Conjunctiva pdf - D. Ahmed

Conjunctiva

Applied anatomy:

The  conjunctiva  is  a  transparent  mucous  membrane  lining  the  inner
surface  of  the  eyelids  and  the  anterior  surface  of  the  globe  as  far  as
the  limbus.  It  is  richly  vascular,  supplied  by  the  anterior  ciliary  and
palpebral arteries. There is a dense lymphatic network, with drainage
to the preauricular and submandibular nodes corresponding to that of
the  eyelids.  It  has  a  key  protective  role,  mediating  both  passive  and
active immunity. Anatomically, it is subdivided into the following:
1-The palpebral conjunctiva starts at the mucocutaneous junction of
the  lid  margins  and  is  firmly  attached  to  the  posterior  tarsal  plates.
The  underlying  tarsal  blood  vessels  can  be  seen  passing  vertically
from the lid margin and fornix.
2-The forniceal conjunctiva is loose and redundant.
3-The  bulbar  conjunctiva  covers  the  anterior  sclera  and  is
continuous with the corneal epithelium at the limbus.

Histology:

1-The  epithelium  is  non-keratinizing  and  around  five  cell  layers
deep.  Basal  cuboidal  cells  evolve  into  flattened  polyhedral  cells
before they are shed from the surface. Goblet cells are located within
the epithelium and are densest inferonasally and in the fornices.
2-The  stroma  (substantia  propria)  consists  of  richly  vascularized
loose  connective  tissue.  The  adenoid  superficial  layer  does  not
develop  until  about  3  months  after  birth,  hence  the  inability  of  the
newborn  to  produce  a  follicular  conjunctival  reaction.  The  deep
fibrous  layer  merges  with  the  tarsal  plates.  The  accessory  lacrimal
glands  of  Krause  and  Wolfring  are  located  deep  within  the  stroma.
Mucus  from  the  goblet  cells  and  secretions  from  the  accessory
lacrimal glands are essential components of the tear film.

Clinical features of conjunctival inflammation:

Symptoms: Non-specific symptoms include lacrimation, grittiness,
stinging and burning. Itching is the hallmark of allergic disease,

although it may also occur to a lesser extent in blepharitis and dry
eye.

Significant pain, photophobia or a marked foreign body sensation
suggest corneal involvement.

Discharge:

1)Watery discharge is composed of a serous exudate and tears and
occurs in acute viral or acute allergic conjunctivitis.

2)Mucoid discharge is typical of chronic allergic conjunctivitis and
dry eye.

3)Mucopurulent discharge typically occurs in chlamydial or acute
bacterial infection.
4)Severe purulent discharge is typical of gonococcal infection.

Conjunctival reaction :

1) Hyperaemia: that is diffuse , beefy-red and more intense away
from the limbus is usual in bacterial infection and should be
distinguished from the ciliary injection of iridocyclitis.

2) Haemorrhages: may occur in viral conjunctivitis , when they are
often multiple , small and discrete ; and severe bacterial conjunctivitis
, when they are larger and diffuse.

3)  Chemosis  (  conjunctival  oedema):  is  seen  as  a  translucent
swelling, which when severe may protrude through the eyelids. Acute
chemosis  indicates  a  hypersensitivity  response  e.g  pollen  whereas
chronic  chemosis  has  numerous  causes  e.g  chonic  allergic
conjunctivitis.

4) Membranes :

a)Pseudomembranes consist of coagulated exudate adherent to the
inflamed conjunctival epithelium. They can be peeled easily leaving
the underlying epithelium intact .

b)True membranes involve the superficial layers of the conjunctival
epithelium so that attempted removal leads to tearing.

c)Causes
•Severe adenoviral conjunctivitis.

•Gonococcal conjunctivitis.

•Ligneous conjunctivitis.

•Acute Stevens–Johnson syndrome.

