IU Indianapolis ScholarWorks :: Browsing by Subject "glaucoma"

Browsing by Subject "glaucoma"

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A Comparison of Objectively- and Subjectively-Measured Adherence in Glaucoma Patients of African Descent
(Office of the Vice Chancellor for Research, 2015-04-17) Awan, Nabeel; Sutaria, Ankita; Bigatti, Silvia M.; Sirk, Emily; Hosty, Elizabeth; Payton, Chloe; Grow, Shelbi; Sutton, Bradley; Torbit, Julie; Racette, Lyne
Purpose. Adherence to medical treatment of glaucoma is challenging. People of African descent (AD) have higher prevalence of open-angle glaucoma (OAG) and have been shown to have worse adherence. The goal of this prospective, observational study was to compare objectively- and subjectively-measured adherence in patients of African descent and to determine their relationship with self-efficacy. Methods. Twenty-one patients of AD diagnosed with OAG in the past five years were included in this study. Patients used a once-daily topical prostaglandin analog eye drop and self-administered their medication. Subjective adherence was assessed through self-report. Adherence was objectively measured using MEMS bottles. The cap of these bottles records the number of times the bottle is opened. Self-efficacy was assessed using the 10-item Glaucoma Medication Self-Efficacy scale and the 6-item Eye Drop Technique Self-Efficacy scale. MEMS adherence percentages were compared to self-reported adherence using a paired sample two-tailed t-test. To assess the relationship between objectively measured adherence and self-efficacy, patients were divided into 3 groups (n=7 each): high, medium and low adherence groups. The Chi-square test was used to determine whether differences in self-efficacy between the groups were present for each question on the two self-efficacy scales. Results. Subjectiveadherence (mean ± standard deviation) (97.34% ± 5.61) was significantly higher than objective adherence (66.34% ± 26.68) (p= 0.01). Of the 21 patients, 17 self-reported higher adherence levels than MEMS adherence levels. 4 patients with the highest levels of objectively measured adherence were the only patients to correctly estimate their adherence by self-report. Only one question was significantly associated with objective adherence: patients with high adherence were significantly more confident about taking their glaucoma medications when they do not experience symptoms (p = 0.04). Conclusions. Results showed that patients with higher adherence are more confident about using their eye drops in the absence of symptoms.
Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms
(ARVO, 2022-02) McDowell, Colleen M.; Kizhatil, Krishnakumar; Elliott, Michael H.; Overby, Darryl R.; Van Batenburg-Sherwood, Joseph; Millar, J. Cameron; Kuehn, Markus H.; Zode, Gulab; Acott, Ted S.; Anderson, Michael G.; Bhattacharya, Sanjoy K.; Bertrand, Jacques A.; Borras, Terete; Bovenkamp, Diane E.; Cheng, Lin; Danias, John; De Ieso, Michael Lucio; Du, Yiqin; Faralli, Jennifer A.; Fuchshofer, Rudolf; Ganapathy, Preethi S.; Gong, Haiyan; Herberg, Samuel; Hernandez, Humberto; Humphries, Peter; John, Simon W. M.; Kaufman, Paul L.; Keller, Kate E.; Kelley, Mary J.; Kelly, Ruth A.; Krizaj, David; Kumar, Ajay; Leonard, Brian C.; Lieberman, Raquel L.; Liton, Paloma; Liu, Yutao; Liu, Katy C.; Lopez, Navita N.; Mao, Weiming; Mavlyutov, Timur; McDonnell, Fiona; McLellan, Gillian J.; Mzyk, Philip; Nartey, Andrews; Pasquale, Louis R.; Patel, Gaurang C.; Pattabiraman, Padmanabhan P.; Peters, Donna M.; Raghunathan, Vijaykrishna; Rao, Ponugoti Vasantha; Rayana, Naga; Raychaudhuri, Urmimala; Reina-Torres, Ester; Ren, Ruiyi; Rhee, Douglas; Chowdhury, Uttio Roy; Samples, John R.; Samples, E. Griffen; Sharif, Najam; Schuman, Joel S.; Sheffield, Val C.; Stevenson, Cooper H.; Soundararajan, Avinash; Subramanian, Preeti; Sugali, Chenna Kesavulu; Sun, Yang; Toris, Carol B.; Torrejon, Karen Y.; Vahabikashi, Amir; Vranka, Janice A.; Wang, Ting; Willoughby, Colin E.; Xin, Chen; Yun, Hongmin; Zhang, Hao F.; Fautsch, Michael P.; Tamm, Ernst R.; Clark, Abbot F.; Ethier, C. Ross; Stamer, W. Daniel; Ophthalmology, School of Medicine
Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.
