Anterior and posterior ischemic optic neuropathy in a child with focal segmental glomerulosclerosis on hemodialysis.

BACKGROUND: Ischemic optic neuropathy (ION) is exceedingly rare in children on dialysis, resulting from poor perfusion of the optic nerve, and presents as sudden acute painless vision loss. CASE-DIAGNOSIS/TREATMENT: We report the case of a 3-year-old male with stage 5 chronic kidney disease (CKD 5) due to focal segmental glomerulosclerosis (FSGS) status post-bilateral nephrectomy on chronic hemodialysis who had acute loss of vision several hours after a hemodialysis session. Earlier that day, he had a drop in blood pressure intra-dialysis to 89/67 mmHg, with at home blood pressures ranging 90/60 to 150/100 mmHg. The patient was treated with tight blood pressure control to maintain blood flow and prevent blood pressure lability, received high-dose corticosteroids with a corticosteroid taper, and placed on high-dose erythropoietin for neuroprotective effect. He regained partial vision beginning approximately 1 month after presentation. CONCLUSIONS: The exact cause of our patient's simultaneous bilateral anterior and posterior ION, confirmed via MRI and fundoscopic examination, is unclear; however, is likely secondary to a combination of fluctuating blood pressure, anemia, anephric status, and hemodialysis. This highlights the need for close blood pressure monitoring, management of anemia, and more diligent ophthalmologic screening in pediatric patients on chronic hemodialysis.

Corrigendum to "Sarcoidosis presenting as Wallenberg syndrome and panuveitisË® Respir. Med. Case Rep. 24 (2018) 16-18.

[This corrects the article DOI: 10.1016/j.rmcr.2018.03.002.].

Neuro-ophthalmology malpractice: A review of the Westlaw Database.

BACKGROUND: Neuro-ophthalmologic conditions are at a higher risk of misdiagnosis compared to other ophthalmic conditions. Increased awareness of the most common diagnostic errors in neuro-ophthalmology that lead to malpractice claims can allow ophthalmologists to further improve their diagnostic workup to reduce delays in diagnosis and management, while also mitigating the risk of litigation. METHODS: Malpractice trials in the Westlaw Legal Database that involved cases of neuro-ophthalmologic diagnostic errors or failures by ophthalmologists were included in this study. RESULTS: A total of 43 cases were included, all citing failure to diagnose as the main reason for litigation. The most common diagnoses missed were cerebrovascular pathologies (30.2%), intracranial tumours (27.9%) and giant cell arteritis (25.6%). The majority of verdicts were in favour of the defendants (48.8%). After adjusting for inflation, the average amount awarded was $1,952,154. CONCLUSION: Nearly half of the cases resulted in a defendant verdict. Settlement and plaintiff verdicts were costly, with average awards of approximately two million inflation-adjusted dollars. Failure to diagnose cerebrovascular pathologies was the most common diagnostic error followed by failure to diagnose intracranial tumours and giant cell arteritis. It is crucial for ophthalmologists to be aware of the most common pitfalls that lead to misdiagnosis or delays in diagnosis of neuro-ophthalmologic conditions.

Bilateral optic nerve compression secondary to skull hyperostosis from vitamin A deficiency.

A 15-year-old boy with a history of autism spectrum disorder presented with bilateral progressive blurry vision and nyctalopia. Initial examinations, including optical coherence tomography scans of the macula and optic nerve, were within normal limits. Subsequent examination revealed trace pallor of the right optic nerve. Computed tomography and magnetic resonance imaging of the brain demonstrated diffuse thickening of calvarial bone with bilateral optic nerve compression. Laboratory evaluation was notable for profound vitamin A deficiency. The patient underwent optic nerve decompression and vitamin A supplementation with postoperative improvement in visual acuity of both eyes.

Eye Protection for Patients With COVID-19 Undergoing Prolonged Prone-Position Ventilation.

