Conjunctiva Flashcards
(122 cards)
1
Q
How many sections can the conjunctiva be anatomically divided into.
A
3 sections.
1
Q
What is the conjunctiva?
A
Thin, transparent membrane that lines the surface of the sclera and the underside of the eyelid.
2
Q
What are the 3 sections of the conjunctiva?
A
- Palpebral.
- Bulbar.
- Forniceal.
3
Q
What is the palpebral conjunctiva?
A
Lines the posterior surface of the eyelid.
4
Q
What is the bulbar conjunctiva?
A
Lines the anterior surface of the sclera.
5
Q
What is the forniceal conjunctiva?
A
A folded layer between the palpebral and bulbar conjunctiva.
6
Q
What is the role of the forniceal conjunctiva?
A
Allows movement of the eyelids.
7
Q
Where does the conjunctiva fuse?
A
Fuses with the sclera at the limbus.
N.B., does not cover the cornea.
8
Q
Which nerve mainly innervates the cornea?
A
CNV1 (ophthalmic branch of the trigeminal nerve).
9
Q
Which nerve innervates the inferior conjunctiva?
A
Infraorbital nerve.
10
Q
Which nerve innervates the limbus?
A
Long ciliary nerve (branch of the nasociliary nerve).
11
Q
Which lymph node does the medial conjunctiva drain into?
A
Submandibular nodes.
12
Q
Which lymph node does the lateral conjunctiva drain into?
A
Pre-auricular nodes.
13
Q
What is hyperaemia? (signs of conjunctival disease)
A
Conjunctival injection - enlargement of conjunctival vessels.
14
Q
What is chemosis? (signs of conjunctival disease)
A
Conjunctival oedema - transparents swelling of the conjunctiva.
15
Q
What are conjunctival membranes? (signs of conjunctival disease)
A
Exudative adherences of the conjunctiva.
16
Q
What is cicatrization? (signs of conjunctival disease)
A
Scarring of the conjunctiva.
17
Q
What are follicles? (signs of conjunctival disease)
A
Discrete lesions which appear like transparent grains of rice. No vessels inside the lesion.
18
Q
What are papillae? (signs of conjunctival disease)
A
Lesions confined to the palpebral conjunctiva with a vascular centre.
19
Q
What are the two distinct clinical appearances of conjunctivitis?
A
- Papillae.
- Follicles.
20
Q
What do papillae look like in conjunctivitis?
A
Red (blood vessel) centre and flat top.
21
Q
Where are papillae more commonly found in conjunctivitis?
A
Upper lid.
22
Q
Which types of conjunctivitis are papillae associated with?
A
- Viral.
- Chlamydia.
- Toxic.
23
Q
What do follicles look like in conjunctivitis?
A
Dome-shaped discrete transparent lesions.
24
Where are follicles more commonly found in conjunctivitis?
Lower lid.
25
Which types of conjunctivitis are follicles associated with?
- Bacterial.
- Allergic.
26
Describe the presentation of bacterial conjunctivitis.
- Acute/hyperacute.
- Red, sticky eyes.
- Purulent discharge.
27
Describe the presentation of viral conjunctivitis.
- Acute.
- Red, watery eyes.
- Lymphadenopathy.
28
Describe the presentation of chlamydial conjunctivitis.
- Subacute.
- Unilateral, red eye.
- Persisting mucopurulent discharge.
- Lymphadenopathy.
29
Describe the presentation of gonococcal conjunctivitis.
- Hyperacute (<24 hours).
- Red eyes.
- Keratitis.
- Severe, purulent discharge.
- STI risk factors.
30
Describe the presentation of allergic conjunctivitis.
- Acute/recurrent.
- Red, itchy eyes.
- Watery discharge.
31
When are conjunctival swabs indicated?
Reserved for severe/atypical cases and not routinely indicated in simple acute bacterial/viral conjunctivitis.
32
What are the common causes of bacterial conjunctivitis in cool climates?
- Streptococcus pneumoniae.
- Haemophilus influenzae.
33
What are the common causes of bacterial conjunctivitis in warm climates?
Haemophilus aegyptius.
34
What are the common causes of bacterial conjunctivitis in children?
Haemophilus influenzae.
35
What does chronic and relapsing conjunctivitis indicate?
The presence of a nearby reservoir colony.
36
When should chronic/relapsing conjunctivitis be suspected?
- Chronic dacryocystitis.
- Staphylococcus blepharitis.
