Outer Layer: Sclera, Cornea, Pupil, and Lens Flashcards
What are features of Subconjunctival Haemorrhage?
- Completely benign
- Vessel rupture painlessly leading to red staining of cornea
- History of trauma or coughing bouts
What are features of Conjunctivitis?
- Most common eye problem
- Irritating but generally pointless
- Conjunctiva may begin to develop follicles (viral cause) or papillae (allergic or bacterial cause)
- Can be bacterial, viral, neonatal or allergic
What are the features associated with bacterial conjunctivitis?
- Purulent discharge
- Eyes get stuck together in the morning upon waking
- Conjunctiva may begin to develop papillae (allergic or bacterial cause)
What are the features associated with viral conjunctivitis?
- Serous Discharge
- There is recent Upper Respiratory Tract Infection.
- Preauricular lymph nodes are present
- Conjunctiva may begin to develop follicles (viral cause)
What are the signs and symptoms of Conjunctivitis?
- Red, itchy and inflamed eyes
- Puffy, swollen orbit and eyelids
- Discharge, especially noticeable upon waking as it builds up over night
- Photophobia indicates corneal involvement
- Conjunctival vessels will be inflamed and dilated
What are risk factors/modes of transmission for Conjunctivitis?
- Contact lenses
- Spread through contact
- Allergies (hay fever, dust allergies, fur)
What are some differential diagnosis for Conjunctivitis?
- Uveitis - more likely to be painful and will reduce visual acuity
- Glaucoma
- Early herpes zoster
- Keratitis - may follow on from conjunctivitis
- Scleritis/episcleritis
What are some investigations for Conjunctivitis?
- Swab any discharge to look for bacterial infection and culture
- If worried about other causes then do slit lamp and send for pressure testing
What are common organisms with Viral and Bacterial conjunctivitis?
- Bacterial: Staph Aureus, Strep Epidermidis, Strep Pneumoniae, H. influenzae, Chlamydia (mucopurulent discharge)
- Virus: Adenovirus, Herpes Simplex Virus
What are the features associated with allergic conjunctivitis?
- Discharge will be watery
- Does not get better with normal treatment
- Bilateral symptoms conjunctival erythema, conjunctival swelling (chemosis)
- Itch is prominent
- Eyelids may also be swollen
- History of atopy
- May be seasonal (due to pollen) or perennial (due to d
How does neonatal conjunctivitis occur?
- Passed through the birth canal
- Can be transmitted from Gonorrheal or Chlamydial infection
- Urgent samples, gram staining and swabs are needed for viral, bacterial and chlamydial infections
How is Conjucntivitis managed?
Normally a self-limiting condition that usually settles without treatment within 1-2 weeks. If it lasts further than this:
- Bacterial
- Topical antibiotic therapy such as Chloramphenicol 0.5% drops are given every 2-3 hours initially or
- Chloramphenicol ointment QDS.
- Topical fusidic acid is an alternative and should be used for pregnant women. Treatment is twice daily
- Non-bacterial
- Lubricant eye drops - ease soreness and stickiness
Contact lens should not be worn during an episode of conjunctivitis
Advice should be given not to share towels and school exclusion is not necessary
How is Allergic Conjunctivitis managed?
First-line: topical or systemic antihistamines
Second-line: topical mast-cell stabilisers, e.g. Sodium cromoglicate and nedocromil
Corticosteroids in severe allergic cases
What are causes of Corneal Abrasions?
- Damage from small objects scraping across the eye
- Foreign bodies, which may be caught under the eyelid
- Chemicals in the eye
- Infection
- Damage from UV light
What are signs of symptoms of Corneal abrasions?
- Foreign body sensation/foreign body can be seen
- Redness and watering
- Pain
- Blurred vision
- Photophobia
What are examinations for individuals with Cornal Abrasions?
- Assess depth of penetration of an injury - Refer immediately in ruptured globes
-
Full slit lamp examination
- View the cornea under blue light with fluorescein dye in the eye
- Damage will appear green under the light, ulcers may show vibrant green areas due to leukocyte build up (hypopyon). The ulcers require scraping so that gram stains and cultures can be sent
- If aqueous is seen to flow out into the laceration and is diluting the fluorescein then the globe has been ruptured (seidel’s test - ask patient not to blind after applying dye and see how fast it dilutes)
- View the cornea under blue light with fluorescein dye in the eye
- Assess visual acuity and carry out fundus examination
What are features of Recurrent Corneal Erosions?
- Erosions may continue to re-open the wounds on cornea leading to repeated episodes of burning in the eye
- During sleep, eyelid may be stuck to abrased area and upon waking may tear again as eyelid opens. Upon waking, there could be redness and photophobia with blurred vision
- Adequate lubrication is only way to reuce recurrence of symptoms
What is superficial punctate epithelial erosions?
