Optic Nerve Angle in Idiopathic Intracranial Hypertension.

BACKGROUND: The tortuosity of the optic nerve can be quantified radiologically by measuring the angle of optic nerve deformation (the "optic nerve angle" [ONA]). In patients with idiopathic intracranial hypertension (IIH), lowering the intracranial pressure (ICP) to a normal range by lumbar puncture leads to straightening of the optic nerve and an increase in the measured sagittal ONA on MRI. It is uncertain whether there is any correlation between ONA and cerebrospinal fluid (CSF) opening pressure or visual function. METHODS: Retrospective study of patients with and without IIH who had MRI of the brain followed by lumbar puncture with CSF opening pressure within 24 hours of MRI. Before LP and within 24 hours of MRI of the brain, all patients with IIH had neuro-ophthalmologic assessment including visual acuity, Humphrey Visual Field (HVF), and fundus photography. Sagittal ONA was measured on multiplanar T2-SPACE images on a DICOM viewer. Papilledema on the fundus photographs was graded using the Frisén scale. RESULTS: Fifty-four patients with IIH and 30 unmatched controls were included. The IIH group was 6.3 years younger (95% CI 2.4-10.3, P = 0.002), had 8.7 kg/m2 higher body mass index (4.9-12.5, P < 0.001), and 26.3% more women (P = 0.011) compared with controls. In both eyes, the ONA was significantly smaller in patients with IIH by 12° compared with controls (7°-17°, P < 0.00001). In the IIH group, no correlation between ONA and the CSF opening pressure was present in either eye (right eye r = 0.19, P = 0.15; left eye r = 0.18, P = 0.19) The ONA did not correlate with logarithm of the minimum angle of resolution visual acuity (right eye r = 0.26, P = 0.063; left eye r = 0.15, P = 0.27), HVF mean deviation (right eye r = 0.0059, P = 0.97; left eye r = -0.069, P = 0.63), or Frisén grade (Spearman's rho right eye 0.058, P = 0.67; left eye 0.14, P = 0.30). CONCLUSIONS: The ONA is significantly smaller in patients with IIH compared to controls, but does not correlate with CSF opening pressure, severity of papilledema, or visual function. The ONA may be useful in identifying patients with raised ICP, but not necessarily those with a poor visual prognosis.

Patient Harm Due to Diagnostic Error of Neuro-Ophthalmologic Conditions.

PURPOSE: To prospectively examine diagnostic error of neuro-ophthalmic conditions and resultant harm at multiple sites. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: A total of 496 consecutive adult new patients seen at 3 university-based neuro-ophthalmology clinics in the United States in 2019 to 2020. METHODS: Collected data regarding demographics, prior care, referral diagnosis, final diagnosis, diagnostic testing, treatment, patient disposition, and impact of the neuro-ophthalmologic encounter. For misdiagnosed patients, we identified the cause of error using the Diagnosis Error Evaluation and Research (DEER) taxonomy tool and whether the patient experienced harm due to the misdiagnosis. MAIN OUTCOME MEASURES: The primary outcome was whether patients who were misdiagnosed before neuro-ophthalmology referral experienced harm as a result of the misdiagnosis. Secondary outcomes included appropriateness of referrals, misdiagnosis rate, interventions undergone before referral, and the primary type of diagnostic error. RESULTS: Referral diagnosis was incorrect in 49% of cases. A total of 26% of misdiagnosed patients experienced harm, which could have been prevented by earlier referral to neuro-ophthalmology in 97%. Patients experienced inappropriate laboratory testing, diagnostic imaging, or treatment before referral in 23%, with higher rates for patients misdiagnosed before referral (34% of patients vs. 13% with a correct referral diagnosis, P < 0.0001). Seventy-six percent of inappropriate referrals were misdiagnosed, compared with 45% of appropriate referrals (P < 0.0001). The most common reasons for referral were optic neuritis or optic neuropathy (21%), papilledema (18%), diplopia or cranial nerve palsies (16%), and unspecified vision loss (11%). The most common sources of diagnostic error were the physical examination (36%), generation of a complete differential diagnosis (24%), history taking (24%), and use or interpretation of diagnostic testing (13%). In 489 of 496 patients (99%), neuro-ophthalmology consultation (NOC) affected patient care. In 2% of cases, neuro-ophthalmology directly saved the patient's life or vision; in an additional 10%, harmful treatment was avoided or appropriate urgent referral was provided; and in an additional 48%, neuro-ophthalmology provided a diagnosis and direction to the patient's care. CONCLUSIONS: Misdiagnosis of neuro-ophthalmic conditions, mismanagement before referral, and preventable harm are common. Early appropriate referral to neuro-ophthalmology may prevent patient harm.

Unilateral Isolated Paucisymptomatic Optic Disc Edema.

