Chronic dacryocystitis is more common than the acute
dacryocystitis.
Etiology
The etiology of chronic dacryocystitis is
multifactorial. The well-established fact is a vicious
cycle of stasis and mild infection of long duration.The
etiological factors can be grouped as under:
A. Predisposing factors
1. Age. It is more common between 40 and 60 years
of age.
2. Sex. The disease is predominantly seen in females
(80%) probably due to comparatively narrow
lumen of the bony canal.
3. Race. It is rarer among Negroes than in Whites;
as in the former NLD is shorter, wider and less
sinuous.
4. Heredity. It plays an indirect role. It affects the
facial configuration and so also the length and
width of the bony canal.
5. Socio-economic status. It is more common in low
socio-economic group.
6. Poor personal hygiene. It is also an important
predisposing factor.
B. Factors responsible for stasis of tears in
lacrimal sac
1. Anatomical factors, which retard drainage of tears
include: comparatively narrow bony canal, partial
canalization of membranous NLD and excessive
membranous folds in NLD.
2. Foreign bodies in the sac may block opening of
NLD.
3. Excessive lacrimation, primary or reflex, causes
stagnation of tears in the sac.
4. Mild grade inflammation of lacrimal sac due to
associated recurrent conjunctivitis may block the
NLD by epithelial debris and mucus plugs.
5. Obstruction of lower end of the NLD by nasal
diseases such as polyps, hypertrophied inferior
concha, marked degree of deviated nasal septum,
tumours and atrophic rhinitis causing stenosis
may also cause stagnation of tears in the lacrimal
sac.
C. Source of infection. Lacrimal sac may get infected
from the conjunctiva, nasal cavity (retrograde
spread), or paranasal sinuses.
D. Causative organisms. These include: staphylococci,
pneumococci, streptococci and Pseudomonas
pyocyanea. Rarely chronic granulomatous
infections like tuberculosis, syphilis, leprosy and
occasionally rhinosporiodosis may also cause
dacryocystitis.
Clinical picture
Clinical picture of chronic dacryocystitis may be
divided into four stages:
1. Stage of chronic catarrhal dacryocystitis. It is
characterised by mild inflammation of the lacrimal sac
associated with blockage of NLD. In this stage the
only symptom is watering eye and sometimes mild
redness in the inner canthus. On syringing the lacrimal
sac, either clear fluid or few fibrinous mucoid flakes
regurgitate. Dacryocystography reveals block in NLD,
a normal-sized lacrimal sac with healthy mucosa.
2. Stage of lacrimal mucocoele. It follows chronic
stagnation causing distension of lacrimal sac. It is
characterised by constant epiphora associated with
a swelling just below the inner canthus (Fig. 15.8).
Milky or gelatinous mucoid fluid regurgitates from
the lower punctum on pressing the swelling.
Dacryocystography at this stage reveals a distended
sac with blockage somewhere in the NLD.
Sometimes due to continued chronic infection,
opening of both the canaliculi into the sac are blocked
and a large fluctuant swelling is seen at the inner
canthus with a negative regurgitation test. This is
called encysted mucocele.
3. Stage of chronic suppurative dacryocystitis. Due
to pyogenic infections, the mucoid discharge
becomes purulent, converting the mucocele into
‘pyocoele’. The condition is characterised by
epiphora, associated recurrent conjunctivitis and
swelling at the inner canthus with mild erythema of
the overlying skin. On regurgitation a frank purulent
discharge flows from the lower punctum. If openings
of canaliculi are blocked at this stage the so called
encysted pyocoele results.
4. Stage of chronic fibrotic sac. Low grade repeated
infections for a prolonged period ultimately result in
a small fibrotic sac due to thickening of mucosa, which
is often associated with persistent epiphora and
discharge. Dacryocystography at this stage reveals
a very small sac with irregular folds in the mucosa.
Complications
Chronic intractable conjunctivitis, acute on chronic
dacryocystitis.
Ectropion of lower lid, maceration and eczema of
lower lid skin due to prolonged watering.
Simple corneal abrasions may become infected
leading to hypopyon ulcer.
If an intraocular surgery is performed in the
presence of dacryocystitis, there is high risk of
developing endophthalmitis. Because of this,
syringing of lacrimal sac is always done before
attempting any intraocular surgery.
Treatment
1. Conservative treatment by repeated lacrimal
syringing. It may be useful in recent cases only. Longstanding
cases are almost always associated with
blockage of NLD which usually does not open up
with repeated lacrimal syringing or even probing.
2. Dacryocystorhinostomy (DCR). It should be the
operation of choice as it re-establishes the lacrimal
drainage. However, before performing surgery, the
infection especially in pyocoele should be controlled
by topical antibiotics and repeated lacrimal syringings.
3. Dacryocystectomy (DCT). It should be performed
only when DCR is contraindicated. Indications of
DCT include: (i) Too young (less than 4 years) or too
old (more than 60 years) patient. (ii) Markedly
shrunken and fibrosed sac. (iii) Tuberculosis, syphilis,
leprosy or mycotic infections of sac. (iv) Tumours of
sac. (v) Gross nasal diseases like atrophic rhinitis (vi)
An unskilled surgeon, because it is said that, a good
‘DCT’ is always better than a badly done ‘DCR’.
4. Conjunctivodacryocystorhinostomy (CDCR). It is
performed in the presence of blocked canaliculi.
Showing posts with label lacrimal. Show all posts
Showing posts with label lacrimal. Show all posts
Thursday, December 30, 2010
CONGENITAL DACRYOCYSTITIS
It is an inflammation of the lacrimal sac occurring in
newborn infants; and thus also known as
dacryocystitis neonatorum.
Etiology
It follows stasis of secretions in the lacrimal sac due
to congenital blockage in the nasolacrimal duct. It
is of very common occurrence. As many as 30 percent
of newborn infants are believed to have closure of
nasolacrimal duct at birth; mostly due to ‘membranous
occlusion’ at its lower end, near the valve of Hasner.
