Download Clinical Evaluation and Management of Ptosis

Clinical
Clinical Evaluation and Management of Ptosis
Dr.S.Krishnakumar, MS Resident, Aravind Eye Hospital, Madurai
Preoperative History and Examination
Thorough evaluation of the patient is essential to
accurately determine the degree and type of ptosis.
These values are needed to select the appropriate
surgical procedure and to inform the patient
about the expectation of the surgical outcome.
Photographic documentation on pre and post
operatively should be done.
Past Medical History
A thorough history with particular attention to signs
/ symptoms of thyroid disease, myasthenia gravis
or muscular disorders such as myotonic dystrophy,
chronic progressive external ophthalmoplegia or
any related myopathies must be elicited. History
of medical allergies, bleeding diathesis and
haematologic problems must be looked into.
Medications
Current use of medications such as cholinesterase
inhibitors for strabismus or glaucoma, platelet
inhibitors of any other anticoagulants, cardiac
and psychoactive agents must be looked into.
Cholinesterase inhibitors must be discontinued at
least 3 weeks prior to surgery to prevent prolonged
respiratory suppression following intra operative
neuromuscular blockade. Anticoagulants are
stopped 1-2 weeks pre operatively.
Past ocular history
The time of onset and associated findings of ptosis
are important. In a child pre and perinatal history
may be helpful in determining whether a ptosis is
congenital or acquired (especially traumatic). Old
photographs are invaluable in these situations.
In acquired ptosis, the age of onset and
duration of progression are noted. History of
variability of eyelid height, diplopia, generalized
fatigability, trauma, infection, prior ophthalmic
surgeries or family history of adult onset may help
determining the aetiology of acquired ptosis.
In adults, it is important to record a history
of asthenopia or irritative symptoms that may
suggest a tear deficiency. Surgery for ptosis in a
patient with history of dry eyes, seventh cranial
nerve palsy or significant extra ocular muscle
abnormalities such as thyroid related orbitopathy,
double elevator palsy or chronic progressive
external ophthalmoplegia should be approached
with caution. Corneal exposure in these patients
may be very difficult to manage.
Clinical Assessment
Visual Acuity
Careful vision test is done using an age appropriate
method. It was felt in earlier day that ptosis alone
did not produce amblyopia and that anisometropic
or strabismus were always the cause. However
stimulus deprivation per se in ptosis can cause
amblyopia. This problem should be looked for
and treated.
Refraction
Cycloplegic test refraction is indicated in all
children with ptosis since it is known that a
significant number have anisometropia primarily
due to astigmatism on the ptotic side. Any
significant refractive error should be corrected.
Ptosis Measurements
Measurements are begun with simple observation
of the patient. The lid level relative to the globe and
the other lid is observed. The presence or absence
of lid fold or lid crease gives a significant clue
about the degree of levator function. An absent
lid crease is often accompanied by poor levator
function. If a lid crease is present, but higher than
normal (normal lid crease is 8-10mm from the lid
margin measured above the pupil) and if there is a
deeper upper lid sulcus on that side these should
be noted as signs of levator disinsertion. When the
2
patient is asked to look up, both the sulcus and the
lid crease may move up superiorly; slightly before
the lid itself moves. This is caused by a delay in
levator action due to attenuation or stretching of
the normal aponeurotic of the tarsus.
Upper lid height
Vertical fissure height is the distance between the
upper lid and lower lid margins measured in the
papillary plane (it is the widest here) with the eyes
in primary gaze. Normal vertical palpebral fissure
height is 7-10 mm in males and about 8-12 mm
in females.2 Upper lid ptosis can also be compared
with normal eye.
This is a measure of the amount of ptosis in
the primary position, with patient’s brows relaxed.
The upper lid can be used as a baseline from which
to measure the amount of ptosis. The upper lid
normally crosses the cornea 0.5 – 2mm below
upper limbus. In normal situation this relationship
is maintained in upgaze and downgaze.
Based on palpebral fissure, ptosis can
be classified as mild, moderate and severe
(corresponding MRDI) Margin reflex distance.
Mild
upto 2mm 2
Moderate 3mm
1
Severe
>4mm
<0
Levator Function
Evaluation of levator function is extremely
important in evaluation of any case with ptosis. In
patient with abnormal levator function, amplitude
of action of the muscle is diminished and the lid
fails to elevate and depress normally producing
a lid lad in down gaze. The involved lid may be
higher than the uninvolved one in downgaze.