•Bacterial

infection

(Streptococcus

spp.,

Corynebacterium

diphtheriae).
5)Subconjunctival scarring: may occur in trachoma and other types
of cicatrizing conjunctivitis.
6)Follicles:
a  Signs.  Multiple,  discrete,  slightly  elevated  lesions  resembling
translucent  grains  of  rice,  most  prominent  in  the  fornices.  Blood
vessels run around or across rather than within the lesions.
b Causes include

•  Viral conjunctivitis.
•  chlamydial conjunctivitis
•  Parinaud oculoglandular syndrome
•  hypersensitivity to topical medications.

7)Papillae: can develop only in the palpebral conjunctiva and in the
limbal  bulbar  conjunctiva  where  it  is  attached  to  the  deeper  fibrous
layer.
a Signs In contrast to follicles, a vascular core is present.
•Micropapillae  form  a  mosaic-like  pattern  of  elevated  red  dots  as  a
result of the central vascular channel.
•  Macropapillae  (<1  mm)  and  giant  papillae  (>1  mm)  develop  with
prolonged inflammation.

b Causes include

•  bacterial conjunctivitis
•  allergic conjunctivitis
•  chronic blepharitis
•  contact lens wear
•  superior limbic keratoconjunctivitis
•  Floppy eyelid syndrome.

Lymphadenopathy:

The  most  common  cause  of  lymphadenopathy  associated  with
conjunctivitis  is  viral infection. It  may also occur in chlamydial and
severe  bacterial  conjunctivitis  (especially  gonococcal),  and  Parinaud
oculoglandular syndrome. The preauricular site is typically affected.
Laboratory Investigations:
There  is  no  need  to  do  routine  investigations  for  every  patient
presented  with  conjunctivitis  unless  has  one  of  the  following
indications.
Indications:
- Severe purulent conjunctivitis.
- Follicular conjunctivitis (viral, chlamydial).
- Atypical conjunctivitis.
- Neonatal conjunctivitis.

Bacterial Conjunctivitis

1- Simple bacterial conjunctivitis:
It is a common disease, and usually it is self-limiting condition.
Common causative organisms are:
- Staphylococcus epidermidis.
- Staphylococcus aureus.
- Others like Streptococcus pneumoniae, H. influenzae.
Symptoms:
- Acute onset of redness.
- Grittines.
- Burning.
- Discharge.

- On morning, eyelids are stuck together due to accumulation of
exudates during the night.
- Both eyes are usually involved.
Signs:
- The eyelids are oedematous (mild oedema).
- Mucopurulent discharge.
- Beefy-red injection, maximally in the fornices.
- pseudoembranes in severe cases.
- Corneal involvement is uncommon.
* Blurred vision may occur due to mucus not due to corneal
involvement.

Treatment:
- Usually resolves within 10-14 days and laboratory tests are not
routinely performed.
- Irrigation to remove excessive discharge .
-Topical drops (Antibiotics): Chloramphenicol, ciprofloxacin,
ofloxacin, gentamicin, neomycin, tobramycin.

- Antibiotic ointments: it gives higher concentration for long period
and usually given at night because it causes blurred vision. e.g.
chloramphenicol, gentamicin.

2- Neonatal bacterial Keratoconjunctivitis:
* bacterial conjunctivitis in neonate is one cause for Ophthalmia
neonatorum
(any infection of the conjunctiva within the first month after delivery).
- Usually appears at 1-3 days of life.
- it is rare condition.

Signs:
- Hyperacute presentation.
- Chemosis.
- Pseudo-membranes.
- Corneal involvement.

Treatment: Systemic and topical antibiotics.

Viral Conjunctivitis

1- Adenoviral keratoconjunctivitis:
- It is a highly contagious virus.
- Transmission is via respiratory or ocular secretion.
-  Dissemination  is  by  contaminated  towels  or  equipments  (e.g.
tonometer: an instrument used to measure the intraocular pressure).
-  Incubation  period  is  4-10  days;  it  is  an  occupational  hazard  of
ophthalmologists  (due  to  contamination  of  their  hands  with  their
pateints).
Conjunctivitis:
Presentation:  acute  onset  of  watery  discharge,  redness,  discomfort
and irritation, both eyes are affected in 60% of cases.
Signs:
- Eyelids are oedematous.
- Watery discharge.
- Follicular reaction.
- Subconjunctival haemorrhages.
- Pseudomembranes. and - Lymphadenopathy is tender.