Cost-Comparison of Two Trabecular Micro-Bypass Stents Versus Selective Laser Trabeculoplasty or Medications Only for Intraocular Pressure Control for Patients with Open-Angle Glaucoma
(Taylor & Francis, 2017) Berdahl, John P.; Khatana, Anup K.; Katz, L. Jay; Herndon, Leon; Layton, Andrew J.; Yu, Tiffany M.; Bauer, Matthew J.; Cantor, Louis B.; Ophthalmology, School of Medicine
Aim: Patients with open-angle glaucoma (OAG) whose intraocular pressure is not adequately controlled by one medication have several treatment options in the US. This analysis evaluated direct costs of unilateral eye treatment with two trabecular micro-bypass stents (two iStents) compared to selective laser trabeculoplasty (SLT) or medications only. Materials and methods: A population-based, annual state-transition, probabilistic, cost-of-care model was used to assess OAG-related costs over 5 years. Patients were modeled to initiate treatment in year zero with two iStents, SLT, or medications only. In years 1–5, patients could remain on initial treatment or move to another treatment option(s), or filtration surgery. Treatment strategy change probabilities were identified by a clinician panel. Direct costs were included for drugs, procedures, and complications. Results: The projected average cumulative cost at 5 years was lower in the two-stent treatment arm ($4,420) compared to the SLT arm ($4,730) or medications-only arm ($6,217). Initial year-zero costs were higher with two iStents ($2,810) than with SLT ($842) or medications only ($996). Average marginal annual costs in years 1–5 were $322 for two iStents, $777 for SLT, and $1,044 for medications only. The cumulative cost differences between two iStents vs SLT or medications only decreased over time, with breakeven by 5 or 3 years post-initiation, respectively. By year 5, cumulative savings with two iStents over SLT or medications only was $309 or $1,797, respectively. Limitations: This analysis relies on clinical expert panel opinion and would benefit from real-world evidence on use of multiple procedures and treatment switching after two-stent treatment, SLT, or polypharmaceutical initial approaches. Conclusions: Despite higher costs in year zero, annual costs thereafter were lowest in the two-stent treatment arm. Two-stent treatment may reduce OAG-related health resource use, leading to direct savings, especially over medications only or at longer time horizons.
Differences in Ocular Blood Flow Between People of African and European Descent With Healthy Eyes
(Lippincott, Williams, and Wilkins, 2016-09) Kaskan, Betül; Ramezani, Koosha; Harris, Alon; Siesky, Brent; Olinde, Carine; WuDunn, Darrell; Eikenberry, Jennifer; Tobe, Leslie A.; Racette, Lyne; Department of Ophthalmology, IU School of Medicine
Purpose: To investigate differences in ocular blood flow between people of African descent (AD) and European descent (ED) with healthy eyes. Materials and Methods: Retrobulbar and retinal capillary blood flow was assessed in 1 eye of 58 participants (24 AD, 34 ED) with healthy eyes with systemic blood pressure lower than 140/90. Retrobulbar blood flow was measured in the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA) and temporal posterior ciliary artery (TPCA). Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) were assessed. Retinal capillary blood flow was assessed using mean retinal flow and avascular space defined as the percent of area measured with no blood flow. Groups were compared using t tests and Pearson correlations were compared using Fisher r-to-z transformation. Results: Compared with people of ED, people of AD had significantly lower EDV in the NPCA (P=0.01), and higher RI in the CRA (P=0.04) and TPCA (P=0.01). No significant differences were observed in mean retinal capillary flow or avascular area. In the CRA, a significant negative correlation was observed between pattern standard deviation and peak systolic velocity (P=0.02) in the AD group and this correlation was significantly different from that observed in the ED group (P=0.01). A significant correlation was also observed between pattern standard deviation and EDV (0.04) in the AD group. Conclusions: This study suggests that retrobulbar blood flow is lower in healthy eyes in persons of AD compared with ED. This may provide a mechanism through which people of AD are at increased risk for ophthalmic diseases such as glaucoma.
