Showing papers by "Byron L. Lam published in 2017"

Altered Macular Microvasculature in Mild Cognitive Impairment and Alzheimer Disease.

Abstract: Background:The goal of the present study was to analyze the macular microvacular network in mild cognitive impirment (MCI) and Alzheimer disease (AD).Methods:Twelve patients with AD and 19 patients with MCI were recruited together with 21 cognitively normal controls with a similar range of ages. Opt

Repeatability and longitudinal assessment of foveal cone structure in cngb3-associated achromatopsia.

Abstract: Purpose Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia. Methods Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed. Results ONL thickness increased slightly compared with baseline (0.184 μm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126). Conclusion Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.

Intraoperative Use of Microscope-Integrated Optical Coherence Tomography for Subretinal Gene Therapy Delivery

Abstract: Intraoperative Use of Microscope-Integrated Optical Coherence Tomography for Subretinal Gene Therapy Delivery With advances in gene therapy biotechnologies, ophthalmology entered a new era of potential prevention, arrest, or reversal of previously untreatable retinal diseases. Key gene therapy trials have focused on degenerative conditions, such as inherited retinal degenerations caused by RPE65 mutations, choroideremia, achromatopsia, age-related macular degeneration, and Stargardt disease.1–4 Adeno-associated virus or lentivirus vectors used in many ongoing trials do not penetrate the retina well because of the relatively impermeable internal limiting membrane and are preferentially delivered via subretinal injection to directly contact the outer retina and the retinal pigment epithelium (RPE). Selective surgical delivery into the sub-RPE or suprachoroidal space has not been attempted as far as we are aware. Confirming delivery to a predefined target zone for therapeutic product injection is desirable in clinical trials and may enhance efficacy. In addition, a means to confirm the volume of injected vector intraoperatively will help to minimize the risk of incomplete dose delivery.1,3 Intraoperative OCT allows visualization of retinal anatomy and provides the surgeon with real-time feedback on instrument–tissue interaction.5 Posterior segment MIOCT images are possible through direct contact lens or a noncontact viewing system. Inclusion of intraoperative OCT has been shown to alter surgeons’ understanding of underlying tissues and surgical approach in 43% of membrane peeling procedures.5 We describe our experience with a novel approach of using microscope-integrated optical coherence tomography (MIOCT) for real-time guidance of subretinal delivery of gene therapy products in clinical trials.

New Methods for Quantification of Visual Photosensitivity Threshold and Symptoms

Abstract: PURPOSE Visual photosensitivity is a common symptom difficult to measure and diagnose, and is found in many ocular and neurological disorders. We developed two novel reproducible quantitative assessments of visual photosensitivity. METHODS We designed and built the ocular photosensitivity analyzer (OPA), an automated instrument to determine light intensity visual photosensitivity threshold (VPT), and developed the Visual Light Sensitivity Questionnaire-8 (VLSQ-8), an eight-question survey to assess the presence and severity of photosensitivity symptoms. We evaluated the test-retest variability and obtained normative values of these two approaches in 35 healthy normal subjects, distributed evenly over five age groups from eight to 60 years. Each subject underwent two test sessions, each with VLSQ-8, eye examination, and OPA, four weeks apart, between April 2015 and June 2016. RESULTS Log-transformed VPTs (log10lux) and VLSQ-8 results were highly reproducible between the two sessions (VPT intraclass correlation coefficient [ICC] = 0.86; 95% confidence interval [CI] = 0.71-0.93; binocular testing, VLSQ-items ICC range = 0.53-0.87). No consistent significant differences in VPTs were found with monocular (P = 0.053, session 1) or binocular (P = 0.26) testing. Subjects in age group >30 to 40 years had significantly higher VPTs than those in other age groups (P ≤ 0.011) except the >40 to 50 years age group (P = 0.11). Photosensitivity symptoms assessed by the VLSQ-8 generally were low and highly reproducible with ≥88% of responses between the 2 sessions being within one category of each other. CONCLUSIONS Our results provide reliability data and normative results toward validation of two novel approaches to quantify visual photosensitivity and provide support for their potential use in ocular and neurologic conditions as well as in clinical trials. TRANSLATIONAL RELEVANCE The new quantitative photosensitivity approaches are potential measures to characterize disease severity, monitor disease progression, and evaluate treatment efficacy.