Keratitis:
Multiple, corneal sub epithelial infiltration and opacification.
Treatment:
a- Avoid transmission following examination of patients:
- Washing of hands.
- Meticulous disinfection of ophthalmologic instruments.
- Infected hospital personnel should not be in contact with patients.
b- Medications:
i- For conjunctivitis:
- Spontaneous resolution occurs within 2 weeks.
- Antiviral agents are ineffective (has no role).

- Topical steroids are indicated only in very severe inflammations
and when Herpes simplex infection has been excluded. The

treatment with steroids is symptomatic and supportive (not used
routinely).

- Artificial tears q.i.d. may be useful for symptomatic relief.
Preservative-free preparations may give superior comfort, and if
supplied in single-dose units may reduce transmission risk.

- Cold (or warm) compresses for symptomatic relief.

- Removal of symptomatic pseudomembranes or membranes.

- Topical antibiotics if secondary bacterial infection is suspected.

ii- For keratitis:
-  Topical  steroids,  which  are  indicated  only  if  the  eye  is
uncomfortable or there is diminishing of the visual acuity by corneal
subepithelial  infiltrates  and  opacifications,  Steroids  should  not  be
used till exclusion of Herpes simplex infection.
Note:  Steroids  do  not  shorten  the  natural  course  of  the  disease  but
suppress the inflammation and relief symptoms.

2- Herpes simplex conjunctivitis:
Conjunctivitis may occur in patients with primary Herpes simplex
infection.
- when the person catches the infection for the first time it is primary,
after treatment, the virus get dormant in the trigeminal nerve ganglia.
If for any reason, the person gets decrease immunity, then secondary
herpes infection is developed.
Signs:
- The eyelids and periorbital skin show unilateral herpetic vesicles,
which may be associated with edema.
- Watery discharge.
- Ipsilateral follicular reaction.
- Lymphadenopathy is tender.
- Keratitis is uncommon.
- Herpes simplex infection is very severe and it can lead to dendritic
ulcer of the cornea.

- No subconjunctival hemorrhage.
Treatment: Antiviral agent (as Acyclovir "Zovirax™") for 21 days to
prevent keratitis.

Chlamydial Conjunctivitis

1- Adult chlamydial Keratoconjunctivitis:
It is a sexually transmitted disease caused by the obligate intracellular
bacterium Chlamydia trachomatis(serotypes D-K).
- Patients are usually young and at least 50% have a concomitant
genital infection (cervicitis in ♀ or urethritis in ♂).
Mode of transmission:
- Autoinoculated from genital secretions.
- Eye to eye spread is rare.
Incubation period: 1 week.

Presentation:
Subacute onset of unilateral or bilateral mucopurulent discharge.
* Without treatment conjunctivitis persists for 3-12 months. So, in
chronic

conjunctivitis

should

think

about

Chlamydial

Keratoconjunctivitis.

Signs:
- Eyelids are lightly oedematous.
- Mucopurulent discharge.
- Large follicles are formed at the inferior fornix.
- Lymphadenopathy (tender).
- Keratitis is uncommon, if it occurs:
* Epithelial Keratitis.
* Sub-epithelial keratitis (opacities).
* Marginal infiltrates (circumferential, i.e. involvement of the limbus
and the periphery of cornea).
- Conjunctival scarring.

- Pannus (sub-epithelial corneal neovascular or fibrovascular
membrane, i.e. affects the cornea not the conjunctiva).

