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Y4 Medicine > Opthamology > Flashcards

Opthamology Flashcards

1
Q

Where is aqeuous humor produced

A

Ciliary body - travels through the anterior chamber, trabecular meshwork and into the canal of schlemm before reaching general circulation

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2
Q

Pathophys of open-angle gluacoma

A

Gradual increase in resistance through the trabecular meshwork makes it more difficult for aqeuous humor to flow through the meshwork + exit the eye therefore the pressure slowly builds up within the eye

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3
Q

Pathophys of closed-angle glaucoma

A

The iris bulges forward and seals off the trabecular meshwork from the anterior chamber preventing any aqueous humor from draining away = opthamological emergency (continuous build up of pressure)

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4
Q

What opthalmoscopy finding suggests increased pressure

A

Cupping of the optic discs

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5
Q

Open-angle glaucoma

A

Sx;
* Often diagnosed by routine screening as remains asymptomatic for a long while
* Gradual loss of peripheral vision / blurred vision
* Fluctuating pain / headaches
* Halo’s appear around lights particularly at nightime

Invx;
1. Gold standard = Goldmann applanation tonometry (measures intraocular pressure)
2. Fundoscopy - optic disc cupping

Management;
–> commence when intraocular pressure is 24mmHg +
1. Prostaglandin analogue eye drops (latanoprost)
2. Beta-blockers (to reduce production of aqueous humor)
3. Carboic anhydrase inhibitors (dorzolamide)

Surgery = trabeculectomy (when eyedrops become ineffective)

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6
Q

Side effects of latanoprost

A

Eyelash growth
Eyelid pigmentation
Iris browning

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7
Q

Closed-angle glaucoma

A

Risk factors = Age / Long-sightedness (hypermetropia) / Pupil dilation / female / FHx / Chinese / Shallow anterior chamber / Medications (e.g TCAs & anticholingerics)

Sx; Rapid onset of
* severely painful red eye
* blurred vision
* Decreased visual acuity
* Halo’s around lights & symptoms worsened with mydriasis
* Associated headache & nausea & vomitting

O/E - the eye will be red & teary with a **hazy cornea + fixed dilated pupil. Eyeball is firm to touch. **

Diagnosis = Both Tanometry + Gonioscopy (slit lamp) are needed

Management;
* same day referral to opthamology
* **Lie patient on back + Pilocarpine eye drops (Inc dose for brown eyes) + Acetazolamide
**

Definitive management = Laser iridotomy

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8
Q

How does Pilocarpine help in close-angle glaucoma

A

= Cholingeric agonsit

It causes miosis (constriction) which therefore contracts the ciliary muscles - opens the trabecular meshwork + increases outflow of aqueous humor

Other uses = Sjogren’s syndrome & Radiotherapy induced dry mouth

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9
Q

Macular degeneration

A

Most common cause of blindness in UK. Common in pts over 75yrs.

2 types;
1. Wet - 10% - worse prognosis and more acute & have development of new vessels (can bleed) stimulated by VEFG.
2. Dry - 90% - characterised by drusen

RF = Age / Smoking / White or Chinese / Fhx / CVD

Presentation;
* Difficulties in dark adaptation
* Gradual worsening of central vision loss
* Reduced visual acuity
* Crooked or wavy appearance to straight lines.

O/E = Reduced visual acuity + scotoma.
* Amsler grid test = distortion of straight lines
* Fundoscopy = Drusen

Diagnosis = slit-lamp fundus examination + optical coherence tomography (1st line for Wet AMD)+/- Fluroscein angiography (2nd line to diagnosed wet AMD)

Management;
–> Refer to opthamology
Dry AMD = conservative management
Wet = Anti-VEGF medication (Ranibizumab, bevacizumab) - *needs to be commenced <3months in to be effective *

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10
Q

Layers of the macula

A
  1. Choroid layer - contains the blood vessels which supply blood to the macula
  2. Bruchs membrane
  3. Retinal pigment epithelium
  4. Photoreceptors
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11
Q

What are drusen

A

Yellow deposits of proteins/lipids between the retinal epithelium + photoreceptors. Normally they are small and hard but get bigger and more of them in macular degeneration.