Optic disc haemorrhages at baseline as a risk factor for poor outcome in the Idiopathic Intracranial Hypertension Treatment Trial

Abstract: Background The risk of optic disc haemorrhages on visual outcome in idiopathic intracranial hypertension (IIH) is unknown. We report the type and frequency of optic disc haemorrhages and other funduscopic abnormalities at baseline in the study eye of the 133 subjects enrolled in the Idiopathic Intracranial Hypertension Treatment Trial completing 6 months of follow-up. Methods We reviewed optic disc photographs to tabulate the frequency and type of optic disc haemorrhages, other funduscopic abnormalities and papilloedema grades of the study eye at baseline and analyse if their presence is associated with a poor visual outcome. Results 27.2% of subjects had nerve fibre layer haemorrhages in at least one eye. Five of seven, 71% of subjects that met criteria for treatment failure, had nerve fibre layer haemorrhages in at least one eye (Fisher9s exact test: p=0.02). There was a good correlation between presence of nerve fibre layer haemorrhages and Frisen grade (Spearman9s correlation, p=0.002; r=0.271). Subjects with nerve fibre layer haemorrhages had a higher cerebrospinal fluid pressure (40.0 mm water, p=0.04). There was poor correlation between nerve fibre layer haemorrhages at baseline and the perimetric mean deviation change at 6 months. Cotton wool spots were present in 4% of subjects, exudates in 3% and pseudodrusen in 4%. Conclusions Nerve fibre layer haemorrhages are common in patients with IIH with mild visual loss and correlate with the severity of the papilloedema. They occur more frequently in treatment failure subjects and therefore may be associated with poor visual outcomes. Trial registration number NCT01003639, Post-results.

Nonsedated handheld electroretinogram as a screening test of retinal dysfunction in pediatric patients with nystagmus.

Abstract: Purpose To assess the feasibility, sensitivity, and specificity of nonsedated handheld cone flicker electroretinogram (ERG) as a screening tool to detect retinal dysfunction in children with nystagmus. Methods Pediatric patients at a tertiary referral center from December 2015 to July 2016 were enrolled and placed into three age-matched groups: normal, nystagmus with a retinal dystrophy, and nystagmus without a retinal dystrophy. Unsedated 30 Hz cone flicker ERG responses were obtained using a handheld device (RETeval) from both eyes of each patient using skin electrode sensors after pupillary dilation. Results A total of 71 children were enrolled; amplitudes and implicit times were successfully obtained in 65 (92%): 31 (mean age ± SD, 5.6 ± 2.7 years; range, 1-12 years) without nystagmus and 34 with nystagmus. Nystagmus patients were grouped by those with (n = 15; mean age, 8.5 ± 4.5 [range, 2-17 years) and without (n = 19; mean age, 4.3 ± 3.0 [range, 6 months-10 years]) a retinal dystrophy. The patients with retinal dystrophies had significantly smaller amplitudes and prolonged or nonmeasurable implicit times than the other two groups (P 33 ms warrants further evaluation. Conclusions Unsedated handheld cone flicker ERG is a feasible screening test that effectively detects retinal dysfunction in children with nystagmus. In conjunction with clinical findings, the test helps reduce the need for sedated ERG in children.

Ophthalmic presentation of giant cell arteritis in African-Americans

Abstract: PurposeTo determine the differences in the presentation of ophthalmic giant cell arteritis between African-Americans and Caucasians.MethodsThis was a multicenter retrospective case series comparing African-American patients with ophthalmic GCA to a previously published Caucasian cohort. Neuro-ophthalmic centers across the United States were contacted to provide data on African-American patients with biopsy-proven ophthalmic giant cell arteritis. The differences between African-American and Caucasian patients with respect to multiple variables, including age, sex, systemic and ophthalmic signs and symptoms, ocular ischemic lesions, and laboratory results were studied.ResultsThe Caucasian cohort was slightly older (mean=76.1 years) than the African-American cohort (mean=72.6 years, P=0.03), and there was no difference in sex distribution between the two cohorts. Headache, neck pain, and anemia were more frequent, while jaw claudication was less frequent in African-Americans (P<0.01, <0.001, 0.02, and 0.03 respectively). Acute vision loss was the most common presentation of giant cell arteritis in both groups, though it was less common in African-Americans (78 vs 98% of Caucasians, P<0.001). Eye pain was more common in African-Americans (28 vs 8% of Caucasians, P<0.01).ConclusionsThe presenting features of ophthalmic giant cell arteritis in African-Americans and Caucasians are not markedly different, although a few significant differences exist, including higher rates of headache, neck pain, anemia, and eye pain, and lower rates of jaw claudication and acute vision loss in African-Americans. Persons presenting with suspicious signs and symptoms should undergo evaluation for giant cell arteritis regardless of race.

