Ophthalmology Flashcards
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2
Q
What is Glaucoma and is it caused by?
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Glaucoma refers to the optic nerve damage that is caused by a significant rise in intraocular pressure. The raised intraocular pressure is caused by a** blockage in aqueous humour** trying to escape the eye.
3
Q
There are two types of glaucoma: WHat are they?
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There are two types of glaucoma: open-angle and closed-angle.
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Q
The vitreous chamber of the eye is filled with _______ _______
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The vitreous chamber of the eye is filled with vitreous humour.
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The anterior chamber between the ________ and the ____ and the posterior chamber between the ____ and the ____ are filled with aqueous humour that supplies nutrients to the cornea.
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The anterior chamber between the cornea and the iris and the posterior chamber between the lens and the iris are filled with aqueous humour that supplies nutrients to the cornea.
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Q
The aqueous humour is produced by the
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The aqueous humour is produced by the ciliary body.
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Q
The aqueous humour flows from the ciliary body, around the lens and under the iris, through the anterior chamber, through the ________ ____ and into the ___ __ _____. From the ____ ____ ____ it eventually enters the general circulation.
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The aqueous humour flows from the ciliary body, around the lens and under the iris, through the anterior chamber, through the trabecular meshwork and into the canal of Schlemm. From the** canal of Schlemm** it eventually enters the general circulation.
9
Q
The normal intraocular pressure is ___ ___ mmHg.
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he normal intraocular pressure is 10-21 mmHg.
10
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How is normal intraocular pressure created
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This pressure is created by the resistance to flow through the trabecular meshwork into the canal of Schlemm.
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13
Q
What is the patho of open angle glucoma
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In open-angle glaucoma, there is a **gradual increase in resistance through the trabecular meshwork. **This makes it more difficult for aqueous humour to flow through the meshwork and exit the eye. Therefore the pressure slowly builds within the eye and this gives a slow and chronic onset of glaucoma.
= increase in resistance in the trabecular meshwork
= increased intracocular pressure
14
Q
What is the patho of acute angle-closure glaucoma
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In acute angle-closure glaucoma, the** iris bulges forward** and seals off the trabecular meshwork from the anterior chamber preventing aqueous humour from being able to drain away. This leads to a continual build-up of pressure. The pressure builds up particularly in the posterior chamber, which causes pressure behind the iris and worsens the closure of the angle.
15
Q
TRUE OR FALSE
acute angle-closure glaucoma is an opthalmology emergency
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TRUE
16
Q
What is cupping
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Increased pressure in the eye causes cupping of the optic disc. In the centre of a normal optic disc is the optic cup. This is a small indent in the optic disc. It is usually less than half the size of the optic disc. When there is raised intraocular pressure, this indent becomes larger as the pressure in the eye puts pressure on that indent making it wider and deeper. This is called “cupping”
17
Q
What is an abnormal size for optic cup?
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An optic cup greater than 0.5 the size of the optic disc is abnormal.
18
Q
RF for GLucoma
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- Increasing age
- Family history
- Black ethnic origin
- Nearsightedness (myopia)
19
Q
Presentation of Open-Angle Glaucoma
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Often the rise in intraocular pressure is** asymptomatic** for a long period of time. It is diagnosed by routine screening when attending optometry for an eye check.
It can present with gradual onset of fluctuating pain, headaches, blurred vision and halos appearing around lights, particularly at night time.
20
Q
Glaucoma affects ________ vision first. Gradually the ________ vision closes in until they experience ____ vision.
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Glaucoma affects peripheral vision first. Gradually the peripheral vision closes in until they experience tunnel vision.
21
Q
How can you measure intracular Pressure
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Non-contact tonometry
Goldmann applanation tonometry
22
Q
What is Non-contact tonometry
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Non-contact tonometry is the commonly used machine for estimating intraocular pressure by opticians. It involves shooting a “puff of air” at the cornea and measuring the corneal response to that air. It is less accurate but gives a helpful estimate for general screening purposes.
23
Q
What is Goldmann applanation tonometry
A
Goldmann applanation tonometry is the gold standard way to measure intraocular pressure. This involves a special device mounted on a slip lamp that makes contact with the cornea and applies different pressures to the front of the cornea to get an accurate measurement of what the intraocular pressure is.
24
Q
Diagnosis of open angle glaucoma
A
Goldmann applanation tonometry can be used to check the intraocular pressure.
Fundoscopy assessment to check for optic disc cupping and optic nerve health.
**Visual field assessment **to check for peripheral vision loss.
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Management of Open-Angle Glaucoma
Management of glaucoma aims to reduce the intraocular pressure. Treatment is usually started at an **intraocular pressure of 24 mmHg or above**. Patients are followed up closely to assess the response to treatment.
**Prostaglandin analogue eye drops **(e.g. latanoprost) are first line. These increase uveoscleral outflow. Notable side effects are **eyelash growth, eyelid pigmentation and iris pigmentation (browning).**
Other options:
**Beta-blockers (e.g. timolol)** reduce the production of aqueous humour
**Carbonic anhydrase inhibitors** (e.g. dorzolamide) reduce the production of aqueous humour
**Sympathomimetics **(e.g. brimonidine) reduce the production of aqueous fluid and increase uveoscleral outflow
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What is Trabeculectomy
Trabeculectomy surgery may be required where eye drops are ineffective. This involves creating a new channel from the anterior chamber, through the **sclera** to a location under the **conjunctiva**. It causes a **“bleb” **under the conjunctiva where the aqueous humour drains. It is then reabsorbed from this bleb into the general circulation.