In a patient with ptosis due to dehiscence
of the levator aponeurosis, the levator muscle
is normal, its function is generally quite good
and the amount of ptosis remains the same in
upgaze and in downgaze. The levator function
is determined by holding the brow immobile,
placing a millimetre ruler over the lid in the plane
of the pupil and measuring the levator excursion
AECS Illumination
from extreme downgaze to extreme upgaze (Berke’s
method)1. As a rule of thumb, in congenital ptosis
patients, mild ptosis is usually accompanied by
good levator function and moderate to marked
ptosis is associated with fair to poor LPS function.
The measurement of degree of ptosis and degree
of levator function require the cooperation of the
patient; usually a child must be a 2-3 years of age
before this cooperation can be obtained.
Levator function can be graded according to
Beard’s classification
Normal : >15mm
Good
: 12 – 14mm
Fair
: 5-11mm
Poor
: <4mm
The amount to ptosis can be also be determined
by MRDI (margin reflex distance1)
MRD1
With the eyes of the examiner and the patient at
the same level, a light held between examiner’s
eyes is directed at the patient. The MRD1 is the
distance in 1mm (positive numbers) from the light
reflex on the patient’s cornea to the level of the
centre of upper lid margin (with the patient gazing
in primary position). If 0-the blepharoptotic eye
is seen, the number of millimetres eyelid is raised
is then recorded as MRDI in negative numbers.
The amount of blepharoptosis in patients
with unilateral ptosis is the difference between
MRD1 on ptotic side and the MRD1 on normal
side. In bilateral ptosis the MRD1 is subtracted
from the normal MRDI of 4.5. The advantage of
MRD1 measurement over palpebral fissure width
measurement in measuring degree of ptosis is that,
lower eyelid level, which may be in an abnormal
position, can be disregarded.
MRD2
MRD2 is a measurement from the corneal light
reflex to the lower eyelid level with patient’s eye in
primary position of gaze. Thus the sum of MRD 1
and MRD2 is equal to the palpebral fissure width.
Vol. XIII, No.4, October - December 2013
MLD (Margin Limbal Distance)
The margin limbal distance can also measure
levator function. The MLD is the distance from
the 6’0’ clock limbus to the central upper lid
margin when the patient looks in extreme up
gaze. Each eyelid is measured separately while
the patient follows a light to the extreme superior
position of gaze. In bilateral blepharoptosis the
upper lid of the eye not being measured is elevated
by the examiner’s finger to prevent to see the light.
In unilateral blepharoptosis, the difference in the
MLD between the normal and abnormal sides
indicates the deficiency in levator function. This
difference multiplied by 3 gives the approximate
number of millimetres of levator that must be
resected. In bilateral blepharoptosis, the amount
of levator to be resected is the MLD subtracted
from the average MLD of 9mm multiplied by 3.
This formula was derived empirically from the preoperative and post operative study of more than
200 transconjunctival levator muscle resections.
In the transconjunctival isolation and
transcutaneous levator resection approach the
formula is useful in determining the site of
placement of the first tarsus levator suture. Some
patients have vertical strabismus associated with
blepharoptosis. In many of these patients, the
strabismus should be corrected 3-6 month prior to
treatment of any residual blepharoptosis. However,
other patients with minimal strabismus require
treatment only of blepharoptosis. In these patients
the MLD is not valid because the 6-0’ clock level in
upgaze is abnormal owing to the vertical deviation.
In such cases MRD3 is used to determine the
degree of levator function and amount of levator
muscle that must be resected3.
MRD3
MRD3 is the distance from the ocular light reflex
to the central upper lid margin when the patient
looks in extreme upgaze. In unilateral ptosis, the
difference between normal and abnormal MRD3
multiplied by 3 approximately shows the amount
of levator that must be resected. Generally MRD3
is equal to MRD1 but in case of associated superior
3
rectus weakness or palsy MRD3 > MRD1. In
bilateral ptosis, the MRD3 is subtracted from the
normal average MRD3 of 7 mm and difference
is multiplied 3 to determine approximately the
number of millimetre of levator muscle to be
respected.
MCD (Margin Crease Distance)
If there is an eyelid crease on either eye, the margin
crease distance (MCD) should be measured preoperatively. The MCD is the distance from the
central eyelid margin to the central upper lid skin
crease with the upper lid in the down position of
gaze and skin fold slightly elevated to expose the
crease. At surgery the central upper lid margin
is elevated from below with the cotton tipped
applicator and the crease corresponds to the
pre-operative MCD is chosen as the site for postoperative eyelid crease.