Other causes of congenital NLD block are: presence
of epithelial debris, membranous occlusion at its
upper end near lacrimal sac, complete noncanalisation
and rarely bony occlusion. Common
bacteria associated with congenital dacryocystitis
are staphylococci, pneumococci and streptococci.
Clinical picture
Congenital dacryocystitis usually presents as a mild
grade chronic inflammation. It is characterised by:
1. Epiphora, usually developing after seven days
of birth. It is followed by copious mucopurulent
discharge from the eyes.
2. Regurgitation test is usually positive, i.e., when
pressure is applied over the lacrimal sac area,
purulent discharge regurgitates from the lower
punctum.
3. Swelling on the sac area may appear eventually.
Differential diagnosis
Congenital dacryocystitis needs to be differentiated
from other causes of watering in early childhood
especially ophthalmia neonatorum and congenital
glaucoma.
Complications
When not treated in time it may be complicated by
recurrent conjunctivitis, acute on chronic dacryocystitis,
lacrimal abscess and fistulae formation.
Treatment
It depends upon the age at which the child is brought.
The treatment modalities employed are as follows:
1. Massage over the lacrimal sac area and topical
antibiotics constitute the treatment of congenital
NLD block, up to 6-8 weeks of age. Massage
increases the hydrostatic pressure in the sac and
helps to open up the membranous occlusions. It
should be carried out at least 4 times a day to be
followed by instillation of antibiotic drops. This
conservative treatment cures obstruction in about
90 percent of the infants.
2. Lacrimal syringing (irrigation) with normal
saline and antibiotic solution. It should be added
to the conservative treatment if the condition is
not cured up to the age of 2 months. Lacrimal
irrigation helps to open the membranous occlusion
by exerting hydraulic pressure. Syringing may be
carried out once or twice a week.
3. Probing of NLD with Bowman’s probe. It should
be performed, in case the condition is not cured
by the age of 3-4 months. Some surgeons prefer
to wait till the age of 6 months. It is usually
performed under general anaesthesia. While
performing probing, care must be taken not to
injure the canaliculus. In most instances a single
probing will relieve the obstruction. In case of
failure, it may be repeated after an interval of 3-
4 weeks.
4. Intubations with silicone tube may be performed
if repeated probings are failure. The silicone tube
should be kept in the NLD for about six months.
5. Dacryocystorhinostomy (DCR) operations: When
the child is brought very late or repeated probing
is a failure, then conservative treatment by
massaging, topical antibiotics and intermittent
lacrimal syringing should be continued till the
age of 4 years. After this, DCR operation should
be performed.
newborn infants; and thus also known as
dacryocystitis neonatorum.
Etiology
It follows stasis of secretions in the lacrimal sac due
to congenital blockage in the nasolacrimal duct. It
is of very common occurrence. As many as 30 percent
of newborn infants are believed to have closure of
nasolacrimal duct at birth; mostly due to ‘membranous
occlusion’ at its lower end, near the valve of Hasner.
Other causes of congenital NLD block are: presence
of epithelial debris, membranous occlusion at its
upper end near lacrimal sac, complete noncanalisation
and rarely bony occlusion. Common
bacteria associated with congenital dacryocystitis
are staphylococci, pneumococci and streptococci.
Clinical picture
Congenital dacryocystitis usually presents as a mild
grade chronic inflammation. It is characterised by:
1. Epiphora, usually developing after seven days
of birth. It is followed by copious mucopurulent
discharge from the eyes.
2. Regurgitation test is usually positive, i.e., when
pressure is applied over the lacrimal sac area,
purulent discharge regurgitates from the lower
punctum.
3. Swelling on the sac area may appear eventually.
Differential diagnosis
Congenital dacryocystitis needs to be differentiated
from other causes of watering in early childhood
especially ophthalmia neonatorum and congenital
glaucoma.
Complications
When not treated in time it may be complicated by
recurrent conjunctivitis, acute on chronic dacryocystitis,
lacrimal abscess and fistulae formation.
Treatment
It depends upon the age at which the child is brought.
The treatment modalities employed are as follows:
1. Massage over the lacrimal sac area and topical
antibiotics constitute the treatment of congenital
NLD block, up to 6-8 weeks of age. Massage
increases the hydrostatic pressure in the sac and
helps to open up the membranous occlusions. It
should be carried out at least 4 times a day to be
followed by instillation of antibiotic drops. This
conservative treatment cures obstruction in about
90 percent of the infants.
2. Lacrimal syringing (irrigation) with normal
saline and antibiotic solution. It should be added
to the conservative treatment if the condition is
not cured up to the age of 2 months. Lacrimal
irrigation helps to open the membranous occlusion
by exerting hydraulic pressure. Syringing may be
carried out once or twice a week.
3. Probing of NLD with Bowman’s probe. It should
be performed, in case the condition is not cured
by the age of 3-4 months. Some surgeons prefer
to wait till the age of 6 months. It is usually
performed under general anaesthesia. While
performing probing, care must be taken not to
injure the canaliculus. In most instances a single
probing will relieve the obstruction. In case of
failure, it may be repeated after an interval of 3-
4 weeks.
4. Intubations with silicone tube may be performed
if repeated probings are failure. The silicone tube
should be kept in the NLD for about six months.
5. Dacryocystorhinostomy (DCR) operations: When
the child is brought very late or repeated probing
is a failure, then conservative treatment by
massaging, topical antibiotics and intermittent
lacrimal syringing should be continued till the
age of 4 years. After this, DCR operation should
be performed.
THE WATERING EYE
It is characterised by overflow of tears from the
conjunctival sac. The condition may occur either due
to excessive secretion of tears (hyperlacrimation) or
may result from obstruction to the outflow of normally
secreted tears (epiphora).
Etiology
(A) Causes of hyperlacrimation
1. Primary hyperlacrimation. It is a rare condition
which occurs due to direct stimulation of the lacrimal
gland. It may occur in early stages of lacrimal gland
tumours and cysts and due to the effect of strong
parasympathomimetic drugs.