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Acute angle-closure glaucoma is an ophthalmology emergency. What happens if treatment is not given immediatley
Premanent vision loss
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Acute angle-closure glaucoma Risk Factors
The risk factors are slightly different to open-angle glaucoma:
* Increasing age
* Females are affected around 4 times more often than males
* Family history
* Chinese and East Asian ethnic origin. Unlike open-angle glaucoma, it is rare in people of black ethnic origin.
* Shallow anterior chamber
* Medication
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Certain medications can precipitate acute angle-closure glaucoma like:
* **Adrenergic **medications such as **noradrenalin**
* **Anticholinergic** medications such as **oxybutynin and solifenacin**
* **Tricyclic** **antidepressants** such as **amitriptyline,** which have anticholinergic effects
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Presentation of Acute angle-closure glaucoma
The patient will generally appear unwell in themselves. They have a short history of:
* Severely painful red eye
* Blurred vision
* Halos around lights
* Associated headache, nausea and vomiting
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Examination Findings of Acute angle-closure glaucoma
* Red-eye
* Teary
* Hazy cornea
* Decreased visual acuity
* Dilatation of the affected pupil
* Fixed pupil size
* Firm eyeball on palpation
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Initial Management of Acute angle-closure glaucoma
NICE CKS 2019 say patients with potentially life-threatening causes of red eye should be referred for same-day assessment by an ophthalmologist. If there is a delay in admission, whilst waiting for an ambulance:
* Lie patient on their back without a pillow
* Give **pilocarpine** eye drops (2% for blue, 4% for brown eyes)
* Give **acetazolamide 500 mg** orally
* Given analgesia and an antiemetic if required
**Pilocarpine **acts on the **muscarinic receptors **in the sphincter muscles in the iris and causes constriction of the pupil. Therefore it is a** miotic agent.** It also causes ciliary muscle contraction. These two effects cause the pathway for the flow of aqueous humour from the ciliary body, around the iris and into the trabecular meshwork to open up.
**Acetazolamide is a carbonic anhydrase inhibitor**. This reduces the production of aqueous humour.
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Secondary Care Management for Acute angle-closure glaucoma
Various medical options can be tried to reduce the pressure:
* **Pilocarpine**
* **Acetazolamide** (oral or IV)
* **Hyperosmotic agents** such as glycerol or mannitol increase the osmotic gradient between the blood and the fluid in the eye
* **Timolol** is a beta-blocker that reduces the production of aqueous humour
* **Dorzolamide **is a carbonic anhydrase inhibitor that reduces the production of aqueous humour
* **Brimonidine **is a sympathomimetic that reduces the production of aqueous fluid and increase uveoscleral outflow
34
What is Laser iridotomy
**Laser iridotomy** is usually required as a definitive treatment. This involves using a laser to make a hole in the iris to allow the aqueous humour to flow from the posterior chamber into the anterior chamber. The relieves pressure that was pushing the iris against the cornea and allows the humour the drain
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What is Age-related macular degeneration (AMD)
Age-related macular degeneration is a condition where there is degeneration in the macula that cause a progressive deterioration in vision.
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In the UK it is the most common cause of blindness is
Age Related Macular Degeneration
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A key finding associated with macular degeneration is ____ seen during fundoscopy.
A key finding associated with macular degeneration is **drusen** seen during fundoscopy.
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There are two types, ____ and ____. 90% of cases are ____ and 10% are ____. ____ age-related macular degeneration carries a worse prognosis.
There are two types, **wet** and** dry**. 90% of cases are **dry **and 10% are **wet.** **Wet **age-related macular degeneration carries a worse prognosis.
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The macula is made of four key layers. At the bottom, there is the _____ _____, which contains blood vessels that provide the blood supply to the macula. Above that is ________ membrane. Above ________ membrane there is the ________ ________ epithelium and above that are the __________.
The macula is made of four key layers. At the bottom, there is the **choroid layer**, which contains blood vessels that provide the blood supply to the macula. Above that is **Bruch’s membrane.** Above **Bruch’s membrane** there is the** retinal pigment epithelium **and above that are the **photoreceptors.**
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What are drusen
Drusen are **yellow deposits of proteins and lipids** that appear between the retinal pigment epithelium and Bruch’s membrane. Some drusen can be normal. Normal drusen are small (< 63 micrometres) and hard. Larger and greater numbers of drusen can be an early sign of macular degeneration. They are common to both wet and dry AMD.
