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Browsing by Author "Mathew, Sunu"
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Item Association of Brain Volume and Retinal Thickness in the Early Stages of Alzheimer’s Disease(IOS Press, 2023) Mathew, Sunu; WuDunn, Darrell; Mackay, Devin D.; Vosmeier, Aaron; Tallman, Eileen F.; Deardorff, Rachael; Harris, Alon; Farlow, Martin R.; Brosch, Jared R.; Gao, Sujuan; Apostolova, Liana G.; Saykin, Andrew J.; Risacher, Shannon L.; Radiology and Imaging Sciences, School of MedicineBackground: The eye has been considered a 'window to the brain,' and several neurological diseases including neurodegenerative conditions like Alzheimer's disease (AD) also show changes in the retina. Objective: To investigate retinal nerve fiber layer (RNFL) thickness and its association with brain volume via magnetic resonance imaging (MRI) in older adults with subjective or objective cognitive decline. Methods: 75 participants underwent ophthalmological and neurological evaluation including optical coherence tomography and MRI (28 cognitively normal subjects, 26 with subjective cognitive decline, 17 patients diagnosed with mild cognitive impairment, and 4 with AD). Differences in demographics, thickness of RNFL, and brain volume were assessed using ANCOVA, while partial Pearson correlations, covaried for age and sex, were used to compare thickness of the peripapillary RNFL with brain volumes, with p < 0.05 considered statistically significant. Results: Mean RNFL thickness was significantly correlated with brain volumes, including global volume (right eye r = 0.235 p = 0.046, left eye r = 0.244, p = 0.037), temporal lobe (right eye r = 0.242 p = 0.039, left eye r = 0.290, p = 0.013), hippocampal (right eye r = 0.320 p = 0.005, left eye r = 0.306, p = 0.008), amygdala (left eye r = 0.332, p = 0.004), and occipital lobe (right eye r = 0.264 p = 0.024) volumes. Conclusion: RNFL thickness in both eyes was positively associated with brain volumes in subjects with subjective and objective cognitive decline. The RNFL, however, did not correlate with the disease, but the small sample number makes it important to conduct larger studies. RNFL thickness may be a useful non-invasive and inexpensive tool for detection of brain neurodegeneration and may assist with diagnosis and monitoring of progression and treatment in AD.Item Can the Treatment of Normal-Pressure Hydrocephalus Induce Normal-Tension Glaucoma? A Narrative Review of a Current Knowledge(MDPI, 2021-03) Hamarat, Yasin; Bartusis, Laimonas; Deimantavicius, Mantas; Lucinskas, Paulius; Siaudvytyte, Lina; Zakelis, Rolandas; Harris, Alon; Mathew, Sunu; Siesky, Brent; Janulevicienė, Ingrida; Ragauskas, Arminas; Radiology and Imaging Sciences, School of MedicineVentriculoperitoneal shunt placement is the most commonly used treatment of normal-pressure hydrocephalus (NPH). It has been hypothesized that normal-tension glaucoma (NTG) is caused by the treatment of NPH by using the shunt to reduce intracranial pressure (ICP). The aim of this study is to review the literature published regarding this hypothesis and to emphasize the need for neuro-ophthalmic follow-up for the concerned patients. The source literature was selected from the results of an online PubMed search, using the keywords "hydrocephalus glaucoma" and "normal-tension glaucoma shunt". One prospective study on adults, one prospective study on children, two retrospective studies on adults and children, two case reports, three review papers including medical hypotheses, and one prospective study on monkeys were identified. Hypothesis about the association between the treatment of NPH using the shunt to reduce ICP and the development of NTG were supported in all reviewed papers. This suggests that a safe lower limit of ICP for neurological patients, especially shunt-treated NPH patients, should be kept. Thus, we proposed to modify the paradigm of safe upper ICP threshold recommended in neurosurgery and neurology into the paradigm of safe ICP corridor applicable in neurology and ophthalmology, especially for shunt-treated hydrocephalic and glaucoma patients.Item Craniofacial Trauma and Vascular Injury(Thieme, 2021) Bernath, Megan M.; Mathew, Sunu; Kovoor, Jerry; Ophthalmology, School of MedicineCerebrovascular injury is a potentially devastating outcome following craniofacial trauma. Interventional radiologists play an important role in detecting, grading, and treating the different types of vascular injury. Computed tomography angiography plays a significant role in the detection of these injuries. Carotid-cavernous fistulas, extra-axial hematomas, pseudoaneurysms, and arterial lacerations are rare vessel injuries resulting from craniofacial trauma. If left untreated, these injuries can lead to vessel rupture and hemorrhage into surrounding areas. Acute management of these vessel injuries includes early identification with angiography and treatment with endovascular embolization. Endovascular therapy resolves vessel abnormalities and reduces the risk of vessel rupture and associated complications.Item Management of Glaucoma in Pregnancy(Wolters Kluwer, 2019-07) Mathew, Sunu; Harris, Alon; Ridenour, Colin M.; Wirostko, Barbara M.; Burgett, Kendall M.; Scripture, Molly D.; Siesky, Brent; Ophthalmology, School of MedicineManagement of glaucoma during pregnancy represents a challenge for the physician. Important disease and patient health decisions begin even prior to conception and continue throughout pregnancy and breastfeeding. Data on this topic is limited due to ethical and legal constraints and challenges of conducting large, prospective, and randomized clinical trials on this patient population. Our review suggests that individually, intraocular pressure is lower in a pregnant woman when compared to a non-pregnant woman. Importantly, the medical management of glaucoma during pregnancy poses special challenges due to the possibility of adverse effects of medications on the fetus and newborn. Laser trabeculoplasty and traditional filtration surgery, as well as minimally invasive glaucoma surgery, represent non-drug management options. Thus, managing glaucoma in pregnancy is a delicate balance between treatment to prevent damage to the optic nerve in the mother and avoidance of interventions potentially