Exophthalmometry, its types, principle, procedure, indications, advantages and disadvantages, Luedde's exopthalmometer, hertel's exophthamlometer

1. Exophthalmomet
ry
Raju Kaiti, M. Optom
Consultant Optometrist

2. Introduction
Orbital disorders can be associated with forward protrusion
or backward displacement of the eyes
Proptosis (exophthalmos):
Abnormal forward protrusion of the eyeball
orbital volume is fixed, thus, excess in volume will
result in protrusion of the globe
Orbit is made out of BONE…It does not yield to
increase pressure within it
Enophthalmos:
abnormal posterior displacement of globe
Sinking of eyeball into orbit

3. Causes of Bilateral Exophthalmos
Cavernous Sinus Thrombosis
Vascular Anomaly
Orbital Psudotumor (Neoplasm)
Wagner’s granulomatosis
Orbital Cellulitis
Orbital Infection
Orbital Inflammation
Metastatic Neuroblastoma
Grave’s eye disease
# 1 Cause (Endocrine)
Mnemonic for proptosis:
VEIINN/COW OMG

4. Causes of Enohthalmos
Orbital blow-out fracture
Age related degeneration of orbital fat
Progressive hemifacial atrophy

5. Causes of
Pseudoexophthalmos
Long axial length of the globe
High axial myopia
Congenital glaucoma
Orbital asymmetry
Congenital
Traumatic
Asymmetry of the palpebral fissures
Lid retraction
Contralateral ptosis (Horner’s syndrome, CN III palsy)
Contralateral Enohthalmos
Entropion or Ectropion
Loss of tonus in EOMs
Third nerve palsy

6. Proptosis Evaluation : Direct
Observation
Family album tomography
(FAT)
old photos
View from above
position of lids under the brow
Detect relative position of cornea under lids

7. MEASUREMENT OF PROPTOSIS
METHODS:
SIGHING OVER THE BROW—
patient is seated and the practitioner standing
behind.
Surgeon holds the patients head in such a manner
that he looks straight down the nose.
Then he rotates the head backward, until he can
see just the apex of cornea.
If he can see more of apex of cornea than the other,
that eye is relatively proptosed.
This method neither permits a record of
exophthalmos for future reference nor as accurate
as instruments.

8. Why perform
Exophthalmometry?
Exophthalmos appearance is not always confirmed by
direct observation
proptosis may be subtle
pseudo-proptosis appearance may be cause by
contralateral ptosis
Presence of lid retraction
normal asymmetry of palpebral fissure

9. Introduction
• Is the clinical procedure used to measure the
anteroposterior position of the globe in the orbit relative to
some orbital landmark, most commonly the lateral angle of
the orbital rim.
• Other terms: “proptometry” or “ophthalmostatometry”
• Exophthalmos, or proptosis, is an abnormal forward
displacement or protrusion of the globe within the orbit.
• Enohthalmos is an abnormal posterior displacement of the
globe or a relative sinking of the globe posteriorly into the
orbit.

10. Exophthalmometry
In Exophthalmometry, a measurement of the distance
between a point on the temporal orbital rim and the
apex of the cornea is made.
During Exophthalmometry, the patient’s gaze should be
directed straight ahead in primary gaze.
There are two basic types of exophthalmometers in
wide use.
These are the Luedde exophthalmometer and the
Hertel exophthalmometer.
Others: Naugle Ophthalmometer, Gormaz
Ophthalmometer

11. Clinical Use
Basic use is the detection, diagnosis, and monitoring of
protrusion or exophthalmos or, less frequently,
Enohthalmos.
Can be very useful in monitoring the progression of
exophthalmos to monitor the status of disorders
Grave’s disease is the single most common cause of
unilateral or bilateral exophthalmos.
Detection and monitoring of Grave’s eye disease
Differentiation of pseudoexophthalmos from true
exophthalmos
Differentiation of pseudoenophthalmos from true

12. Common ways to determining globe
position: Exophthalmometers
Allows for images of corneal apex to project on a mm
ruler
Hertel (1905)
Most common
Luedde (1938)

13. •
LUEDDES Exophthalmometer
LUEDDES
Exophthalmometer is a
simple transparent plastic
scale with a groove which fits
into outer bony margin of
orbit, and amount of
protrusion is read from scale.
Consists of a clear, square
plastic rod that is about a
centimeter in thickness.

14. LUEDDES Exophthalmometer
The rod is ruled in millimeters on both sides (minimizes
parallax error), with a scale from 0 to 40 mm.
The zero point of the scale is at the tapered end of the
rod.
The tapered end of the rod is notched to fit firmly against
the lateral orbital margin, and the instrument is oriented
perpendicular to the plane of the face.