Importance: Critically ill patients with coronavirus disease 2019 (COVID-19) who are unresponsive to maximum optimal ventilator settings may be in a prone position for at least 16 hours per day to improve oxygenation. This extended duration of prone positioning puts patients at risk of developing orbital compartment syndrome if direct pressure to the orbit and the globe occurs and concomitant protection of the eyes is not undertaken. Objective: To report 2 cases of orbital compartment syndrome, as well as optic disc edema and retinal hemorrhages, in the setting of prolonged prone positioning of patients in the intensive care unit during the COVID-19 pandemic. Design, Setting, and Participants: The cases took place from April 27, 2020, to May 4, 2020, at a COVID-19 intensive care unit of a tertiary care hospital. Four of 16 patients in the intensive care unit required prolonged prone-position ventilation. A bedside eye examination was performed on 4 selected patients due to the observed presence of substantial periorbital edema. Main Outcomes and Measures: Intraocular pressures and fundus findings of 4 patients with periorbital edema. Results: Two of 4 patients who were in the prone position for extended periods of time had bilateral fundoscopic findings of optic disc edema and retinal hemorrhages, possibly consistent with a papillophlebitis. Additionally, both patients had a substantial increase in intraocular pressure of 2- to 3-fold in the prone position compared with the supine position. Conclusions and Relevance: Prolonged prone positioning of patients with COVID-19 can be associated with elevated intraocular pressure from periorbital edema, direct compression on the eye, and increased orbital venous pressure. Orbital compartment syndrome can be avoided by the use of protective cushioning around the eyes and maintaining the patient's head position above heart level during prone positioning. Patients with COVID-19 may also develop papillophlebitis with optic disc edema and retinal hemorrhages, which may be associated with a hypercoagulable state caused by COVID-19. These observations suggest awareness for the possible presence of these ophthalmic findings while treating severely ill patients with COVID-19.

Sarcoidosis presenting as Wallenberg syndrome and panuveitis.

Sarcoidosis is a multi-system disease with neurological involvement being one of the more rare manifestations. We report a case of a patient who presented with the lateral medullary syndrome and panuveitis as her initial manifestation of sarcoidosis. The patient's course was further complicated by renal involvement. Lacrimal gland and renal biopsies showed noncaseating granulomas without evidence of infection, establishing the diagnosis. Intracranial vertebral artery involvement was confirmed by brain imaging. Bilateral hilar lymphadenopathy with upper lobe predominant nodules on chest imaging was consistent with asymptomatic pulmonary involvement. Systemic steroid therapy is indicated for treatment of ocular sarcoidosis, with standard stroke management indicated for the treatment of lateral medullary syndrome.

Erectile Dysfunction Agents and Nonarteritic Anterior Ischemic Optic Neuropathy.

Phosphodiesterase-5 inhibitors (PDE5I) are used for treatment of erectile dysfunction and pulmonary arterial hypertension and have been implicated as a causative factor for development of nonarteritic anterior ischemic optic neuropathy (NAION). Controversy remains regarding a cause and effect between PDE5I use and NAION because the mechanism by which NAION occurs is still not well understood. Because neuro-ophthalmologists have accepted that there is a potential relationship between ingestion of the PDE5I class of medications and NAION, the neuro-ophthalmologist should inquire about PDE5I use when evaluating a patient with a new diagnosis of NAION, and counsel patients regarding the implication of continued use of PDE5I.

The Relationship Between Phosphodiesterase-5 Inhibitors and Nonarteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND: A cause and effect relationship between phosphodiesterase-5 inhibitor (PDE5I) use and nonarteritic anterior ischemic optic neuropathy (NAION) has been hypothesized based on case reports. EVIDENCE ACQUISITION: Review of literature. RESULTS: Thirty-nine case reports in the peer-reviewed medical literature have documented a possible relationship between PDE5I consumption and NAION. However, pertinent details, such as the dose and frequency of PDE5I use, and elapsed time between ingestion and onset of vision loss, are lacking from many of these reports. Investigations regarding alterations in ocular perfusion in research subjects who ingested sildenafil have been inconclusive because they have not been performed on subjects with "disc at risk" or risk factors for NAION. One case-crossover study demonstrated a 2-fold increase in risk of NAION after ingestion of PDE5I. CONCLUSIONS: When a diagnosis of NAION is made, an inquiry should be made as to whether any PDE5I was ingested before the onset of vision loss. If so, the patient should be counseled regarding the possibility that continued PDE5I use may increase the risk of NAION in the fellow eye. Patients with a known history of previous NAION should be cautioned regarding the use of PDE5I for erectile dysfunction or pulmonary hypertension because of the potential increased risk of fellow eye involvement.

Complete binasal hemianopia.

Binasal hemianopia is a rarely encountered visual field defect. We examined two asymptomatic female patients, aged 17 and 83, with complete binasal hemianopia. Both patients had unremarkable eye exams except for the visual field deficits and minimally reduced visual acuity and color vision. Both patients had normal neuroimaging. These are the first reported cases of complete binasal visual field defects without an identifiable ocular or neurologic cause.

Carotid-cavernous fistula as a mimicker of myasthenia gravis.