harmful to the fetus. This literature review of published individual and population-based studies was performed in order to explore current knowledge and guidelines in the management of glaucoma in pregnancy.Item Noninvasive Monitoring and Neurointerventional Management of Idiopathic Intracranial Hypertension(Thieme, 2020-04) Lang, Matthew; Mathew, Sunu; Harris, Alon; Tejada, Juan; Kovoor, Jerry M.; Ophthalmology, School of MedicineIdiopathic intracranial hypertension (IIH) is characterized by isolated rise in intracranial pressure (ICP) leading to chronic, debilitating headaches, tinnitus, and vision loss. Conventional diagnostics and monitoring primarily require the use of invasive procedure like lumbar puncture to measure ICP, while traditional management strategies involve weight reduction and medical treatment with acetazolamide. In an effort to reduce the need for invasive procedures, noninvasive methods of ICP monitoring such as optic nerve sheath diameter measurements and two-depth transcranial Doppler ultrasonography have been developed. In cases of refractory and fulminant IIH, surgical management strategies such as optic nerve sheath fenestration (ONSF), ventriculoperitoneal (VP) and lumboperitoneal (LP) shunting, and transverse venous sinus stenting are used to relieve symptoms via ICP reduction. While ONSF and VP/LP shunting exhibit utility primarily for the treatment of vision loss and headache, respectively, venous sinus stenting may prove to be an effective option in the management of all symptoms of IIH. Most importantly, consideration of the patient’s individual symptoms and values should be taken into account when choosing the optimal surgical management strategy for patients with IIH.Item Ocular blood flow as a clinical observation: Value, limitations and data analysis(Elsevier, 2020) Harris, Alon; Guidoboni, Giovanna; Siesky, Brent; Mathew, Sunu; Verticchio Vercellin, Alice C.; Rowe, Lucas; Arciero, Julia; Radiology and Imaging Sciences, School of MedicineAlterations in ocular blood flow have been identified as important risk factors for the onset and progression of numerous diseases of the eye. In particular, several population-based and longitudinal-based studies have provided compelling evidence of hemodynamic biomarkers as independent risk factors for ocular disease throughout several different geographic regions. Despite this evidence, the relative contribution of blood flow to ocular physiology and pathology in synergy with other risk factors and comorbidities (e.g., age, gender, race, diabetes and hypertension) remains uncertain. There is currently no gold standard for assessing all relevant vascular beds in the eye, and the heterogeneous vascular biomarkers derived from multiple ocular imaging technologies are non-interchangeable and difficult to interpret as a whole. As a result of these disease complexities and imaging limitations, standard statistical methods often yield inconsistent results across studies and are unable to quantify or explain a patient's overall risk for ocular disease. Combining mathematical modeling with artificial intelligence holds great promise for advancing data analysis in ophthalmology and enabling individualized risk assessment from diverse, multi-input clinical and demographic biomarkers. Mechanism-driven mathematical modeling makes virtual laboratories available to investigate pathogenic mechanisms, advance diagnostic ability and improve disease management. Artificial intelligence provides a novel method for utilizing a vast amount of data from a wide range of patient types to diagnose and monitor ocular disease. This article reviews the state of the art and major unanswered questions related to ocular vascular anatomy and physiology, ocular imaging techniques, clinical findings in glaucoma and other eye diseases, and mechanistic modeling predictions, while laying a path for integrating clinical observations with mathematical models and artificial intelligence. Viable alternatives for integrated data analysis are proposed that aim to overcome the limitations of standard statistical approaches and enable individually tailored precision medicine in ophthalmology.Item Prevalence Rates and Risk Factors for Primary Open Angle Glaucoma in the Middle East(Knowledge E, 2021-10-25) Torabi, Rana; Harris, Alon; Siesky, Brent; Zukerman, Ryan; Oddone, Francesco; Mathew, Sunu; Januleviciene, Ingrida; Verticchio Vercellin, Alice C.; Ophthalmology, School of MedicineGlaucoma is a multifactorial disease and a leading cause of irreversible blindness worldwide. Current data has demonstrated the approximate distribution of primary open-angle glaucoma (POAG) in patients of European, African, Hispanic, and Eastern Asian descent. However, a significant gap in the literature exists regarding the prevalence of POAG in Middle Eastern (ME) populations. Current studies estimate ME POAG prevalence based on a European model. Herein we screened 65 total publications on ME prevalence of POAG and specific risk factors using keywords: “glaucoma”, “prevalence”, “incidence”, “risk factor”, “Middle East”, “Mideast”, “Persian”, “Far East”, as well as searching by individual ME countries through PubMed, Embase, Ovid, Scopus, and Trip searches with additional reference list searches from relevant articles published up to and including March 1, 2021. Fifty qualifying records were included after 15 studies identified with low statistical power, confounding co-morbid ophthalmic diseases, and funding bias were excluded. Studies of ME glaucoma risk factors that identify chromosomes, familial trend, age/gender, socioeconomic status, lifestyle, intraocular pressure, vascular influences, optic disc hemorrhage, cup-to-disc ratio, blood pressure, obstructive sleep apnea, and diabetes mellitus were included in this systematic review. We conclude that the prevalence of POAG in the ME is likely higher than the prevalence rate that European models suggest, with ME specific risk factors likely playing a role. However, these findings are severely limited by the paucity of population-level data in the ME. Well-designed, longitudinal population-based studies with rigorous inclusion and exclusion criteria are ultimately needed to accurately assess the epidemiology and specific mechanistic risk factors of glaucoma in ME populations.