Treatment:
a- Topical therapy: Tetracycline ointment 4 times\ day for 6 weeks.
b- Systemic therapy: One of the following:
i- Doxycycline: 100mg X 1 for 1-2 weeks.
ii- Tetracycline: 250mg X 4 for 6 weeks.
iii- Erythromycin: 250mg X 4 for 6 weeks.

2- Neonatal chlamydial conjunctivitis:
-  The  most  common  cause  of  neonatal  conjunctivitis  (ophthalmia
Neonatorum).
-  It  may  be  associated  with  systemic  infection,  e.g.  otitis,  rhinitis  or
pneumonitis.
- It is transmitted from the mother genital tract during delivery.
Presentation:
The child is usually presented between 5 & 19 days after birth.
Signs:
-  Papillary  conjunctivitis  (there  is  no  follicular  reaction  as  the
lymphoid tissue develops 3 months after delivery).
- Mucopurulent discharge.
Complications (if not treated):
There is Conjunctival scarring and superior corneal pannus.
Treatment:
a- Topical Erythromycin.
b- Oral Erythromycin, 250mg/kg body weight daily for 14 days.

3- Trachoma:
(Compare it with Adult Chlamydial Keratoconjunctivitis)
- It is an infection caused Chlamydia trachomatis(serotypes A,B,Ba
and C).
- It is a disease of underprivileged populations with poor conditions of
hygiene (low socioeconomic status).

Transmission:  Common  fly  is  the major  vector,  currently  trachoma
is the leading cause of preventable blindness in the world.
Presentation: is usually during childhood.
Signs:
1- Follicular reaction.
2-  Chronic  conjunctival  inflammation  causes  conjunctival  scarring
that involves the entire conjunctiva but most prominent on the upper
tarsus.
3- Keratitis: either * Superficial epithelial keratitis.
* Anterior stromal inflammation and pannus formation.
4- Progressive conjunctival scarring: if it is severe lead to:
* Destruction of lids.
*  Trichiasis:  Misdirection  of  eyelashes  towards  the  cornea  causing
rubbing of cornea, it is either true Trichiasis (due to affection of hair
follicles) or pseudo (due to entropion of lid margin).
* Entropion: the inward turning of the eyelid.
* Dry eyes, due to destruction of conjunctival goblet cells, accessory
lacrimal cells and lacrimal ducts of main lacrimal duct.
5- End-stage trachoma:
*  Corneal  ulceration  (due  to  dry  eye  and  Trichiasis).  Superficial
corneal  ulcers  usually  heal  by  regeneration  so  the  cornea  remains
transparent,  while  deep  ulcers  do  not  regenerate  but  heal  by
fibroblasts  to  fibrous  tissue  leading  to  opacification,  which  lead  to
diminished visual acuity or even blindness in severe cases.

World Health Organization (WHO) grading:
TF: Trachoma follicles (5 or more follicles in the superior tarsal
conjunctiva).
TI: Trachomatous intense inflammation diffusely involving the tarsal
conjunctiva.
TS: Trachomatous conjunctival scarring.
TT: Trachomatous trichiasis touching the cornea.
CO: Corneal opacity.

Treatment of trachoma:-indicated for stages I & II (TF & TI) only,
as there is no benefit from treating stages III, IV &V (there is no
active inflammation).
- Preventive measures: strict personal hygiene, especially washing the
face of young children (single face wash at the morning is enough to
prevent the infection).

- Topical Tetracycline or Erythromycin eye ointment plus Single dose
of systemic erythromycin.

Neonatal conjunctivitis

is  defined  as  conjunctival  inflammation  developing  within  the  first
month  of  life.  It  is  the  most  common  infection  of  any  kind  in
neonates, occurring in up to 10%.

Causes:

• C. trachomatis, N. gonorrhoeae (now rare in developed countries)
and occasionally herpes simplex virus (typically HSV-2), which may
be associated with severe ocular or systemic complications.

•Staphylococci are usually responsible for mild conjunctivitis

•Topical preparations used as prophylaxis against infection , may
themselves cause conjunctival irritation.

