ENT Flashcards
1
Q
What is an orbit and what are its main 2 functions?
A
An orbit is bony socket containing the eye. it serves to:
- protect the eye
- provide a mounting point for the striatal muscles that control ocular movement
2
Q
What is the function of basic tears?
A
To maintain a tear film on the corneal surface for optical, metabolic and lubricant purposes - in essence to keep it moist
3
Q
What is the function of reflex tears?
A
To induce response to chemical or mechanical irritation e.g. cold, light etc. - so when something is in the eye, reflex tears tries to get it out
4
Q
What are the functions of the tear film? (4)
A
- Prevention of corneal drying
- Transport oxygen and nutrients to the cornea
- Maintenance of cornea clean and smooths out the surface
- Protection against infection
5
Q
What is the pH of normal tears?
A
pH 7.4
N.B. It’s more alkaline in the case of diseases such as dry eyes and more acidic on contact-lens wearers
6
Q
What are the 3 functions of the cornea?
A
- Passage of light
- Refraction of light
- Protection
7
Q
What is uveitis?
A
Uveitis is the inflammation of the middle layer of the eye, called the uvea or uveal tract.
8
Q
What are the symptoms of Uveitis (6)
A
- Aching, painful, red eye
- Small pupil, irregular outline
- Blurred vision
- Eye looks cloudy
- Headaches
- Light sensitivity
9
Q
What are the causes of uveitis? (2)
A
- inflammation of the uvea (inside of the eye) and/or iris
- associated with trauma or autoimmune response
n.b. affects mainly children and young adults
10
Q
What are the available treatments for Uveitis? (3)
A
- Corticosteroids eye drops e.g. Dexamethasone
- Corticosteroid injections
- Mydriatic eye drops e.g. atropine sulfate
11
Q
What is blepharitis?
A
A chronic inflammation of the eyelids
12
Q
What are the symptoms of blepharitis? (6)
A
- Itchy, sore red eyelids
- Eyelids stick together, problems opening and waking
- Crusty eyelashes
- Burning, gritty sensation in the eyes
- Photophobia
- Abnormal eyelash growth/ eyelash loss
13
Q
What are the possible causes of blepharitis? (5)
A
- Staphylococcal infection
- Infestation of lice or demodex mites
- Allergic reactions e.g. mascara
- Fungal infection
- Viral infection
14
Q
What is the typical therapy for someone with blepharitis?
A
- Daily eyelid-cleaning routine can control the symptoms
2. More severe cases may require antibiotics
15
Q
What is the treatment for someone with blepharitis?
A
- Daily eyelid-cleaning routine can control the symptoms
2. More severe cases may require antibiotics
16
Q
What is a stye?
A
A small. painful lump on the inside or outside of the eyelid
17
Q
What are the possible causes of styes? (5)
A
- Acute staphylococcal infection of the sebaceous glands
- In-growing eyelash
- Can be associated with blepharitis
- Recurrent in diabetics
- Positive correlation with stress
18
Q
What are the symptoms of style? (4)
A
- Swollen/lumpy eyelids
- Redness
- Swelling and tenderness that last several days
- Often a ‘white-head’ in centre of swelling
19
Q
What is the typical therapy for people with style?
A
- Topical antibiotics
N.B. Most styes get better without treatment within a few days or weeks
20
Q
Name the types of conjunctivitis
A
- bacterial
- allergic
- chlamydial
21
Q
Name the symptoms associated with conjunctivitis (7)
A
- Bilateral/ unilateral
- Sudden onset (Seasonal)
- Reddening of the eyes
- Itchy eyes
- Watery eyes
- Swollen eyelids
- Soreness
22
Q
What is the typical treatment for conjunctivitis? (2)
A
- Allergic conjunctivitis: azelastine hydrochloride eye drops
- Infective conjunctivitis: chloramphenicol or fusidic acid
N.B. Conjunctivitis often doesn’t require treatment as the symptoms usually clear up within a couple of weeks
23
Q
What is keratitis?
A
An inflammation of the cornea
24
Q
What are the symptoms of Keratitis? (5)
A
- Eyelid oedema
- Conjunctivital inflammation
- Discharge
- Corneal ulceration
- ‘Pink eye’
25
What are the possible causes of keratitis? (4)
1. Bacterial (contact lenses, trauma)
2. Viral (herpes simplex)
3. Fungal
4. Parasitic pools, hot tubs, contact lens solution
N.B. This is the most common cause of blindness
26
What are the possible treatments of keratitis?