Effects of Sex Hormones on Ocular Blood Flow and Intraocular Pressure in Primary Open Angle Glaucoma: A Review
(Wolters Kluwer, 2018-10) Patel, Pooja; Harris, Alon; Toris, Carol; Lang, Matthew; Tobe, Leslie; Belamkar, Aditya; Ng, Adrienne; Verticchio Vercellin, Alice C.; Matthew, Sunu; Siesky, Brent; Ophthalmology, School of Medicine
Primary open-angle glaucoma (POAG) is a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and visual field loss. Some speculate that gender plays a role in the risk of developing POAG and that the physiologic differences between men and women may be attributed to the variable effects of sex hormones on intraocular pressure (IOP), ocular blood flow, and/or neuroprotection. Estrogen, in the form of premenopausal status, pregnancy, and post-menopausal hormone therapy is associated with increase in ocular blood flow, decrease in IOP and neuroprotective properties. The vasodilation caused by estrogen and its effects on aqueous humor outflow may contribute. On the other hand, although testosterone may have known effects in the cardiovascular and cerebrovascular systems, there is no consensus as to its effects in ocular health or POAG. With better understanding of sex hormones in POAG, sex hormone-derived preventative and therapeutic considerations in disease management may provide for improved gender-specific patient care.
Estimation of the Co-prevalence of Age-related macular degeneration and Glaucoma
(Office of the Vice Chancellor for Research, 2015-04-17) Dunn, Evan N.; Racette, Lyne; Rupp, Jason D.; Myers, Lorraine A.; Ozobu, Lawrence C.; Phan, Anh-Danh T.
Purpose: Age-related macular degeneration (AMD) and glaucoma are the two most common blinding eye diseases in the U.S. and may be further disabling when concomitant. The purpose of this study is to estimate the past, present and future co-prevalence of AMD and glaucoma by national surveys and population projection data. Methods: We combined the age, race and ethnicity data from the latest 2005 to 2008 National Health and Nutrition Examination Survey (NHANES) and the 2002 and 2008 National Health Interview Survey (NHIS). Participants’ positive answers were defined as a “yes” when asked if they had ever been told by a doctor/health care professional that they had macular degeneration or glaucoma (or high pressure of the eye). The co-prevalence of AMD and glaucoma was determined by dividing the number of individuals who answered “yes” to both questions by the total number of respondents. Mean and age-stratified estimates were obtained for non-Hispanic Whites, Hispanics and non-Hispanic Blacks separately. The 2008 National Population Projection data was used to determine the number of affected individuals presently as well as in 2030 and 2050. Results: Using previous NHANES and NHIS data, the mean co-prevalence of AMD and glaucoma varied among racial/ethnic groups: 0.5% in Whites; 0.3% in Hispanics; and 0.2% in Blacks. Co-prevalence increased with increasing age: for Whites, estimates ranged from 0% in those aged 40-49 years to 2.7% for 80 years and older; this trend was observed among the other groups but was more dramatic in Hispanics (0.1% to 2.9%) than Blacks (0% to 0.3%). Using National Population Projection data for 2015, the estimated current population is 535,270 (83% Whites; 10% Hispanics; 7% Blacks). The number of affected individuals will continue to grow but demonstrate changing demographics: in 2030 to 800,111 (80% Whites; 14% Hispanics; 7% Blacks); and in 2050 to 1,082,731 (71% Whites; 22% Hispanics; 6% Blacks). Conclusions: The mean co-prevalence of AMD and glaucoma is greatest among non-Hispanic Whites and individuals 70 years and older. More than half-a-million Americans, predominantly non-Hispanic Whites, suffer from concomitant eye diseases presently. Growing populations in the coming years will affect an increasing number of Hispanics. This new information suggests that future health care policy decisions would need to adapt to this growing, changing population.