Diagnosis:

1) Timing of onset
• Chemical irritation: first few days.
• Gonococcal: first week.
• Staphylococci and other bacteria: end of the first week.
• Herpes simplex: 1–2 weeks.
• Chlamydia: 1–3 weeks
2) History

• Instillation of a prophylactic chemical preparation.
• Parental symptoms of sexually transmitted infections.
• Recent conjunctivitis in close contacts.
•  Systemic  illness  such  as  pneumonitis,  rhinitis  and  otitis  in
chlamydial  infection,  skin  vesicles  and  features  of  encephalitis  in
herpes simplex.
•  Prior  persistent  watering  without  inflammation  may  indicate  an
uncanalized nasolacrimal duct.
3) Signs
• The type of discharge varies according to the underlying cause.
• Reflux of mucopurulent material on pressure over the lacrimal sac is
suggestive of delayed canalization of the lacrimal duct.
• Severe eyelid oedema occurs in gonococcal infection .
• Eyelid and periocular vesicles may occur in HSV infection.
• Keratitis in gonococcal or HSV infection.

Allergic conjunctivitis

1- Acute allergic conjunctivitis:

is a common condition caused by an acute conjunctival reaction to
an environmental allergen, usually pollen. It is typically seen in
younger children after playing outside in spring or summer.

Presentation is with acute itching and watering, associated with
severe chemosis .

Treatment is not usually required and the conjunctival swelling
settles within hours as the acute increase in vascular permeability
resolves. Cool compresses can be used and a single drop of
adrenaline 0.1% may reduce extreme chemosis.

2- Vernal keratoconjunctivitis (spring catarrh):

is a recurrent bilateral disorder in which both IgE- and cell-mediated
immune  mechanisms  play  important  roles.  It  primarily  affects  boys
and onset is generally from about the age of  5 years onwards (mean
age  7  years).  Ninety-five  per  cent  of  cases  remit  by  the  late  teens
although  many  of  the  remainder  develop  atopic  keratoconjunctivitis.
VKC often occurs on a seasonal basis, with a peak incidence over late
spring and summer.

Classification

1)Palpebral  VKC  primary  involves  the  upper  tarsal  conjunctiva.  It
may  be  associated  with  significant  corneal  disease  as  a  result  of  the
close  apposition  between  the  inflamed  conjunctiva  and  the  corneal
epithelium.

2)Limbal disease typically affects black and Asian patients.

3)Mixed VKC has features of both palpebral and limbal disease.

Clinical features:
1)Symptoms consist of intense itching, which may be associated with
lacrimation, photophobia, a foreign body sensation, burning and thick
mucoid discharge. Increased blinking is common.

2)Palpebral disease
• Early-mild disease is characterized by conjunctival hyperaemia and
diffuse papillary hypertrophy on the superior tarsus.

• Macropapillae (<1 mm).
• Progression to giant papillae (>1 mm) can occur, as adjacent smaller
lesions amalgamate when dividing septa rupture.
• Mucus deposition between giant papillae.

3)Limbal disease
• Gelatinous limbal conjunctiva papillae that may be associated with
transient apically-located white cellular collections (Horner-Trantas
dots).

4)Keratopathy  is  more  frequent  in  palpebral  disease  and  may  take
the following forms:
a Superior punctate epithelial erosions.
b  Epithelial  macroerosions  caused  by  a  combination  of  epithelial
toxicity from inflammatory  mediators and a direct  mechanical effect
from papillae.
c  Plaques  and  ‘shield’  ulcers  may  develop  in  palpebral  or  mixed
disease  when  the  exposed  Bowman  membrane  becomes  coated  with
mucus  and  calcium  phosphate,  leading  to  inadequate  wetting  and
delayed reepithelialization.
d Subepithelial scars that may affect vision.
e  Pseudogerontoxon  can  develop  in  recurrent  limbal  disease.  It  is
characterized by a paralimbal band of superficial scarring.
Treatment:
1- Topical steroids: (its use is mandatory)
- As the patients will not cure until around puberty by any drug, so we
should use weak steroids as fluorometholone or Clobetasone. Potent
topical steroids likes dexamethasone, betamethasone or prednisolone
should be avoided as their corneal penetration and their risk to
increase IOP and causing cataract is more than weak steroids.
- It should be of short course.
2- Mast cell stabilizers:
nedocromil 0.1% drops *2 daily
or lodoxomide 0.1% drops *4 daily.
or sodium cromoglycate 2% *4 daily
They are not effective as steroids in controlling acute exacerbation.
3-  Acetylcyseine  5%  drops  *4  daily,  as  treatment  of  early  plaque
formation (mucolytic).
4- Topical cyclosporin A: used in steroids resistant cases.

