Painful red eye Flashcards

Question

What's the most common form of angle-closure glaucoma?

Answer 1

Primary angle-closure glaucoma (PACG)

Answer 2

Causes of secondary open angle glaucoma: Eye pathologies that make the drainage of aqueous humour difficult, including: * **_Pseudoexfoliative glaucoma_** * The deposition of proteins within the anterior segment can block the trabecular meshwork resulting in aqueous outflow obstruction * Seen in old people * Cause unknown * **_Pigmentary glaucoma_** * Pigment from the back of the iris deposited in the trabecular meshwork restricts outflow of the aqueous humor * **_Neovascular glaucoma_** * **__**New blood vessels formed in response to ischaemia (e.g. diabetic retinopathy or CRVO) block the outflow of aqueous humor through the trabecular meshwork * **_Uveitic glaucoma_** * Inflammatory cells and proteins in the anterior chamber block the outflow through the trabecular meshwork * \*\*Note that the IOP can be low, normal or high in anterior uveitis * _**\*\*Steroid-induced glaucoma**_ * In susceptible people, corticosteroids increase the resistance to outflow of the aqueous humour by affecting the transport of aqueous humor by trabeculocytes in the trabecular meshwork * Most commonly seen with eye drop preparations tho it may develop when steroids are administered by other routes * **_Angle-recession glaucoma_** * Trauma to the drainage angle structures reduces outflow of the aqueous humor Primary open angle glaucoma and primary angle closure glaucoma are **_idiopathic_**

Answer 3

The answer is D - Glaucoma! Blunt ocular trauma with associated hyphema is a high-risk scenario of raised IOP. This is due to the blood causing a blockage in the drainage of the aqueous humour.

Answer 4

Causes of secondary angle closure glaucoma: Eye pathologies that cause narrowing/ closing of the iridocorneal angle, which can be divided into: * Conditions that 'push' the iris/ ciliary body towards the trabecular meshwork * **_Space occupying lesion in the eye_** * Conditions that 'pull' the iris towards the trabecular meshwork * Things that cause neovascularisation of the iris (rubeosis iridis) which leads to neovascular glaucoma: * **_Ischaemia_** (e.g. diabetic retinopathy, CRVO, ocular ischaemic syndrome) * **_Inflammation_** (e.g. chronic anterior uveitis, Behcet's disease, endophthalmitis) * **_Tumours_** of the iris, ciliary body... Ischaemic, inflammatory, and carcinogenic tissues --\> **_VEGF (angiogenic factor)_** --\> passes into the anterior segment --\> neovascularisation of the iris--\> these abnormal new vessels have a surrounding **_contractile fibrovascular membrane_** which **_causes the iridocorneal angle to be pulled closed by peripheral anterior synechiae_** --\> acute angle-closure glaucoma In addition, these new blood vessels are **_leaky_**, so proteins and plasma can flow into the anterior chamber promoting **_secondary open-angle glaucoma_**. Blood vessels forming on top of the trabecular meshwork can block the drainage directly!

Answer 5

Raised IOP Age FHx and genetics **_Black ethnicity_** **_Myopia (longer eyeball)_** **_Corticosteroids_** **_T2DM_** **_HTN and cardiovascular disease_**

Answer 6

* Age * **_Women (as women tend to have shallower anterior chambers than men)_** * **_Asians (esp Chinese)_** * **_Hyperopia (shorter eyeball)_** - think about a sofa in a room. A sofa in a small room makes the room more crowded while a sofa in a big room makes it less crowded * FHx and genetics * **_Anticholinergic (mydriatic) eye drops (e.g. atropine, tropicamide)_** or **_adrenergic eye drops (e.g. phenylephrine)_** --\> **_Pupil dilation_** --\> **_pushes the iris against the meshwork, blocking the outflow_** * Doesn't have to be an eye drop, can also be caused by medications administered via other routes e.g. oral TCA (antimuscarinic) * **_Anything that causes pupil dilation can precipitate/ trigger acute angle-closure glaucoma e.g. watching TV in dim light, during stress (increases sympathetic activity which causes pupil dilation) or excitement, at night, or reading in a semi-prone position_** * **_Systemic medications e.g. antimuscarinic or adrenergic medications_**