2. Reflex hyperlacrimation. It results from stimulation
of sensory branches of fifth nerve due to irritation of
cornea or conjunctiva. It may occur in multitude of
conditions which include:
Affections of the lids: Stye, hordeolum internum,
acute meibomitis, trichiasis, concretions and
entropion.
Affections of the conjunctiva: Conjunctivits which
may be infective, allergic, toxic, irritative or
traumatic.
Affections of the cornea: These include, corneal
abrasions, corneal ulcers and non-ulcerative
keratitis.
Affections of the sclera: Episcleritis and scleritis.
Affections of uveal tissue: Iritis, cyclitis,
iridocyclitis.
Acute glaucomas.
Endophthalmitis and panophthalmitis.
Orbital cellulitis.
3. Central lacrimation (psychical lacrimation). The
exact area concerned with central lacrimation is still
not known. It is seen in emotional states, voluntary
lacrimation and hysterical lacrimation.
(B) Causes of epiphora
Inadequate drainage of tears may occur due to
physiological or anatomical (mechanical) causes.
I Physiological cause is ‘lacrimal pump’ failure due
to lower lid laxity or weakness of orbicularis muscle.
II Mechanical obstruction in lacrimal passages may
lie at the level of punctum, canaliculus, lacrimal sac
or nasolacrimal duct.
1. Punctal causes include:
Eversion of lower punctum: It is commonly
seen in old age due to laxity of the lids. It may
also occur following chronic conjunctivitis,
chronic blepharitis and due to any cause of
ectropion.
Punctal obstruction: There may be congenital
absence of puncta or cicatricial closure
following injuries, burns or infections. Rarely
a small foreign body, concretion or cilia may
also block the punctum. Prolonged use of
drugs like idoxuridine and pilocarpine is also
associated with punctal stenosis.
2. Causes in the canaliculi. Canalicular obstruction
may be congenital or acquired due to foreign
body, trauma, strictures and canaliculitis.
Commonest cause of canaliculitis is actinomyces.
3. Causes in the lacrimal sac. These include
congenital mucous membrane folds, traumatic
strictures, dacryocystitis, specific infections like
tuberculosis and syphilis, dacryolithiasis, tumours
and atonia of the sac.
4. Causes in the nasolacrimal duct. Congenital
lesions include non-canalization, partial
canalization or imperforated membranous valves.
Acquired causes of obstruction are traumatic
strictures, inflammatory strictures, tumours and
diseases of the surrounding bones.
Clinical evaluation of a case of ‘Watering eye’
1. Ocular examination with diffuse illumination
using magnification should be carried to rule out
any cause of reflex hypersecretion located in lids,
conjunctiva, cornea, sclera, anterior chamber, uveal
tract and so on. This examination should also exclude
punctal causes of epiphora and any swelling in the
sac area.
2. Regurgitation test. A steady pressure with index
finger is applied over the lacrimal sac area above the
medial palpebral ligament. Reflux of mucopurulent
discharge indicates chronic dacryocystitis with
obstruction at lower end of the sac or the nasolacrimal
duct.
3. Fluorescein dye disappearance test (FDDT). In
this test 2 drops of fluorescein dry eye are instilled in
both the conjunctival sacs and observations are made
after 2 minutes. Normally, no dye is seen in the
conjunctival sac. A prolonged retention of dye in
conjunctival sac indicates inadequate drainage which
may be due to atonia of sac or mechanical obstruction.
4. Lacrimal syringing test. It is performed after
topical anaesthesia with 4 percent xylocaine (Fig. 15.5).
Normal saline is pushed into the lacrimal sac from
lower punctum with the help of a syringe and lacrimal
cannula. A free passage of saline through lacrimal passages
into the nose rules out any mechanical
obstruction.
In the presence of partial obstruction, saline
passes with considerable pressure on the syringe.
In the presence of obstruction no fluid passes
into nose and it may reflux through same punctum
(indicating obstruction in the same or common
canaliculus) or through opposite punctum
(indicating obstruction in the lower sac or
nasolacrimal duct).
5. Jones dye tests. These are performed when partial
obstruction is suspected. Jones dye tests are of no
value in the presence of total obstruction.
i. Jones primary test (Jones test I). It is performed
to differentiate between watering due to partial
obstruction of the lacrimal passages from that
due to primary hypersecretion of tears. Two drops
of 2 percent fluorescein dye are instilled in the
conjunctival sac and a cotton bud dipped in 1
percent xylocaine is placed in the inferior meatus
at the opening of nasolacrimal duct. After 5
minutes the cotton bud is removed and inspected.
A dye-stained cotton bud indicates adequate
drainage through the lacrimal passages and the
cause of watering is primary hypersecretion
(further investigations should aim at finding the
cause of primary hypersecretion). While the
unstained cotton bud (negative test) indicates
either a partial obstruction or failure of lacrimal
pump mechanism. To differentiate between these
conditions, Jones dye test-II is performed.
ii. Jones secondary test (Jones test II). When primary
test is negative, the cotton bud is again placed
in the inferior meatus and lacrimal syringing is
performed. A positive test suggests that dye was
present in the sac but could not reach the nose
due to partial obstruction. A negative test
indicates presence of lacrimal pump failure.
6. Dacryocystography. It is valuable in patients with
mechanical obstruction. It tells the exact site, nature
and extent of block (Fig. 15.6). In addition, it also
gives information about mucosa of the sac, presence
of any fistulae, diverticulae, stone, or tumour in the
sac.
To perform it a radiopaque material such as lipiodol,
pentopaque, dianosil or condray-280 is pushed in the
sac with the help of a lacrimal cannula and X-rays are
taken after 5 minutes and 30 minutes to visualize the
entire passage. For better anatomical visualization the
modified technique known as substraction
macrodacryocystography with canalicular
catheterisation should be preferred.