C2orf71 mutations as a frequent cause of autosomal-recessive retinitis pigmentosa: Clinical analysis and presentation of 8 novel mutations

Abstract: Purpose To define the phenotype of C2orf71 associated retinopathy and to present novel mutations in this gene. Methods A retrospective multicenter study of patients with retinopathy and identified C2orf71 mutations was performed. Ocular function (visual acuity, visual fields, electroretinogram [ERG] responses); retinal morphology (fundus, optical coherence tomography); and underlying mutations were analyzed. Results Thirteen patients from 11 families, who were aged 7 to 63 years (mean: 32.1 years) at their first examination with presumed compound heterozygous (6/13 patients) or homozygous (7/13 patients) C2orf71 mutations were identified. Eight of the mutations were novel. Truncation mutations were responsible in all cases. Nyctalopia was observed in less than 50% of patients. Visual acuity ranged from 20/20 to light perception. Severe visual loss was associated with atrophic maculopathy. Full-field ERG responses showed severe progressive cone-rod or rod-cone dysfunction. Typical fundus changes were progressive symmetrical retinopathy with an early mild maculopathy and patchy circular midperipheral RPE atrophy. Normal retinal lamination was preserved despite early disruption of the ellipsoid zone and RPE irregularities. Outer retinal tubulations were associated with better-preserved visual acuity. Conclusions On the basis of our multicenter analysis, C2orf71 might represent a more frequently mutated gene in autosomal recessive retinitis pigmentosa in some populations. The phenotype analysis over a wide age range showed a variable and progressive retinal degeneration with early onset maculopathy and a better visual potential before the age of 30 years.

Reaching the Unreachable: Novel Approaches to Telemedicine Screening of Underserved Populations for Vitreoretinal Disease

Abstract: Telemedicine involves electronic communication between a physician in one location and a patient in another location to provide remote medical care. Ophthalmologists are increasingly employing telemedicine, particularly in retinal disease screening and monitoring. Telemedicine has been utilized to decrease barriers to care and yield greater patient satisfaction and lower costs, while maintaining high sensitivity and specificity. This review discusses common patient barriers to eye care, innovative approaches to retinal disease screening and monitoring using telemedicine, and eye care policy initiatives needed to enact large-scale telemedicine eye disease screening programs.

Eye Health Knowledge and Eye Health Information Exposure Among Hispanic/Latino Individuals