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Other features that are common to wet and dry AMD are:
* Atrophy of the retinal pigment epithelium
* Degeneration of the photoreceptors
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What is vascular endothelial growth factor (VEGF)
In **wet AMD** there is the development of **new vessels** growing from the **choroid layer** into the **retina**. These vessels can leak fluid or blood and cause **oedema** and more rapid loss of vision. A key chemical that stimulates the development of new vessels is **vascular endothelial growth factor (VEGF)** and this is the target of medications to treat **wet AMD.**
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Risk Factors of AMD
* Age
* Smoking
* White or Chinese ethnic origin
* Family history
* Cardiovascular disease
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Presentation of AMD
There are some key visual changes to remember for spotting AMD in your exams:
* Gradual **worsening central visual field loss**
* Reduced **visual acuity**
* **Crooked or wavy appearance to straight lines**
**Wet age-related macular degeneration** presents more acutely. It can present with a loss of vision over days and progress to full loss of vision over 2-3 years. It often progresses to bilateral disease.
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Examination of AMD
* Reduced acuity using a **Snellen chart**
* **Scotoma** (a central patch of vision loss)
* **Amsler grid test** can be used to assess the distortion of straight lines
* **Fundoscopy**. Drusen are the key finding.
**Slit-lamp biomicroscopic fundus examination** by a specialist can be used to diagnose AMD.
**Optical coherence tomography **is a technique used to gain a cross-sectional view of the layers of the retina. It can be used to diagnose wet AMD.
**Fluorescein angiography **involves giving a fluorescein contrast and photographing the retina to look in detail at the blood supply to the retina. It is useful to show up any oedema and neovascularisation. It is used second line to diagnose wet AMD if optical coherence tomography does not exclude wet AMD.
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Management for Dry AMD
Refer suspected cases to an ophthalmologist for assessment and management.
Dry AMD
There is no specific treatment for dry age-related macular degeneration. Management focuses on lifestyle measure that may slow the progression:
* Avoid smoking
* Control blood pressure
* Vitamin supplementation has some evidence in slowing progression
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Management of Wet AMD
Refer suspected cases to an ophthalmologist for assessment and management.
**Anti-VEGF medications** are used to treat wet age-related macular degeneration. V**ascular endothelial growth factor **is involved in the development of new blood vessels in the retina. Medications such as **ranibizumab, bevacizumab and pegaptanib block VEGF** and slow the development of new vessels. They are injected directly into the **vitreous chamber** of the eye once a month. They slow and even reverse the progression of the disease. They typically need to be started within 3 months to be beneficial.
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What is Diabetic Retinopathy
Diabetic retinopathy is a condition where the blood vessels in the retina are damaged by prolonged exposure to **high blood sugar levels (hyperglycaemia) **causing a progressive deterioration in the health of the retina.
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Hyperglycaemia leads to damage to the_____ ____ _____ and ________ cells . Increased vascular permeability leads to leakage from the blood vessels, blot haemorrhages and the formation of hard exudates. Hard exudates are __ __ deposits of lipids in the retina.
Hyperglycaemia leads to damage to the **retinal small vessels** and **endothelial cells.** Increased vascular permeability leads to leakage from the blood vessels, blot haemorrhages and the formation of hard exudates. Hard exudates are **yellow/white** deposits of lipids in the retina.
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What is Microaneurysms and Venous Bleeding
Damage to the blood vessel walls leads to microaneurysms and venous beading. **Microaneurysms** are where weakness in the wall causes small bulges. **Venous beading** is where the walls of the veins are no longer straight and parallel and look more like a string of beads or sausages.
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Damage to nerve fibres in the retina causes fluffy white patches to form on the retina called
cotton wool spots
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What is Intraretinal microvascular abnormalities (IMRA)
is where there are dilated and tortuous **capillaries **in the retina. These can act as a** shunt** between the arterial and venous vessels in the retina.
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What is Neovascularisation
Neovascularisation is when growth factors are released in the retina causing the development of new blood vessels.
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Diabetic retinopathy can be split into two broad categories:
non-proliferative and proliferative
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Non-proliferative is often called
background or pre-proliferative retinopathy as it can develop in to proliferative retinopathy.
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A condition called ______ __________ also exists separate from non-proliferative and proliferative diabetic retinopathy.
A condition called **diabetic maculopathy** also exists separate from non-proliferative and proliferative diabetic retinopathy.
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how is Diabetic Retinopathy classified
based on the findings on fundus examination.
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Findings on examination
Non-proliferative Diabetic Retinopathy
**Mild:
Moderate:
Severe: **
**Mild:** microaneurysms
**Moderate:** microaneurysms, blot haemorhages, hard exudates, cotton wool spots and venous beading
**Severe:** blot haemorrhages plus microaneurysms in 4 quadrants, venous beading in 2 quadrates, intraretinal microvascular abnormality (IMRA) in any quadrant
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Findings on examination
Proliferative Diabetic Retinopathy
* Neovascularisation
* Vitreous haemorrhage
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Findings of Diabetic Maculopathy
* Macular oedema
* Ischaemic maculopathy
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Complications of Diabetic Retinopathy
* **Retinal detachment**
* **Vitreous haemorrhage** (bleeding in to the vitreous humour)
* **Rebeosis iridis **(new blood vessel formation in the iris)
* **Optic neuropathy**
*** Cataracts**
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Management of Diabetic Retinopathy
* **Laser photocoagulation**
* **Anti-VEGF** medications such as **ranibizumab and bevacizumab**
* **Vitreoretinal surgery** (keyhole surgery on the eye) may be required in severe disease
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What is Hypertensive Retinopathy
Hypertensive retinopathy describes the damage to the small blood vessels in the retina relating to **systemic hypertension. **This can be the result of years of **chronic hypertension** or can develop quickly in response to **malignant hypertension.** There are a number of signs that occur within the retina in response to the effects of hypertension in these vessels.