7. Radionucleotide dacryocystography (lacrimal
scintillography). It is a non-invasive technique to
assess the functional efficiency of lacrimal drainage
apparatus. A radioactive tracer (sulphur colloid or
technitium) is instilled into the conjunctival sac and
its passage through the lacrimal drainage system is
visualised with an Anger gamma camera
conjunctival sac. The condition may occur either due
to excessive secretion of tears (hyperlacrimation) or
may result from obstruction to the outflow of normally
secreted tears (epiphora).
Etiology
(A) Causes of hyperlacrimation
1. Primary hyperlacrimation. It is a rare condition
which occurs due to direct stimulation of the lacrimal
gland. It may occur in early stages of lacrimal gland
tumours and cysts and due to the effect of strong
parasympathomimetic drugs.
2. Reflex hyperlacrimation. It results from stimulation
of sensory branches of fifth nerve due to irritation of
cornea or conjunctiva. It may occur in multitude of
conditions which include:
Affections of the lids: Stye, hordeolum internum,
acute meibomitis, trichiasis, concretions and
entropion.
Affections of the conjunctiva: Conjunctivits which
may be infective, allergic, toxic, irritative or
traumatic.
Affections of the cornea: These include, corneal
abrasions, corneal ulcers and non-ulcerative
keratitis.
Affections of the sclera: Episcleritis and scleritis.
Affections of uveal tissue: Iritis, cyclitis,
iridocyclitis.
Acute glaucomas.
Endophthalmitis and panophthalmitis.
Orbital cellulitis.
3. Central lacrimation (psychical lacrimation). The
exact area concerned with central lacrimation is still
not known. It is seen in emotional states, voluntary
lacrimation and hysterical lacrimation.
(B) Causes of epiphora
Inadequate drainage of tears may occur due to
physiological or anatomical (mechanical) causes.
I Physiological cause is ‘lacrimal pump’ failure due
to lower lid laxity or weakness of orbicularis muscle.
II Mechanical obstruction in lacrimal passages may
lie at the level of punctum, canaliculus, lacrimal sac
or nasolacrimal duct.
1. Punctal causes include:
Eversion of lower punctum: It is commonly
seen in old age due to laxity of the lids. It may
also occur following chronic conjunctivitis,
chronic blepharitis and due to any cause of
ectropion.
Punctal obstruction: There may be congenital
absence of puncta or cicatricial closure
following injuries, burns or infections. Rarely
a small foreign body, concretion or cilia may
also block the punctum. Prolonged use of
drugs like idoxuridine and pilocarpine is also
associated with punctal stenosis.
2. Causes in the canaliculi. Canalicular obstruction
may be congenital or acquired due to foreign
body, trauma, strictures and canaliculitis.
Commonest cause of canaliculitis is actinomyces.
3. Causes in the lacrimal sac. These include
congenital mucous membrane folds, traumatic
strictures, dacryocystitis, specific infections like
tuberculosis and syphilis, dacryolithiasis, tumours
and atonia of the sac.
4. Causes in the nasolacrimal duct. Congenital
lesions include non-canalization, partial
canalization or imperforated membranous valves.
Acquired causes of obstruction are traumatic
strictures, inflammatory strictures, tumours and
diseases of the surrounding bones.
Clinical evaluation of a case of ‘Watering eye’
1. Ocular examination with diffuse illumination
using magnification should be carried to rule out
any cause of reflex hypersecretion located in lids,
conjunctiva, cornea, sclera, anterior chamber, uveal
tract and so on. This examination should also exclude
punctal causes of epiphora and any swelling in the
sac area.
2. Regurgitation test. A steady pressure with index
finger is applied over the lacrimal sac area above the
medial palpebral ligament. Reflux of mucopurulent
discharge indicates chronic dacryocystitis with
obstruction at lower end of the sac or the nasolacrimal
duct.
3. Fluorescein dye disappearance test (FDDT). In
this test 2 drops of fluorescein dry eye are instilled in
both the conjunctival sacs and observations are made
after 2 minutes. Normally, no dye is seen in the
conjunctival sac. A prolonged retention of dye in
conjunctival sac indicates inadequate drainage which
may be due to atonia of sac or mechanical obstruction.
4. Lacrimal syringing test. It is performed after
topical anaesthesia with 4 percent xylocaine (Fig. 15.5).
Normal saline is pushed into the lacrimal sac from
lower punctum with the help of a syringe and lacrimal
cannula. A free passage of saline through lacrimal passages
into the nose rules out any mechanical
obstruction.
In the presence of partial obstruction, saline
passes with considerable pressure on the syringe.
In the presence of obstruction no fluid passes
into nose and it may reflux through same punctum
(indicating obstruction in the same or common
canaliculus) or through opposite punctum
(indicating obstruction in the lower sac or
nasolacrimal duct).
5. Jones dye tests. These are performed when partial
obstruction is suspected. Jones dye tests are of no
value in the presence of total obstruction.
i. Jones primary test (Jones test I). It is performed
to differentiate between watering due to partial
obstruction of the lacrimal passages from that
due to primary hypersecretion of tears. Two drops
of 2 percent fluorescein dye are instilled in the
conjunctival sac and a cotton bud dipped in 1
percent xylocaine is placed in the inferior meatus
at the opening of nasolacrimal duct. After 5
minutes the cotton bud is removed and inspected.
A dye-stained cotton bud indicates adequate
drainage through the lacrimal passages and the
cause of watering is primary hypersecretion
(further investigations should aim at finding the
cause of primary hypersecretion). While the
unstained cotton bud (negative test) indicates
either a partial obstruction or failure of lacrimal
pump mechanism. To differentiate between these
conditions, Jones dye test-II is performed.
ii. Jones secondary test (Jones test II). When primary
test is negative, the cotton bud is again placed
in the inferior meatus and lacrimal syringing is
performed. A positive test suggests that dye was
present in the sac but could not reach the nose
due to partial obstruction. A negative test
indicates presence of lacrimal pump failure.
