John Chen - Academia.edu (original) (raw)

Papers by John Chen

Albert and Jakobiec's Principles and Practice of Ophthalmology, 2021

Clinical Ophthalmology, 2021

Purpose: To determine the population-based incidence of ocular neovascularization (NV) following ... more Purpose: To determine the population-based incidence of ocular neovascularization (NV) following central retinal artery occlusion (CRAO) and systemic risk factors associated with its development. Methods: Diagnosis of CRAO between January 1, 1976, and September 9, 2016, was identified using the Rochester Epidemiology Project, a medical records linkage system for all medical care provided to residents of Olmsted County, Minnesota. Records were reviewed to confirm the diagnosis of CRAO, and data were collected on ocular NV and associated systemic diseases. Results: There were 89 patients with CRAO. Subsequent ocular neovascularization developed in 14 (16%) patients. Neovascularization of the iris (NVI) was present in 9/14 (64%) of these patients, neovascularization of the angle (NVA) in 10/14 (71%), neovascularization of the disc (NVD) in 2/14 (14%), and neovascularization elsewhere (NVE) in 1/14 (7%). Of these 14 patients with NV, 9 (64%) developed neovascular glaucoma (NVG). The mean time from CRAO diagnosis to NV was 82 days (range 22 to 268 days). Excluding the patients with proliferative diabetic retinopathy or CRAO caused by CRVO, the mean time to NV diagnosis was 80 days and the shortest time to NV diagnosis was 22 days. Diabetes mellitus was present in 64% of those with NV compared to 23% of those without NV (P = 0.003). Conclusion: The population-based incidence of ocular neovascularization following CRAO is 16% and developed within 2 months in half the cohort. Patients with diabetes mellitus are at increased risk for NV complications.

JAMA Network Open, 2020

IMPORTANCE The study of health conditions associated with papilledema will augment the clinical j... more IMPORTANCE The study of health conditions associated with papilledema will augment the clinical judgment of eye care professionals treating patients with optic disc edema in determining the urgency of additional evaluation and counseling patients accordingly. OBJECTIVES To determine the incidence, demographic characteristics, and etiologies of papilledema based on a unique records-linkage research platform; and to describe the demographic and clinical differences between patients with idiopathic intracranial hypertension (IIH) and other causes of papilledema. DESIGN, SETTING, AND PARTICIPANTS Retrospective population-based cross-sectional study of patients treated for papilledema at outpatient eye clinics in Olmsted County, Minnesota, using the

Neurology, Jan 21, 2018

A 68-year-old woman presented with increased frequency of headaches accompanied by double vision.... more A 68-year-old woman presented with increased frequency of headaches accompanied by double vision. The patient had a history of migraines, which she typically experienced on a monthly basis. In the month prior to presentation, the frequency of her headaches gradually increased to daily and had become more common at night and upon waking from sleep. She also noted the recent development of double vision with vertical and horizontal gaze. Finally, she reported associated nausea, light, and noise sensitivity, which was typical of her usual migraines, as well as generalized fatigue and a feeling of being "off-kilter." Her medical history was significant for right-sided breast cancer treated with radical mastectomy, since then in remission. On physical examination, the patient was afebrile with normal vital signs. Her mental status and language function were normal. Visual fields were intact and pupils were reactive to light without anisocoria. There was no evidence of papilledema. Extraocular movement examination demonstrated a mild elevation and adduction deficit consistent with a partial pupil sparing right-sided oculomotor nerve palsy. There was no ptosis. Cranial nerve examination was otherwise unremarkable. She had a normal motor and sensory examination, and symmetrically reduced deep tendon reflexes throughout. Her gait examination was significant for astasiaabasia. Questions for consideration: 1. Is intracranial imaging warranted as part of the initial workup for this case? 2. Which elements of the patient's presentation argue for or against the need for imaging? GO TO SECTION 2

Neurology, Jan 5, 2018

Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant b... more Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.