- Giant fornix syndrome.
37
What is giant fornix syndrome characterised by?
Sequestration of bacteria in the upper fornix of the conjunctiva. Typically seen in the elderly.
38
Describe the presentation of bacterial conjunctivitis.
- Acute/hyperacute, red, sticky eyes with purulent discharge.
- Starts unilateral, becomes bilateral.
- Eyes stuck together in the morning.
39
What investigations are done for bacterial conjunctivitis? When are swabs required?
- Clinical diagnosis.
- Swabs only required in unresolving cases or severe infections.
40
When can bacterial conjunctivitis become dangerous?
Involvement of the cornea (keratitis).
41
What is the initial management of bacterial conjunctivitis?
- Good hand and eye hygiene.
- Advise to return if unresolved in a week.
- Stop contact lenses temporarily.
42
Which medications are prescribed for bacterial conjunctivitis?
Topical chloramphenicol drops.
43
When are systemic antibiotics prescribed for bacterial conjunctivitis?
- Gonococcal disease in adults.
- H. influenzae/meningococcal disease in children.
44
Which antibiotic is preferred in appropriate cases of bacterial conjunctivitis?
PO co-amoxiclav.
45
Which organism causes adult inclusion body chlamydial conjunctivitis?
Chlamydia trachomatis.
46
Which serotype of Chlamydia trachomatis causes adult inclusion body chlamydial conjunctivitis?
Serotypes D-K.
47
Which immunotypes of Chlamydia trachomatis cause lymphogranuloma venereum?
L1, L2 and L3.
48
Describe the presentation of adult inclusion body chlamydial conjunctivitis.
- Subacute (2-3 weeks).
- Unilateral conjunctivitis in young people.
- Associated with STI symptoms such as urethritis.
- Inferior follicular conjunctivitis with persisting mucopurulent discharge and lymphadenopathy.
49
Which investigations are used to diagnose adult inclusion body chlamydial conjunctivitis? What do they show?
Swab > PCR > prompt diagnosis.
Giemsa stain shows basophilic intracystoplasmic inclusion bodies.
50
Describe the management of adult inclusion body chlamydial conjunctivitis.
1g PO azithromycin STAT
OR
100mg doxycycline BD for 14 days.
51
What is trachoma?
Highly infectious epidemic conjunctivitis in developing countries.
52
What is the leading cause of preventable blindness worldwide?
Trachoma.
53
Which organism causes trachoma?
Chlamydia trachomatis.
54
Which serotypes of chlamydia trachomatis cause trachoma?
Serotypes A-C.
55
Describe the pathology of trachoma.
- Acute conjunctivitis caused by pore-like infectious particle (elementary body) of chlamydia.
- Type 4 hypersensitivity reaction after initial infection > scarring > trichiasis and entropion > corneal damage > blindness.
56
Describe the presentation of trachoma.
- Seen in poverty and crowded places.
- Chronic superior follicular conjunctivitis.
- Herbert pits (depressions of the superior limbus).
- Arlt's line (a thick band of scar tissue in the conjunctiva).
- Trichiasis and entropion.
57
What is a Herbert pit (trachoma)?
Depressions of the superior limbus.
58
What is Arlt's line (trachoma)?
A thick band of scar tissue in the conjunctiva.
59
Describe the management for trachoma. (mnemonic: SAFE)
- Surgery for trichiasis (bilamellar rotation).
- Azithromycin 1mg PO.
- Facial hygiene.
- Environmental improvement.
60
Which organism causes adult gonococcocal conjunctivitis?
Neisseria gonorrhoea, gram negative diplococcus.
61
Describe the presentation of adult gonococcal conjunctivitis.
- Severely unwell patients.
- Hyperacute and severe pain, tearing and red eye.
- Conjunctival membranes and pre-auricular lymphadenopathy.
62
Which investigations are used to diagnose adult gonococcal conjunctivitis?
- Treat all with ofloxacin drops.
- Ceftriaxone IM 1g STAT to treat gonorrhoea.
- If keratitis > admit for IV ceftriaxone.
63
What is ophthalmia neonatorum?
Conjunctivitis within the first 30 days of life.
64
Which are the 4 organisms that can cause ophthalmia neonatorum? Which is most common?
- Chlamydia (most common).
- Gonococcus.
- HSV.
- Staphylococcus.
65
Describe the treatment for chlamydial ophthalmia neonatorum.
PO erythromcycin.
66
What can chlamydial ophthalmia neonatorum progress into?