Answer 7

a) . Primary open angle glaucoma **_affects both sexes equally_** b) . **_Black ethnicity_** are more commonly affected by primary open angle glaucoma c) . True - myopia (shorter eyeball) increases the risk of primary open angle glaucoma

Answer 8

a) . Primary angle closure glaucoma affects women more b) . Asians, esp Chinese are more commonly affected by primary angle closure glaucoma c) . False! It's hyperopia (or hypermetropia) i.e. longer eyeball that increases the risk of developing primary angle closure glaucoma

Answer 9

a) . **_Primary angle closure glaucoma_** is more common b) . PACG affects **_women_** more c) . PACG affects **_asian population_** more, particularly the **_Chinese_** d) . **_The prevalence of PACG increases with increasing age_**. It affects 0.4% of people in the UK \> 40 yrs old and 0.95% in those \> 70 yrs old

Answer 10

* Increased sympathetic nervous system activity increases production of aqueous humor * **_Secretion of aqueous humour is increased by stimulation of beta-2 receptors and decreased by stimulation of alpha-2 receptors of the sympathetic nervous system_** that are located on cells of the ciliary body * Increased parasympathetic nervous system activity increases outflow (drainage)

Answer 11

Presentations: Symptoms * Severe eye pain, headache, N&V * Red eye (usually **_unilateral_**) * **_Reduced visual acuity (or vision loss) - due to corneal oedema_** * Halos around lights - caused by a diffraction effect as light passes through the pupil (aperture) * Photophobia - light makes the pain worse due to ischaemic iris caused by markedly elevated IOP * **_Symptoms worse with pupil dilation_** (e.g. watching a TV in a darkened room, feeling stressed or excited, reading in a semi-prone position, use of an adrenergic e.g. phenylephrine or antimuscarinic drug e.g. atropine or tropicamide eye drops) * They usually happen at night time as light exposure decreases, resulting in pupil dilation and exacerbation of symptoms * Symptoms usually get better when sleeping as increased parasympathetic activity causes pupil constriction! * Previous episodes of attacks Signs * **_Hazy cornea due to corneal oedema --\> reduced visual acuity/ visual loss, loss of red reflex_** * Normally, the endothelium of the cornea pumps fluid out of the cornea. This keeps your vision clear and your eyes working as they should. Raised IOP makes it hard for the fluid to be pumped out, so fluid accumulates in the cornea, causing corneal oedema --\> haziness * **_Semi-dilated, oval, fixed (non-reactive) pupil - due to ischaemia of the iris sphincter muscles which can no longer constrict the pupils_** * A tender, hard eye on palpation * Markedly raised IOP * Hyperopia (risk factor for acute angle closure glaucoma)

Answer 12

**_Antimuscarinic_** (e.g. atropine, tropicamide, TCA) and **_adrenergic_** medications (e.g. phenylephrine)

Answer 13

Presentations: * Insidious onset (just like primary open angle glaucoma) * **_Asymptomatic_** in most cases - usually picked up on routine ophthalmic examination * **_Raised IOP_** * **_Visual field defects_** * People are often unaware that they have a visual field defect, even when it's severe, as the visual fields of each eye overlap, and so a visual field defect in one eye may well be compensated for by the other eye until that too becomes affected * In addition, small visual field loss (scotoma) in glaucoma is usually compensated by the brain 'filling in these missing gaps/ information' so people often don't notice the visual field defect * **_Cupped optic disc_** * Signs of angle closure as detected by gonioscopy * A gonioscopy is often used together with a slit lamp to view the iridocorneal angle! (see image)

Answer 14

Ix: * **_Clinical diagnosis_** - painful red eye, reduced visual acuity/ visual loss * **_Gonioscopy_** - should be performed in ALL PATIENTS with suspected angle-closure glaucoma - this allows assessment of the anterior chamber including the iridocorneal angle * **_Ophthlamoscopy/ slit lamp examination_** may show cupping of the optic disc i.e. an **_increased cup-to-disc ratio_** * **_Optical Coherence Tomograophy (OCT)_** to assess the retina * USS biomicroscopy