Depending on the severity of the infection, an oral antibiotic may be prescribed with an antibiotic ointment or eye drops
27
What is ectropion?
It's a condition in which the eyelids turns outward
28
What are the possible causes of ectropion? (4)
1. Weak muscles around the eyes (associated with old age)
2. Injury to the skin around the eyes
3. Bell's palsy (also known as facial palsy)
4. Congenital (genetic) defect
29
What are the available treatments for ectropion?
Mild cases may not need any treatment.
In severe cases, an operation may be recommended
30
What are the available treatments for ectropion?
Mild cases may not need any treatment.
In severe cases, an operation may be recommended
31
What is exophthalmos?
It's an abnormal protusion of the eyeball
32
What are the symptoms of exophthalmos? (5)
1. Eyelids forced apart
2. Staring expression
3. Impaired eye movement
4. Double/blurred vision
5. Dry and itchy eyes
33
What are the possible causes of exophthalmos? (4)
1. Increase in the volume of tissue behind the eyes
2. associated with hyperthyroidism
3. Hereditary disease (Grave's)
4. Infection of the sinuses (in children)
34
What is cataracts?
A clouding of the lens in the eye
35
What are the symptoms of cataracts? (7)
1. Blurred, cloudy and/or misty vision
2. Gradual visual deteriroation
3. Age- and environment-related
4. Discomfort in bright light
5. Colours appear faded
6. Reading, watching TV more difficult than used to be
7. Glasses becoming less effective
36
What are the causes for developing cataracts? (4)
1. Protein aggregation in lens
2. Eye injury
3. Diabetes
4. Uveitis
37
What are the risk factors for developing cataracts? (3)
1. Smoking
2. Overexposure to sunlight
3. Steroids for long time
38
What is keratoconjuctivitis sicca (dry eye syndrome)?
It's a decreased tear production or increased tear film evaporation
39
What are the symptoms of keratoconjuctivitis sicca?
1. Occular irritation (dryness, grittiness, soreness)
2. Typically bilateral presentation
3. Worsens through the day
4. Redness of eyes
40
What are the causes for keratoconjuctivitis sicca? (5)
1. Environmental factors
2. concomitant illness
3. hormonal changes
4. ageing
5. loss of tear fluid (defects in: lacrimal gland, eyelid, cornea, tear ducts)
41
What is the typical therapy for keratoconjuctivitis sicca? (1)
1. Occular lubricants e.g. eye drops with carbomers or hydroxymethylcellulose
42
What are the symptoms of glaucoma? (7)
1. largely asymptomatic due to slow onset. age-related
2. Impairment of peripheral vision
3. Hazy or blurred vision
4. The appearance of rainbow-coloured circles around bright lights
5. Severe eye and head pain
6. Nausea or vomiting (accompanying severe eye pain)
7. Sudden sight loss
43
What are the causes of glaucoma? (4)
1. Triggers unknown
2. Glaucoma is related to the damage of the optic nerve usually associated with excessive pressure within the eye
3. this excessive intraocular pressure is caused by misbalance in production and drainage in the aqeous humour
4. trabecular meshwork progressively impaired/blocked
44
What are the 2 types of glaucoma?
1. Open-angle glaucoma
| 2. Angle-closure glaucoma
45
Describe open-angle glaucoma (4)
- it's the most common
- it involves the slow clogging of the drainage canals
- develops slowly
- a lifelong condition
46
What are the risks factors in developing glaucoma? (6)
1. Age (primary open angle glaucoma is more common with increasing age over 40)
2. Blood pressure (people with low blood pressure have a greater risk)
3. Race (people with african or afro-caribbean origin are at increased risk of developing chronic open-angle glaucoma and people of asian origin are at increased risk of developing acute angle-closure glaucoma
4. Family history
5. Short site or long site (people who are short-sighted are more likely to develop chronic open-angle glaucoma)
6. Medical history (people with diabetes may be at an increased risk)
47
Name the treatments for glaucoma along with examples (5)
1. Prostaglandin analogues (which increases flow of fluid out of the eye, which reduces pressure within the eye (intraocular pressure)) e.g. Latanoprost
2. Beta-blockers (reduces intraocular pressure by slowing down the production of aqeous humour in the eye) e.g. Timolol maleate
3. Carbonic anhydrase inhibitors (reduces the amount of aqueous humour produced in your eye, which reduces intraocular pressure) e.g. Brinzolamide
4. Sympathomimetics (Reduces rate of production of aqueous humour and increases the flow of aqueous humour out of the eyes) e.g. Brimonidine tartrate
5. Miotics (work by opening up the blocked trabecular meshwork, which should improve drainage out of the eye) e.g. Pilocarpine HCl
48
Name some causes of possible acute injuries (foreign body/ corneal scratch)
1. Superficial trauma (scratch)
2. Fingernails
3. Working with powertools
4. Sand, grit, mud
49
What is diabetic retinopathy?