6. Dacryocystography. It is valuable in patients with
mechanical obstruction. It tells the exact site, nature
and extent of block (Fig. 15.6). In addition, it also
gives information about mucosa of the sac, presence
of any fistulae, diverticulae, stone, or tumour in the
sac.
To perform it a radiopaque material such as lipiodol,
pentopaque, dianosil or condray-280 is pushed in the
sac with the help of a lacrimal cannula and X-rays are
taken after 5 minutes and 30 minutes to visualize the
entire passage. For better anatomical visualization the
modified technique known as substraction
macrodacryocystography with canalicular
catheterisation should be preferred.
7. Radionucleotide dacryocystography (lacrimal
scintillography). It is a non-invasive technique to
assess the functional efficiency of lacrimal drainage
apparatus. A radioactive tracer (sulphur colloid or
technitium) is instilled into the conjunctival sac and
its passage through the lacrimal drainage system is
visualised with an Anger gamma camera
THE DRY EYE
The dry eye per se is not a disease entity, but a
symptom complex occurring as a sequelae to
deficiency or abnormalities of the tear film.
Etiology
1. Aqueous tear deficiency. It is also known as
keratoconjunctivitis sicca. It is seen in conditions
like congenital alacrimia, paralytic hyposecretion,
primary and secondary Sjogren’s syndrome, Riley Day
syndrome and idiopathic hyposecretion.
2. Mucin deficiency dry eye. It occurs when goblet
cells are damaged, as in hypovitaminosis A
(xerophthalmia) and conjunctival scarring diseases
such as Stevens-Johnson syndrome, trachoma,
chemical burns, radiations and ocular pemphigoid.
3. Lipid deficiency and abnormalities. Lipid
deficiency is extremely rare. It has only been
described in some cases of congenital anhydrotic
ectodermal dysplasia along with absence of
meibomian glands. However, lipid abnormalities are
quite common in patients with chronic blepharitis and
chronic meibomitis.
4. Impaired eyelid function. It is seen in patients
with Bell’s palsy, exposure keratitis, dellen,
symblepharon, pterygium, nocturnal lagophthalmos
and ectropion.
5. Epitheliopathies. Owing to the intimate
relationship between the corneal surface and tear film,
alterations in corneal epithelium affect the stability
of tear film.
Clinical features
Symptoms suggestive of dry eye include irritation,
foreign body (sandy) sensation, feeling of dryness,
itching, non-specific ocular discomfort and
chronically sore eyes not responding to a variety of
drops instilled earlier.
Signs of dry eye include: presence of stringy mucus
and particulate matter in the tear film, lustureless
ocular surface, conjunctival xerosis, reduced or absent
marginal tear strip and corneal changes in the form of
punctate epithelial erosions and filaments.
Tear film tests
These include tear film break-up time (BUT), Schirmer-
I test, vital staining with Rose Bengal, tear levels of
lysozyme and lactoferrin, tear osmolarity and
conjunctival impression cytology. Out of these BUT,
Schirmer-I test and Rose Bengal staining are most
important and when any two of these are positive,
diagnosis of dry eye syndrome is confirmed.
1. Tear film break-up (BUT). It is the interval between
a complete blink and appearance of first randomly
distributed dry spot on the cornea. It is noted after
instilling a drop of fluorescein and examining in a
cobalt-blue light of a slit-lamp. BUT is an indicator of
adequacy of mucin component of tears. Its normal
values range from 15 to 35 seconds. Values less than
10 seconds imply an unstable tear film.
2. Schirmer-I test. It measures total tear secretions. It
is performed with the help of a 5 × 35 mm strip of
Whatman-41 filter paper which is folded 5 mm from
one end and kept in the lower fornix at the junction of
lateral one-third and medial two-thirds. The patient is
asked to look up and not to blink or close the eyes
(Fig. 15.4). After 5 minutes wetting of the filter paper
strip from the bent end is measured. Normal values of
Schirmer-I test are more than 15 mm. Values of 5-10
mm are suggestive of moderate to mild
keratoconjunctivitis sicca (KCS) and less than 5 mm
of severe KCS.
3. Rose Bengal staining. It is a very useful test for
detecting even mild cases of KCS. Depending upon
the severity of KCS three staining patterns A, B and
C have been described: ‘C’ pattern represents mild or
early cases with fine punctate stains in the
interpalpebral area; ‘B’ the moderate cases with
extensive staining; and ‘A’ the severe cases with
confluent staining of conjunctiva and cornea.
Treatment
At present, there is no cure for dry eye. The following
treatment modalities have been tried with variable
results:
1. Supplementation with tear substitutes. Artificial
tears remains the mainstay in the treatment of dry
eye. These are available as drops, ointments and slowrelease
inserts. Mostly available artificial tear drops
contain either cellulose derivatives (e.g., 0.25 to 0.7%
methyl cellulose and 0.3% hypromellose) or polyvinyl
alcohol (1.4%).
2. Topical cyclosporine (0.05%, 0.1%) is reported to
be very effective drug for dry eye in many recent
studies. It helps by reducing the cell-mediated
inflammation of the lacrimal tissue.
3. Mucolytics, such as 5 percent acetylcystine used
4 times a day help by dispersing the mucus threads
and decreasing tear viscosity.
4. Topical retinoids have recently been reported to
be useful in reversing the cellular changes (squamous
metaplasia) occurring in the conjunctiva of dry eye
patients.
5. Preservation of existing tears by reducing
evaporation and decreasing drainage.
Evaporation can be reduced by decreasing room
temperature, use of moist chambers and protective
glasses.
Punctal occlusion to decrease drainage can be
carried out by collagen implants, cynoacrylate
tissue adhesives, electrocauterisation, argon laser
occlusion and surgical occlusion to decrease the
drainage of tears in patients with very severe
dry eye
symptom complex occurring as a sequelae to
deficiency or abnormalities of the tear film.