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________ ________ or ________ ________ is where the walls of the arterioles become thickened and sclerosed causing increased reflection of the light.
**Silver wiring** or** copper wiring** is where the walls of the arterioles become thickened and sclerosed causing increased reflection of the light.
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What is Arteriovenous nipping
is where the arterioles cause compression of the veins where they cross. This is again due to sclerosis and hardening of the arterioles.
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What are cotton wool spots caused by
Cotton wool spots are caused by **ischaemia** and **infarction** in the retina causing damage to nerve fibres
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Hard exudates are caused by
damaged vessels leaking lipids into the retina.
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Retinal haemorrhages are caused by
damaged vessels rupturing and releasing blood into the retina.
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Keith-Wagener Classification (4 stages)
Stage 1: Mild narrowing of the arterioles
Stage 2: Focal constriction of blood vessels and AV nicking
Stage 3: Cotton-wool patches, exudates and haemorrhages
Stage 4: Papilloedema
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Papilloedema is caused by
**ischaemia** to the **optic nerve** resulting in optic nerve swelling (oedema) and blurring of the disc margins.
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Management of Hypertensive Retinopathy
Management is focused on controlling the blood pressure and other risk factors such as smoking and blood lipid levels.
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What are cataracts
Cataracts are where the lens in the eye becomes cloudy and opaque. This reduces visual acuity by reducing the light that enters the eye.
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The job of the ____ is to focus light coming into the eye onto the retina at the back of the eye. It is held in place by ________ ________ attached to the ciliary body. The ciliary body contracts and relaxes to focus the lens. When the ciliary body contracts it releases tension on the suspensory ligaments and the lens ________. When the ciliary body relaxes it increases the tension in the suspensory ligaments and the lens ________ The lens is nourished by the surrounding fluid and doesn’t have a blood supply. It grows and develops throughout life.
The job of the **lens** is to focus light coming into the eye onto the retina at the back of the eye. It is held in place by **suspensory ligaments** attached to the ciliary body. The ciliary body contracts and relaxes to focus the lens. When the ciliary body contracts it releases tension on the suspensory ligaments and the lens **thickens.** When the ciliary body relaxes it increases the tension in the suspensory ligaments and the lens **narrows**. The lens is nourished by the surrounding fluid and doesn’t have a blood supply. It grows and develops throughout life.
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Congenital cataracts occur before birth and are screened for using the ____ ____ during the neonatal examination.
Congenital cataracts occur before birth and are screened for using the **red reflex** during the neonatal examination.
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Risk Factors of Cataracts
* Increasing age
* Smoking
* Alcohol
* Diabetes
* Steroids
* Hypocalcaemia
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Presentation of cataracts
Symptoms are usually **asymmetrical **as both eyes are affected separately. It presents with:
* Very slow reduction in vision
* Progressive blurring of vision
* Change of colour of vision with colours becoming more brown or yellow
* **“Starbursts”** can appear around lights, particularly at night time
A key sign for cataracts is the loss of the **red reflex.** The lens can appear grey or white when testing the red reflex. This might show up on photographs taken with a flash.
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Differentiation
Cataracts causes...
Glaucoma causes...
Macular degeneration causes...
* Cataracts cause a **generalised reduction** in visual acuity with starbursts around lights.
* Glaucoma causes a **peripheral loss of vision** with halos around lights.
* Macular degeneration causes a **central loss of vision** with a crooked or wavy appearance to straight lines.
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Management for Cataracts
If the symptoms are manageable then no intervention may be necessary.
Cataract surgery involves drilling and breaking the lens into pieces, removing the pieces and then implanting an **artificial lens **into the eye. This is usually done as a day case under local anaesthetic. It usually gives good results.
It is worth noting that cataracts can prevent the detection of other pathology such as macular degeneration or diabetic retinopathy. Once cataract surgery is performed these conditions may be detected. Therefore, the surgery may treat the cataract but they may still have poor visual acuity due to other causes.
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What is Endophthalmitis
Endophthalmitis is a rare but serious complication of cataract surgery. It is **inflammation **of the inner contents of the eye, usually caused by infection. It can be treated with **intravitreal antibiotics** injected into the eye. This can lead to loss of vision and loss of the eye itself.
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**Pupil Constriction**
There are ____ muscles in the iris that cause pupil constriction. They are stimulated by the ____________ nervous system using ____________ as a neurotransmitter. The fibres of the ________________ system innervating the eye travel along the ____________ (third cranial) nerve.
There are **circular** muscles in the iris that cause pupil constriction. They are stimulated by the **parasympathetic** nervous system using **acetylcholine** as a neurotransmitter. The fibres of the **parasympathetic **system innervating the eye travel along the **oculomotor** (third cranial) nerve.
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Pupil Dilation
The ________ muscles of the pupil arranged like spokes on a bicycle wheel travelling straight from the inside to the outside of the iris. They are stimulated by the ________ nervous system using ____________ as a neurotransmitter.
