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

to look at a bright red colored object with each eye separately on every sunday, and to report to me immediately if he notices any change in brightness of the color in one eye. If color vision is defective in the proptosed eye, evaluate very carefully the pupil for RAPD, do a very detailed fundus evaluation for the presence of optic disc edema, pallor, presence of opticociliary shunts, retinal/choroidal striae, retinal detachment. Visual field assessment is mandatory.

PBCT: Limitation of ocular motility in proptosis is mostly due to restrictive pathology as in thyroid associated orbitopathy (Figures 2.41A and B), Idiopathic orbital inflammation (myositis component) (Figures 2.42A to D), myocysticercosis (Figures 2.43A and B), and fungal granuloma (Figures 2.44A to C). Another important cause is CCF, wherein the restriction is paralytic in nature (Figures 2.45A to C). Large mass lesions can cause mechanical restriction. Limitation of ocular motility following

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Figures 2.43A and B: This young girl presented with proptosis of left eye since 4 weeks. She also complained of pain and diplopia.

Note the fullness of upper lid, mild congestion of conjunctiva on the medial side and convergent squint. (A) CT scan of orbit revealed myocysticercosis involving the superior oblique muscle. Note 2 cysts, one involving the muscle belly and the other the reflected tendon of superior oblique (B)

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Figures 2.44A to C: This elderly male, (A) an agricultural worker by occupation, presented with gross proptosis with frozen globe (B).

His vision was PL. Retropulsion was positive. FDT was positive in all directions. CT scan of the orbit revealed a heterogenous mass lesion occupying the entire orbit. Note the molding of the lesion to the globe (red arrow), the tenting of posterior pole (blue arrow) and involvement of anterior ethmoidal sinus. Histopathology showed it to be a fungal granuloma (C)

trauma can be due to soft tissue edema, entrapment of muscle or its sheath in orbital fracture and rarely due to injury to the muscle itself. I came across a rare cause wherein after trauma; the displaced bone itself caused limitation of motility (Figures 2.46A to D). I routinely quantify the ocular motility in degrees, just like Hirschberg's, so that it is easier to compare the course of the disease over a long period.

When ocular motility is limited, I routinely do FDT (Forced Duction Test) and differential tonometry to know whether it is due to restrictive pathology or paralytic. I prefer FDT to FGT (force generation test).In restrictive pathology FDT is positive and you feel resistance when you try to move the globe in the direction of limitation. Elevation of intraocular pressure by more than 5 mm

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Figures 2.45A to C: This girl presented with diplopia and restricted motility following trauma. Note subconjunctival hemorrhage in right eye. (A) FDT was positive. Clinical diagnosis was blowout fracture of floor of orbit with muscle entrapment. But CT scan of orbit revealed fracture roof of orbit with the bony spicule mechanically restricting the ocular motility. (B) Elevation restored to normal after removing the bony spicule (C)

from the base pressure when the patient attempts to move the globe in the direction of limitation of movement is significant. This occurs in restrictive pathology as the globe is compressed between the constricting muscle and its opponent which can not relax. Quantify the motility restriction, with PBCT (Prism Bar Cover Test) in different directions. This helps to know what is happening to the extraocular muscles, especially when you have to follow a patient for a long time like thyroid associated orbitopathy, and to decide if the patient benefits with prescription of prisms.

Periorbital Changes: There are numerous periorbital changes which help us in understanding the pathology of the lesion and aid in clinical diagnosis. Some of these make the diagnosis very

Clinical Approach to Proptosis 45

obvious (like the lid retraction of thyroid associated orbitopathy, Salmon patch of lymphoma, temporal fullness of sphenoid ridge meningioma) while others throw light into the disease process and its activity.

Temporal Fullness: This is very characteristic of sphenoid wing meningioma, especially of lateral part (Figure 2.36) Sphenoid wing meningioma of lateral half typically presents as proptosis with fullness of the temple, which often exhibits pulsations. Sphenoid wing meningioma of medial half presents as proptosis with restricted ocular motility (Figures 2.47A and B). Another very rare cause of temporal fullness is a dumbbell dermoid (Figures 2.48A and B), in which eyeball can move forwards on mastication due to contraction of temporalis muscle.

Lid changes: The important lid changes include lid retraction, lid lag, sinuous lid margin, tumors of the lid (primary malignant tumors of the lid with secondary orbital extension, primary vascular neoplasia with components of orbit and lid, or multiple tumors involving the lids and orbit like neurofibromatosis (Von Recklinghausen)).