5-  Debridement:  of  early  mucus  plaques  to  get  speed  repair  of
persistent epithelial defect, done under topical anesthesia with cotton-
tipped applicator.
6-Lamellar  keratectomy:  For  densely  adherent  plaques  or
subepithelial  scarring,  and  sometimes  we  may  need  corneal
replacement (corneal graft).
7- Supratarsal injection of steroids: it is very effective in patients with
severe disease and Giant tarsal papillae. It is used to avoid ocular side
effect of topical medications.

Conjunctival Degenerations

1- Pinguecula:
It  is  an  extremely  common  lesion  which  consists  of  a  yellow-white
deposit  on  the  bulbar  conjunctiva  adjacent  to  the  nasal  or  temporal
aspect of the limbus and it is usually asymptomatic.
Histology:  There  is  degeneration  of  the  collagen  fibers  of  the
conjunctival  stroma,  thinning  of  the  overlying  epithelium  and
occasionally calcification.
Some  pingueculae  may  enlarge  very  slowly  but  surgical  excision  is
seldom required. (usually, it need no treatment)

2- Concretions (ocular lithiasis) :
- They are small yellow-white deposits.
- Commonly present in the palpebral conjunctiva of the elderly.
- Also in patients with chronic meibomian gland disease.
- Usually asymptomatic, but occasionally causes foreign body
sensation when erode through the epithelium.

Treatment: They can be easily removed with a needle.
3- Pterygium:
- It is a triangular sheet of conjunctival fibrovascular tissue invades
the cornea.
- Occurs in patients who have been living in outdoor, hot climates.
- May represent a response to chronic dryness and exposure to the sun

Signs:
a- Small, grey, corneal opacities near the nasal limbus.
b- Then, the conjunctiva overgrows these opacities and progressively
invades onto the cornea in a triangular fashion.
c-  A  deposit  of  iron  (Stocker  line)  may  be  present  in  the  corneal
epithelium anterior to the advancing head of the pterygium.
* Usually asymptomatic.
Treatment:
a- Surgical excision: indicated only in the following cases: i- If it is
threatening  the  visual  axis.  ii-  Severe  irritation.  iii-  For  cosmetic
reason.
b-Lamellar  keratoplasty:  required  if  the  visual  axis  is  affected  by
opacification.
Surgical excision, it is an easy procedure but should be avoided unless
there is indication because the recurrent rate is high (about 80%) and
the  recurrent  ptrygium  is  uglier,  rapidly  progress  and  causing  more
severe symptoms.

Subconjunctival Haemorrhage:

is  a  very  common  phenomenon  that  may  result  from  surgery,
conjunctivitis and trauma (from minor unnoticed to severe skull base),
but  is  often  idiopathic  and  apparently  spontaneous,  particularly  in
older patients. The bleed is usually asymptomatic until noticed by the
patient  or  others.  Coughing,  sneezing  and  vomiting  are  common
precipitants.  In  younger  people  contact  lens  wear  is  a  common
association,  and  in  older  individuals  systemic  vascular  disease  is
prevalent, especially hypertension. Bleeding diatheses are a very rare
association.

The vision is usually unaffected . Spontaneous resolution over a week
or two is typical.