Chlamydial pneumonitis.
67
Describe the treatment for gonococcal ophthalmia neonatorum.
IM ceftriaxone + IV penicillin.
68
When does gonococcal ophthalmia neonatorum typically present?
Within 3 days of birth.
69
Describe the treatment for HSV ophthalmia neonatorum.
IV aciclovir.
70
Describe the presentation of HSV ophthalmia neonatorum.
- Watery discharge.
- Vesicular rash.
71
Which is the most common cause of viral conjunctivitis?
Adenovirus.
72
How is definitive diagnosis achieved for viral conjunctivitis?
PCR.
73
Describe the management for viral conjunctivitis.
Cold compress + artificial tears.
74
What are 3 clinical syndromes of viral conjunctivitis?
- Acute non-specific follicular conjunctivitis (ANFC).
- Pharyngoconjunctival fever.
- Epidemic keratoconjunctivitis.
75
Describe the presentation of acute non-specific follicular conjunctivitis (ANFC).
- Unilateral, red, itchy, watery eye.
- Progressive involvement of the fellow eye.
- Lymphadenopathy.
76
Describe the presentation of pharyngoconjunctival fever.
- Unilateral, red, itchy, watery eye.
- Progressive involvement of the fellow eye.
- Lymphadenopathy.
- Pharyngitis/URTI.
- Fever.
77
Which serotype of adenovirus causes pharyngoconjunctival fever?
3, 4 and 7.
78
Describe the presentation of epidemic keratoconjunctivitis.
- Follicular conjunctivitis as ANFC.
- Unilateral, red, itchy, watery eye.
- Progressive involvement of the fellow eye.
- Lymphadenopathy.
- Keratitis characterised by microcysts and punctate epithelial lesions.
79
Which serotype of adenovirus causes epidemic keratoconjunctivitis?
8, 19 and 37.
80
What is the pathology of allergic conjunctivitis?
Type 1 (immediate IgE) reaction involving mast cell degranulation.
81
What are the 4 types of allergic conjunctivitis?
Common:
- Seasonal.
- Perennial.
Clinically serious:
- Vernal keratoconjunctivitis (VKC).
- Atopic keratoconjunctivitis (AKC).
82
What in the pathology differentiates seasonal and perennial conjunctivitis from VKC and AKC?
VKC and AKC have a chronic/recurrent component mediated by type 4 sensitivity in addition to the acute type 1 reaction.
83
Describe the basic course of treatment for allergic conjunctivitis.
Treatment ladder:
1. Artificial tears to dilute allergen and restore surface integrity.
2. Mast cell stabilisers and/or anti-histamines.
3. Topical steroids.
4. Systemic immunosuppression with steroids or steroid-sparing agents such as cyclosporine.
5. Surgical debridement and/or keratectomy to address corneal ulcers in vision-threatening disease.
84
What is seasonal conjunctivitis?
- Subacute, seen in hayfever.
- Triggered by pollen in Summer.
- Type 1 hypersensitivity with mast cell degranulation.
85
Describe the presentation of seasonal conjunctivitis.
- Subacute, bilateral, itchy conjunctivitis.
- Characteristic seasonal pattern of onset and prior episodes.
86
Describe the management of seasonal conjunctivitis.
Benign and self-limiting:
- Artificial tears to dilute the allergen and restore surface integrity.
- Mast cell stabilisers and/or antihistamines.
87
What is perennial conjunctivitis?
- Like hayfever but can occur at any point and does not follow a seasonal pattern.
- Triggered by moults and dust mites.
- Type 1 hypersensitivity with mast cell degranulation.
88
What is vernal keratoconjunctivitis (VKC)?
- Recurrent conjunctivitis.
- Acute type 1 hypersensitivity reaction with mast cell degranulation follows by chronic type 4 hypersensitivity mediated by T cells.
89
Which demographic does VKC typically affect?
Teenage boys.
90
What are the subtypes of VKC? What are they based on?
1. Palpebral.
2. Limbal.
3. Mixed.
91
Describe the presentation of VKC.
- Adolescent boys in dry climates.
- Initial onset in Summer.
- Also involves cornea.
- Affects upper conjunctiva with characteristic cobblestone appearance.
92
Describe the management of VKC.