Clinical ophthalmology (Auckland, N.Z.), 2017

To develop and validate a diagnostic prediction model for patients with suspected giant cell arte... more To develop and validate a diagnostic prediction model for patients with suspected giant cell arteritis (GCA). A retrospective review of records of consecutive adult patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at seven university centers. The pathologic diagnosis was considered the final diagnosis. The predictor variables were age, gender, new onset headache, clinical temporal artery abnormality, jaw claudication, ischemic vision loss (VL), diplopia, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelet level. Multiple imputation was performed for missing data. Logistic regression was used to compare our models with the non-histologic American College of Rheumatology (ACR) GCA classification criteria. Internal validation was performed with 10-fold cross validation and bootstrap techniques. External validation was performed by geographic site. There were 530 complete TABx records: 397 were negative and 133 positive for GCA. ...

Ophthalmology, Jul 1, 2017

Abbreviations and Acronyms: FAP ¼ familial amyloid polyneuropathy; logMAR ¼ logarithm of the mini... more Abbreviations and Acronyms: FAP ¼ familial amyloid polyneuropathy; logMAR ¼ logarithm of the minimum angle of resolution; TTR ¼ transthyretin.

Ophthalmology, Jun 1, 2017

An ironic, awesome paradox of contemporary scientific technology is that so apparently esoteric a... more An ironic, awesome paradox of contemporary scientific technology is that so apparently esoteric a discipline as abstract mathematics and so apparently dehumanized a device as a digital computer can be used to help clinicians improve the practical humanistic art of patient care.

Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society, Dec 9, 2016

Optical coherence tomography (OCT) has become an important tool for diagnosing optic nerve diseas... more Optical coherence tomography (OCT) has become an important tool for diagnosing optic nerve disease. The structural details and reproducibility of OCT continues to improve with further advances in technology. However, artifacts and misinterpretation of OCT can lead to clinical misdiagnosis of diseases if they go unrecognized. A literature review using PubMed combined with clinical and research experience. We describe the most common artifacts and errors in interpretation seen on OCT in both optic nerve and ganglion cell analyses. We provide examples of the artifacts, discuss the causes, and provide methods of detecting them. In addition, we discuss a systematic approach to OCT analysis to facilitate the recognition of artifacts and to avoid clinical misinterpretation. While OCT is invaluable in diagnosing optic nerve disease, we need to be cognizant of the artifacts that can occur with OCT. Failure to recognize some of these artifacts can lead to misdiagnoses and inappropriate invest...

Neuro-Ophthalmology, 2014

Wegener's granulomatosis often affects the orbit, typically presenting with painful proptosis. Th... more Wegener's granulomatosis often affects the orbit, typically presenting with painful proptosis. The authors describe a 14 year-old girl, with limited Wegener's granulomatosis, who initially presented with an isolated painless abduction deficit that spontaneously resolved over several weeks. She subsequently developed painful proptosis and diplopia, followed by facial and oral nodules. This case demonstrates that limited Wegener's granulomatosis can rarely present with an isolated painless abduction deficit.

Neuro-Ophthalmology, 2012

Journal of Neurology, Neurosurgery & Psychiatry, 2012

Figure 1 MRI and CT brain in acquired ocular motor apraxia. Post-contrast T1-weighted MRI brain 2... more Figure 1 MRI and CT brain in acquired ocular motor apraxia. Post-contrast T1-weighted MRI brain 2 months before presentation demonstrates metastases in the right and left frontal lobes (A). Non-contrast CT brain at the time of presentation demonstrates haemorrhage at the metastasis sites, extending to involve both frontal eye fields (B).

Investigative ophthalmology & visual science, 2015

To determine the etiology and prognosis of visual acuity loss in idiopathic intracranial hyperten... more To determine the etiology and prognosis of visual acuity loss in idiopathic intracranial hypertension (IIH) at presentation and to provide objective measures to predict visual outcome. A retrospective review of 660 patients with IIH (2009-2013) identified 31 patients (4.7%) with 48 eyes having best-corrected visual acuity (BCVA) of 20/25 or worse on initial presentation. Fundus photography, optical coherence tomography (OCT) of the optic disc and macula, and perimetry were used to determine the causes and prognosis of vision loss. Segmentation of the macula OCT was performed using the Iowa Reference Algorithm to determine the retinal ganglion cell-inner plexiform layer complex (GCL-IPL) thickness. Outer retinal changes alone caused decreased BCVA at initial presentation in 22 eyes (46%): subretinal fluid in 16, chorioretinal folds in 5, and peripapillary choroidal neovascularization in 1. The vision loss was reversible except for some eyes with chorioretinal folds. Optic neuropathy ...