Pupil Dilation
The **dilator** muscles of the pupil arranged like spokes on a bicycle wheel travelling straight from the inside to the outside of the iris. They are stimulated by the **sympathetic **nervous system using **adrenalin** as a neurotransmitter.
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Trauma to the sphincter muscles in the iris can cause an irregular pupil.
What is this caused by?
This could be caused by cataract surgery and other eye operations.
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____________ ________can cause adhesions (scar tissue) in the iris that make the pupils misshapen.
**Anterior uveitis** can cause adhesions (scar tissue) in the iris that make the pupils misshapen.
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________ _______ _______glaucoma can cause ischaemic damage to the muscles of the iris causing an abnormal pupil shape, usually a vertical oval.
**Acute angle closure** glaucoma can cause ischaemic damage to the muscles of the iris causing an abnormal pupil shape, usually a vertical oval.
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____________ ________ (neovascularisation in the iris) can distort the shape of the iris and pupil. This is usually associated with poorly controlled diabetes and diabetic retinopathy.
**Rubeosis iridis** (neovascularisation in the iris) can distort the shape of the iris and pupil. This is usually associated with poorly controlled diabetes and diabetic retinopathy.
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________ is a congenital malformation in the eye. This can cause a ________ in the iris causing an irregular pupil shape.
**Coloboma **is a congenital malformation in the eye. This can cause a **hole **in the iris causing an irregular pupil shape.
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________ ____ is where there is spasm in a segment of the iris causing a misshapen pupil. This is usually temporary and associated with migraines.
**Tadpole pupil **is where there is spasm in a segment of the iris causing a misshapen pupil. This is usually temporary and associated with migraines.
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Causes of Mydriasis (Dilated Pupil)
* Third nerve palsy
* Holmes-Adie syndrome
* Raised intracranial pressure
* Congenital
* Trauma
* Stimulants such as cocaine
* Anticholinergics
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Causes of Miosis (Constricted Pupil)
* Horners syndrome
* Cluster headaches
* Argyll-Robertson pupil (in neurosyphilis)
* Opiates
* Nicotine
* Pilocarpine
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A third nerve palsy causes:
* **Ptosis **(drooping upper eyelid)
* Dilated non-reactive pupil
* **Divergent strabismus **(squint) in the affected eye. It causes a **“down and out” **position of the eye
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The third cranial nerve is the oculomotor nerve. It supplies all of the extraocular muscles except the
The third cranial nerve is the oculomotor nerve. It supplies all of the extraocular muscles except the **lateral rectus and superior oblique.**
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Therefore when the extraocular muscles are no longer getting signals from the oculomotor nerve, the eyes moves ________ and ________ due to the effects of the lateral rectus and superior oblique still functioning without resistance
Therefore when these muscles are no longer getting signals from the oculomotor nerve, the eyes moves **outward **and **downward** due to the effects of the lateral rectus and superior oblique still functioning without resistance
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What other muscle does oculomotor nerve supply and what happens to this muscle when the nerve is injured?
It also supplies the **levator palpebrae superioris,** which is responsible for lifting the upper eyelid. Therefore third nerve palsy causes a **ptosis.**
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How is a dilated fixed pupil caused?
The oculomotor nerve also contains **parasympathetic** fibres that innervate the **sphincter muscle** of the iris. Therefore third nerve palsy causes a dilated fixed pupil
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What can cause compress of the oculomotor nerve and a third nerve palsy
The oculomotor nerve travels directly from the brainstem to the eye in a straight line. It travels through the **cavernous sinus** and close to the **posterior communicating artery**. Therefore, **cavernous sinus thrombosis and a posterior communicating artery aneurysm** can cause compression of the nerve and a third nerve palsy.
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A third nerve palsy with sparing of the pupil suggests a **microvascular** cause as the **parasympathetic** fibres are spared. This may be due to:
* Diabetes
* Hypertension
* Ischaemia
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A full third nerve palsy is caused by compression of the nerve, including the parasympathetic fibres. This is called a ______ ______ due to the physical compression:
A full third nerve palsy is caused by compression of the nerve, including the parasympathetic fibres. This is called a** “surgical third”** due to the physical compression:
* Idiopathic
* Tumour
* Trauma
* Cavernous sinus thrombosis
* Posterior communicating artery aneurysm
* Raised intracranial pressure
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Horner syndrome is a triad of:
* Ptosis
* Miosis
* Anhidrosis (loss of sweating)
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What is enopthalmos?
They may also have enopthalmos, which is a sunken eye. Light and accommodation reflexes are not affected.
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What is Horner syndrome caused by
damage to the sympathetic nervous system supplying the face.
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The journey of the sympathetic nerves to the head is relevant for the causes of Horner syndrome. Explain this.
* The sympathetic nerves arise from the** spinal cord** in the chest.
* These are **pre-ganglionic nerves.**
* They then enter into the** sympathetic ganglion** at the base of the neck and exit as post-ganglionic nerves.
* These **post-ganglionic nerves** then travel to the head, running alongside the **internal carotid artery**
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How do you determine the location of Horner syndrome?
The location of the Horner syndrome can be determined by the** anhidrosis.**
* **Central lesions** cause anhidrosis of the arm and trunk as well as the face.