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12
Q

What is the most common cause of blindness among 35-65yr olds

A

Diabetic retinopathy

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13
Q

How does Diabetes cause retinopathy

A

Prolonged hyperglycemia causes damage to small vessels in the retina + endothelium. It increases vascular permeability which causes leakage to blood from blood vessels (blot haemorrhages) and lipid deposits (hard exudates)

Damage to blood vessel walls causes **microaneurysms + venous bleeding. **
Damage to retinal nerve fibres causes Cotton wool spots
As the disease progresses there is neovascularisation (Due to VEGF)

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14
Q

Features/Staging of non-proliferative diabetic retinopathy

A

Mild = microaneurysms
Moderate = microaneurysms + Blot haemorrhages + Hard exudates + cotton-wool spots
Severe = Microaneurysm/blot haemorrhage in 4 quadrants + cotton-wool spots in 2

Management = Generally just observe + prevent it getting worse. if severe = laser photocoagulation.

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15
Q

Proliferative Diabetic retinopathy

A

Presence of Neovascularisation (may lead to vitreous haemorrhage)
May have macular oedema

Management = Panretinal laser photocoagulation
Consider Anti-VEGF (e.g ranibizumab)
If vitreous haemorrhage = vitreoretinal surgery

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16
Q

Keith-Wagner classification of Hypertensive retinopathy

A

Stage 1 = Silver-wiring
Stage 2 = AV nipping
Stage 3 = Flame/blot haemorrhages (macular star) + Cotton-wool spots + hard exudates
Stage 4 = Papillodema

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17
Q

Cataracts

A

When the lens becomes cloudy + opaque thus reducing visual acuity by reducing the light entering the eye.

RF = age / Smoking / Alcohol / DM / Steroids / Hypocalcemia (hypoparaythyroidism)

Presentation;
* Usually unilateral / asymmetrical
* Very slow reduction in visual acuity
* Change of colour vision - colours may appear more browny/yellow
* “Starbursts” may appear around lights - particularly at night

O/E = loss of the red reflex.

Management = surgical replacement

18
Q

Endopthalmitis

A

= complication of cataract surgery where inner eye contents become inflammaed due to infection.
(treat with intravitreal Abx)

19
Q

Unilateral Mydriasis which is sluggish to react to light
+ associated absent ankle/knee reflexes

A

Holmes-Adie syndrome
- usually caused by viral infection causing damage to post-ganglionic parasympathetic fibres

20
Q

Miotic, irregularly shaped pupil which accomodates but does NOT react to light

A

Argyll-robertson pupil (“prostitutes pupil”)
- specific finding in neurosyphillis.

21
Q

Blepharitis

A

Inflammation of eye margins
Causes a gritty, dry & itchy sensation in the eyes + may cause styes / chalazions.

Management = conservative (hot compresses/cleaning) + Lubricating eye drops (hypromellose, carbomer etc)

22
Q

Ectropion

A

Where the eyelid turns outwards exposing the inner aspect of eyelid.
Can result in **exposure keratopathy **
Management = Lubricating eyedrops.

23
Q

Peri-orbital cellulitis

A

Skin infection in front of the orbital septum

Presentation;
* Swelling of eyelids
* Erythema + hot skin on eyelid

*note - it is important to differentiate this from orbital cellulitis which is a site + life threatening emergency (CT scan needed)

Management = Oral Abx (IV if systemically unwell or vulnerable)

24
Q

Orbital cellulitis

A

Infection around the eyeball involving tissues behind the orbital septum.

Key features (which differentiates it from peri-orbital)
* Pain on eye movement
* Reduced eye movement
* Changes in vision
* Abnormal pupil reactions
* Proptosis

Management = Medical emergency!!! IV antibiotics needed and may need surgical drainage if abscess occurs.

25
Q

Conjunctivitis

A

Unilateral/bilateral red, itchy or gritty eyes.
Can be purulent or non-purulent.

*NOTE - does not cause pain or reduced visual acuity (vision may be blurry due to discharge)

Management = conservative (should clear up in 1-2wks)
If bacterial -** give Chloramphenicol/Fusidic acid eye drops**

**If age <1 month = Urgent opthamology referall **

26
Q

Anterior uveitis

A

= Inflammation of the uvea (the anterior chamber becomes infiltrated by neutrophils, lymphocytes + macrophages)

Sx;
* Unilateral
* Dull, achey painful red eye - WORSE ON MOVEMENT
* May have floaters / flashers
* Miosis + Hypopyon
* Lacrimation
* Ciliary flush (redness around cornea)

*NOTE - Acute uveitis is associated with HLA-B27 (IBD, AS, reactive arthritis & psoriatic arthritis)
Chronic - is associated with Sarcoidosis + Syphillis + TB + Lyme disease + Herpes

Management = Same day referall.
1. Steroids
2. Mydriatic meds e.g Atropin/cyclopenolate eye drops
3. Immunosupressants if HLA-B27

27
Q

Scleritis

A

= Inflammation of the full thickness of the sclera. Can be necrotising.