- Small erosions which occur commonly in patients
- May be completely asymptomatic but if symptomattic then can be pain and burning sensations
- Likely to clear up once dry eyes resolve
What is the management for corneal abrasions, ulcers and erosions?
-
Chemical burns require irrigation with saline and immediate referral
- Steroids to calm the inflammation
- Debridement of necrotic tissue
- Analgesia (paracetamol and ibuprofen) for eye pain
- Remove any foreign bodies if possible
-
Prevent infection
- Prophylactic chloramphenicol eye drops
- Prophylactic levofloxacin is indicated in contact lens users as they are more likely to be infected with pseudomonas aeruginosa, which is often resistant to chloramphenicol
- Foreign bodies may require tetanus
-
Treat infected ulcers with antibiotics
- Levofloxacin and cefuroxime hourly (5 in apart so they don’t dilute each other) for 48 hours
- Give atropine as well to paralyse the ciliary body - reduces pain, improves healing and reduces risk of adhesions
What are sign and symptoms of Episcleritis?
Symptoms
- Classically not painful (in comparison to scleritis), but mild pain may be present
- Localised (sectoral or diffuse)
- Visual acuity not altered
- Watering and mild photophobia may be present
Signs
- Red Eye
- Episcleral vessels blanch with phenylephrine drops. If the eye redness improves after phenylephrine a diagnosis of episcleritis can be made
- In episcleritis, the injected vessels are mobile when gentle pressure is applied on the sclera. In scleritis, vessels are deeper, hence do not move
What are signs and symptoms of Scleritis?
Symptoms
- Watering and photophobia
- Appearance bluish-red (localised, diffuse, nodular)
- Classically painful (in comparison to episcleritis), but sometimes only mild pain/discomfort is present
Signs
- Scleral vessels appear darker and follow a radial pattern
- They are immobile and do not blanch
- Gradual decrease in vision
What is the management of Episcleritis?
- Usually self-limiting (may last for months)
- Lubricant or artificial tears
- Oral NSAIDs
- Rarely topical steroids may be necessary to reduce inflammation
What is the management for Scleritis?
- Oral NSAIDs and prednisolone
- If above not effective, then immunosuppressants such as methotrexate and biological response modifiers such as infliximab can be used
- Rheumatoid screen and be screened for inflammatory markers, as the disease may arise due to systemic inflammatory disorders
What is Keratitis?
Keratitis describes inflammation of the cornea. Microbial keratitis is not like conjunctivitis - it is potentially sight threatening and should therefore be urgently evaluated and treated.
What is the aetiology of Keratitis?
- Bacterial
- typically Staphylococcus aureus
- Pseudomonas aeruginosa is seen in contact lens wearers
- Fungal
- Amoebic
- Acanthamoebic keratitis
- accounts for around 5% of cases. Increased incidence if eye exposure to soil or contaminated water
- Parasitic: onchocercal keratitis (‘river blindness’)
- Viral: herpes simplex keratitis
- Environmental
- photokeratitis: e.g. welder’s arc eye
- exposure keratitis
- contact lens acute red eye (CLARE)
What are clinical features of Keratitis?
- Red eye: pain and erythema
- Photophobia
- Foreign body, gritty sensation
- Hypopyon may be seen
Who is reffered for suspicion of Keratitis?
Contact lens wearers
- Assessing contact lens wearers who present with a painful red eye is difficult
- An accurate diagnosis can only usually be made with a slit-lamp, meaning same-day referral to an eye specialist is usually required to rule out microbial keratitis
How is Keratitis managed?
- Stop using contact lens until the symptoms have fully resolved
- Topical antibiotics typically quinolones are used first-line
- Cycloplegic for pain relief e.g. cyclopentolate
What are complications of Keratitis?
- Corneal scarring
- Perforation
- Endophthalmitis
- Visual loss
What are the features of Herpes Simplex Keratitis?
- Red, painful eye
- Photophobia
- Epiphora
- Visual acuity may be decreased
- Fluorescein staining may show an epithelial ulcer
How is Herpes Simplex Keratitis managed?
Immediate referral to an ophthalmologist
- Topical aciclovir
What is Periorbital Cellulitis (preseptall cellulitis)?
- Infection of soft tissues anterior to orbital septum which includes eyelids, skin, and subcutaneous tissues of the face but not content of the orbit
- Infection usually spreads to structures surrounding orbit from other nearby sites through breaks in skin or local infections such as sinusitis or other respiratory tract infections
- Most frequent organisms are Staph. aureus, Staph. epidermidis, Streptococci and Anaerobic bacteria.
What are some epidemiological factors associated with Periorbital Cellulitis?
