The Conjunctiva
The conjunctivais athin mucous membrane that lines the inside of the eyelids and covers the sclera.
The function:
The conjunctiva helps to lubricate the eye by producing mucous and tears,also contributes to immune
surveilance and helps to prvent the entrance of microbes into the eye.
Anatomy:
Tte conjunctiva is divided into 3 anatomical regions:
1.palpebral(tarsal)conjunctiva that lines the inside of the eyelids.
2.bulbar co junctiva that covers the sclera.
3.forniceal conjunctiva in between the palpebral anc bulbar conjuncti vae that lines the fornix.
Histology:
The co junctiva as any mucous membrane is composed of:
1.Epithelium
2.Stroma.
the stroma is of 2 layers;
a.lymphoid layer.
b.fibrous layer.
Clinical Evaluation:
The clinical evaluation of apatient with conjunctival disorder should include the following:
1. appearance of the conjunctia; redness,palor,hyperaemia,edema,chemosis,scarring.
2.dichage. -------- watery------viral infection
Purulent------bacterial infection
mucopurulent----Chlamydial infection
serous-------------allergic conjun tivitis
3.membrane and pseudo-membrane
The membrane is firmly attached to the conjunctival epithelium(on removal will caucs bleeding)
Causes;mainly bactefial cause(Diphtheria)
chemical burns is anothef cause
The pseudo-membraneis loosely attachedto the conjunctival epithelium(no bleeding on removal)
Causes; viral onjunctivitis,Steven's Johnson syndrome,allrgic conjunctivitis.
4.lymphadenopathy:palpation of the pre-auricular and sub-mandibular lymph nodes, enlarged in viral
conjunctivitis.
5.Papillary reaction:clinically will appear as conjunctival elevations due to hyperplasia of the conjunctival
epithelium,either small papillae or large papillae(Giant Papillary Conjuctivitis-GPC-)
Causes; -----allergic reaction (vernal disease)
-----chronic irritation of the conjunctiva su h as by contact lenses. surgical sutre,
6.Folli ular reaction:clinically will appear as conjunctival elevations caused by hypertrophy of the
Iymphoid layer.
Causes:--- viral infection,Chlamydial infection.chronic drug toxicity.
Conjunctival Disorders
A---Infective zDisorders
B---Allergic Disorders
C---Degenerative Disorders
Infecive disorders
1.bacterial conjjnctivitis
2.viral conjunctivitis
3. chlamydial conjunctivitis
1. Bactefial Conjun tivitis
a.Simple bacterial conjunctivitis
caused by Staph. aureus, Strept.pneumonae,Hemophylus infleunzae.
Cli incal features:
acute onset of unilateral or bilateral conjuntival infammation,with pus
discharge,edema,hyperemia and redness.Vision is not affected.
Papillary reaction.
Treatment:
Topical antibiotics,eye drop and ointment.
b.Gonococcal conjunctivitis:
Adult and Neonate gonococcal conjunctivitis
Sexually transmitted disease caused by Gonococci(GC bacteria).
Clinical Features:
hyperacute onset of profuse creamy pus discharge with
papillary reaction,redness,hyperemia.
Vision is affected if the cornea is involved(keratitis[hazy cornea])
Treatment:systemic and topiczl antibiotics,systemic antibiotic by parenteral
injection for 2 days if the cornea is not involved,and for 3---5 days if cornea
is involved.
2.Viral Conjunctivitis
common disorder caused by adenovirus.
Clinical Features:
acute presentation of eye redness,watery discharge and
blurring of vision if the cornea is involved(keratitis).
Treatment:
self-limited disease,so the treatment is symptomatic by cold
compresses, antihistamine tablets,topical antibiotics if there is secodary
bacterial infection.Topical steroid is indicated if there is an indication such as
corneal involvement(keratitis), subconjunctival hemrrhage.
3.Chlamydial conjunctivitis
a. Adult chlamdial conjunctivitis
Neonatal chlamydial conjuntivitis
Seually transmitted disease(neonates acquire it from the birth canal
during labor) caused by Chlamydia trachomatis
Clinical features: sub-acute onset of mucopurulent discharge with slight
features of conjunctival hyperemia,redness and swelling.
Follicular reaction.
Traetment:
topical and systemic tetracycline.
Systemic erythromycin if systemic tetracycline is contraidicated
as in pregnent and lactatig women and in children less than 12
years of age.
Trachoma: chronic conjunctival infection caused by Chlamydia trachomatis
serotypes (D----K). Prevalent in areas with poor personal hygiene and poor
sanitation.The main preventive measure is go enhance the community
sanittation and to improve personal hygiene.
Azithromycin orally is for prevention and for treatment in early stages
WHO Grading of trachoma:it is a grading done by WHO for the purpooses of
prevention and treatment of trachoma.(for this grading see the image of
WHO Grading of trachoma).
B.Aergic Disorders of the Conjunctiva
a.Allergic Rhino-Conjunctivitis(ARC)
b.Vernal Kerato-Conjunctivitis(VKC) vernal disease
C.Atopic Kerato-Conjunctivitis(AKC)
itching and discomfort of the eye,serou discharge,hyperemia,redness,
papillary reaction(giant papillae in vernal disease).
Associated with other general features such as nasal discharge in ARC,
eczema(dermatitis) in AKC.
Treatment:
Sestemic antihistamjne,topical steroid,topical mast cell stabilizers.
C.Degenerative Disorders
1.pingueculum:yellowish soft degeneration on bulbar conjunvtiva.
Treatment:observation to exclude infammation or change into another type
of degeneration.
2.pterygium:fibro-vascular growth from the conjunctiva onto the cornea.
Pterygium typically develops in patients who have been living in hot climates
and may represent a response to chronic dryness and ultra-violet exposure.
Treatment: surgical excision.
3.Concretions:hard chalky white degeneration.
Treatment:removal under topical anesthesia by hhpodermic needle.
4.Retention cyst containing clear fluid.
Treatment: puncture under topical anesthesia by hypodermic needle.
