Unilateral Painless Visual Loss in Sphenoid Mucoceles with Optic Neuropathy

Abstract

Introduction: Mucoceles are benign, slow-growing cystic formations located within the paranasal sinuses, caused by complete ostial obstruction and accumulation of mucous secretions. Here, we report a case of a patient who initially presented with unilateral painless visual impairment and was ultimately diagnosed with bilateral sphenoid sinus mucoceles (SSMs) after two hospitalizations.

Case presentation: A 67-year-old woman presented with a 7-day history of decreased vision in her left eye. She denied any orbital pain, headache, or restricted eye movement and was diagnosed with retrobulbar ischemic optic neuropathy on the first admission. After drug treatment, the visual acuity of patient improved significantly, but 3 months after discharge, the patient was hospitalized again due to recurrent vision loss accompanied by left orbital pain and left temporal pulsatile headaches. After multiple imaging examinations, the patient was ultimately diagnosed with SSMs and her visual acuity was restored after surgical treatment.

Conclusions: The majority of SSMs are associated with ocular symptoms, with only a minority presenting solely with unilateral or bilateral vision loss, as exemplified in this case. Therefore, understanding the clinical features of visual disturbances secondary to SSMs is crucial to aiding more prompt diagnosis and treatment.

Keywords: Compressive optic neuropathy; Sphenoid sinus mucoceles; Visual impairment.

Fig. 1.

CT scans (a, b) and MRI scans (c, d) of the paranasal sinuses revealed a dense shadow (red arrow) within the bilateral sphenoid sinuses and posterior ethmoid sinuses. Bone destruction is evident on the walls of the bilateral sphenoid sinuses and posterior ethmoid sinuses, as well as on the medial wall of the left orbit. The left lateral rectus muscle and optic nerve exhibit mild compression.

Fig. 2.

The pathological examination of the mucocele revealed chronic mucosal inflammation accompanied by the formation of retention cysts. Additionally, minimal bone tissue (a, red arrow) and osteoblasts (b, white arrow) were observed in the surrounding area.

Fig. 3.

Preoperatively, the visual field testing revealed a superior visual field defect on the right side (a) and complete visual field loss on the left side (b). c Six months postoperatively, the visual field of the right eye returns to normal. d Additionally, there was an observed enlargement of the physiological blind spot in the left eye, accompanied by a partial peripheral visual field defect.

Fig. 4.

Six months postoperatively, axial (a, red arrow) and coronal (b, white arrow) cranial MRI scans demonstrated resolution of the previously noted abnormal high-signal intensity in the left sphenoid sinus.

Fig. 5.

An axial (a, red arrow) and a coronal (b, white arrow) brain MRI scan revealed a T2 hyperintense signal within the sphenoid sinus.