Bell’s Phenomenon
To test for Bell’s phenomenon, the examiner
attempts to separate the lids while the patients
close them tightly. Eye with normal bell’s
phenomenon will be upgaze. If the eyes are not in
upgaze or if they move to other position of gaze,
such as downgaze (inverse Bell’s phenomenon)
lagophthalmos after surgical correction of ptosis
may be associated with increased incidence of
exposure keratopathy.
Marcus Gunn Jaw Winking Phenomenon
This synkinesis is best demonstrated by having
the patient move the jaw the opposite side, but
widely opening the mouth or moving the jaw
forward would also elevate eyelid. The internal
pterygoid may be involved, but more rarely. In
such a situation, cleaching the teeth will elevate
the eyelid. The patient is instructed to open and
close the mouth and to move the jaw side while
the examiner observes the blepharoptotic eyelid
for associated movement.
Hering’s Law
In certain circumstance of bilateral ptosis, if one
side has marked ptosis and the other side has
4
minimal ptosis, the side with minimal ptosis may
droop more after the greater ptotic side has been
corrected. This is due to the Hering’s law. This is
important to predict the postoperative results of
ptosis surgery. The patient may have to be warned
that the contralateral eye may droop following
correction of the greater ptotic lid.
Strabismus
The patient should also be examined for
strabismus. If there is hypotropia on the side
of ptosis, a pseudoptosis may exist secondary
to depression of the eye. Since correction of the
strabismus may relieve the blepharoptosis ocular
muscle should be performed prior to treatment
of blepharoptosis. An exception may be made for
cosmetically acceptable strabismus for which only
blepharoptosis needs to be treated. If the patient
has horizondal strabismus with ptosis, surgery for
both strabismus and ptosis can be performed at
the same sitting because the result of one rarely
influences the result of the other.
Function of Muller’s Muscle
The function of muller’s is treated by applying
drops of 10% phenylephrine to the eye on the
side of blepharoptosis. If the upper lid assumes a
normal level 10-15 minutes after instillation of the
drops, as operation to resect muller’s muscle and
conjunctiva can relieve blepharoptosis.
Phenylepherine stimulates the sympathetically
innervated muller’s muscle and gives the surgeon an
idea of what can be accomplished by strengthening
it through the resection and advancement of
muller’s muscle and conjunctiva.
The level of the upper lid after phenylephrine
test correlates well with its level after the muller’s
muscle conjunctiva resection procedure. To
measure the response to phenylephrine, it is
necessary to measure the MRDI before and after
its instillation rather than palpebral fissure width,
because the lower lid retracts with stimulation of
muller’s muscle and conjunctiva.
The level of the upper lid after phenylephrine
test correlates with its level after the muller’s
muscle conjunctiva resection procedure. To
AECS Illumination
measure the response to phenylephrine, it is
necessary to measure the MRD1 before and after
its instillation rather than palpebral fissure width,
because the lower lid retracts with stimulation of
muller’s in the lower lid. This would give a false
value of the palpebral fissure height.
Disinsertion of the Levator Aponeurosis
Disinsertion of the levator aponeurosis from the
tarsus is the cause of some cases of congenital
and many cases of acquired ptosis. At times a
thin eyelid and a high upper lid crease and fold
may indicate a disinserted levator aponeurosis
preoperatively. The upper lid crease is formed
by levator extension attached to the skin. As the
levator aponeurosis recedes into the orbit, it carries
the crease with it, leading to higher crease and fold.
The upper lid is pulled over the cornea in primary
position of gaze. If the iris marking can be seen
through the translucent upper lid pulled over the
eye, the levator with or without muller’s muscle
may be disinserted or recessed.
Visual Field Test
Visual field tests may be obtained in patients
who are able to cooperate in order to document
peripheral and superior visual field restriction.
Slit Lamp Examination
Slit lamp examination of anterior, intraocular
pressure and fundus examination are a must prior
to surgery to rule out other pathologies. Corneal
sensation and staining must be done to detect
the presence of corneal anaesthesia or decreased
sensation as they might result in injury to the
cornea post-operatively.
Tear Film Assessment
Tear film abnormality must be looked for and
ideally Schirmer’s test is done in all cases, which
are going to be taken up for surgery, especially in
acquired ptosis. In adults, measures of basal tear
secretion is obtained by Schirmer's testing on the
anaesthetized eye. In addition, the cornea tear
film should be evaluated for evidence of abnormal
debris or tear break up.
Vol. XIII, No.4, October - December 2013
Dry eye syndrome would be a contraindication
for ptosis surgeries, especially sling surgeries as it
may cause corneal damage post operatively.
