Major orbital complications of endoscopic sinus surgery

Abstract

BACKGROUND—The paranasal sinuses are intimately related to the orbit and consequently sinus disease or surgery may cause severe orbital complications. Complications are rare but can result in serious morbidity, the most devastating of which is severe visual loss.
METHODS—A retrospective review was undertaken of four cases of severe orbital trauma during endoscopic sinus surgery.
RESULTS—All the cases suffered medial rectus damage, one had additional injury to the inferior rectus and oblique, and two patients were blinded as a result of direct damage to the optic nerve or its blood supply.
CONCLUSION—Some ophthalmic complications of endoscopic sinus surgery are highlighted, the mechanisms responsible are discussed, and recommendations for prevention, early recognition, and management are proposed. 



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Figure 1  .

Case 1: a 52 year old man who presented 11 days after right orbital entry during endonasal ethmoidectomy showing (A) marked right exotropia and (B) good right abduction but no adduction of the right eye with (C) marked hypotropia on attempted left gaze. Nine months after orbital repair he had intermittent exotropia (D-F) and markedly improved right ocular ductions (G, H).

Figure 2  .

Case 1: (A) axial CT scan showing a defect in the right lamina papyracea to which the medial rectus appears adherent (arrow); the eye is abducted and there is minor enophthalmos. Only the anterior part of the muscle can be seen but this could be because of the plane of image. There is extensive sinus disease. (B)-(D) Direct coronal sections showing a large air containing postoperative space in continuity with the right nasal cavity. The medial rectus muscle is clearly visible in (B) just in front of the defect; its high density is artefactual. The muscle is seen to be displaced medially (arrow) into the defect in (C) and cannot be discerned in (D) which passes through its posterior end.

Figure 3  .

Case 1: Hess charts (A) 6 weeks and (B) 8 months after orbital surgery showing delayed recovery of medial rectus function after release of the entrapped muscle.

Figure 4  .

Case 2: presentation at 14 months after right orbital injury during endoscopic sinus surgery with (A) right exotropia, (B) normal right abduction, and (C) an inability to reach the midline on attempted adduction of the right eye. (D) View of the anterior part of the right medial rectus showing loss of most muscle fibres (arrow) in the anterior third of the muscle at the site of previous orbital injury.

Figure 5  .

Case 2: (A) axial and (B) direct coronal CT scans showing marked enophthalmos and abduction of the right eye with prolapse of orbital soft tissue into a defect in the lamina papyracea. There has been extensive nasal surgery. The medial rectus cannot be identified at the level of the bone defect but, more anteriorly, small threads of tissue are seen in its normal position (A, arrow).

Figure 6  .

Case 3: orbital entry during endoscopic sinus surgery a year before presentation has resulted in a markedly sunken and blind left eye with a divergent squint and no adduction.

Figure 7  .

Case 3: (A) axial CT scan showing the left optic nerve (open arrows) in abnormal position, angulated just behind the eye and inseparable from soft tissue along the lamina papyracea. A small dense area presumably represents a flake of bone driven into the orbit. There is 5 mm left enophthalmos and the eye is abducted. The direct coronal scan (B) shows the optic nerve (arrow) and the bone fragment to form part of a mass of soft tissue density which, through a defect in the lamina papyracea, is continuous with tissue in the ethmoid sinuses. There is widespread sinus and nasal disease.

Figure 8  .

Case 4: (A) a 55 year old man presenting with a divergent blind right eye 4 days after sinus surgery; there is an extensive subconjunctival haemorrhage and eyelid bruising. Red-free photograph of the right fundus (B) shows the foveal sparing retinal oedema of an acute central retinal artery occlusion; poor image quality is the result of anterior chamber cellular reaction.

Figure 9  .

Case 4: (A) and (B) axial T1 and T2 weighted images showing 4 mm right enophthalmos and abduction. The right medial rectus muscle cannot be identified and the anterior portion of the medially deviated optic nerve is difficult to see. There is a fluid level in the right side of the sphenoid sinus in (B). (C)-(E) Coronal T1 weighted images (anterior to posterior) show a structure just behind the eye ((C), electronic arrow) which can be traced back to the optic nerve/sheath complex in (E), intimately related to a bone defect; there is no clear demonstration of the medial rectus muscle. The paranasal sinus and nasal cavity return low signal compatible with swollen mucosa. The coronal T2 weighted image through the mid orbit (F) shows extensive high signal extending from the area of the bone defect across the lower part of the retrobulbar fat and, more posteriorly (G), the optic nerve sheath (arrow) appears collapsed, suggesting transection of the sheath and leakage of cerebrospinal fluid into the fat.