Case Presentation:

An 82-year-old woman with dementia, right eye blindness, prior right retinal surgery, atrial fibrillation, and prior stroke presented to an outside hospital with a six-month history of weakness, confusion, ataxia, and falls. 

A head computed tomographic (CT) scan showed hyperdensity of the right globe, scleral thickening, and an identically hyperdense lesion superolateral to the right globe and contiguous with it.  Neither area of hyperdensity enhanced with IV contrast.  There were no abnormal enhancing intracranial lesions and no evidence of acute stroke.  Due to concern for malignancy, she was transferred for further evaluation.

Subsequent examination of the right eye showed complete fill with silicone oil.  Retinal laser scars and a scleral buckle were also noted, evidence of prior retinal surgery.

Records were obtained from the patient’s outside ophthalmologist.  The patient had undergone two prior right eye surgeries for treatment of retinal detachment, which included vitrectomy with intraocular infusion of silicone oil.  The second surgery was complicated by extravasation of oil into the subconjunctival space.  The silicone oil was not removed after the second retinal surgery.

Given this additional history, and the identical hyperintensity of the right globe and adjacent, contiguous superolateral lesion, the head CT findings were felt due to prior intraocular silicone oil injection during retinal surgery, complicated by extravasation of oil into the retina and adjacent portions of the eye.  The hyperattenuation noted on CT prior to IV contrast and the subsequent lack of contrast enhancement were not consistent with neoplasm.

The patient’s presenting symptoms were ultimately felt due to progression of dementia, deconditioning, and difficulties with ambulation and balance related to lack of stereo vision associated with right eye blindness.

Discussion:

There are various methods to treat retinal tears and detachment.  One such method involves vitrectomy, repair of retinal tear(s) with laser or cryotherapy, and filling the eye with gas or silicone oil.  The gas or oil tamponades the retina against the retinal pigment epithelium while healing occurs.  Silicone oil is used rather than gas in patients (e.g. children, patients with cognitive impairment) who are unable to maintain necessary post-operative head and eye positioning.  Oil is also preferred for patients who need to fly soon after surgery and those with proliferative vitreoretinopathy.  Intraocular silicone oil is usually removed a few months after surgery but in some cases may be kept in place indefinitely.  It appears hyperintense on CT scanning.

Conclusions:

Heuristics are simple, efficient rules, hardwired by prior experience, which may be utilized in the setting of complex problems or incomplete information.  For hospitalists, this often occurs in the current era of multiple, elaborate electronic medical record systems which lack interconnectivity.  Hospitalists must remain cognizant that failed heuristics (e.g. premature closure) may lead to diagnostic error when they replace careful history, examination, and independent review and verification of data.

Hospitalists frequently manage patients who present with vague symptoms and have abnormal head imaging.  Although malignancy is unfortunately common, this case accentuates the need to also consider alternate, non-neoplastic etiologies in such situations.