* **Pre-ganglionic lesions** cause anhidrosis of the face.
* **Post-ganglionic** lesions do not cause anhidrosis.
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Horner's syndrome:
How can you remember the causes of the each lesion
The causes can be remembered as the 4 Ss, 4 Ts and 4 Cs. S for Sentral, T for Torso (pre-ganglionic) and C for Cervical (post-ganglionic).
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Horner Syndrome
Central lesion causes:
S – **S**troke
S – Multiple **S**clerosis
S – **S**welling (tumours)
S – **S**yringomyelia (cyst in the spinal cord)
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Horner Syndrome
-Pre-ganglionic lesions causes:
T – **T**umour (Pancoast’s tumour)
T – **T**rauma
T – **T**hyroidectomy
T – **T**op rib (a cervical rib growing above the first rib above the clavicle)
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Horner Syndrome
-Post-ganglionic lesions causes:
C – **C**arotid aneurysm
C – **C**arotid artery dissection
C – **C**avernous sinus thrombosis
C – **C**luster headache
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Congenital Horner syndrome is associated with ____________ which is a difference in the colour of the iris on the affected side.
Congenital Horner syndrome is associated with **heterochromia,** which is a difference in the colour of the iris on the affected side.
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What type of drops can be used to test for Horner Syndrome
Cocaine eye drops
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How does cocaine eye drops work
Cocaine acts on the eye to stop **noradrenalin re-uptake** at the **neuromuscular junction**. This causes a normal eye to dilate because there is more noradrenalin stimulating the dilator muscles of the iris. In Horner syndrome, the nerves are not releasing noradrenalin to start with so blocking re-uptake does not make a difference and there is no reaction of the pupil.
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What is the alternative to cocaine eye drops
Alternatively, a **low concentration adrenalin** eye drop (0.1%) won’t dilate a normal pupil but will dilate a Horner syndrome pupil.
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What is Holmes Adie Pupil
A Holmes Adie pupil is a unilateral dilated pupil that is sluggish to react to light with slow dilation of the pupil following constriction. Over time the pupil will get smaller. This is caused by damage to the **post-ganglionic parasympathetic fibres**. The exact cause is unknown but may be viral.
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What is Holmes Adie Syndrome?
Holmes Adie Syndrome is where there is a Holmes Adie pupil with **absent ankle and knee reflexes**.
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What is Argyll-Robertson Pupil
An Argyll-Robertson pupil is a specific finding in **neurosyphilis.** It is a **constricted** pupil that **accommodates** when focusing on a near object but does not react to light. They are often irregularly shaped. It is commonly called **“prostitutes pupil”** due to the relation to neurosyphilis and because **“it accommodates but does not react“.**
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Name some Eyelid Disorders
* Blepharitis
* Stye
* Chalazion
* Entropion
* Ectropion
* Trichiasis
* Periorbital Cellulitis
* Orbital Cellulitis
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What is Blepharitis and what does it cause
inflammation of the eyelid margins.
It causes a gritty, itchy, dry sensation in the eyes.
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Blepharitis is associated with the dsyfunction of what gland?
It can be associated with dysfunction of the **Meibomian glands**, which are responsible for secreting oil onto the surface of the eye. It can lead to styes and chalazions.
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Mx for Blepharitis
Management is with hot compresses and gentle cleaning of the eyelid margins to remove debris using cotton wool dipped in sterilised water and baby shampoo.
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Blepharitis
Lubricating eye drops can be used to relieve symptoms: Name some
* **Hypromellose** is the least viscous. The effect lasts around10 minutes.
* Polyvinyl alcohol is the middle viscous choice. It is worth starting with these.
* Carbomer is the most viscous and lasts 30 – 60 minutes.
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What is the two different types of Stye
Hordeolum externum
Hordeolum internum
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What is the difference between Hordeolum externum and
Hordeolum internum
Hordeolum externum is an infection of the** glands of Zeis or glands of Moll.** The glands of Moll are sweat glands at the base of the eyelashes. The glands of Zeis are sebaceous glands at the base of the eyelashes. A stye causes a tender red lump along the eyelid that may contain pus.
Hordeolum internum is infection of the **Meibomian glands.** They are deeper, tend to be more painful and may point inwards towards the eyeball underneath the eyelid
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Mx of Stye
Styes are treated with hot compresses and analgesia. Consider topic antibiotics (i.e. chloramphenicol) if it is associated with conjunctivitis or persistent.
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What is Chalazion and its Mx
A chalazion occurs when a **Meibomian gland** becomes blocked and swells up. It is often called a **Meibomian cyst.** It presents with a swelling in the eyelid that is typically not tender. It can be tender and red.
Treatment is with **hot compress and analgesia**. Consider topic antibiotics (i.e. chloramphenicol) if acutely inflamed.
Rarely if conservative management fails then **surgical drainage** may be required.
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What is Entropion
Entropion is where the eyelid turns inwards with the lashes against the eyeball.
This results in pain and can result in **corneal damage and ulceration.**
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Mx of Entropion
nitial management is by taping the eyelid down to prevent it turning inwards. Definitive management is with surgical intervention. When the eyelid is taped down it is essential to prevent the eye drying out by using regular lubricating eye drops.