Etiology
1. Aqueous tear deficiency. It is also known as
keratoconjunctivitis sicca. It is seen in conditions
like congenital alacrimia, paralytic hyposecretion,
primary and secondary Sjogren’s syndrome, Riley Day
syndrome and idiopathic hyposecretion.
2. Mucin deficiency dry eye. It occurs when goblet
cells are damaged, as in hypovitaminosis A
(xerophthalmia) and conjunctival scarring diseases
such as Stevens-Johnson syndrome, trachoma,
chemical burns, radiations and ocular pemphigoid.
3. Lipid deficiency and abnormalities. Lipid
deficiency is extremely rare. It has only been
described in some cases of congenital anhydrotic
ectodermal dysplasia along with absence of
meibomian glands. However, lipid abnormalities are
quite common in patients with chronic blepharitis and
chronic meibomitis.
4. Impaired eyelid function. It is seen in patients
with Bell’s palsy, exposure keratitis, dellen,
symblepharon, pterygium, nocturnal lagophthalmos
and ectropion.
5. Epitheliopathies. Owing to the intimate
relationship between the corneal surface and tear film,
alterations in corneal epithelium affect the stability
of tear film.
Clinical features
Symptoms suggestive of dry eye include irritation,
foreign body (sandy) sensation, feeling of dryness,
itching, non-specific ocular discomfort and
chronically sore eyes not responding to a variety of
drops instilled earlier.
Signs of dry eye include: presence of stringy mucus
and particulate matter in the tear film, lustureless
ocular surface, conjunctival xerosis, reduced or absent
marginal tear strip and corneal changes in the form of
punctate epithelial erosions and filaments.
Tear film tests
These include tear film break-up time (BUT), Schirmer-
I test, vital staining with Rose Bengal, tear levels of
lysozyme and lactoferrin, tear osmolarity and
conjunctival impression cytology. Out of these BUT,
Schirmer-I test and Rose Bengal staining are most
important and when any two of these are positive,
diagnosis of dry eye syndrome is confirmed.
1. Tear film break-up (BUT). It is the interval between
a complete blink and appearance of first randomly
distributed dry spot on the cornea. It is noted after
instilling a drop of fluorescein and examining in a
cobalt-blue light of a slit-lamp. BUT is an indicator of
adequacy of mucin component of tears. Its normal
values range from 15 to 35 seconds. Values less than
10 seconds imply an unstable tear film.
2. Schirmer-I test. It measures total tear secretions. It
is performed with the help of a 5 × 35 mm strip of
Whatman-41 filter paper which is folded 5 mm from
one end and kept in the lower fornix at the junction of
lateral one-third and medial two-thirds. The patient is
asked to look up and not to blink or close the eyes
(Fig. 15.4). After 5 minutes wetting of the filter paper
strip from the bent end is measured. Normal values of
Schirmer-I test are more than 15 mm. Values of 5-10
mm are suggestive of moderate to mild
keratoconjunctivitis sicca (KCS) and less than 5 mm
of severe KCS.
3. Rose Bengal staining. It is a very useful test for
detecting even mild cases of KCS. Depending upon
the severity of KCS three staining patterns A, B and
C have been described: ‘C’ pattern represents mild or
early cases with fine punctate stains in the
interpalpebral area; ‘B’ the moderate cases with
extensive staining; and ‘A’ the severe cases with
confluent staining of conjunctiva and cornea.
Treatment
At present, there is no cure for dry eye. The following
treatment modalities have been tried with variable
results:
1. Supplementation with tear substitutes. Artificial
tears remains the mainstay in the treatment of dry
eye. These are available as drops, ointments and slowrelease
inserts. Mostly available artificial tear drops
contain either cellulose derivatives (e.g., 0.25 to 0.7%
methyl cellulose and 0.3% hypromellose) or polyvinyl
alcohol (1.4%).
2. Topical cyclosporine (0.05%, 0.1%) is reported to
be very effective drug for dry eye in many recent
studies. It helps by reducing the cell-mediated
inflammation of the lacrimal tissue.
3. Mucolytics, such as 5 percent acetylcystine used
4 times a day help by dispersing the mucus threads
and decreasing tear viscosity.
4. Topical retinoids have recently been reported to
be useful in reversing the cellular changes (squamous
metaplasia) occurring in the conjunctiva of dry eye
patients.
5. Preservation of existing tears by reducing
evaporation and decreasing drainage.
Evaporation can be reduced by decreasing room
temperature, use of moist chambers and protective
glasses.
Punctal occlusion to decrease drainage can be
carried out by collagen implants, cynoacrylate
tissue adhesives, electrocauterisation, argon laser
occlusion and surgical occlusion to decrease the
drainage of tears in patients with very severe
dry eye
Structure of tear film
Wolff was the first to describe the detailed structure
of the fluid covering the cornea and called it
precorneal film. He described this film to consist of
three layers, which from posterior to anterior are
mucus layer, aqueous layer and lipid or oily layer
(Fig. 15.2).
1. Mucus layer. It is the innermost and thinnest
stratum of the tear film. It consists of mucin secreted
by conjunctival goblet cells and glands of Manz. It
converts the hydrophobic corneal surface into
hydrophilic one.
2. Aqueous layer. The bulk of tear film is formed by
this intermediate layer which consists of tears
secreted by the main and accessory lacrimal glands.
The tears mainly comprise of water and small
quantities of solutes such as sodium chloride, sugar,
urea and proteins. Therefore, it is alkaline and salty
in taste. It also contains antibacterial substances like
lysozyme, betalysin and lactoferrin.
3. Lipid or oily layer. This is the outermost layer of
tear film formed at air-tear interface from the secretions
of Meibomian, Zeis, and Moll glands. This layer
prevents the overflow of tears, retards their
evaporation and lubricates the eyelids as they slide
over the surface of the globe.
Functions of tear film
1. Keeps the cornea and conjunctiva moist.
2. It provides oxygen to the corneal epithelium.
3. Washes away debris and noxious irritants.
4. Prevents infection due to presence of antibacterial
substances.
