Considering this neurological finding, a comprehensive neurological
consultation was promptly requested to further assess the patient’s
condition.
As part of the neurological evaluation, a non-contrast computed
tomography (CT) scan of the brain was ordered to rule out any
intracranial pathology that could potentially be contributing to the
patient’s strabismus. The CT scan would provide valuable information
regarding the structural integrity of the brain, including any evidence
of methadone-induced neurotoxicity, cerebral edema, or other
abnormalities that may have developed secondary to the methadone
overdose.
Upon further evaluation of the patient’s neurological status, a
comprehensive eye examination was performed to assess the extent and
nature of the strabismus and to rule out any other ocular abnormalities
related to the methadone poisoning. The patient’s visual acuity was
measured at 20/25 in the right eye (OD) and 20/30 in the left eye (OS).
The pupillary examination revealed pupils that were equal in size and
reactive to light bilaterally, with no evidence of a relative afferent
pupillary defect (RAPD).
Extraocular motility testing demonstrated a full range of motion in all
directions of gaze in the left eye. However, the right eye exhibited a
restricted adduction, with a full range of motion in all other
directions. A 30-prism diopter right exotropia was noted in primary
gaze, consistent with the patient’s reported symptom of diplopia.
Confrontation visual fields were full to finger counting in all
quadrants bilaterally.
Slit-lamp examination of the anterior segment was unremarkable, with
normal lids, lashes, conjunctiva, sclera, cornea, anterior chamber,
iris, and lens in both eyes. Intraocular pressure was measured at 14
mmHg in the right eye and 15 mmHg in the left eye, both within normal
limits.
A dilated fundus examination was performed to assess the posterior
segment of the eye. The vitreous was clear bilaterally, and the optic
nerves appeared normal with sharp margins and no signs of edema. The
cup-to-disc ratio was 0.3 in both eyes. The macula exhibited a normal
foveal reflex without any signs of edema, and the vasculature was of
normal caliber with no evidence of occlusion or hemorrhage. The
peripheral retina was flat and intact in both eyes.
The comprehensive eye examination confirmed the presence of a
significant left exotropia, measuring 30 prism diopters, which was
consistent with the patient’s reported diplopia. The restricted
adduction in the left eye further supported the diagnosis of lateral
strabismus.
The emergence of strabismus in the context of methadone poisoning is a
relatively uncommon neurological manifestation. However, it is crucial
to thoroughly investigate any neurological signs or symptoms in patients
presenting with opioid toxicity, as they may be indicative of more
severe central nervous system dysfunction. By promptly recognizing and
evaluating the patient’s strabismus, the medical team aimed to identify
any underlying neurological complications and provide appropriate
management to prevent further deterioration and ensure the best possible
outcome for the patient.
The patient’s methadone toxicity was managed with intravenous naloxone
and supportive care, including mechanical ventilation. The patient’s
altered mental status and respiratory depression resolved with treatment
on hospital day 3.
The patient’s strabismus was managed conservatively with observation and
serial ophthalmological examinations. Over the course of her hospital
stay, the right exotropia gradually improved, with a residual deviation
of 10 prism diopters at the time of discharge on hospital day 7. The
patient was advised to follow up with ophthalmology as an outpatient for
further monitoring and management of her residual strabismus.