BACKGROUND: A carotid-cavernous fistula (CCF) is an abnormal communication between the carotid arterial system and the cavernous sinus. Common symptoms of CCFs include proptosis and ophthalmoplegia, but fluctuating diplopia and presence of ptosis are not typical. CASE DESCRIPTION: We present an unusual case of CCF with fluctuating binocular diplopia and ptosis, mimicking myasthenia gravis. Electrodiagnostic testing, which included repetitive nerve stimulation and single-fiber electromyography, was normal. Magnetic resonance imaging of the brain and orbits was initially normal, but later magnetic resonance angiography revealed enlargement of the left superior ophthalmic vein along with a left CCF. Patient underwent a successful left cavernous sinus embolization. CONCLUSION: Fluctuating ophthalmic symptoms are a typical presentation of myasthenia gravis; however, there may be an association of these symptoms with a CCF. Repetitive nerve stimulation and single-fiber electromyography played a key role in diagnosis of this case, as the normal result led to further investigations revealing a CCF.

Horner syndrome after tonsillectomy: an anatomic perspective.

BACKGROUND: Horner syndrome after tonsillectomy has been reported rarely in the literature. Furthermore, postoperative Horner syndrome lasting more than a 1 month is an even more rare occurrence. PATIENT: We present a persistent postoperative Horner syndrome in a 5-year-old child following tonsillectomy. RESULTS: Clinical diagnosis of Horner syndrome is confirmed pharmacologically, and damage to the oculosympathetic pathway at the level of the superior cervical ganglion is radiographically demonstrated. CONCLUSION: Conventional monopolar electrosurgical dissection led to irreversible damage of ganglionic neural tissue at the level of the palatine tonsilar fossa and permanent Horner syndrome.

Neuroprotective effects of brimonidine treatment in a rodent model of ischemic optic neuropathy.

Ischemic optic neuropathy (ION) is a common disorder caused by disruption of the arterial blood supply to the optic nerve. It can result in significant loss of visual acuity and/or visual field. An ischemic optic nerve injury was produced in rats by intravenous injection of Rose Bengal dye followed by argon green laser application to the retinal arteries overlying the optic nerve, causing a coagulopathy within the blood vessels and disruption of optic nerve and retinal perfusion. The effect of brimonidine tartrate eye drops on survival of retinal ganglion cell axons in this experimental paradigm was studied. One eye was treated and the contralateral eye served as a control. Four groups of animals were used for this study. Group 1 received 7 days of treatment with 0.15% brimonidine tartrate eye drops twice a day prior to the ischemic injury. Group 2 animals received 0.15% brimonidine tartrate eye drops twice a day for 14 days after photocoagulation injury. Animal groups 3 and 4 received eye drops of 0.9% NaCl twice a day either daily for 7 days before injury or daily for 14 days, respectively. All rats were sacrificed 5 months after the injury to ascertain long-term optic axon survival. Coagulopathy-induced optic nerve ischemia resulted in a 71% loss of optic axons. Treatment with brimonidine daily for the 7 days prior to the injury resulted in a greater survival of optic axons, with only a 56.1% loss compared to control. Brimonidine treatment every day for 14 days after the ischemic injury did not result in a significant rescue of optic axons compared to injury alone. In summary, the application of brimonidine eye drops for one week prior to an ischemic injury resulted in a statistically significant increase in survival of optic axons within the injured optic nerves. Brimonidine treatment of the eye after the ischemic injury did not result in axon rescue, and axon loss was similar to the injured optic nerves treated with saline only. These results suggest that brimonidine may have potential use for prevention of ION in at-risk patients.

Histological and morphometric evaluation of transient retinal and optic nerve ischemia in rat.

Non-arteritic anterior ischemic optic neuropathy is caused by a transient optic nerve ischemia and results in permanent vision loss. Currently, there is no effective treatment for this ischemic optic nerve injury. This study characterized the duration and extent of ischemia induced after a coagulopathy injury to the optic nerve of adult rats. Acute ischemia was induced in adult rats by intravenous injection of Rose Bengal dye, followed by argon green laser treatment of the vessels at the optic disc. Rats were assessed in the short-term for hypoxyprobe-1 binding and expression of hypoxia inducible factor-1alpha (HIF-1 alpha) and fractin, markers of neuronal injury. Five months after injury, optic axon number was quantified. The coagulopathy injury resulted in short-term hypoxia in the optic nerve and retina. Tissues were hypoxic within 15 min of the coagulopathy injury, but normoxic by 24 h as measured by hypoxyprobe-1 staining. Both HIF-1alpha and fractin were upregulated in ganglion cells variably across the retina. Five months after the ischemic injury, there was a 71% reduction in optic axon number compared to controls. It is critical to have a reproducible and relevant method for producing transient hypoxia in order to test therapeutic strategies for rescuing injured neurons. The coagulopathy induced in this study resulted in a reproducible and transient ischemic optic nerve injury and long-term axonal loss. This ischemia shows similar, although not identical, morphological and physiological changes to those seen in the human eye after optic nerve ischemia. We are currently testing therapeutic strategies to protect ganglion cells from degeneration after this ischemic injury.