Ординатура / Офтальмология / Английские материалы / Surgical Atlas of Orbital Diseases_Mallajosyula_2009

Down and in displacement of the globe is mostly due to enlargement of lacrimal gland, due to infection (Dacryoadenitis), inflammation (idiopathic orbital inflammation, Mukulitz syndrome (Figures 2.25A to C), or neoplasia. Pleomorphic adenoma (Figures 2.26A to D) is the most common benign tumor while Adenoidcystic carcinoma of the lacrimal gland (Figures 2.27A to D) is the most common and

dreaded malignant tumor of the lacrimal gland. Other rare causes include lymphoma (Figures 2.28A to D) pleomorphic adenocarcinoma, adenocarcinoma, squammous cell carcinoma and reactive lymphoid hyperplasia. Other lesions of the fossa of lacrimal gland like dermoids (Figures 2.29A to D) can also cause eccentric proptosis with globe displaced down and in.

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Figures 2.26C and D: The mass was excised through superior lid crease incision. Note the well encapsulated tumor (C) and well hidden incision in the lid crease (D) Histopathology confirmed it to be pleomorphic adenoma of lacrimal gland

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Figures 2.28A and B: Note the fullness of left upper lid with globe pushed down and in (A). CT scan of orbit shows enlarged lacrimal gland, molding to the globe (B)

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Upward displacement of globe is due to either an extension of lesion of maxillary sinus into orbit (neoplasia, fungal granuloma or dumbbell dermoid) or lesions of inferior space like cavernous hemangioma, neurofibroma, schwannoma, cystic lesions like myocysticercosis involving inferior rectus (Figures 2.30A to C). Many a time lesions of maxillary sinus extend into frontoethmoidal sinuses, or nose. Anterior extension leads to fullness of cheek (Figures 2.31A to C). It is my experience that orbital extension of lesions from paranasal sinuses is a common cause of eccentric proptosis.

Measurement of proptosis is a very important part of evaluation of the patient. The displacement of the globe should be quantified in all the 3 directions, anteroposterior (axial), horizontal and vertical axes. Naphzeiger’s test is a useful bedside

clinical test to detect mild proptosis (Figures 2.32A and B). Ask the patient to look at a distant object, located at the same level as that of the patient’s eye. Stand behind the patient, and gently tilt the head backwards and look down over the patient’s forehead. The proptosed eye appears ahead of the other.

Another simple bedside test to detect mild proptosis is with the help of a scale. Ask the patient to gently close the eyes, and keep a scale across the eye in contact with his forehead and cheek. Normally there will be space between the scale and the closed lid. In the presence of proptosis this space is obliterated (Figures 2.33A and B).

Axial proptosis is best measured with Hertel's exophthalmometer (Figure 2.34A). Leudde's exophthalmometry is less accurate and inter-observer variation is more significant.

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Figures 2.30A to C: This female, 42 years in age, presented with proptosis left eye, which was displaced upwards (A). Note the mass lesion in lower lid, which was transilluminant (B). This demoid cyst was removed through swinging lower lid approach. Note the minimal swelling of lower lid on 2nd postoperative day (C)

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Figures 2.32A and B: Naphzeiger’s test: Note the prominence of left eye (arrow). The right eye is not visible

Figure 2.33A: Note the space between the closed right eye and the scale in a normal eye

Clinical Approach to Proptosis 37

compare results over a period of time. When once the BR is recorded, subsequent readings should be taken with the same BR so that the results are comparable.

Another very important factor you have to remember is that while performing exophthalmometry, you should occlude the unexamined eye with your thumb, (Figure 2.34C) so that the eye being examined comes to the primary position. Then only the readings are accurate.