Presentation;
* Severe pain on movement of eye + on palpation of eye
* Photophobia
* Reduced visual acuity
* Eye watering
* Abnormal reaction to light

*Note - associated with RA, SLE, Sarcoidosis, Wegners.

Management = same day referral.
Consider underlying condition
NSAIDs + Steroids + Immunosupressants

28
Q

Corneal abrasians

A

= Scratches or damage to the cornea

Presentation;
* History of lens/foreign body in eye
* Painful red eye
* Blurred vision/photophobia

Diagnosis = flourescein stain - highlights abrasians

29
Q

Keratitis

A

Inflammation of the cornea - commonly caused by contact lenses or viral infection (herpes)

Diagnosis = Fluorescein stain - shows dendritic ulcer
Slit lamp may be diagnostic.

If herpes related = oral aciclovir. Abx if contacts

30
Q

Posterior vitreous detachment

A

Clasically presents with Photopsia (flashes of light in periphery) + Floaters (often on temporal side of ventral vision)
Harmless + associated with age

31
Q

Retinal detachment

A

Dense shadow that starts peripherally and comes in (like a curtain closing)
Central vision loss
Straight lines appear curved / Spider webs, flashers, floaters
Painless
Management = Sight-threatening emergency, urgent referall!
Can have a vicrectomy, scleral bucling or retinoplexy

32
Q

Sudden painless loss of vision. O/E there are flame/blot haemorrhages / macula oedema and optic disc oedema

A

Retinal vein occlusion

RF = HTN / DM / smoking etc

Management = urgent referal. Laser photocoagulation/anti-VEGF

33
Q

Sudden painless loss of vision + Relative afferent pupillary defect. O/E there is a pale retina with cherry-red spot

A

Central retinal artery occlusion

Most common cause = atherosclerosis or Giant cell arteritis (temporal arteritis - RF women >50yrs with polymyalgia)

Manageemnt = immediate referall.
ESR / Temporal artery biopsy should be done (to find giant cell)
High dose prednisolone

34
Q

Retinitis pigmentosa

A

= Congenital autisomal condition

Presentation;
* Night blindness (due to rod degeneration)
* Tunnel vision loss (initially peripheral then central later)
* V slow onset (usually diagnosed aged 25-40)

Fundoscopy = Bone-spicule black pigmentation in peripheral retina & Mottling of retina epithelium.

Associated conditions;
1. Usher’s syndrome = this + hearing loss
2. Refsum disease = this + Cerebellar ataxia + Peripheral neuropathy + deafness + skin changes
3. Alport’s syndrome

Management;
–> Refer to opthamology. Also genetic counselling + Vision aids.
Wear sunglasses to protect from further damage
Driving limitations + must inform DVLA

To slow disease progression consider acetazolamide + Steroids + Anti-VEGF (e.g ravicuzumab)

35
Q

Causes of Amaurosis fugax

A
  1. Ischemic / Vascular (e.g arterial disease, TIA, ischemic optic neuropathy, retinal artery/vein occlusion etc)
  2. Vitreous haemorrhage
  3. Retinal detachment
  4. Retinal migraine
36
Q

Ancanthamoeba infection

A

Associated with contact lens wearing.
Presents with watery, gritty, painful eye + hypopyons

37
Q

Horner’s syndrome + Causes

A

Triad of;
1. Ptosis
2. Miosis
3. Anhidrosis
+/- enopthalmus

Central lesions (4 Ss) = Head + Arm + Trunk anhidrosis
1. Stroke
2. MS
3. Swelling/tumours
4. Syringomyelia

Pre-ganglionic (4 Ts) = Anhidrosis confined to the face
1. Tumour (pancoast)
2. Trauma
3. Thyroidectomy
4. Top rib growth

Post-ganglionic (4 Cs) = No anhidrosis
1. Carotid aneurysm
2. carotid artery dissection
3. cavernous sinus thrombosis
4. cluster headache

38
Q

How should you manage a contact lens wearer presenting with acute painful red eye

A

Urgent referall to opthamology
- to exclude microbial keratitis

39
Q

Marcus Gunn Pupil

A

Relative afferent pupillary defect
Associated with MS (optic neuritis)
Diagnosed on swinging light test - The pupil will abnormally dilate when light is shone into it and on the swinging test as the light is moved from good - bad eye both will dilate (instead of both constricting)

Accomodation will be normal

40
Q

Risk factors for retinal detachment

A
  • Myopia
  • Posterior vitreous detachment
  • Old age
  • Trauma e.g boxing
  • Diabetes
  • previous cataract surgery
41
Q

Most common cause of keratitis in contact lens wearers

A

Pseudomonas

Y4 Medicine (22 decks)

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