Answer 15

Opportunistic testing * **_Elderly patients_** - people \>/= 60 yrs old should be examined every 2 yrs until they are 70 yrs of age, when they should be examined annually * Free examination through the NHS is available * **_FHx of glaucoma_** - people \> 40 yrs old with an affected 1st degree relative (parent, sibling, or child) should have their eyes checked annually * Free examination through the NHS is available. However, if they are stated by an ophthalmologist to be at high risk of glaucoma, then they are entitled to have free eye examinations * **_Ethicity_** - those of black African origin \> 40 yrs old should be examined annually * Free examination through the NHS is NOT available

Answer 16

Mx: Acute angle-closure glaucoma is a MEDICAL EMERGENCY! Initial Mx: * Primary care * **_ADMIT IMMEDIATELY + URGENT REFERRAL TO AN OPHTHALMOLOGIST_** * If immediate admission is not possible, start emergency treatment: * Lie the person flat with their face up and head NOT supported by pillows, this will relieve some of the pressure on the angle * Give **_a combination of eyedrops_**, including: * **_Topical parasympathomimetic_** (e.g. **_pilocarpine_** --\> contraction of ciliary muscles --\> opening the trabecular meshwork --\> increased drainage of the aqueous humour) * **_Carbonic anhydrase inhibitors_** (e.g. **_oral acetazolamide_** or topical brinzolamide) - reduces secretion of aqueous humour * This can be given as IV in secondary care or if the patient is unable to swallow * **_Topical beta-blocker_** (e.g. **_timolol)_** - blocks beta-2 adrenoceptors to reduce production of aqueous humour by the ciliary epithelium * **_Topical alpha-2 agonist_** (e.g. **_apraclonidine_**, **_brimonidine tartrate_**) - reduces secretion of aqueous humour + increases uveoscleral outflow * If all of the above fail --\> **_hyperosmotic agents_** (e.g. **_mannitol_**) - reduces IOP by extracting fluid from the aqueous humour * **_Analgesics_** and **_antiemetics_** * Secondary care * If initial medical management in primary care can't immediately relieve the IOP --\> **_anterior chamber paracentesis_** Definitive Mx: * **_Laser peripheral iridotomy_** - creates a hole in the iris * This allows aqueous humor to flow freely from the posterior chamber into the anterior chamber without having to go through the pupil. This equilibrises the pressure between the two chambers, freeing the angle and reducing IOP * **_The unaffected eye is usually also treated preventively with laser iridotomy due to a high risk of developing acute angle closure in the future_**

Answer 17

Mx: * **_Laser peripheral iridotomy_** to bypass the 'pupillary block' - this allows equilibrisation of pressure between the posterior and anterior chambers thereby preventing a buildup of pressure in the posterior chamber * Pupillary block (see image) occurs when the flow of aqueous humour from the posterior chamber to the anterior chamber is obstructed by a functional block between the pupillary portion of the iris and the anterior part of the lens * If treatment failure due to significant scarring of the trabecular meshwork from previous contact with the iris --\> treat it as open-angle glaucoma

Answer 18

If left untreated, it accounts for half of glaucoma-related blindness worldwide With early recognition and treatment, the prognosis is good

Answer 19

a) . Affects both sexes equally b) . RARE in people under aged 40 yrs old (prevalence increases with age) c) . It affects 2% of adults over the age of 40 yrs old in the UK d) . FALSE ! It's more common in black ethnicity

Answer 20

Presentations: * **_Insidious onset_**! * **_Asymptomatic_** in most cases until late stages of disease - diagnosis usually made on routine ophthalmic examination * However, in those who are symptomatic: * **_Visual field loss_** (**_nasal scotomas --\> 'tunnel vision' --\> central vision loss (late stages)_** * People are often unaware that they have a visual field defect, even when it is severe. This is because the visual fields of the eyes overlap, and so a visual field defect in one eye may be well compensated for by the other eye until that too becomes affected. Small visual field defect is hard to notice as the brain will try to "fill out the missing gaps' in the visual field * **_Decreased visual acuity_** * **_Raised IOP_** * Fundoscopy shows: * **_Optic disc cupping_** * **_Cup-to-disc ratio \> 0.7_** (normal = 0.4-0.7) * **_Optic disc pallor --\> optic atrophy_** (due to raised IOP causing damage on the optic nerve) * **_Bayonetting of blood vessels_** - this is when bvs bend or kink sharply when they pass over the edge of the cup * Cup notching (usually on the inferior side where vessels enter disc), disc haemorrhages