1. Artificial tears to dilute allergen and restore surface integrity.
2. Mast cell stabilisers and/or antihistamines.
3. Topical steroids.
4. Systemic immunosuppression with steroids or steroid-sparing agents such as cyclosporine.
5. Surgical debridement and/or keratectomy to address corneal ulcers in vision-threatening disease.
93
What is atopic keratoconjunctivitis (AKC)?
- Recurrent conjunctivitis.
- Acute type 1 hypersensitivity reaction with mast cell degranulation follows by chronic type 4 hypersensitivity mediated by T cells.
94
Describe the presentation of AKC.
- Affects the lower conjunctiva.
- More associated with lid diseases such as blepharitis and eczema.
95
Describe the management of AKC.
1. Artificial tears to dilute allergen and restore surface integrity.
2. Mast cell stabilisers and/or antihistamines.
3. Topical steroids.
4. Systemic immunosuppression with steroids or steroid-sparing agents such as cyclosporine.
5. Surgical debridement and/or keratectomy to address corneal ulcers in vision-threatening disease.
N.B., Calcineurin inhibitors are highly effective in exacerbations of AKC.
96
What is cicatricial conjunctivitis?
Inflammation of the conjunctiva > scarring > formation of cicatrix.
97
Describe the pathology of cicatricial conjunctivitis.
Inflammation > loss of goblet cells > failure of ocular surface integrity > limbitis and limbal stem cell failure > keratopathy + scarring.
98
What is ocular mucous membrane pemphigoid?
Chronic blistering type 2 hypersensitivity reaction of the mucosal surfaces.
99
When should we suspect ocular mucous membrane pemphigoid?
Severe, bilateral cases of papillary conjunctivitis with evidence of cicatrisation and systemic cutaneous involvement.
100
Describe the pathology of ocular mucous membrane pemphigoid.
- Linear deposits of IgA, IgG and complement in the basement membranes of mucosal surfaces.
- This can be seen on conjunctival autofluorescence.
- Antibodies target hemidesmosomes and components of the basement membranes.
101
Describe the management of mild ocular mucous membrane pemphigoid.
Dapsone.
102
Describe the management of moderate ocular mucous membrane pemphigoid.
Mycophenolate, methotrexate or azathioprine.
103
Describe the management of severe ocular mucous membrane pemphigoid.
IV methylprednisolone and/or cyclophosphamide or rituximab long term.
104
What is an important side effect of rituximab?
Pulmonary toxicity.
105
What are erythema multiforme, SJS and TEN?
- Spectrum of diseases where TEN is the most severe.
- Inflammation of the vessels of the mucous membranes and skin, driven by type 4 hypersensitivity to a variety of triggers.
106
What are common triggers of erythema multiforme, SJS and TEN?
- HSV.
- Drugs (sulphonamides, allopurinol, AEDs).
107
Describe the presentation of SJS and TEN.
- Acutely unwell with target lesions, bullae and mucous membrane inflammation.
- Nikolsky sign.
108
What is Nikolsky sign?
Sloughing sheets of skin.
109
Describe the management of acute SJS and TEN.
Steroids and burns unit.
110
Describe the management of acute SJS and TEN.
Same as for ocular mucous membrane pemphigoid.
- Mild → dapsone.
- Moderate → mycophenolate, methotrexate or azathioprine.
- Severe → IV methylprednisolone and/or cyclophosphamide or rituximab long term (side effect: pulmonary toxicity)).
111
What are pterygium and pinguecula?
Conjunctival surface degenerations.
112
How do pterygium and pinguecula invade?
Start nasally and invade laterally.
113
What are the risk factors for pterygium and pinguecula?
UV light and age.
114
When is surgery required for pterygium and pinguecula?
Only required in pterygium if vision is obscured.
115
What is the key difference between pterygium and pinguecula?
- Pterygium invades into the cornea.
- Pinguecula does not.
116
What is superior limbic keratoconjunctivitis?
A chronic disease of the superior limbus and conjunctiva.
117
What is superior limbic keratoconjunctivitis secondary to?
Superior bulbar conjunctival laxity.
118
What is ligneous conjunctivitis?
An idiopathic chronic conjunctivitis of children, associated with systemic disease.
119
What is characteristic about ligneous conjunctivitis?
Recurrent 'wood' like pseudomembranes of the conjunctiva and other mucous membranes.
120
What is the symptom triad for parinaud oculoglandular syndrome?
- Unilateral granulomatous conjunctivitis.
- Ipsilateral pre-auricaular lymphadenopathy.
- Fever.
121
Which organism causes parinaud oculoglandular syndrome?
Bartonella henselae.
