Tonic Pupil as the Presenting Sign of Relapsed Acute Myeloid Leukemia

Abstract

A 23-year-old woman complained of photophobia, lacrimation, and redness of the left eye of 1 week's duration and a dilated left pupil. Acute myeloid leukemia (AML) had been diagnosed 5 years earlier and treated with a stem cell transplant. She had developed graft vs host disease (GVHD) affecting her skin and had undergone psoralen plus UVA (PUVA) treatment. The AML had been in remission for 3 years before her ophthalmic visit. Medications included acyclovir, fluconazole, penicillin, cyclosporine, and mycophenolate. Systemic corticosteroid treatment had recently been discontinued. Best-corrected visual acuities were 20/20 in the right eye and 20/40 in the left eye, improving to 20/30 with pinhole. In the left eye, the palpebral fissure was slightly narrow but with normal levator function, the tear break-up time was reduced, and there was punctate staining of the cornea. The pupils measured 2 mm in the right eye and 4 mm in the left eye in minimal illumination. On bright light stimulation with the indirect ophthalmoscope light, the right pupil constricted to 1 mm and the left remained at 4 mm. After stimulation by a near target the left pupil also constricted to 1 mm. The left eye showed vermiform movements of the iris on slit lamp examination. Dilute pilocarpine (0.125%) was then instilled in both eyes. After this both pupils measured 2 mm, demonstrating hypersensitivity of the left pupil. She was orthophoric and had a full range of ocular movements. Posterior subcapsular lens opacities were present in both eyes. Ophthalmoscopy was normal. The punctuate epitheliopathy of the cornea was attributed to GVHD and the cataracts to the use of systemic corticosteroids. Left tonic pupil was diagnosed. Lubricants were prescribed for the epitheliopathy. Two days later, she returned complaining of blurred vision. Best-corrected visual acuities were 20/80 in the right eye and 20/40 in the left eye. There was no change in the anterior segment findings of either eye. Ophthalmoscopy showed localized elevation of the retina in the macular region in both eyes. B scan ultrasound showed thickening and irregular elevations of the choroid in both eyes (Fig. 1). Fluorescein angiography showed pinpoint areas of hyperfluorescence of increasing brightness in the macular region of both eyes.FIG. 1: B scan ultrasound of the left eye shows thickening and irregularity of the choroid (arrowhead) and overlying serous retinal detachment.Blood tests showed an elevated white cell count, indicating relapse of leukemia. Brain and orbit MRI showed only faint mucosal thickening of the sinuses. Chemotherapy was begun. The leukemia could not be controlled, and she subsequently died of systemic complications. Tonic pupil can be caused by Adie syndrome, systemic neuropathic diseases, or local lesions (1). Adie syndrome is characterized by tonic pupil and disturbance of deep tendon reflexes without evidence of local ocular or orbital disease or generalized peripheral or autonomic system dysfunction. Orbito-ocular causes of tonic pupil include inflammation, infection, or infiltration that affects ciliary ganglion or the ciliary nerves in the retrobulbar region or in the suprachoroidal space. Tonic pupil has been reported in siderosis caused by retained intraocular foreign body (2); injury to the final cholinergic fibers within the suprachoroidal space was postulated as the likely pathologic mechanism. Postganglionic denervation by damage within the suprachoroidal space has also been reported with retinal detachment surgery using explants (3) and after laser photocoagulation for diabetic retinopathy (4). Leukemia can cause tonic pupil by direct infiltration of the orbit or the choroid. However, postganglionic nerve injury at the level of the eye in choroidal cancer has been reported only once (5). In our patient, there was no imaging evidence of orbital infiltration at presentation. The ultrasound study showed extensive choroidal thickening and irregularity. The fluorescein evidence of pinpoint leaks and serous retinal detachment indirectly indicated dysfunction of the retinal pigment epithelium. A similar phenomenon caused by choroidal infiltration has been reported (6). Hence it is likely that the damage to the ciliary nerves occurred at the suprachoroidal level. Mandagere R. Vishwanath, FRCSEd Stephen J. Charles, MA, MD, FRCOphth Manchester Royal Eye Hospital Manchester, United Kingdom [email protected]