15. The Luedde
Transparent plastic mm ruler
Notch conforms to angle of lateral orbital rim
scale readings: 0mm (end of notch**) to 40mm
parallax is minimized by using scale on both sides of
the rod**
** Are advantages of using Luedde over a standard
ophthalmic mm ruler

16. Luedde Procedure
1. Palpate the lateral orbital rim to locate the deepest angle of the
rim.
2. Carefully place the notched end of the exophthalmometer
against the deepest point orbital rim
i. Scale should face out on the side
ii. Keep Luedde perpendicular to plane of face
3. From the patient’s temporal side look through the
exophthalmometer and sight the corneal apex
4. Slightly adjust the position of your head to superimpose the
markings on both sides of the ruler, specifically those that
corresponds to the corneal apex
5. Read the marking that is tangent to the corneal apex
6. Repeat the reading and record the reading in millimeter as well
as the name of the instrument used, for example
Luedde<17, 18
17, 17

17. LUEDDES Exophthalmometer
The examiner views the eye from the temporal side and
notes the position of the corneal apex relative to the
exophthalmometer scale.
This instrument suffers from the same problem
encountered if the examiner attempts to measure the
position of the cornea with a millimeter ruler-there is no
way to make sure that the ruler is held perpendicular to
the facial plane and the examiner’s line of sight is parallel
to the facial plane.
It is not possible to simultaneously compare readings for
the two eyes, as in Hertel.

18. HERTELS exophthalmometer
• Most commonly used
• The Hertel is designed such
that both lateral orbital margins
and corneal apices are visible
to examiner in rapid succession
(almost simultaneously).
• Normal values varies
between—(10—21mm),and are
symmetrical in both eyes.
• A difference of more than
2mm,between two eyes is
considered significant.

19. The Hertel exophthalmometer uses a mirror
system (Bausch and Lomb) or Prism
(Rodenstock) that allows the examiner to
measure the protrusion of each eye while facing
the patient.

20. The Hertel
Foot-plates (or yokes) “ grooved arc” fit over bony
temporal margin of lateral orbital rim
crossbar
Establish baseline to allow for biocular reading
**B&L’s or Lombart’s design
Lock

24. Exophthalmometry Set
upPatient to look straight ahead
Palpate the bony ridge
locating deepest angle of the orbital rim

25. Hertel Procedure
Loosen the lock (B&L or Lombart)
slide mirrors or prisms along the horizontal bar to
adjust footplates with corresponding lateral orbital
rims
Bring Hertel forward toward patient, keeping it
parallel to floor with crossbar scale visible in front
Position footplates against each lateral orbital rim
independently
Read of the cross bar scale (near BASE)

26. Hertel Procedure
patient eye open widely & at your eye level
Look at the mirror
Take mm measurement where apex of cornea (lower) is
superimposed on the mm scale (upper)
corneal reflex lower mirror & mm scale upper mirror
OU

27. Hertel vs. Luedde
Hertel
biocular reading
baseline for
sequential
readings
• Luedde
• Strabismus
• Facial asymmetry
• Since facial asymmetry
can cause measurement
error in particular with
Hertel, Luedde are use for
those occasions

28. Recording
measurement is made in mm
For Hertel measurement record finding for each
eye along with separation of instrument (BASE)

29. Example
Hertel
17/18mm @ 100 base
OD 20mm & OS 21mm @ 115 base
Luedde
OD,OS 17mm

30. Analysis measurements
Eyes are compared…
Comparative
Relative
Absolute

31. Interpretation
Comparative
serial exophthalmometry readings of the same eye are
compared over time
Use same instrument
best to use Hertel over Luedde
Base reading
Commonly employed as a test on patients with
Grave’s disease

32. Interpretation
Relative
comparison of readings b/t two eyes
normal: </= 2mm
Absolute
comparison of readings to norms
whites 12 to 20 mm (10-22mm)
average 15 -17mm
blacks 12 to 24 mm
average 2mm higher than whites

33. Exophthalmometry
interpretations
Age
lower readings for children
average 14mm
b/t age 10-18 there is a 3mm increase
Sex
males have higher readings
1mm
Posture
In supine position NORMAL eyes sink back 1-3mm
Grave’s disease patients eye are not affected by
this phenomena

34. Exophthalmometry
interpretations
Ethnicity
Blacks have higher reading
12-24mm
Asian have smaller ranges
12-18mm

35. Final Note
Reliability may be affected by
poor fixation or convergence
parallax errors (tilting instrument)
minor deviations in position result in gross
variations in reading
Narrow base on Hertel
Blepharospasm
Facial bone dysformity may cause unreliable
measurements due to unparallel placement of
device
Inter-observer variation is common problem associate with reliability

36. AFTER Exophthalmometry
measurements:
When to further evaluate…
Difference of >/=3 mm b/t eyes
Readings greater than the norm