Answer 21

Bayonetting of blood vessels --\> primary open angle glaucoma

Answer 22

Diagnosis is usually made during ophthalmic examination at optometrists: * **_Ophthalmoscopy_** - shows cupping of optic disc, pale optic disc (optic atrophy), bayonetting of bvs * **_Visual field assessment_** * **_Check IOP_** - usually raised, however, some patients can develop glaucoma with a normal IOP * **_Gonioscopy_** - check anterior chamber, the internal drainage system and the iridocorneal angle * **_Pachymetry_** (see image) to assess corneal thickness - IOP readings vary depending on corneal thickness. Those with a thicker corneal thickness may show a higher reading of IOP than actually exists

Answer 23

Mx: * 1st line: * **_Topical prostaglandin analogue (e.g. Latanoprost)_**, OR * 1st line if patient has a **_Hx of asthma_**! * Mechanism of action - increases uveoscleral outflow * ADRs - brown pigmentation of the iris, increased eyelash length, and periocular pigmentation (bilateral dark circles/ rings on the infraorbital regions) * **_Topical beta-blocker (e.g. Timolol)_** * **__**Mechanism of action - reduces aqueous production * ADRs - non-selective side effects --\> bradycardia, bronchoconstriction, diarrhoea, peripheral coldness, confusion (from hypotension), heart failure * Contraindications - asthmatics, COPD, heart block * 2nd line treatment options may include: * Switch to a drug in the other 1st line drug class (e.g. if latanoprost doesn't work, give timolol, vice versa), OR * Combine a topical prostaglandin analogue with a topical beta-blocker, OR * Switching to, or adding in, a 2nd line drug, which are: * **_Topical sympathomimetic (alpha-2 agonist) e.g. brimonidine tartrate_** * **__**Mechanism of action - reduces aqueous production and increases uveoscleral outflow * ADRs - hyperaemia of the skin, dry mouth, headache, dizziness, unpleasant taste * Avoid if taking MAOI or TCA * Contraindications - pregnancy, breastfeeding * **_Topical carbonic anhydrase inhibitor e.g. brinzolamide or dorzolamide_** * **__**Mechanism of action - reduces aqueous production * ADRs - eye discomfort, altered taste, vision disorders, systemic absorption of brinzolamide can produce sulphonamide-like reactions * **_Topical miotic (muscarinic receptor agonist) e.g. pilocarpine_** * **__**Mechanism of action - increases uveoscleral outflow * ADRs - excessively constricted pupil, headache, blurred vision, diarrhoea, hypersalivation, hyperhidrosis * If more advanced/ refractory cases --\> **_surgery (trabeculectomy)_** OR **_laser treatment (selective laser trabeculoplasty)_**

Answer 24

Inflammation of the sclera with maximal congestion in the **_deep vascular plexus_**

Answer 25

* Conjunctiva * Lies on top of the 3 layers of sclera * Contains **_c_****_onjunctival plexus_** * **_No particular pattern_** * **_Freely mobile_** * _**\*In conjunctivitis - they appear bright red when inflamed**_ From outer to innermost, the 3 layers of the sclera are: * Episclera (see image) * Contains the **_superficial episcleral plexus_** * Lies within the superficial episclera * **_Radial configuration_** * **_Mobile over deeper layers_** * _**\*In episcleritis - they appear salmon pink when inflamed**_ * Contains the **_deep vascular plexus_** * Lies deep to tenon's capsule and directly over the scleral stroma * **_Criss-cross pattern_** * **_Immobile_** * _**\*In scleritis - they appear violaceous (bluish red) when inflamed**_ * Stroma * Avascular middle layer and is made of type 1 collage * Lamina fusca * Anchors the sclera to the underlying choroid **_So in episcleritis, it's the superficial episcleral plexus that gets inflamed while in scleritis it's the deep vascular plexus that gets inflamed!_**