5. Facilitates movements of the lids over the globe.
Secretion of tears
Tears are continuously secreted throughtout the day
by accessory (basal secretion) and main (reflex
secretion) lacrimal glands. Reflex secretion is in
response to sensations from the cornea and
conjunctiva, probably produced by evaporation and
break-up of tear film. Hyperlacrimation occurs due to
irritative sensations from the cornea and conjunctiva.
Afferent pathway of this secretion is formed by fifth
nerve and efferent by parasympathetic (secretomotor)
supply of lacrimal gland.
Elimination of tears
Tears flow downward and medially across the surface
of eyeball to reach the lower fornix and then via lacus
lacrimalis in the inner canthus. From where they are
drained by lacrimal passages into the nasal cavity
(Fig. 15.3A). This is brought about by an active
lacrimal pump mechanism constituted by fibres of the
orbicularis (especially Horner’s muscle) which are
inserted on the lacrimal sac. When the eye lids close
during blink, contraction of these fibres distends the
fundus of the sac, creates therein a negative pressure
which syphons the tears through punctum and
canaliculi into the sac (Fig. 15.3B). When the eyelids
open, the Horner’s muscle relaxes, the lacrimal sac
collapses and a positive pressure is created which
forces the tears down the nasolacrimal duct into the
nose (Fig. 15.3C). Therefore, in atonia of sac, tears
are not drained through the lacrimal passages, in
spite of anatomical patency; resulting in epiphora.
of the fluid covering the cornea and called it
precorneal film. He described this film to consist of
three layers, which from posterior to anterior are
mucus layer, aqueous layer and lipid or oily layer
(Fig. 15.2).
1. Mucus layer. It is the innermost and thinnest
stratum of the tear film. It consists of mucin secreted
by conjunctival goblet cells and glands of Manz. It
converts the hydrophobic corneal surface into
hydrophilic one.
2. Aqueous layer. The bulk of tear film is formed by
this intermediate layer which consists of tears
secreted by the main and accessory lacrimal glands.
The tears mainly comprise of water and small
quantities of solutes such as sodium chloride, sugar,
urea and proteins. Therefore, it is alkaline and salty
in taste. It also contains antibacterial substances like
lysozyme, betalysin and lactoferrin.
3. Lipid or oily layer. This is the outermost layer of
tear film formed at air-tear interface from the secretions
of Meibomian, Zeis, and Moll glands. This layer
prevents the overflow of tears, retards their
evaporation and lubricates the eyelids as they slide
over the surface of the globe.
Functions of tear film
1. Keeps the cornea and conjunctiva moist.
2. It provides oxygen to the corneal epithelium.
3. Washes away debris and noxious irritants.
4. Prevents infection due to presence of antibacterial
substances.
5. Facilitates movements of the lids over the globe.
Secretion of tears
Tears are continuously secreted throughtout the day
by accessory (basal secretion) and main (reflex
secretion) lacrimal glands. Reflex secretion is in
response to sensations from the cornea and
conjunctiva, probably produced by evaporation and
break-up of tear film. Hyperlacrimation occurs due to
irritative sensations from the cornea and conjunctiva.
Afferent pathway of this secretion is formed by fifth
nerve and efferent by parasympathetic (secretomotor)
supply of lacrimal gland.
Elimination of tears
Tears flow downward and medially across the surface
of eyeball to reach the lower fornix and then via lacus
lacrimalis in the inner canthus. From where they are
drained by lacrimal passages into the nasal cavity
(Fig. 15.3A). This is brought about by an active
lacrimal pump mechanism constituted by fibres of the
orbicularis (especially Horner’s muscle) which are
inserted on the lacrimal sac. When the eye lids close
during blink, contraction of these fibres distends the
fundus of the sac, creates therein a negative pressure
which syphons the tears through punctum and
canaliculi into the sac (Fig. 15.3B). When the eyelids
open, the Horner’s muscle relaxes, the lacrimal sac
collapses and a positive pressure is created which
forces the tears down the nasolacrimal duct into the
nose (Fig. 15.3C). Therefore, in atonia of sac, tears
are not drained through the lacrimal passages, in
spite of anatomical patency; resulting in epiphora.
Lacrimal Apparatus Anatomy
The lacrimal apparatus comprises (1) Main lacrimal
gland, (2) Accessory lacrimal glands, and (3) Lacrimal
passages, which include: puncta, canaliculi, lacrimal
sac and nasolacrimal duct (NLD) (Fig. 15.1).
Main lacrimal gland
It consists of an upper orbital and a lower palpebral
part. (1) Orbital part is larger, about the size and
shape of a small almond, and is situated in the fossa
for lacrimal gland at the outer part of the orbital plate
of frontal bone. It has got two surfaces — superior
and inferior. The superior surface is convex and lies
in contact with the bone. The inferior surface is
concave and lies on the levator palpebrae superioris
muscle. (2) Palpebral part is small and consists of
only one or two lobules. It is situated upon the course
of the ducts of orbital part from which it is separated
by LPS muscle. Posteriorly, it is continuous with the
orbital part.
Ducts of lacrimal gland. Some 10-12 ducts pass
downward from the main gland to open in the lateral
part of superior fornix. One or two ducts also open in
the lateral part of inferior fornix.
Accessory lacrimal glands (Fig. 14.4)
1. Glands of Krause. These are microscopic glands
lying beneath the palpebral conjunctiva between
fornix and the edge of tarsus. These are about 42
in the upper fornix and 6-8 in the lower fornix.
2. Glands of Wolfring. These are present near the
upper border of the superior tarsal plate and
along the lower border of inferior tarsus.
Structure, blood supply and nerve supply
Structure. All lacrimal glands are serous acini, similar
in structure to the salivary glands. Microscopically
these consist of glandular tissue (acini and ducts),
connective tissue and puncta.
Blood supply. Main lacrimal gland is supplied by
lacrimal artery which is a branch of ophthalmic artery.