It's damage that occurs to the retina due to diabetes
- There's few, if any, early warning symptoms
- Early stages only detectable by fundus photography
- Early stages: non-proliferative diabetic retinopathy
- Later stages: vessels proliferates and vision deteriorates
50
What is subconjuctival haemorrhage?
It's when blood from a burst blood vessel covers the surface of the eyeball.
Blood is not in the eyeball itself. There's initial pain but disappears quickly. There's no change in vision
No treatment is needed in the absence of infection or significant trauma
51
What is age-related macular degeneration (AMD)?
It's a painless eye condition that causes loss of central vision, usually in both eyes
52
What are some of the symptoms of AMD? (3)
1. Reading becomes difficult
2. Colours appear less vibrant
3. People's faces are difficult to recognise
N.B. AMD does not affect the peripheral vision
53
What is dry AMD?
Dry AMD develops when the cells of the macular become damaged by a build-up of deposits called drusen. It's the most common type of AMD
N.B. No treatment or cure
54
What is wet AMD?
Wet AMD develops when abnormal blood vessels form underneath the macula and damage its cells
N.B. No treatment or cure
55
What are the ocular barriers in topical drug delivery? (5)
1. Poor permeability of the cornea
2. Tear reflex
3. Nasolacrimal drainage
4. Blinking
5. Non-corneal absorption
56
What is the usual route for hydrophilic drugs and large molecules such as insulin?
Penetration across conjunctiva and underlying sclera into vitreous humour (non-corneal absorption)
N.B. Sclera is more permeable than cornea
57
What is the optimal volume for installed eye-drops?
8-15 microlitres
58
Latanoprost is an example of a pro-drug. What is it used for?
It's used to control the progression of glaucoma or ocular hypertension by reducing intraocular pressure
N.B. It is inactive until it is hydrolysed by esterases in the cornea
59
What's the purpose of cataract surgery?
To remove the lens of a patient's eye
60
What are the possible risks of cataract surgery? (4)
1. Infection
2, Postoperative inflammation
3. Posterior capsule opacification
4. Secondary cataracts caused by epithelial cell adhesion
61
LASIK surgery is performed to reshape the cornea in order to improve visual acuity.
Name some of the possible risks and side effects associated with LASIK (laser in situ keratectomy) / laser eye surgery (7)
1. hazy/ blurry vision
2. difficultly with night vision and/or driving at night; scratchiness, dryness and other symptoms of dry eye
3. glare
4. halos or starbursts around light
5. light sensitivity
6. discomfort or pain
7. small pink or red patches on the sclera
62
What is given to patients before ocular surgery?
Povidone-iodine 5% w/v eye drops
63
What is given to patients post-operation of ocular surgery? (2)
1. Acular (R)
| 2. Azyter eye drops (azithromycin) - antibiotics
64
Cerumenolytic products act by softening the cerum and lubricating the canal. Name some of these products (6)
1. Water
2. Olive or almond oil ear drops
3. Sodium bicarbonate ear drops
4. Exterol
5. Cerumol
6. Waxsol
65
In typical liquid nasal formulations, what is benzalkonium chloride used as?
An antimicrobial preservative
66
In typical liquid nasal formulations, what is butylated hydroxytoluene used as?
An antioxidant
67
In typical liquid nasal formulations, what is glycol derivatives used as?
solubilising agents or co-solvents
68
In typical liquid nasal formulations, what is glycerol used as?
humectants
69
In typical liquid nasal formulations, what is methylcellulose used as?
viscosity-enhancing agents
