Risk Factors
- Pathophysiology?
- Causes?
**Open-angle glaucoma (also chronic glaucoma): **generally bilateral, progressive loss of optic nerve fibers with open chamber angles (often with increased IOP), not caused by another systemic or local condition
Primary cause unclear
**Risk factors **
1. Age > 40 years
2. Increased IOP
3. European or African descent
4. Diabetes mellitus
5. Familial predisposition
6. Myopia
7. Steroid use
Open Angle Glaucoma
- Clinical features? (4)
- Diagnostics? (5)
Open Angle Glaucoma - Clinical features
1. Initially often asymptomatic
2. Over time, nonspecific symptoms such as mild headaches, impaired adaptation to darkness
3. Generally bilateral, progressive visual field loss (from peripheral to central)
4. Arcuate scotoma: arch-shaped scotoma that starts from the blind spot
Describe an approach to the Treatment of open-angle glaucoma?
Describe an approach to the pharmacological Treatment of open-angle glaucoma?
- First line?
- Second line?
- Refractory?
List & Describe 3 Procedures that lower IOP by facilitating drainage of aqueous humor used in the treatment of glaucoma?
What is Cyclodestructive surgery?
Define Angle-closure glaucoma?
- Acute?
- Chronic?
- 7 Risk Factors?
Etiology/risk factors
1. Anatomic features predisposing to angle closure: shallow anterior chamber (e.g., hyperopia, short eye)
2. Advanced age
3. Female sex
4. Asian or Inuit ethnicity
5. Eye injury with scarring and adhesions
6. Rubeosis iridis
7. Mydriasis - Drug-induced: anticholinergics (e.g., atropine), sympathomimetics, decongestants, Darkness, Stress/fear response
Describe the pathophysiology of Primary angle-closure glaucoma.
Common pathophysiology of angle-closure glaucoma: blockage of the trabecular meshwork → ↓ drainage of aqueous humor from the eye → ↑ IOP
Describe the pathophysiology of Secondary angle-closure glaucoma.
List the 7 Clinical features of Acute angle-closure glaucoma.
List 2 clinical features of Chronic angle-closure glaucoma.
Describe an approach to the diagnosis of Acute angle-closure glaucoma.
Glaucoma Diagnostics - Tonometry & Gonioscopy
- Indications?
- Procedure?
- Characteristics findings in Acute & Chronic ACG?
Glaucoma Diagnostics - Slit Lamp Exam & Direct fundoscopy
- Indication?
- Supportive findings?
Glaucoma Diagnostics - Visual Acuity & Visual Field Testing
- Indications?
- Techniques?
- Characteristic findings?
Visual acuity
Indication: all patients with glaucoma
Supportive findings
1. Acute angle-closure glaucoma:
2. Corneal edema may decrease visual acuity even in the absence of glaucomatous optic neuropathy.
3. Chronic angle-closure glaucoma:
4. There may be decreased central vision or complete blindness in advanced disease.
Describe the treatment of Acute angle-closure glaucoma?
- General Considerations?
- Initial pharmacotherapy/
Acute angle-closure glaucoma is an emergency and should be initially managed with IOP-decreasing medications that have a rapid onset of action. Once IOP has decreased, patients should undergo a definitive procedure as soon as possible to prevent recurrence.
General considerations
- Emergency ophthalmology consultation
- Place the patient in a supine position.
- Ensure the contralateral eye has been
- evaluated for urgent treatment, even if it is asymptomatic.
- Administer supportive care as needed.
- Analgesics (see pain management)
- Antiemetics (e.g., ondansetron)
Describe the treatment of Acute angle-closure glaucoma?
- What should you do if IOP is still elevated 30–60 minutes after giving the initial pharmacological therapy?
- What should you do if IOP is decreasing?
List & Describe 2 Urgent surgical interventional therapies for acute angle-closure glaucoma?
Describe the treatment of chronic primary angle-closure glaucoma.
List and describe 3 interventional therapies for Acute angle-closure glaucoma and chronic primary angle-closure with pupillary block?
- Indications?
- Procedure?