BACKGROUND: Unilateral isolated optic disc edema (UIODE) represents a challenging clinical presentation that frequently precipitates an extensive diagnostic work-up. Patients without an apparent diagnosis despite appropriate investigations are often categorized as having "papillophlebitis," an entity that is poorly defined in the existing literature. Our aim was to describe the characteristics of a series of patients with paucisymptomatic UIODE, determine the optimal diagnostic approach to such cases, and clarify the clinical features of presumed papillophlebitis. METHODS: We retrospectively identified 29 patients with UIODE who were seen by neuro-ophthalmologists at a single center between 2005 and 2019. Each patient presented with isolated, unilateral disc edema that was either entirely asymptomatic or associated with minimal visual symptoms. Patients underwent a comprehensive neuro-ophthalmic evaluation and several ophthalmic and systemic investigations. Data from the initial visit and all subsequent clinical visits were collected, including patient demographics, examination findings, and details of the diagnostic work-up. RESULTS: Our 29 patients with UIODE were found to have a variety of underlying diagnoses including unilateral papilledema due to idiopathic intracranial hypertension (10 patients), optic nerve sheath meningioma (5), incipient nonarteritic anterior ischemic neuropathy (4), vitreopapillary traction (3), orbital masses (2), a peripapillary choroidal neovascular membrane (1), and presumed papillophlebitis (4). The duration of disc edema varied considerably based on the etiology, but most patients had favorable visual outcomes. CONCLUSIONS: A systematic approach to the evaluation of UIODE, combined with long-term follow-up, led to a definite diagnosis in a majority of patients, with only 4 patients presumed to have papillophlebitis, a diagnosis the actual existence of which remains controversial.

Idiopathic Intracranial Hypertension in Pregnancy.

Idiopathic intracranial hypertension (IIH) is a syndrome characterized by elevated intracranial pressure without an identifiable underlying cause. Pregnancy has unique and important diagnostic and therapeutic implications for patients with IIH. Despite these implications, there are no guidelines to assist clinicians in managing IIH during pregnancy. Our review aims to summarize the key considerations related to the diagnosis and management of IIH during pregnancy, to optimize the care of these patients and mitigate the risk of disease-related complications. The optimal management of IIH in pregnancy should include a multidisciplinary team, including an obstetrician (or maternal-fetal medicine specialist), a neurologist, and an ophthalmologist (or neuro-ophthalmologist).

Status of Canadian undergraduate medical education in ophthalmology.

OBJECTIVE: To use the perspectives of undergraduate program directors to assess the current structure and adequacy of undergraduate ophthalmology curricula at Canadian medical schools. DESIGN: Cross-sectional survey. PARTICIPANTS: Undergraduate ophthalmology program directors at each English-speaking Canadian medical school. METHODS: Program directors were identified and invited to participate in an online survey. The 18-question survey focused on key areas of undergraduate ophthalmology curricula, including length, timeline, setting, and nature of medical students' exposure to ophthalmology. A period of 4 months was allowed for responses. Information from medical school web sites was combined with survey responses. RESULTS: Responses were obtained from 7 of the 14 (50%) program directors. All of the respondents represented metropolitan institutions of greater than 100 seats. After combining survey and web site data, only 5 of 14 (35.7%) schools were found to have a mandatory clinical clerkship ophthalmology rotation. In each case, the mandatory rotation is less than 2 weeks. A core curriculum based on the International Council of Ophthalmology (ICO) guidelines is used in only 20% of schools. Extracurricular ophthalmology exposure in the form of research opportunities and interest groups exists in 100% and 71.4% of schools, respectively. CONCLUSIONS: The proportion of schools requiring mandatory clerkship ophthalmology rotations is only 35.7%. However, most departments use strategies to optimize the limited time allotted to ophthalmology rotations during medical school. A greater degree of adherence to the ICO curriculum guidelines may help to ensure that medical students develop an appropriate level of proficiency in managing patients with eye disease.

Comparison of intraocular pressure post penetrating keratoplasty vs Descemet's stripping endothelial keratoplasty.

OBJECTIVE: To compare the effect of Descemet's stripping endothelial keratoplasty (DSEK) with penetrating keratoplasty (PKP) on intraocular pressure (IOP) and use of ocular antihypertensives. DESIGN: Retrospective cohort study. PARTICIPANTS: Thirty-five eyes in 33 patients undergoing PKP and 43 eyes in 38 patients undergoing DSEK were included in the analysis. Fifteen eyes undergoing PKP and 12 undergoing DSEK had diagnosed glaucoma. Patients undergoing corneal transplant because of trauma, keratoconus, pellucid marginal degeneration, or prior failed transplant were excluded. METHODS: Charts were obtained for all patients who underwent PKP or DSEK by a single surgeon at the Ivey Eye Institute between 2003 and 2010. IOP and all IOP-lowering medications were recorded preoperatively and at 1, 4, 8, 12, and 24 weeks postoperatively. Complications, graft survival, and glaucoma surgeries were noted. RESULTS: There was no significant difference in preoperative IOP between the 2 groups (p = 0.30). Postoperatively, IOP was significantly higher in the PKP group at 1 week (p < 0.01), 4 weeks (p < 0.01), and 8 and 12 weeks (p < 0.05), but not at 24 weeks (p = 0.62). Mean IOP increased significantly post-transplant in all groups (p < 0.05). In patients without glaucoma, postoperative IOP elevation requiring treatment occurred in 68% of PKP eyes and 23% of DSEK eyes. In patients with prior glaucoma, an increased requirement for ocular antihypertensives occurred in 60% of PKP eyes and 20% of DSEK eyes. Three trabeculectomies and 1 tube shunt were performed in the cohort with glaucoma undergoing PKP. No glaucoma surgery was required in the DSEK cohort. CONCLUSIONS: Elevation of IOP requiring treatment occurred at a lower rate after DSEK compared with PKP. This difference was significant during the early postoperative course but nonsignificant at 24 weeks. Additional long-term studies on the effect of DSEK on glaucoma and IOP control are warranted.