Figure 2.33B: Note the obliteration of space. The scale is in contact with the eyelid of proptosed left eye

Hertel’s exophthalmometry consists of 2 foot plates - one is fixed and the other sliding. Each foot plate has a viewing mechanism (Figure 2.34B) where the eye being examined is seen in profile below a scale in millimeters (Figure 2.34D). There are 2 red lines for reference to avoid parallax error. Rest the fixed footplate on the anterior part of lateral wall of right orbit and slide the other footplate on the scale till it rests on the anterior part of lateral wall of left orbit. Note the distance between the 2 foot plates from the scale. This is called the “Base Reading” (BR). It is very important to record the base reading since the exophthalmometry values change with base reading. In other words, if you take 2 readings on the same patient one after the other with 2 different base readings, the values you get will be different. In fact the one with wider BR will give larger value! If you forget to note the BR, you can not accurately

To measure the horizontal displacement of the eye, put a mark on the center of root of the nose. Measure the distance from that point to the nasal limbus of the proptosed eye, with the other eye being covered. Repeat the same for the normal eye, covering the proptosed eye. The difference between these two readings gives you the horizontal displacement (Figures 2.35A and B).

Vertical displacement is measured with the help of 2 rulers. Hold the first scale in line with the lateral canthi. Measure the distance from this scale to the 6 O'clock limbus of each eye.

A larger reading of proptosed eye means that the globe is pushed inferiorly, and a lesser reading is obtained when the globe is displaced up (Figures 2.36A and B).

Pulsations: Pulsations of globe in proptosis can be either vascular pulsations or transmitted

pulsations. Vascular pulsations are due to increased blood flow and is typically seen in CarotidCavernous Fistula (CCF). It is almost always seen in high-flow CCF (Figures 2.37A to C). The other important causes include meningioma (Figures 2.38A to C), orbital varix, aneurysms, etc. Transmitted pulsations are due to cerebral pulsations which are transmitted due to bony deficiency as in

neurofibroma (Figures 2.39A and B). I have seen a child who presented with pulsatile proptosis due to herniation of frontal lobe of brain into orbit following trauma (Figures 2.40A and B).

To detect pulsations observe from a side. Subtle pulsations can be recognized while recording IOP with an applanation tonometer.

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Figures 2.37A to C: Note the caput medusae of conjunctival congestion with limitation of abduction of left eye (A). She has a pulsatile proptosis, 3 months after head injury. The IOP was 28 mm of Hg. Bruit was heard with the stethoscope (B). CT scan of orbit revealed a very grossly enlarged superior ophthalmic vein (green arrow), typical of carotid cavernous fistula (C)

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Figures 2.38A to C: This lady of 58 years, presented with pulsatile proptosis of right eye since 1 year (A). Note the temporal fullness, (blue arrow) which was showing pulsations (B), CT scan revealed a mass from temporal lobe and involving the sphenoid wing with extension in to orbit and the temple (C). Note the hyperostosis of Sphenoid bone (red arrow) This is a case of meningioma

Pupil: Examination of pupil and its reaction is very important. The presence of Relative Afferent Pupillary Defect (RAPD) indicates that optic nerve is being damaged. Optic nerve can be damaged either due to tumors of the optic nerve or its sheaths, or by compression due to any space occupying lesion of central space, by enlarged extraocular muscles as in thyroid associated orbitopathy, or by nonspecific inflammations of the orbit. Due to narrowing of the orbital space at the apex, a smaller lesion at the orbital apex can lead to optic nerve compression. Optic nerve damage is also seen in severe stretching of optic nerve, as seen by "tenting" of the posterior pole on CT scan.

Perception of Color Vision: This is an important, simple and very sensitive way to know the status of the optic nerve. This statement is relevant for the following reasons. In very early optic nerve compression the vision can still be 20/20. The patient may not notice defective vision in the presence of diplopia, watering and discomfort/ pain. In bilateral cases, RAPD may not be elicited. During fundus examination, very early Optic disc compression can be missed. Visual field analysis may not detect any abnormality in very early cases. Hence the importance of color vision testing can not be over emphasized. When a patient of proptosis is under observation, as in a case of TAO, I instruct the patient