Answer 26

Usually **_systemic inflammatory diseases_** (50% of cases) rather than infectious Autoimmune-related: * _**\*Rheumatoid arthritis (most common)**_ * SLE * IBD * Sjogren's syndrome * Wegener's granulomatosis (Rarely, it can occur secondary to ocular surgery or infections e.g. TB, current or previous herpes zoster ophthalmicus)

Answer 27

Presentations: Symptoms * **_Severe boring pain + painful eye movement_** * Headaches * **_Red eye (bluish red/ violaceous/ dull pink)_**, may have overlying bright red vessels * Localised * Diffuse * Nodular * Watering and photophobia * Reduced visual acuity (late sign in severe scleritis) * Clinical features of rheumatoid arthritis Signs * **_Very tender to touch_** * Recurring scleritis can result in **_scleral thinning_**, exposing the underlying choroid --\> giving the sclera a blue appearance (see image). It can also cause **_corneal thinning_**

Answer 28

Mx: * Primary care * **_Urgent referral to an ophthalmologist for same-day assessment_** * **_Treat underlying cause_** * Rheumatoid arthritis (most common) * cDMARD monotherapy (methotrexate/ leflunomide/ sulfasalazine) +/- a short course of bridging prednisolone * Offer additional cDMARD * For flares --\> Oral/ IM corticosteroids * Infections (rare) * Abx (e.g. RHZE if TB) * NSAIDs * Corticosteroids * Immunosuppression

Answer 29

**_Episcleritis_** is extremely common! | (Scleritis is rare)

Answer 30

Episclera inflammation (non-infective) with maximal congestion in **_superficial episcleral plexus_**. It's **_extremely common_**, particularly in **_young adults_**! Half of the cases are bilateral!

Answer 31

**_No obvious precipitants_** for episcleritis, though symptoms tend to recur Rarely a manifestation of a systemic disease

Answer 32

Presentations: Symptoms * **_NOT painful_** (mild discomfort at most) - patients are often **_asymptomatic_** * Mild tearing/ irritation * **_Red eye: localised (sectoral) or diffuse hyperaemia_**, with **_dilated bright red vessels running superficially ("subconjunctival injection")_** * **__**Episclera is located beneath the conjunctiva, hence "subconjunctival" * Watering and mild photophobia may be present * No discharge and not sight-threatening Signs * Tender to touch * **_Vessels are mobile when gentle pressure is applied on the sclera using a swab (and topical anaesthesia)_** * This helps distinguish episcleritis from scleritis, as the vessels in scleritis are deeper so they do not move * **_Vessels blanch with phenylephrine eye drops (vasoconstrictor) leading to an improvement in eye redness_** * This helps distinguish episcleritis from scleritis, as phenylephrine blanches the conjunctival and episcleral vessels but not the scleral vessels (too deep for the medication to reach)

Answer 33

Mx: * **_Self-limiting_** * Simple analgesia (NSAIDs) * Topical lubricants * Rarely, low dose steroids

Answer 34

From outer to innermost, the layers of the cornea are: * **_Corneal epithelium_** * Thin and multicellular * Non-keratinised stratified squamous epithelium - made of 6 layers of cells which are shed constantly on the exposed layer and are regenerated by multiplication in the basal layer * **_Bowman's layer_** * A tough layer composed of mainly type 1 collagen and other fibres * Protects the underlying corneal stroma * **_Corneal stroma_** * A thick transparent middle layer, consisting of regularly arranged type 1 collagen fibres along with sparsely distributed interconnected keratocytes, which are the cells for repair and maintenance * **_Descemet's membrane_** * Thin and acellular * Serves as the basement membrane of the corneal endothelium * Composed of type IV collagen * **_Corneal endothelium_** * Simple squamous monolayer * Role - regulates fluid and solute transport between the aqueous and corneal stromal compartments * Bathed by aqueous humour, not by blood or lymph * Unlike the corneal epithelium, the cells of the endothelium do not regenerate. Instead, they stretch to compensate for dead cells which reduces the overall cell density of the endothelium, which affects fluid regulation. If the endothelium can no longer maintain a proper fluid balance, stromal swelling due to excess fluids and subsequent loss of transparency will occur and this may cause corneal edema and interference with the transparency of the cornea and thus impairing the image formed