A same-day referral to ophthalmology is required if there is a risk to sight.
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What is Ectropion
Ectropion is where the eyelid turns outwards with the inner aspect of the eyelid exposed. It usually affects the bottom lid
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Ectropion results in
** exposure keratopathy** as the eyeball is exposed and not adequately lubricated and protected.
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Ectropion Mx
Mild cases may not require treatment. Regular lubricating eye drops are used to protect the surface of the eye. More significant cases may require surgery to correct the defect.
A same-day referral to ophthalmology is required if there is a risk to sight.
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What is Trichiasis?
Trichiasis is inward growth of the eyelashes. This results in pain and can result in corneal damage and ulceration.
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Trichiasis Mx
Management by a specialist is to remove the eyelash **(epilation)**. Recurrent cases may require electrolysis, cryotherapy or laser treatment to prevent the lash regrowing.
A same day referral to ophthalmology is required if there is a risk to sight.
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What is Periorbital Cellulitis
Periorbital cellulitis (also known as preorbital cellulitis) is an eyelid and skin infection in front of the orbital septum (in front of the eye). It presents with swelling, redness and hot skin around the eyelids and eye.
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It is essential to differentiate Periorbital Cellulitis from orbital cellulitis, which is a sight and life threatening emergency. How do you do this
CT scan can help distinguish between the two.
Key features that differential this from periorbital celluitis is** pain on eye movement, reduced eye movements, changes in vision, abnormal pupil reactions** and forward movement of the eyeball (proptosis).
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Mx of Periorbital Cellulitis
Treatment is with **systemic antibiotics** (oral or IV). Preorbital cellulitis can develop into orbital cellulitis so vulnerable patients (e.g. children) or severe cases may require admission for observation while they are treated.
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Mx Orbital Cellulitis
This is a medical emergency that requires admission and IV antibiotics. They may require surgical drainage if an abscess forms.
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What is Conjunctivits?
This is a medical emergency that requires admission and IV antibiotics. They may require surgical drainage if an abscess forms.
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What are the main types of conjunctivitis
There are three main types:
* Bacterial
* Viral
* Allergic
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Conjunctivitis presents with:
* Unilateral or bilateral
* Red eyes
* Bloodshot
* Itchy or gritty sensation
* Discharge from the eye
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TRUE OR FALSE
Conjunctivitis causes pain, photophobia or reduced visual acuity.
FALSE
Conjunctivitis **does not **cause pain, photophobia or reduced visual acuity.
Vision may be blurry when the eye is covered with discharge, however when the discharge is cleared the acuity should be normal
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What is the difference between bacterial and viral conjunctivitis
**Bacterial conjunctivitis** presents with a **purulent discharge **and an inflamed conjunctiva. It is typically worse in the morning when the eyes may be stuck together. It usually starts in one eye and then can spread to the other. It is highly contagious.
**Viral conjunctivitis** is common and usually presents with a clear discharge. It is often associated with other symptoms of a viral infection such as dry cough, sore throat and blocked nose. You may find tender **preauricular** lymph nodes (in front of the ears). It is also contagious.
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Differential Diagnosis of Acute **Painless** Red Eye
* Conjunctivitis
* Episcleritis
* Subconjunctival Haemorrhage
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Differential Diagnosis of Acute **Painful** Red Eye
* Glaucoma
* Anterior uveitis
* Scleritis
* Corneal abrasions or ulceration
* Keratitis
* Foreign body
* Traumatic or chemical injury
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General Mx for Conjunctivitis
Conjunctivitis usually resolves without treatment after 1-2 weeks.
Advise on good hygiene to avoid spreading (e.g. avoid sharing towels or rubbing eyes and regularly washing hands) and avoiding the use of contact lenses. Cleaning the eyes with cooled boiled water and cotton wool can help clear the discharge.
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Mx of Bacterial conjunctivitis
If bacterial conjunctivitis is suspected then antibiotic eye drops can be considered, however bear in mind it will often get better without treatment. **Chloramphenicol and fuscidic acid **eye drops are both options.
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Mx for Patients under the age of 1 month of age with conjunctivitis
Patients under the age of 1 month of age with conjunctivitis need urgent ophthalmology review as **neonatal conjunctivitis** can be associated **gonococcal infection** and can cause loss of sight and more severe complications such as pneumonia.
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What is allergic conjuctivitis and Mx
Allergic conjunctivitis is caused by contact with **allergens.** It causes swelling of the **conjunctival sac **and **eye lid **with a significant watery discharge and itch.
**Antihistamines** (oral or topical) can be used to reduce symptoms.
Topical **mast-cell stabilisers** can be used in patients with chronic seasonal symptoms. They work by preventing mast cells releasing histamine. These require use for several weeks before showing any benefit.
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Eyelid Disorders
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Eyelid Disorders
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Eyelid Disorders
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Eyelid Disorders
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What is Anterior Uveitis
Anterior uveitis is inflammation in the anterior part of the uvea. The uvea involves the **iris, ciliary body and choroid.** The choroid is the layer between the retina and the sclera all the way around the eye. Sometimes anterior uveitis is referred to as **iritis.**
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Patho and causes of Anterior Uveitis
It involves** inflammation** and** immune cells **in the **anterior chamber** of the eye. The anterior chamber of the eye becomes infiltrated by **neutrophils, lymphocytes and macrophages**. This is usually caused by an **autoimmune** process but can be due to **infection, trauma, ischaemia or malignancy. Inflammatory cells** in the anterior chamber cause floaters in the patient’s vision.