Nerve supply. (1) Sensory supply comes from lacrimal
nerve, a branch of the ophthalmic division of the fifth
nerve. (2) Sympathetic supply comes from the carotid
plexus of the cervical sympathetic chain. (3)
Secretomotor fibres are derived from the superior
salivary nucleus.
Lacrimal passages
1. Lacrimal puncta. These are two small, rounded or
oval openings on upper and lower lids, about 6 and
6.5 mm, respectively, temporal to the inner canthus.
Each punctum is situated upon a slight elevation
called lacrimal papilla which becomes prominent in
old age. Normally the puncta dip into the lacus
lacrimalis (collection of tear fluid in the inner canthus).
2. Lacrimal canaliculi. These join the puncta to the
lacrimal sac. Each canaliculus has two parts: vertical
(1-2 mm) and horizontal (6-8 mm) which lie at right
angle to each other. The horizontal part converges
towards inner canthus to open in the sac. The two
canaliculi may open separately or may join to form
common canaliculus which opens immediately into
the outer wall of lacrimal sac. A fold of mucosa at this
point forms the valve of Rosenmuller which prevents
reflux of tears.
3. Lacrimal sac. It lies in the lacrimal fossa located in
the anterior part of medial orbital wall. The lacrimal
fossa is formed by lacrimal bone and frontal process
of maxilla. It is bounded by anterior and posterior
lacrimal crests. When distended, lacrimal sac is about
15 mm in length and 5-6 mm in breadth. It has got
three parts: fundus (portion above the opening of
canaliculi), body (middle part) and the neck (lower
small part which is narrow and continuous with the
nasolacrimal duct).
4. Nasolacrimal duct (NLD). It extends from neck of
the lacrimal sac to inferior meatus of the nose. It is
about 15-18 mm long and lies in a bony canal formed
by the maxilla and the inferior turbinate. Direction of
the NLD is downwards, backwards and laterally.
Externally its location is represented by a line joining
inner canthus to the ala of nose. The upper end of the
NLD is the narrowest part.
There are numerous membranous valves in the
NLD, the most important is the valve of Hasner, which
is present at the lower end of the duct and prevents
reflux from the nose.
gland, (2) Accessory lacrimal glands, and (3) Lacrimal
passages, which include: puncta, canaliculi, lacrimal
sac and nasolacrimal duct (NLD) (Fig. 15.1).
Main lacrimal gland
It consists of an upper orbital and a lower palpebral
part. (1) Orbital part is larger, about the size and
shape of a small almond, and is situated in the fossa
for lacrimal gland at the outer part of the orbital plate
of frontal bone. It has got two surfaces — superior
and inferior. The superior surface is convex and lies
in contact with the bone. The inferior surface is
concave and lies on the levator palpebrae superioris
muscle. (2) Palpebral part is small and consists of
only one or two lobules. It is situated upon the course
of the ducts of orbital part from which it is separated
by LPS muscle. Posteriorly, it is continuous with the
orbital part.
Ducts of lacrimal gland. Some 10-12 ducts pass
downward from the main gland to open in the lateral
part of superior fornix. One or two ducts also open in
the lateral part of inferior fornix.
Accessory lacrimal glands (Fig. 14.4)
1. Glands of Krause. These are microscopic glands
lying beneath the palpebral conjunctiva between
fornix and the edge of tarsus. These are about 42
in the upper fornix and 6-8 in the lower fornix.
2. Glands of Wolfring. These are present near the
upper border of the superior tarsal plate and
along the lower border of inferior tarsus.
Structure, blood supply and nerve supply
Structure. All lacrimal glands are serous acini, similar
in structure to the salivary glands. Microscopically
these consist of glandular tissue (acini and ducts),
connective tissue and puncta.
Blood supply. Main lacrimal gland is supplied by
lacrimal artery which is a branch of ophthalmic artery.
Nerve supply. (1) Sensory supply comes from lacrimal
nerve, a branch of the ophthalmic division of the fifth
nerve. (2) Sympathetic supply comes from the carotid
plexus of the cervical sympathetic chain. (3)
Secretomotor fibres are derived from the superior
salivary nucleus.
Lacrimal passages
1. Lacrimal puncta. These are two small, rounded or
oval openings on upper and lower lids, about 6 and
6.5 mm, respectively, temporal to the inner canthus.
Each punctum is situated upon a slight elevation
called lacrimal papilla which becomes prominent in
old age. Normally the puncta dip into the lacus
lacrimalis (collection of tear fluid in the inner canthus).
2. Lacrimal canaliculi. These join the puncta to the
lacrimal sac. Each canaliculus has two parts: vertical
(1-2 mm) and horizontal (6-8 mm) which lie at right
angle to each other. The horizontal part converges
towards inner canthus to open in the sac. The two
canaliculi may open separately or may join to form
common canaliculus which opens immediately into
the outer wall of lacrimal sac. A fold of mucosa at this
point forms the valve of Rosenmuller which prevents
reflux of tears.
3. Lacrimal sac. It lies in the lacrimal fossa located in
the anterior part of medial orbital wall. The lacrimal
fossa is formed by lacrimal bone and frontal process
of maxilla. It is bounded by anterior and posterior
lacrimal crests. When distended, lacrimal sac is about
15 mm in length and 5-6 mm in breadth. It has got
three parts: fundus (portion above the opening of
canaliculi), body (middle part) and the neck (lower
small part which is narrow and continuous with the
nasolacrimal duct).
4. Nasolacrimal duct (NLD). It extends from neck of
the lacrimal sac to inferior meatus of the nose. It is
about 15-18 mm long and lies in a bony canal formed
by the maxilla and the inferior turbinate. Direction of
the NLD is downwards, backwards and laterally.
Externally its location is represented by a line joining
inner canthus to the ala of nose. The upper end of the
NLD is the narrowest part.
There are numerous membranous valves in the
NLD, the most important is the valve of Hasner, which
is present at the lower end of the duct and prevents
reflux from the nose.
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