Title: When is Not the Diagnosis Authors: Steven Chang OD, Pediatric Optometry Resident SUNY State College of Optometry Denise Alexopoulos OD, Pediatric Optometry Resident SUNY State College of Optometry Formatted: Left Abstract: Amblyopia is a diagnosis of exclusion and a dilated fundus examination is critical. This report discusses a case of an asymptomatic pre-pubescent patient who presents with reduced acuity and bilateral swollen optic nerves. Formatted: Left I. Case History: A 5-year-old Hispanic male was referred by his pediatrician for a second opinion as he had failed multiple vision screenings with corrective lenses. Ocular history was remarkable for bilateral refractive amblyopia and multiple prescription changes over the past few weeks prior to the exam. Medical history was remarkable for prior lead poisoning and polycythemia vera. No allergies or medications were reported.

II. Pertinent Findings: Entering prescription: OD: +3.50-1.75x180 OS: +4.25-1.50x175 with distance acuities of 20/40- 2 and 20/150+ respectively, and near acuities of 20/30-2 and 20/50. testing with the Hardy Rand Rittler booklet yielded no defects OD and deutan defect OS. Stereopsis was not appreciated. Extraocular motility was full. No was present. PERRL with no relative afferent pupillary defect (RAPD). Refraction did not improve visual acuities. Digital intraocular pressures were soft and equal OD/OS. Dilated fundus examination revealed bilateral disc edema with central myelination, OS greater than OD, which was confirmed with optical coherence tomography. The macula was flat with no hemorrhages or exudates OU. Retinal vasculature showed mild tortuosity OU. The patient was promptly referred and was admitted into the ER the same day and was examined by a neuro-ophthalmologist and a hematologist over the course of the next few days. Their assessment is as follows: Lumbar puncture was performed with opening pressures of 33 centimeters of water (cm H2O) with titration of closing pressure to17 cm H2O. Magnetic resonance imaging with and without was only remarkable for protrusion of bilateral optic discs, consistent with the diagnosis of . Hemoglobin levels were elevated at 23.5 grams/deciliter. Magnetic resonance venography was unremarkable for a venous sinus thrombosis.

III. Differential diagnosis: Idiopathic intracranial hypertension, space-occupying lesion,

IV. Diagnosis and Discussion: Idiopathic intracranial hypertension (IIH) is a condition becoming more recognized in the pediatric population. IIH is characterized by elevated intracranial pressure with normal cerebral spinal fluid (CSF) composition and is typically diagnosed following the modified Dandy criteria1. The annual incidence of IIH in the general population is 1 in 100,000 a year. The typical profile of those affected are young obese women, where incidence can be as high as 19 in 100,000.2 Children with IIH do not follow the typical profile, rather, both males and females are equally affected, and obesity is less prevalent.3 Classic symptoms of IIH include headaches, nausea, and vomiting. However, affected children may not always complain of headaches and are more likely to present with a strabismus (most commonly a cranial nerve VI palsy), a stiff neck, or even shimmering visual disturbances.4 This case is unique in that an otherwise seemingly healthy and asymptomatic pre- pubescent patient was promptly admitted into the emergency room with bilateral disc edema. With the diagnosis of polycythemia vera, not only was a phlebotomy performed, but a prompt MRI was ordered to rule out a cerebral venous thrombosis, which is a common presentation in those with polycythemia and can cause papilledema.5 His reduction in vision may have suggested longstanding papilledema, rather than the previously diagnosed amblyopia.

V. Treatment / Management: The mainstay of treatment for IIH, if symptomatic is generally with diuretics, which serve to reduce the CSF production.6 Randomized controlled clinical trial data is lacking in assessing different treatment options and the efficacy and dosing in the pediatric population2. Prescribing for adolescents as such is based off of adult IIH common practice. When medical treatment does not suffice, surgical options must then be considered.6 This patient was started on oral acetazolamide 125mg twice a day, and subsequently increased to 250mg twice a day. Follow up optometric examinations did not show improvement in ocular findings despite treatment. He then underwent sheath fenestration in both eyes a few months following the initial presentation. The patient remained asymptomatic, yet there was no resolution of the papilledema. A ventriculo-pertitoneal shunt was then implanted to help divert CSF away from the . At his most recent optometric examination, the vision remains reduced, despite both surgical and pharmaceutical intervention. As refraction did not improve visual acuities, the patient will be evaluated by a low vision specialist to determine if any devices would be of benefit.

References: 1. Friedman DI, Jacobson DM. Diagnostic Criteria For Idiopathic Intracranial Hypertension. Neurology 2002;59:1492-5. 2. Ko MW, Liu GT. Pediatric Idiopathic Intracranial Hypertension (Pseudotumor Cerebri). Horm Res Pediatr 2010;74:381-9. 3. Durcan FJ, Corbett JJ, Wall M. The Incidence of Pseudotumor Cerebri: Population Studies in Iowa and Louisiana. Arch Neurol 1998;45:875-7. 4. Soler D, Cox T, Calver DM, et al. Diagnosis and Management of Benign Intracranial Hypertension. Arch Dis Child 1998;78:89-94. 5. Ferro JM, Canhao P, Stam J, et al. Prognosis of Cerebral Vein and Dural Sinus Thrombosis: Results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Stroke 2004;35(3):664-70. 6. Spitze A, Lam P, Al-Zubidi N, et al. Controversies: Optic Nerve Sheath Fenestration Versus Shunt Placement for the Treatment of Idiopathic Intracranial Hypertension. Indian J Ophthalmol. 2014; 62(10): 1015-1021.

VI. Conclusion: Idiopathic intracranial hypertension when occurring in children may have varying symptoms and may not manifest with the more typical symptoms of adult IIH such as headaches, dizziness, or vomiting. A careful dilated examination must be performed when reduction of vision is present without refractive improvement. Prompt referral for imaging and lumbar puncture is important, especially in children with bilateral swollen optic nerves. Formatted: Font color: Text 1