Abstract: Importance Routine eye care is important to maintaining eye health and preventing visual impairment. However, poor knowledge of ocular risk factors and disease as well as minimal exposure to eye health information may compromise adherence to eye care recommendations. Studies have shown that Hispanic/Latino people have poor eye care utilization, but little is known about their knowledge of eye health and exposure to eye health information. Objective To examine factors associated with more eye health knowledge and greater exposure to eye health information among Hispanic/Latino people. Design, Setting, and Participants This was a cross-sectional ocular study of 1235 participants living in the Miami, Florida, site of the Hispanic Community Health Study/Study of Latinos, a multisite epidemiologic study of disease prevalence and development among Hispanic/Latino people. Data were collected from October 1, 2011, through September 30, 2013, and data analyses were conducted between May 28, 2014, and March 18, 2015. Descriptive and multivariable regression analyses were performed for 3 ocular health care outcomes. Regression models were built sequentially, with variables conceptually grouped according to Andersen’s Behavioral Model of Health Services Use and Behavioral Model for Vulnerable Populations. Main Outcomes and Measures Ability to identify 8 factors on a general eye health knowledge scale and number of eye health information sources seen or heard about in the past 12 months. Results Of the 1235 participants, 748 (73.4%) self-identified as being of Cuban descent and 407 (19.2%) self-identified as being from Central or South America, 478 (46.7%) were women and 757 (53.3%) were men, and the mean (SD) age was 53.6 (8.1) years. Participants with at least a high school degree or general educational development certificate had greater eye health knowledge (incidence rate ratio [IRR], 1.08; 95% CI, 1.01-1.15 and IRR, 1.11; 95% CI, 1.04-1.17, respectively) as did those with a higher mental health score on the Short Form 12-Item, version 2, Health Survey (IRR, 1.03; 95% CI, 1.01-1.04). Those with educational attainment beyond a high school degree or a general educational development certificate (IRR, 1.29; 95% CI, 1.07-1.54), those who were 60 years or older (IRR, 1.32; 95% CI, 1.06-1.63), and those with a household income in US dollars of $20 001 to $40 000 (IRR, 1.23; 95% CI, 1.05-1.44) or greater than $40 000 (IRR, 1.25; 95% CI, 0.98-1.59) were more likely to be exposed to at least 5 sources of eye health information in the past 12 months. Conclusions and Relevance Among Hispanic/Latino people, age, educational level, income, and mental health may be important correlates of eye disease knowledge and eye health information exposure. These findings might be used to support the development of targeted interventions designed to improve eye health in this population.

Notice of retraction: Role of Cerebrospinal Fluid in Spaceflight-induced Ocular Changes and Visual Impairment in Astronauts

Abstract: Notice of retraction: the article “Role of Cerebral Spinal Fluid in Space Flight Induced Ocular Changes and Visual Impairment in Astronauts” by Alperin et al This article has been retracted due to security concerns raised by NASA, the sponsoring agency. © RSNA, 2017

Eye health knowledge and eye health information exposure among hispanic/latino individuals results from the hispanic community health study/ study of latinos

Abstract: Importance Routine eye care is important to maintaining eye health and preventing visual impairment. However, poor knowledge of ocular risk factors and disease as well as minimal exposure to eye health information may compromise adherence to eye care recommendations. Studies have shown that Hispanic/Latino people have poor eye care utilization, but little is known about their knowledge of eye health and exposure to eye health information. Objective To examine factors associated with more eye health knowledge and greater exposure to eye health information among Hispanic/Latino people. Design, Setting, and Participants This was a cross-sectional ocular study of 1235 participants living in the Miami, Florida, site of the Hispanic Community Health Study/Study of Latinos, a multisite epidemiologic study of disease prevalence and development among Hispanic/Latino people. Data were collected from October 1, 2011, through September 30, 2013, and data analyses were conducted between May 28, 2014, and March 18, 2015. Descriptive and multivariable regression analyses were performed for 3 ocular health care outcomes. Regression models were built sequentially, with variables conceptually grouped according to Andersen’s Behavioral Model of Health Services Use and Behavioral Model for Vulnerable Populations. Main Outcomes and Measures Ability to identify 8 factors on a general eye health knowledge scale and number of eye health information sources seen or heard about in the past 12 months. Results Of the 1235 participants, 748 (73.4%) self-identified as being of Cuban descent and 407 (19.2%) self-identified as being from Central or South America, 478 (46.7%) were women and 757 (53.3%) were men, and the mean (SD) age was 53.6 (8.1) years. Participants with at least a high school degree or general educational development certificate had greater eye health knowledge (incidence rate ratio [IRR], 1.08; 95% CI, 1.01-1.15 and IRR, 1.11; 95% CI, 1.04-1.17, respectively) as did those with a higher mental health score on the Short Form 12-Item, version 2, Health Survey (IRR, 1.03; 95% CI, 1.01-1.04). Those with educational attainment beyond a high school degree or a general educational development certificate (IRR, 1.29; 95% CI, 1.07-1.54), those who were 60 years or older (IRR, 1.32; 95% CI, 1.06-1.63), and those with a household income in US dollars of $20 001 to $40 000 (IRR, 1.23; 95% CI, 1.05-1.44) or greater than $40 000 (IRR, 1.25; 95% CI, 0.98-1.59) were more likely to be exposed to at least 5 sources of eye health information in the past 12 months. Conclusions and Relevance Among Hispanic/Latino people, age, educational level, income, and mental health may be important correlates of eye disease knowledge and eye health information exposure. These findings might be used to support the development of targeted interventions designed to improve eye health in this population.