Additional Observation
The lid contour and lashes are also evaluated. In
adults, redundant skin and ptosis of the brow
may mask a true ptosis or produce ptosis due
to mechanical factors. Orbicularis oculi muscle
function should be tested. Palpation of the lids
and orbit is important because it may reveal the
presence of a mass not otherwise appreciable as the
cause of acquired ptosis. The destiny of the ptosis
operation is determined by the thoroughness of
preoperative lid examination.
Normal Measurements of the Lid4,5
The normal palphebral fissure is 26 to 30mm
in horizontal dimension and 8-10mm in height
(7-10 mm in males and 8-12mm in females).
The distance from the papillary light reflex to the
upper lid (MRDI) ranges between 2 to 5mm and
the distance from papillary light reflex to lower
eyelid (MRD2) is between 4.5mm to 5.5mm.
The normal lid rests 1-2mm below 12’0 clock
border of the limbus and lower eyelid at 6’o clock
border of the limbus, although it may be slightly
above or below this level. The distance between
2 medial acanthi is normally 30 to 34 mm. The
puncta are approximately 6 -7 mm from medial
canthal angle. Medial canthal angle is 0 to 2mm
below the lateral canthal angle in most individuals.
The tarsus is approximately 1mm in thickness and
24 mm to 28 mm in length. The height of the
upper lid tarsus is usually 10mm, and the average
height of lower lid tarsus is 3-7mm.
Evaluation of Infantile Ptosis
The office evaluation of infantile ptosis elicits
information similar to the adult ptosis examination
but requires the physician to practice preverbal
entertainment skills and be willing to approximate
measurements.
As in any case of ptosis, palpebral fissure,
margin reflex distance, lagophthalmos and levator
function are assessed. The presence of bell’s and
5
integrity of corneal epithelium are assessed.
Motility is examined, especially superior rectus
weakness. Head tilt and the use of the brow for
lid elevation are documented. Sucking or chewing
are used to elicit jaw wink response. The most
important measurement however, is the levator
function. The levator function is measured in
millimetres as the full excursion of lid from
downgaze to upgaze, excluding lift resulting from
frontalis muscle. Levator function may be classified
as good, fair or poor. Millimeter values can be
placed on these descriptions.
Good
: <8mm
Fair
: 4-7mm
Poor
: <4mm
However, exact measurements in the infant
are difficult to obtain and only be estimated. The
phenylephrine hydrochloride test is performed to
judge potential benefit of an internal lid elevating
procedure. 2.5% phenylephrine is placed in the
eye to stimulate sympathetic response of muller’s
muscle. When instillation results in a good lid
position, there is a positive correlation with a good
surgical response to a conjunctival mullerectomy.
When the levator function is in the good/fair
range, an internal muller’s procedure or a levator
resection will achieve lift. For levator function
brow suspension is the option of choice. The leg
of the infant is too small to allow harvesting of
autogenously fascia lata. Donor fascia lata may be
considered. Even in order children, most parents
would prefer to compromise on appearance rather
than excise normal tissue.
Treatment of Ptosis
Surgery is often the only option offered to the
patient for the treatment of ptosis. Inspite of the
variety and ingenuity of remedical operations,
the results of ptosis surgery are by no means
invariably brilliant. The greatest care is necessary
in the selection of cases and the type of procedure
adopted must be individually suitable to each case.
Though surgery would be the definite treatment,
other temporary options may be offered to the
patient.
6
Non-surgical Treatment1
1. Lid crutches may be used to support a drooping
lid mechanically. The type used is a wire
support in the form of a semi lunar soldered
to the upper part of the rims of a pair of
spectacles.
2. Haptic contact lens with a shelf on which the
margin of upper lid rests may be used.
3. Elevation of the lid by a mechanic force: a strip
of highly magnetically metal is implanted in
the upper lid and a magnet is placed behind
the upper rim of the frame.
Surgical treatment however, is required in
most cases of ptosis to obtain a satisfactory result
from cosmetic and functional points of view. Over
100 modifications of techniques are to be found
in literature all of which can be resolved into a few
general procedures.
When to correct ptosis surgically6
Correction of ptosis in a child can often be delayed
until the patient is several years old, although
consistent chin up positionings / complete
ptosis may justify early surgery6. In general,
congenital ptosis should be repaired when accurate
measurements are obtainable and before the child
begins school. Most children can undergo repair
around 4-5 years of age. Severe ptosis, which may
cause amblyopia, must be surgically repaired as
soon as possible to preserve normal vision.
Note : An acquired ptosis from a traumatic
injury or a third nerve palsy should not be operated
on before 6 months of age, because often some
levator function will return. Any other acquired
ptosis may be repaired when the cause has been
determined. Specially myasthenia gravis must be
ruled out.