- Periorbital cellulitis occurs most commonly in children - 80% of patients are under 10 and the median age of presentation is 21 months
- More common in the winter due to the increased prevalence of respiratory tract infections.
What are symptoms of Periorbital Cellulitis?
- The patient presents with a red, swollen, painful eye of acute onset.
- They are likely to have symptoms associated with fever.
What are signs of Periorbital Cellulitis?
- Erythema and oedema of the eyelids, which can spread onto the surrounding skin
- Partial or complete ptosis of the eye due to swelling
Orbital signs (pain on movement of the eye, restriction of eye movements, proptosis, visual disturbance, chemosis, RAPD) must be absent in preseptal cellulitis - their presence would indicate orbital cellulitis
What are investigations of Periorbital Cellulitis?
- Bloods - raised inflammatory markers
- Swab of any discharge present
- Contrast CT of the orbit may help to differentiate between preseptal and orbital cellulitis. It should be performed in all patients suspected to have orbital cellulitis
What is the management of Periorbital Cellulitis?
- All cases should be referred to secondary care for assessment
- Oral antibiotics are frequently sufficient - usually co-amoxiclav
- Children may require admission for observation
What are complications for Periorbital Cellulitis?
Bacterial infection may spread into the orbit and evolve into orbital cellulitis
What are differentials for Periorbital Cellulitis?
- Orbital cellulitis
- Allergic reaction
What is Herpes zoster ophthalmicus?
Herpes zoster ophthalmicus (HZO) describes the reactivation of the varicella-zoster virus in the area supplied by the ophthalmic division of the trigeminal nerve. It accounts for around 10% of case of shingles.
What are features of Herpes zoster ophthalmicus?
- Vesicular rash around the eye, which may or may not involve the actual eye itself
- Hutchinson’s sign: rash on the tip or side of the nose. Indicates nasociliary involvement and is a strong risk factor for ocular involvement
How is Herpes zoster ophthalmicus managed?
- Oral antiviral treatment for 7-10 days
- Ideally started within 72 hours
- Intravenous antivirals may be given for very severe infection or if the patient is immunocompromised
- Topical antiviral treatment is not given in HZO
- Topical corticosteroids may be used to treat any secondary inflammation of the eye
- Ocular involvement requires urgent ophthalmology review
What are complications of Herpes zoster ophthalmicus?
- Ocular: conjunctivitis, keratitis, episcleritis, anterior uveitis
- Ptosis
- Post-herpetic neuralgias
What is Orbital Cellulitis?
- Medical emergency requiring hospital admisiton and senior review
- Infection affecting fat and muscles posterior to orbital septum within the orbit but not involving globe
- Usually caused by spreading upper respiratory tract infection from sinuses and carries high mortality rate.
What are risk factors for Orbital Cellulitis?
- Childhood
- Previous sinus infection
- Lack of Haemophilus influenzae type b (Hib) vaccination
- Recent eyelid infection/ insect bite on eyelid (Peri-orbital cellulitis)
- Ear or facial infection
How does Orbital Cellulitis present?
- Redness and swelling around the eye
- Severe ocular pain
- Visual disturbance
- Proptosis
- Ophthalmoplegia/pain with eye movements
- Eyelid oedema and ptosis
- Drowsiness +/- Nausea/vomiting in meningeal involvement (Rare)
How does Orbital Cellulitis differ to Periorbital Cellulitis?
These features are NOT consistent with preseptal cellulitis:
- Reduced visual acuity
- Proptosis
- Ophthalmoplegia/pain with eye movements
What are the investigations for Orbital Cellulitis?
- Full blood count – WBC elevated, raised inflammatory markers.
- Clinical examination involving complete ophthalmological assessment – Decreased vision, afferent pupillary defect, proptosis, dysmotility, oedema, erythema.
- CT with contrast – Inflammation of the orbital tissues deep to the septum, sinusitis.
- Blood culture and microbiological swab to determine the organism. Most common bacterial causes – Streptococcus, Staphylococcus aureus, Haemophilus influenzae B.
How is Orbital Cellulitis managed?
- Admission to hospital for IV antibiotics
What are features of Corneal Ulcers?
Corneal ulcers are more common in contact lens users
- Eye pain
- Photophobia
- Watering of eye
- Focal fluorescein staining of the cornea
How is Hyphema due to ocular trauma managed?
- Hyphema (blood in the anterior chamber of the eye) especially in the context of trauma warrants urgent referral to an ophthalmic specialist for assessment and management
- Main risk to sight comes from raised intraocular pressure which can develop due to the blockage of the angle and trabecular meshwork with erythrocytes.
- Strict bed rest is required as excessive movement can redisperse blood that had previously settled; therefore high-risk cases are often admitted. Even isolated hyphema will require daily ophthalmic review and pressure checks initially as an outpatient
