Browsing by Author "Siaudvytyte, Lina"

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    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 Medicine
    Ventriculoperitoneal 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.
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    The Effect of Diluted Penetration Enhancer in Nebulized Mist versus Liquid Drop Preparation Forms on Retrobulbar Blood Flow in Healthy Human Subjects
    (MDPI, 2012-08-08) Primus, Sally; Januleviciene, Ingrida; Siesky, Brent; Gerber, Austin; Egan, Patrick; Amireskandari, Annahita; Siaudvytyte, Lina; Barsauskaite, Ruta; Harris, Alon; Ophthalmology, School of Medicine
    The aim of this study was to compare the effects of nebulized mist and liquid drop applications on retrobulbar blood flow. A prospective, non-randomized clinical trial was used to collect data from 40 healthy human eyes. Color Doppler Imaging determined peak systolic (PSV) and end diastolic (EDV) blood flow velocities and resistance index (RI) in the ophthalmic artery after both applications. Measurements were taken at baseline and at 1 min post-treatment in both eyes with 5 min measurements in the treatment eye only. p values ≤ 0.05 were considered statistically significant. Mist application to treatment eye produced an increase in 1 min and 5 min PSV and EDV (0.001 < p < 0.03) and a decrease in 5 min RI (p = 0.01), with no significant changes in PSV, EDV or RI of control eye or in treatment eye 1 min RI (p > 0.05). Drop application to treatment eye produced an increase in PSV (p < 0.001) and EDV (p = 0.01) at 1 min, with an increase in control eye 1 min PSV and EDV (p = 0.03). There were no statistically significant changes in treatment eye PSV, EDV and RI after 5 min (p > 0.05). The use of nebulized mist may provide an effective alternative to liquid drop medication application.
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    Update in intracranial pressure evaluation methods and translaminar pressure gradient role in glaucoma
    (Wiley, 2015-02) Siaudvytyte, Lina; Januleviciene, Ingrida; Ragauskas, Arminas; Bartusis, Laimonas; Siesky, Brent; Harris, Alon; Department of Cellular & Integrative Physiology, IU School of Medicine
    Glaucoma is one of the leading causes of blindness worldwide. Historically, it has been considered an ocular disease primary caused by pathological intraocular pressure (IOP). Recently, researchers have emphasized intracranial pressure (ICP), as translaminar counter pressure against IOP may play a role in glaucoma development and progression. It remains controversial what is the best way to measure ICP in glaucoma. Currently, the ‘gold standard’ for ICP measurement is invasive measurement of the pressure in the cerebrospinal fluid via lumbar puncture or via implantation of the pressure sensor into the brains ventricle. However, the direct measurements of ICP are not without risk due to its invasiveness and potential risk of intracranial haemorrhage and infection. Therefore, invasive ICP measurements are prohibitive due to safety needs, especially in glaucoma patients. Several approaches have been proposed to estimate ICP non-invasively, including transcranial Doppler ultrasonography, tympanic membrane displacement, ophthalmodynamometry, measurement of optic nerve sheath diameter and two-depth transcranial Doppler technology. Special emphasis is put on the two-depth transcranial Doppler technology, which uses an ophthalmic artery as a natural ICP sensor. It is the only method which accurately and precisely measures absolute ICP values and may provide valuable information in glaucoma.