Trends in Glaucoma Medication Expenditure

Abstract: Methods: We analyzed glaucoma medication expenditure trends among participants of the 2001-2006 Medical Expenditure Panel Survey, a subsample of the National Health Interview Survey, which is a continuous multipurpose, multistage area probability survey of the US civilian noninstitutionalized population. After adjustingforsurveydesignandinflationusingthe2009inflation index, data from 1404 participants 18 years and older using glaucoma medication were analyzed.

Quantitative retinal autofluorescence mapping with multimodal imaging technology

Abstract: Imaging systems and methods of using the same are provided for monitoring the quantity of fluorescent pigment, for example lipofuscin, in the retinal pigment epithelium (RPE) layer of a retina in vivo. Various imaging modalities can be integrated into a single system and excited by a single broadband light source for the monitoring of the fluorescent pigment. The influence of varying optical properties found in the optical path of the pigment's auto-fluorescence between the RPE and an image receiver can be corrected.

Central Retinal Artery Occlusion and Cerebral Infarction Following Stem Cell Injection for Baldness.

Abstract: W e read with interest the recent article by Ragam et al (1) on “Ipsilateral ophthalmic and cerebral infarctions following cosmetic polylactic acid injection into the forehead.” We present a case of a different injected material, also used for cosmetic purposes, which produced vision loss and neurologic complications. A 57-year-old man was injected with stem cells into the left frontotemporal region of the scalp in a facility outside the United States, with the aim of enhancing hair growth. He immediately developed shortness of breath and severe pain at the injection site. He then experienced acute loss of vision in the left eye and paralysis of the right hand. He was admitted to an intensive care unit, where he was diagnosed with a cerebral infarct. Vision in the left eye worsened to no light perception over 5 days, and the right hand paralysis resolved over 15 days. The patient was referred by a neuro-ophthalmologist in his home country to our institution 1 month later. At this time, he had mild pain of the left upper eyelid and eyebrow and intermittent frontal headaches. A large depressed fibrotic scar of the left frontal region of the scalp was evident. Visual acuity was 20/20, right eye, and no light perception, left eye, with an amaurotic left pupil. The right fundus appeared normal, but the left fundus showed changes consistent with a central retinal artery occlusion (Fig. 1). Review of the patient's brain MRI demonstrated an acute left frontal cerebral infarct (Fig. 2). Although central retinal artery occlusion and cerebral infarction have not previously been reported with stem cell injection, there have been cases of central retinal artery occlusion after dermal injection of cosmetic fillers to the forehead (1,2). Rich anastomoses between the external carotid and internal carotid systems are present in the scalp (3). We propose that, upon forceful intraarterial injection into the scalp, retrograde flow allowed toxic material contained in the stem cell injection to gain access to the internal carotid system through these anastomoses. After crossing into the internal carotid circulation, the material likely propagated to the ophthalmic, central retinal, and intracerebral arteries. The patient's retinal findings are consistent with an acute intravascular toxic injury. Our case adds to the growing literature of the risks associated with unregulated stem cell therapy. These therapies have wide appeal, claims of efficacy in treating a host of conditions, and the lay perception that the benefits outweigh the risks (4). However, as many countries offer stem cell treatments without oversight of medical regulatory agencies, the procedures may or may not contain stem cells and may cause devastating FIG. 1. Left fundus shows diffuse optic disc pallor, macular exudates with perimacular retinal edema and scattered hemorrhage, and attenuated and sheathed retinal arterioles and attenuated retinal veins. FIG. 2. Axial fluid-attenuated inversion recovery imaging (FLAIR) reveals a left frontal lobe infarction and scattered white matter defects in both cerebral hemispheres.

ABCA4 Mutation in a Patient With Juvenile Neuronal Ceroid Lipofuscinosis

Abstract: A 5-year-old Ecuadorian male, previously diagnosed with cone-rod dystrophy, presented for a second opinion after experiencing subjective bilateral rapid vision loss over an 18-day period, 4 months ...

Invasive Aspergillosis Mimicking Sphenoid Wing Meningioma.

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