Lid Retraction is the most common lid change seen in thyroid associated orbitopathy. It can involve both upper and lower eyelids. It is measured by recording MRD values and subtracting the normal values (4 mm and 5 mm) from it. The lid retraction of TAO is due to over action of sympathetic system (Müller's muscle) and can also be due to hypotropia and limitation of elevation, so that with the attempt to move the globe, the upper lid goes up and lid retraction worsens. The lid retraction can be unilateral or bilateral. As per the NOSPECS classification, the lid retraction is classified as follows: mild if the lid margin is at limbus, moderate if up to

4 mm of sclera is seen and severe if > 4 mm of sclera is seen (Figures 2.49A to C). Usually in TAO, the contor of lid is altered in that the highest point of the upper lid is at the lateral part (lateral flare).

Lid lag: Lid lag is the second most common lid change in thyroid orbitopathy. It can be unilateral or bilateral. Lag-ophthalmos is a very important finding one has to look for. It can lead to exposure keratopathy which in the early stages can present with pain and photophobia (Figures 2.50A and B). There may be associated defective vision. If the lagophthalmos is severe and prolonged, it can lead to frank corneal ulcer and even perforation. Hence it is very important to detect lag ophthalmos as early as possible and take remedial measures. To detect early lagophthalmos, look from below (Figures 2.51A and B). Severe lagophthalmos is usually seen in very gross proptosis which can be due to a very large benign tumor, but more often due to faster growing lesions like metastatic lesions (Figures 2.52A to C).

Mass: Look at the details of any visible mass (Figures 2.53A and B), like its surface, look for any vasculature, transillumination (Figure 2.30B), the margins, and posterior extent of the borders. Measure the size of the mass lesion. Some times there can be more than 1 mass lesion as in Von Recklinghausen (Figures 2.55A to C). The mass can

have an orbital and a lid component (Figures 2.54A and B).

Conjunctival changes: The common conjunctival changes in proptosis are Salmon patch, chemosis, caput medusae, and subconjunctival hemorrhage. Occasionally tumor components may be visible.

Salmon patch is a pinkish, smooth mass, typically seen in the subconjunctival plane, either at the limbus, or fornix (Figures 2.57A to C). It is very typical of lymphoma. The lesion at the fornix, which is more commonly seen, is due to the extension of the tumor, as it moulds to the adjacent globe and extends anteriorly along the sub-tenon's plane and can extend upto the limbus. The isolated limbal mass is due to proliferation of the lymphocytes.

Caput medusae: Engorged blood vessels, typically around the limbus are seen in AV malformations and fistula (Figures 2.58A and B). The engorgement is usually due to increased venous pressure due to A- V communication. It can be very subtle and can be easily over looked by the novice. In high flow fistula the caput medusae can be very significant and point towards the diagnosis. Some times it can be associated with chemosis of conjunctiva.

Chemosis: Chemosis is divided into 3 grades, grade 1 is when the chemosed conjunctiva covers up to half the lid margin, grade 2 when it covers the entire lid margin and grade 3 when it overhangs the lid margin (Figures 2.59A to C). Conjunctival

chemosis can be because of active infections and inflammations like orbital cellulitis, orbital abscess, thyroid orbitopathy, or due to high flow arteriovenous communications, lymphangioma (Figures 2.60A to C)

Subconjunctival hemorrhage is an important feature of lymphangioma, leukemia, trauma and bleeding diathesis. In a case of trauma, apart from associated ocular and systemic injuries, look for RAPD, retrobulbar hemorrhage and orbital fractures. If retrobulbar hemorrhage is present, do canthotomy and cantholysis (Figures 2.61A and B).

Val salva: Increase in proptosis after Val salva maneuver is typically due to Orbital Varix (Figures 2.62A to C)

Examination of nasal cavity and oral cavity is mandatory, especially in the presence of paranasal sinus involvement (Figures 2.63A and B). It is much easier to get a biopsy done from these lesions to know the nature of the lesion.

Other important periocular changes involving cornea, ocular motility, pupil, visual acuity, fundus examination, color vision were already mentioned earlier.

Palpation: Palpate the orbital margin, look for any palpable mass lesion and assess the orbital pressure by retropulsion. While palpating the orbit, ask the patient to look in the direction in which you are palpating, so that the orbital septum is relaxed. Use the pulp of your finger to palpate the orbit for any mass. If a mass is palpable, note its consistency, tenderness, extent, surface, reducibility, posterior extent. Assess the orbital tone by gently applying pressure over the closed eyelids and pushing the globe into the orbit. Compare the resistance offered by the proptosed eye with that of the normal. From this you can know if the orbital lesion is compressible or unyielding mass.

Auscultation: In pulsatile proptosis, auscultate with the bell of a stethoscope for any bruit. It is typically heard in high flow fistula.

Common causes of bilateral proptosis in children are congenital skeletal deformities, followed by lymphoma, leukemia and other lymphoproliferative