Indications for surgery in congenital
ptosis
In most instances the primary reason for correcting
congenital ptosis is cosmetic. In case of unilateral
congenital ptosis of such severity that normal
visual development is compromised by total
AECS Illumination
occlusion of visual axis, surgical intervention may
be indicated shortly after birth.
In cases of severe bilateral ptosis that interferes
with the child’s learning walk, surgery may be
indicated early. The levator action in these children
is always so poor that a frontails sling procedure
is necessary.
In general, ptosis causing significant stimulus
deprivation or head posturing must be surgically
treated without fail. Milder degrees of ptosis need
to be corrected only if the patient desires good
cosmesis.
Contraindications
Poor orbicularis muscle function may produce
lagophthalmos and corneal exposure. Loss
of blink reflex or corneal sensitivity, paralysis
of orbicularis or significant keratitis sicca are
definite contraindications for ptosis surgery. Total
ophthalmoplegia may also result in postoperative
corneal exposure as the cornea is exposed during
sleep.
Some ophthalmologists feel the presence or
absence of Bell’s phenomenon is of significant
importance in ptosis surgery in most circumstances,
its absence is not a contraindication for surgery in
patients with congenital ptosis. However, extreme
caution should be exercised in these patients, as
also in those with decreased random movement
during sleep.
Choice of Surgery for Ptosis
In general there are three major groups of ptosis
surgery.
1. External levator resection (including
aponeurotic repair) for >4mm for levator
function.
2. Posterior tarso muller muscle resection (not
generally used in congenital ptosis unless due
to congential horners).
3. Frontalis suspension.
In severe unilateral ptosis, bilateral suspension
can be considered combined with weakening of
opposite normal levator. This beard technique
Vol. XIII, No.4, October - December 2013
leads to excellent symmetric results. However
many surgeons prefer to leave the normal eyelid
alone.
Principles of surgical correction of ptosis
One inherent drawback to all ptosis procedure
is that perfect cosmetic and functional results
cannot be expected in every case. In general, the
7
final result depends on the nature of ptosis, the
type of operation selected and the skill with which
operation is performed6.
Levator resection is performed on all levator
maldevelopment (congenital dysmyogenic) ptosis
cases with levator action of 4 or more whereas
frontalis sling is performed when the levator action
is 3 mm or less.
Guidelines for correction of levator maldevelopment ptosis in millimeters6.
Degree of Ptosis
Levator Function
Amount of levator
resection
Ideal preoperative
correction
1.5 – 2 mm (mild) Good (8 or more)
Small (10-13)
Good (8 or more)- usual Moderate (14 -17)
Under correct by
1 - 3mm
3 mm (moderate)
Fair (5-7) – sometimes
Poor (4 or less) – rare
Large (18-22)
Maximal (23 or more)
Match the level of
normal lid and correct
ptosis fully.
4 or more (severe)
Fair (5-7) – sometimes
Poor (4 or less) – usual
Super maximal
(27 or more)
Frontalis sling
Over correct by 1-2mm
If in doubt most surgeons prefer to overcorrect,
because, over correction is easier to treat than an
under correction. An under-correction requires
a second ptosis surgery under less favourable
conditions than the first. This is because the
second surgery will have to be done in the presence
of scar tissue, bleeding, obliteration and / or
distortion of normal anatomic landmarks.
The aim of any operation should be to lift
the ptotic lid above the papillary aperture when
the eyes are in the primary position. The height
of the two lids regardless of whether the ptosis
is unilateral or bilateral should be equal. There
should also be adequate mobility of the lid when
blinking, a normal lid fold and no diplopia.
References
1. System of ophthalmology edited by Sur Stewart Duke Elder. Congenital deformities Vol.3 part. 2
2. Clinical ophthalmology. Jack J. Kanski. Fifth Edition. Butterworth Heinemann publishers. P 32-39.
3. Allen M Puttrman. Basic oculoplastic surgery in Vol.3. Chap 33 P.2251. Edited by Peyman GA, Sanders
DR, Goldberg MF. Ist Indian eition. Jaypee brothers.
4. Putterman Am: Basic oculoplastic surgery. In Peyman GA, Sanders DR, Goldberg MF (eds). Principles of
practice of ophthalmology. P2248-2250 philadelphia, WB saunders, 1980.
5. Putterman Am: Evaluation of the cosmetic oculoplastic surgery 2nd Ed. P12-26. Philadelphia, WB
saunders, 1993.
6. Paediatric Ophthalmology and Strabismus Sec.6. 2001-2002. P-172.