Journal of Neuro-Ophthalmology, 2022

Background: The use of remote interpretation of data has risen in neuro-ophthalmology to increase... more Background: The use of remote interpretation of data has risen in neuro-ophthalmology to increase efficiency and maintain social distancing due to the coronavirus disease-19 pandemic. The purpose of this study is to characterize the use and efficiency of remote interpretation of visual fields (VFs) in an academic center and to determine how often the VF interpretation was consistent with the patient's clinical history and imaging at the time of the consult. Methods: This is a retrospective study at a single academic center that enrolled all patients receiving a remote interpretation of VF from January 1, 2012, through December 31, 2012. Data were collected regarding the referring department, indication for the VF, interpretation of the VF and comparison with any prior VFs, any associated interventions with the VF, and available follow-up VFs. The main outcome measures included 1) characterizing the use of remote VF interpretations and 2) how many remote VF interpretation results were consistent with the referring diagnosis based on the patient's clinical history and imaging. Results: One hundred eighty patients received remote interpretation of VFs. The most frequent referring departments were endocrinology (79; 44%), neurology (51; 28%), and neurosurgery (43; 24%). The VF indications included parasellar lesion (107; 59%), seizure disorder (26; 14%), meningioma (19; 11%), vascular lesion (11; 6%), and others (17; 9%). There were 78 patients (43%) that had an intervention before the VF, whereas 49 (27%) were preoperative VFs. Eighty-seven (48%) of the VFs were interpreted as abnormal. Of all the 180 remote interpretation of VFs, 156 (87%) had VF interpretations that were consistent with the clinical question posed by the referring provider based on clinical history and imaging. Among the other 24 remote VF interpretations (13% of total remote VF interpretations), there was no clear interpretation because of either additional unexpected VF defects (n = 5, 21%), VF defect mismatch (n = 6, 25%), or unreliable VFs (n = 13, 54%). The median wait time for patients receiving remote VF interpretations was 1 day. Conclusions: Remote interpretation of VFs was most often requested by endocrinology, neurology, and neurosurgery and could be performed very quickly. The most common indications were parasellar lesions, and just less than half of patients receiving remote VF interpretations had a prior intervention. A majority of remote VF interpretations were able to answer the clinical question, given the patient's clinical history and imaging. Remote interpretation of VFs may thus offer referring departments a more efficient method of obtaining VF interpretations than in-office neuro-ophthalmology examinations.

Frontiers in Neurology, 2019

Importance: Prior studies evaluating opening pressure (OP) have mostly involved lumbar puncture (... more Importance: Prior studies evaluating opening pressure (OP) have mostly involved lumbar puncture (LP) for diagnosis of neurologic disease or small cohorts of healthy volunteers and therefore the normal OP is not well-defined. Objective: The goal of this study was to establish the normal range of OP in a community-based population using the Mayo Clinic Study of Aging (MCSA) and to evaluate factors that contribute to OP variability. Design: LP OP were obtained from participants aged 32-95 years between 11/1/07 and 10/1/17, as part of routine data collection for the MCSA, a longitudinal, population-based study of residents of Olmsted County, Minnesota. Setting: A longitudinal, population-based study of residents of Olmsted County, Minnesota. Participants: There were 639 participants (56.8% male; 98.5% white) who underwent LP with recorded OP as part of the MCSA. Intervention: LP. Main Outcome(s) and Measure(s): LP OP was recorded along with variables that could possibly influence its variability, including age, body mass index (BMI), and obstructive sleep apnea (OSA). Results: Six hundred thirty-nine participants (56.8% men) underwent LP with recorded OP; average age was 71.0 years (SD 10.9) with a mean BMI of 28.0 (SD 4.6). Mean OP was 155.4 mmH 2 O (SD 41.9) with a 95% reference interval of 82-242 mmH 2 O (range 60-314; Q1, Q3: 124, 182). Increasing age was associated with lower OP (p < 0.001), while increasing BMI was associated with higher OP (p < 0.001). Twelve (2%) participants had OP ≥ 250 mmH 2 O; they were younger [58.5 (SD 8.2), p < 0.001], had higher BMI [33.6 (SD 4.6), p < 0.001], and were more likely to have OSA (75%, p < 0.001). Among the 79 participants with repeat LPs within 2.5 years, the coefficient of repeatability (CR) was 64.9. Ten (12.7%) had an OP difference ≥50 mmH 2 O between serial LPs. Wang et al. Population-Based Lumbar Puncture Opening Pressures Conclusions and Relevance: This large population-based study showed that LP OP can vary significantly among individuals. Higher OPs were associated with higher BMI and younger age.

