Workbook Flashcards
A 47 year old woman is a frequent attender at your General Practice. She has a 2 year history of bilateral itchy eyes and crusting lid margins which tend to be worse in the mornings. She has come to see you today, complaining of a foreign body type sensation in her eyes.
What is your diagnosis?
Superficial punctate keratitis on a background of a long history of blepharitis
Inflammation can lead to abnormalities in the tear film and damage to the outer layer of the cornea over time.
What is your initial advice about managing punctate staining of the cornea on a background of blepharitis?
Punctate staining of the cornea is often a sign of dry eye disease.
It is a chronic condition that is not sight threatening and can be well controlled. Advise good lid hygiene, for example cleaning with hot compresses at least twice daily and removing any visible debris with a cotton swab. Can use lubricating eye drops for comfort
Further medical mx of superficial punctate keratitis?
Artificial tears and antibiotic drops e.g. chloramphenicol to prevent secondary bacterial infection of any abrasions
A 27 year-old lady comes into the emergency Department. She is complaining of severe eye pain, watering and sensitivity to light, having splashed oven cleaner in her eye.
What is your immediate management?
This is an ophthalmic emergency.
Check the pH of the eyes (in the lower fornix) and the commence immediate irrigation with 1L of normal saline. Irrigate for 10 mins continuously and then recheck the pH, continuing until the pH is 7.5. Provide analgesia for the pain. Refer to ophthalmology for specialist advice.
Which type of chemical injuries are more severe and why?
Alkaline agents as they are lipophilic and can permeate deeper into the ocular surface than acidic substances. They can stimulate matrix metalloproteases which cause further damage.
What should you ask someone who has had a chemical eye injury?
- Type of chemical
- Prior irrigation
- Mechanism and details of injury
Someone how has had a chemical injury to their eye present with red eye, expect for pallor of vessels close to the limbus in the interpalpebral fissure. What is the cause of this unusual conjunctival injection?
Limbal ischemia: damage to the limbus which the border between the transparent cornea and opaque sclera (contains stem cells)
How to assess for limbal ischaemia:
Check capillary refill at the limbal edge by using a cotton bud to compress the limbal vessels to observe for reperfusion.
Why is limbal ischaemia important to note if someone has had a chemical injury to their eye?
The degree of limbal ischemia (blanching) is a significant prognostic indicator in ocular burns- because the limbal stem cells are responsible for repopulating the corneal epithelium and so affect corneal healing.
After emergency management and irrigation, how can chemical injuries to the eye be managed?
- Early use of topical steroids
- Antibiotic ointment to lubricate the eyes
- Oral Vitamin C to aid healing (inhibtis metalloproteases)
What are the potential complications of chemical injuries to the eye?
Reduction in visual acuity
Persistent epithelial defect due to epithelium not being regenerated
Recurrent erosions
May require a stem cell graft
A 71 year old man is referred by his optometrist with reduced visual acuity associated with a substantial change in his spectacle prescription over the last six months. He tells you he is having problems driving at night and often gets glare when looking at oncoming vehicles.
What are the most likely causes for his symptoms?
cataracts
open angle glaucoma may cause halos around things at night but the notable feature would be loss of peripheral vision not overall visual acuity
How do cataracts cause a reduction in visual acuity?
When a patient has a cataract, their lens becomes increasingly opaque, which alters the way that light is refracted, causing a reduction in visual acuity. It makes the patient more myopic.
What are the options for surgical mx of cataracts?
Pseudophakia – replacing the lens with an artificial one
- Phacoemulsification – high frequency US to break up the cataract
- Femtosecond laser-assisted cataract surgery (FLACS) – laser used to open lens capsule instead of an incision
At what level of vision do patients typically undergo cataract surgery?
6/12 vision – driving standard
Although cataract surgery isn’t rationed on the basis of visual acuity, and it depends on the individual patient and the impact on their ADLs.
How would you explain a cataract procedure to a patient?
We remove your lens by making a small incision, then we use ultrasound waves to break up all the cloudy bits, and then we put a nice new lens there in place of the old one.
This is done under local anaesthetic so you will be awake, but you won’t be able to feel what we are doing.
This patient has scleritis. What is the cause of the paler area within the redness?
Nodular scleritis – inflammatory cells