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Anterior uveitis can be acute or chronic. Chronic anterior uveitis is more ________________ (has more macrophages) and has a less severe and longer duration of symptoms, lasting more than 3 months.
Anterior uveitis can be acute or chronic. Chronic anterior uveitis is more **granulomatous** (has more macrophages) and has a less severe and longer duration of symptoms, lasting more than 3 months.
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Acute anterior uveitis is associated with** HLA B27** related conditions:
* Ankylosing spondylitis
* Inflammatory bowel disease
* Reactive arthritis
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Chronic anterior uveitis is associated with:
* Sarcoidosis
* Syphilis
* Lyme disease
* Tuberculosis
* Herpes virus
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Presentation of anterior uveitis
**unilateral** symptoms that start spontaneously without a history of trauma or precipitating events. They may occur with a flare of an associated disease such as **reactive arthritis**.
Symptoms include:
* Dull, aching, painful red eye
* **Ciliary flush** (a ring of red spreading from the cornea outwards)
* Reduced visual acuity
* Floaters and flashes
* Sphincter muscle contraction causing **miosis** (constricted pupil)
* **Photophobia** due to ciliary muscle spasm
* Pain on movement
* Excessive tear production **(lacrimation)**
* Abnormally shaped pupil due to **posterior synechiae (adhesions)** pulling the iris into abnormal shapes
* A **hypopyon** is a collection of white blood cells in the anterior chamber, seen as a yellowish fluid collection settled in front of the lower iris, with a fluid level
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Management of anterior uveiti
NICE Clinical Knowledge Summaries on red eye say patients with potentially sight threatening causes of red eye should be referred for same day assessment by an ophthalmologist. They need fully slit lamp assessment of the different structures of the eye and intraocular pressures to establish the diagnosis.
The ophthalmologist will guide treatment choices:
* **Steroids **(oral, topical or intravenous)
* **Cycloplegic-mydriatic** medications such as **cyclopentolate or atropine** eye drops. **Cycloplegic** means paralysing the ciliary muscles. **Mydriatic** means dilating the pupils. Cyclopentolate and atropine are **antimuscarinic** medications that blocks to the action of the** iris sphincter** muscles and **ciliary body**. These dilate the pupil and reduce pain associated with ciliary spasm by stopping the action of the ciliary body.
* **Immunosuppressants** such as **DMARDS** and **TNF inhibitors**
* Laser therapy, cryotherapy or surgery (vitrectomy) are also options in severe cases.
*
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What is Episcleritis
Episcleritis is benign and self-limiting inflammation of the episclera, the outermost layer of the sclera. The episclera is situated just underneath the conjunctiva.
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Who is Episcleritis most commonly seen in
It is relatively common in young and middle-aged adults and is not usually caused by infection. It is often associated with inflammatory disorders such as **rheumatoid arthritis and inflammatory bowel disease**
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Presentation of Episcleritis
Episcleritis usually presents with acute onset unilateral symptoms:
* Typically not painful but there can be mild pain
* Segmental redness (rather than diffuse). There is usually a patch of redness in the lateral sclera.
* Foreign body sensation
* Dilated episcleral vessels
* Watering of eye
* No discharge
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Management of Episcleritis
If in doubt about the diagnosis, refer to ophthalmology.
Episcleritis is usually self limiting and will recover in 1-4 weeks. In mild cases no treatment is necessary. Lubricating eye drops can help symptoms.
Simple** analgesia, cold compresses and safetynet advice** are appropriate.
More severe cases may benefit from systemic **NSAIDs **(e.g. naproxen) or topical steroid eye drops
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What is Scleritis
Scleritis involves inflammation of the full thickness of the sclera. This is more serious than episcleritis. It is not usually caused by infection.
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The most severe type of scleritis is called
necrotising scleritis. Most patients with necrotising scleritis have visual impairment but may not have pain. It can lead to **perforation of the sclera.** This is the most significant complication of scleritis.
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There is an associated systemic condition in around 50% of patients presenting with scleritis. This may be:
* Rheumatoid arthritis
* Systemic lupus erythematosus
* Inflammatory bowel disease
* Sarcoidosis
* Granulomatosis with polyangiitis
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Scleritis usually presents with an acute onset of symptoms. Around 50% of cases are bilateral. Other presentations are:
* Severe pain
* Pain with eye movement
* Photophobia
* Eye watering
* Reduced visual acuity
* Abnormal pupil reaction to light
* Tenderness to palpation of the eye
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Management of Scleritis
NICE Clinical Knowledge Summaries on red eye say patients with potentially sight threatening causes of red eye should be referred for same day assessment by an ophthalmologist.
Management in secondary care involves:
* Consider an underlying systemic condition
* **NSAIDS **(topical / systemic)
* **Steroids **(topical / systemic)
* **Immunosuppression** appropriate to the underlying systemic condition (e.g. methotrexate in rheumatoid arthritis)
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