Removal Of The Eye And Orbital Contents

ANTERIOR APPROACH In the vast majority of instances, the eye is removed by the anterior approach. (For the removal of orbital contents, see below under "Intracranial Approach.") The eyelids are held apart with the aid of retractors (Fig. 7-2). Using curved scissors, the conjunctival attachments to the limbus are severed, care being taken not to cut the eyelids. Tenon's capsule is left intact to avoid leakage into the empty socket. The four rectus muscles are cut so that approx 5.0 mm of muscle are left attached to the globe; this allows orientation of the globe at a later time. The inferior oblique muscle is then severed. Rotation of the eye temporally by traction on the stump of the inferior oblique muscle allows access to the optic nerve and ensures that a long piece of the intraorbital portion of the optic nerve is obtained. It is not deemed necessary to ligate the optic stalk as only a portion of the leakage after enucleation arises from the severed end of the optic nerve. The socket is dried with a towel and a silastic mold is placed in position (Fig. 7-3). The disadvantage of this anterior approach is that it excludes adequate examination of the orbital contents and the lacrimal gland.

INTRACRANIAL APPROACH (EXENTERATION PROCEDURE) This method is advisable when there is pathology of the orbit and the eye. Such conditions include inflammation, neoplasia, vascular disease, and disease of the orbital portion of the optic nerve. The method consists of first cutting the con-junctival attachments at the limbus by the anterior approach as outlined earlier, and using the intracranial approach to expose the orbital contents.

After removal of the brain, two saw cuts are made, one vertically downward opposite the cribriform plate of the ethmoid and the second downward and medially, immediately anterior to the lateral end of the lesser wing of the sphenoid. The orbital plate is broken with a chisel and hammer and the bone is removed piecemeal with the aid of bone forceps. Care must be taken not to damage the optic nerve and other contents of the optic foramen as this area is exposed. Curved scissors are used to free the globe and its attached muscles. The superior oblique muscle is cut from the body of the sphenoid bone and the inferior oblique muscle is cut from the floor of the medial orbit. Freeing of the conjunctival attachments must proceed with caution in order to avoid damage to the eyelids and anterior chamber of the eye.

Fig. 7-1. Aspiration of vitreous. Upper, Needle inserted 5 mm lateral to the limbus (corneo-scleral junction). Lower, Needle enters vitreous through pars plana of ciliary body.
Fig. 7-2. Eyelids held apart by Weeks' speculum. This allows enucleation or biopsy of the lacrimal gland.

The eye with optic nerve, surrounding nerves, muscles, and fat, are freed from the walls of the orbit. Again, Tenon's capsule is left intact in order to avoid leakage into the empty socket. The orbit and lacrimal fossa should be palpated after the exentera-tion procedure to determine the presence or absence of any abnormality such as a neoplasm.

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