JAMA ophthalmology, Jan 28, 2018

Ophthalmology, Jan 28, 2018

To determine the aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG)... more To determine the aquaporin-4 and myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) serostatus and visual outcomes in patients with recurrent optic neuritis (rON) initially seeking treatment. Cross-sectional cohort study. The study identified patients by searching the Mayo Clinic computerized central diagnostic index (January 2000-March 2017). The 246 eligible patients fulfilled the following criteria: (1) initially seeking treatment for at least 2 consecutive episodes of optic neuritis (ON) and (2) serum available for testing. Serum was tested for aquaporin-4 IgG and MOG IgG1 using an in-house validated flow cytometric assay using live HEK293 cells transfected with M1 aquaporin-4 or full-length MOG. Aquaporin-4 IgG and MOG IgG1 serostatus, clinical characteristics, and visual outcomes. Among 246 patients with rON at presentation, glial autoantibodies were detected in 32% (aquaporin-4 IgG, 19%; MOG IgG1, 13%); 186 patients had rON only and 60 patients had rON with subs...

Frontiers in neurology, 2018

To evaluate and compare the performance of ocular ultrasonography (US) and magnetic resonance ima... more To evaluate and compare the performance of ocular ultrasonography (US) and magnetic resonance imaging (MRI) for detecting increased intracranial pressure (ICP) in patients with idiopathic intracranial hypertension (IIH). Twenty-two patients with papilledema from IIH and 22 with pseudopapilledema were prospectively recruited based on funduscopic and clinical findings. Measurements of optic nerve sheath diameters (ONSDs) 3 mm behind the inner sclera were performed on B-scan US and axial T2-weighted MRI examinations. Pituitary-to-sella height ratio (pit/sella) was also calculated from sagittal T1-weighted MRI images. Lumbar puncture was performed in all patients with IIH and in five patients with pseudopapilledema. Average US and MRI ONSD were 4.4 (SD ± 0.7) and 5.2 ± 1.4 mm for the pseudopapilledema group and 5.2 ± 0.6 and 7.2 ± 1.6 mm for the papilledema group ( < 0.001). Average MRI pit/sella ratio was 0.7 ± 0.3 for the pseudopapilledema group and 0.3 ± 0.2 for the papilledema gr...

Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society, Jan 21, 2017

Glial fibrillary acidic protein (GFAP) autoantibody-positive meningoencephalitis is a newly descr... more Glial fibrillary acidic protein (GFAP) autoantibody-positive meningoencephalitis is a newly described entity characterized by a corticosteroid-responsive meningoencephalomyelitis. Some patients with GFAP autoantibody-positive meningoencephalitis have been found to have optic disc edema, which has previously not been well characterized. We performed a retrospective, observational case series of Mayo Clinic patients found to have GFAP-IgG and optic disc edema from January 1, 2000, to December 31, 2016. We identified 40 patients with GFAP-IgG seropositivity by tissue-based immunofluorescence and cell-based assay. Patients were screened for the following inclusion criteria: 1) serum, cerebrospinal fluid, or both that yielded a characteristic astrocytic pattern of mouse tissue immunostaining with confirmation of IgG reactive with specific GFAPα isoform by cell-based assay; 2) meningoencephalitis or encephalitis; and 3) optic disc edema. We excluded those with coexisting aquaporin-4-IgG o...

JAMA ophthalmology, Jan 11, 2018