A hybridizable discontinuous Galerkin method for nonlinear porous media viscoelasticity with applications in ophthalmology
(2016-12) Prada, Daniele; Guidoboni, Giovanna
The interplay between biomechanics and blood perfusion in the optic nerve head (ONH) has a critical role in ocular pathologies, especially glaucomatous optic neuropathy. Elucidating the complex interactions of ONH perfusion and tissue structure in health and disease using current imaging methodologies is difficult, and mathematical modeling provides an approach to address these limitations. The biophysical phenomena governing the ONH physiology occur at different scales in time and space and porous media theory provides an ideal framework to model them. We critically review fundamentals of porous media theory, paying particular attention to the assumptions leading to a continuum biphasic model for the phenomenological description of fluid flow through biological tissues exhibiting viscoelastic behavior. The resulting system of equations is solved via a numerical method based on a novel hybridizable discontinuous Galerkin finite element discretization that allows accurate approximations of stresses and discharge velocities, in addition to solid displacement and fluid pressure. The model is used to theoretically investigate the influence of tissue viscoelasticity on the blood perfusion of the lamina cribrosa in the ONH. Our results suggest that changes in viscoelastic properties of the lamina may compromise tissue perfusion in response to sudden variations of intraocular pressure, possibly leading to optic disc hemorrhages.
The joint structure–function dynamics of glaucoma progression
(Taylor and Francis, 2015) Racette, Lyne; Helm, Jonathan E.; Dul, Mitchell; Marin-Franch, Iván; Department of Ophthalmology, IU School of Medicine
While the presence and rate of glaucoma progression influence treatment decisions, the methods currently available to detect and monitor progression are imprecise and do not allow clinicians to make accurate assessments of the status of their patients. Models that focus on combining structural and functional parameters may improve our ability to detect and monitor glaucoma progression. Several of these models, however, are limited by their reliance on population statistics and on the static assumptions they make about the nature of glaucoma progression. Dynamic modeling of glaucoma progression may lead to a better understanding of glaucoma progression that could eventually translate into making individualized treatment decisions.
Literature review and meta-analysis of translaminar pressure difference in openangle glaucoma
(Nature, 2015-07) Siaudvytyte, L.; Januleviciene, I.; Daveckaite, A.; Ragauskas, A.; Bartusis, L.; Kucinoviene, J.; Siesky, Brent; Harris, A.; Department of Ophthalmology, IU School of Medicine
There is increasing evidence in the literature regarding translaminar pressure difference’s (TPD) role in the pathophysiology of glaucoma. The optic nerve is exposed not only to intraocular pressure in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Although pilot studies have identified the potential importance of TPD in glaucoma, limited available data currently prevent a comprehensive description of the role that TPD may have in glaucomatous pathophysiology. In this review, we present all available qualified data from a systematic review of the literature of the role of TPD in open-angle glaucoma (OAG). PubMed (Medline), OVID Medline, ScienceDirect, SpringerLink, and all available library databases were reviewed and subsequent meta-analysis of pooled mean differences are presented where appropriate. Five papers including 396 patients met criteria for inclusion to the analysis. Importantly, we included all observational studies despite differences in ICP measurement methods, as there is no consensus regarding best-practice ICP measurements in glaucoma. Our results show that not only TPD is higher in glaucoma patients compared with healthy subjects, it is related to structural glaucomatous changes of the optic disc. Our analysis suggests further longitudinal prospective studies are needed to investigate the influence of TPD in OAG, with a goal of overcoming methodological weaknesses of previous studies.
Long-term efficacy of endoscopic cyclophotocoagulation in the management of glaucoma following cataract surgery in children
(Elsevier, 2018) Cantor, Adam J.; Wang, Jingyun; Li, Shanshan; Neely, Daniel E.; Plager, David A.; Ophthalmology, School of Medicine
Purpose To report the long-term efficacy of endoscopic cyclophotocoagulation (ECP) in pediatric glaucoma following cataract surgery (GFCS). Methods ECP was performed on 35 eyes of 25 patients <16 years of age with GFCS. Patients were followed for a minimum of 2 years. Treatment failure was defined as consecutive postoperative intraocular pressure (IOP) of >24 mm Hg, alternative glaucoma procedure following ECP, or occurrence of visually significant complications. Analysis was performed to estimate risk factors for failure. Results A total of 27 aphakic and 8 pseudophakic eyes were included. Pretreatment IOP averaged 33.9 ± 7.9 mm Hg. Final IOP after a mean follow-up period of 7.2 years was 18.9 ± 8.8 mm Hg (P < 0.001). The success rate was 54% (19/35 eyes). The failure rate was not increased in pseudophakic patients relative to aphakic patients. Patients with single ECP demonstrated preserved visual acuity from baseline to final follow-up. Conclusions In this patient cohort, with average follow-up period of 7.2 years, ECP was useful in the treatment of pediatric GFCS.

Browsing by Subject "glaucoma"

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