Answer 35

CNV1 - ophthalmic division of the trigeminal nerve (The density of pain receptors in the cornea is 300-600 times greater than skin and 20-40 times greater than dental pulp, making any injury to the structure excruciatingly painful!) Corneal reflex: Afferent limb - CNV1 (ophthalmic of trigeminal) Efferent limb - CN7 (facial)

Answer 36

**_Keratitis is inflammation of the cornea_** **_Microbial keratitis_** (bacterial, fungal, amoebic, parasitic) are **_sight-threatening_** so they must be urgently evaluated and treated! (Don't confuse keratitis with conjunctivitis. Conjunctivitis is inflammation of the conjunctiva and is rarely serious)

Answer 37

Aetiology: * _**\*Bacterial**_ * **_Staphylococcus aureus (most common)_** * Staphylococcus epidermidis * **_Pseudomonas aeruginosa (contact lens wearers) - most aggressive as it contains enzymes that can digest the cornea_** * Streptococcus pyogenes, streptococcus pneumoniae * Fungal * Aspergillus fumigatus * Candida albicans * Amoebic * Acanthamoeba (contact lens wearers) * Parasitic: onchocercal keratitis ('river blindness') - follows Onchocerca volvulus infection by infected blackfly bite. These blackfly usually dwell near fast-flowing African streams, hence the name "river blindness" * _**\*Viral**_ * **_Herpes simplex keratitis (HSV)_** * **_H_****_erpes zoster keratitis (VZV)_** * Environmental * Photokeratitis e.g. welder's arc eye - painful eye caused by exposure of insufficiently protected eye to the UV rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) sources * Exposure keratitis * Contact lens acute red eye (CLARE)

Answer 38

Common bacteria: * Staphylococcus aureus * Staphylococcus epidermidis * Pseudomonas aeruginosa * Streptococcus pyogenes, Streptococcus pneumoniae

Answer 39

**_Staphylococcus aureus_**

Answer 40

**_Pseudomonas aeruginosa_** ## Footnote **(It causes a particularly aggressive infection as it contains enzymes that can digest the cornea)**

Answer 41

Risk factors: * **_Contact lens wear (usually soft lenses with extended use; rare with hard lenses)_** * Corneal trauma (including abrasion by eyelashes due to entropion) * A chronically compromised ocular surface e.g. dry eye, blepharitis, and bullous keratopathy (endothelial failure) * Herpetic keratitis * Corneal expsure (facial nerve palsy, proptosis) * Facial nerve palsy --\> impaired corneal reflex --\> eyes unable to blink when foreign material irritates the eye * Proptosis - more eye surface exposed to air * Corneal anaesthesia (neurotrophic keratopathy) - a rare degenerative disease of the cornea characterised by reduction/ loss of corneal sensitivity * Immunosuppression, including topical steroid use

Answer 42

Presentations: Symptoms * Severe eye pain + red eye * Purulent conjunctivitis --\> discharge * Watering and photophobia * FB, gritty sensation * Reduced visual acuity Signs * Corneal ulcer * Corneal oedema --\> haziness * In severe case --\> hypopyon, which is a sign of intraocular infection (endophthalmitis) --\> blindness

Answer 43

Ix: * Culture of conjunctival and corneal samples * Blood agar (for most fungi and bacteria except Neisseria) * Chocolate agar (for Neisseria and Moraxella) * Sabouraud agar (for fungi)

Answer 44

Mx: * Primary care * **_Urgent same-day referral to an ophthalmologist for anyone with a red eye who wears contact lenses_** * Assessing contact lens wearers who present with a painful red eye is difficult, an accurate diagnosis can only be made with a slit-lamp, hence the need for an urgent referral * Stop using contact lens until symptoms have fully resolved * Broad-spectrum topical Abx * 1st line - **_quinolones (topical ofloxacin)_** * Initially - administer hourly * Subsequently 2 hourly (waking hours) * Tapered * Cycloplegic (**_cyclopentolate_**) for pain relief * **_Topical steroids_** are only used when cultures become sterile (indicating resolution of the infection) with evidence of improvement (7-10 days after initiation of treatment)

Answer 45

Viruses: * Herpes Simplex Virus type 1 (HSV1) * Varicella-zoster virus (VZV)

Answer 46

**_HSV1_**: * Primary infection usually occurs subclinically in childhood but can cause a blepharoconjunctivitis and a dendritic corneal ulcer. The virus then lies dormant in the trigeminal ganglion * Secondary infection occurs when the virus reactivates and travels along the ophthalmic division of the trigeminal nerve to the cornea of the eye, causing a **_dendritic ulcer_** - this corneal involvement of the HSV infection is called **_herpes simplex keratitis_**. HSV1 can also travel along the maxillary or mandibular division of the trigeminal nerve to cause cold sores in upper and lower lips * Reactivation is usually due to weakened immune system e.g. old age, immunosuppression (steroids, chemo, diabetes) **_VZV_**: * Primary infection (chickenpox) may cause a conjunctivitis and, rarely, a dendritic ulcer. The virus then lies dormant in the trigeminal ganglion * Secondary infection occurs when the latent virus in the trigeminal ganglion reactivates and travels along the trigeminal nerve (ophthalmic division) to the ophthalmic area to cause shingles --\> **_herpes zoster ophthalmicus_** (accounts for 10% of all cases of shingles) * If the cornea is involved in herpes zoster ophthalmicus, it can result in a **_pseudodendritic ulcer_** - this corneal involvement of VZV infection is called **_herpes zoster keratitis_**

Answer 47

Presentations * Red, painful eye * Watering (epiphora) and photophobia * Reduced visual acuity * Fluorescein staining under cobalt blue light shows **_dendritic corneal ulcer_** * Decreased corneal sensation * Recurrent cold sores * Hx of illness, stress, run down, sunlight exposure, menstrual period * **_Steroid use in dendritic ulcer --\> geographical ulcer_** * **__**Branches of dendritic ulcer enlarges and coalesces to form 'amoeboid' or 'geographical' configuration * \*‘**_Do not apply steroids to the undiagnosed red eye_**’. This is because **_applying steroid to a herpes simplex keratitis will likely result in a ‘geographic ulcer’, or a very large, irregular epithelial defect (as you have impaired the body’s immune response)._** If the infection is confined to the corneal epithelium, healing occurs without scarring. However, if it affects the corneal stroma, it will cause scarring of the cornea +/- anterior uveitis

Answer 48

Ix: * Confirm the diagnosis by identification of the virus from cells scraped from the ulcer edge * This is important particularly because infection maybe recurrent and may mimic many other types of corneal infection and inflammation

Answer 49

Mx: * Primary care * Urgent same-day referral to an ophthalmologist to anyone with corneal ulcer * Topical aciclovir * Cyclopentolate for pain relief * Oral aciclovir can be given long term as prophylaxis against recurrent disease * Topical steroids to minimise scarring, esp when treating stromal disease and anterior uveitis. However, they can ONLY be given after healing of corneal ulcer * Topical steroids applied to a herpetic corneal ulcer will cause a geographical/ amoeboid ulcer (fucking massive!), which is slow to heal and very hard to treat

Answer 50

Presentations: * **_Vesicular rash (crusting and ulceration of skin) in ophthalmic (CNV1) territory_** - may or may not involve the cornea * If cornea is involved --\> **_pseudodendritic ulcer_** (**_herpes zoster keratitis_**) * The skin rash is dermatomal, involving the forehead to occiput and the upper lid, tending to spare the lower lid but usually affecting the side of the nose * **_Hutchinson's sign_** - rash on the tip or side of the nose. This indicates nasociliary involvement and is a strong risk factor for ocular involvement

Answer 51

* Ocular complications: viral conjunctivitis, keratitis, anterior uveitis, scleritis, episcleritis, optic neuritis, ptosis * Post-herpetic neuralgia

Answer 52

Mx: * Primary care * Urgent same-day referral to an ophthalmologist for anyone with a corneal ulcer (ocular involvement) * Oral aciclovir for 7-10 days, ideally started within 72 hrs of onset of vesicles * IV aciclovir maybe given for very severe infection or if the patient is immunocompromised * Topical aciclovir is NOT given in HZO * Topical corticosteroids maybe used to treat any secondary inflammation of the eye

Answer 53

The answer is d! **_Contact lens wearers who present with a red painful eye_** should be referred to eye casualty to exclude microbial keratitis and corneal ulcer