Browsing by Author "Ramezani, Koosha"

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    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.
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    Impact of self-efficacy and demographic factors on adherence to treatment in glaucoma patients of African descent
    (Investigative Ophthalmology and Visual Science Journal, 2017) Alkhairy, Sameerah; Chu, Fang-I; Ramezani, Koosha; McIntyre, Elizabeth; Sutton, Bradley; Torbit, Julie; Bigatti, Silvia
    Purpose : To determine whether self-efficacy and demographic factors influence adherence to the medical treatment of glaucoma in patients of African descent. Methods : 37 patients with a clinical diagnosis of primary open-angle glaucoma were included in this cross-sectional study. All patients were of African descent, used self-administered once-daily prostaglandin analog eye drops. Adherence was measured in 34 patients during a one-month period (mean 28.8 days) using Medical Event Monitoring System (MEMS) caps. The caps of these bottles electronically record the date and time at which the bottle is opened. All patients completed the four following questionnaires: Q1) glaucoma medication self-efficacy scale, Q2) eye drop technique self-efficacy scale, Q3) reported adherence to medication questionnaire and Q4) brief illness perception questionnaire. All answers were treated as ordinal variable and total scores for each questionnaire were computed. The impact of these four self-efficacy scores on adherence was assessed using linear regression models. We also determined how demographic factors (age, gender, education, marital status, employment status, and income) modulated this relationship. Finally, we assessed the influence of these demographic factors on the self-efficacy scores. Results : The mean age was 60.89±9.81 and 45.95% of patients were female. Eye drop technique self-efficacy (Q2) had a borderline negative impact on adherence (slope=−3.64, p=0.05), such that higher self-efficacy resulted in lower adherence. This result was minimized by being older (p=0.03) or divorced/separated (p=0.04) compared to being single/widowed (increase in the impact of self-efficacy on adherence). Similarly, the relationship between glaucoma medication self-efficacy (Q1) and adherence was negatively modulated by being married/partnered (p=0.04) compared to being single/widowed (decrease in the impact of self-efficacy on adherence). A negative impact of being male was also observed on Q1 (score=−6.28, p=0.05). Conclusions : Overall, patients who were confident in how to administer their eye drops had worse adherence, but this effect was minimized in older and divorced individuals. Overall, being male had a negative impact on self-efficacy as it relates to glaucoma medication. These results suggest that the relationship between self-efficacy and adherence is complex and affected by several factors. This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
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    Lipodermoid Cyst: A Report of a Rare Caruncular Case
    (Medknow Publications, 2015-10) Rajabi, Mohammad Taher; Ramezani, Koosha; Department of Ophthalmology, IU School of Medicine
    Ocular lipodermoid cysts and solid dermoid tumors are choristomas which are described as normal tissue growth in an abnormal location. Congenital epibulbar lipodermoid comprises adipose tissue that is covered by connective tissue. They are usually located superotemporally, and basically tend not to involve the peripheral cornea. If the dermoid or lipodermoid is accompanied by other systemic conditions or ocular anomalies in young children, a consultation with an Internist or pediatrician is required to rule out Goldenhar syndrome which is a oculoauriculovertebral dysplasia. This paper reports a unilateral lipodermoid cyst which is remarkable regarding its caruncular origin, in an otherwise healthy adult female.
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    Prediction Accuracy of the Dynamic Structure-Function Model for Glaucoma Progression Using Contrast Sensitivity Perimetry and Confocal Scanning Laser Ophthalmoscopy
    (Wolters Kluwer, 2018-09) Ramezani, Koosha; Marín-Franch, Iván; Hu, Rongrong; Swanson, William H.; Racette, Lyne; Ophthalmology, School of Medicine
    PURPOSE: The purpose of this study was to determine whether combining a structural measure with contrast sensitivity perimetry (CSP), which has lower test-retest variability than static automated perimetry (SAP), reduces prediction error with 2 models of glaucoma progression. METHODS: In this retrospective analysis, eyes with 5 visits with rim area (RA), SAP, and CSP measures were selected from 2 datasets. Twenty-six eyes with open-angle glaucoma were included in the analyses. For CSP and SAP, mean sensitivity (MS) was obtained by converting the sensitivity values at each location from decibel (SAP) or log units (CSP) to linear units, and then averaging all values. MS and RA values were expressed as percent of mean normal based on independent normative data. Data from the first 3 and 4 visits were used to calculate errors in prediction for the fourth and fifth visits, respectively. Prediction errors were obtained for simple linear regression and the dynamic structure-function (DSF) model. RESULTS: With linear regression, the median prediction errors ranged from 6% to 17% when SAP MS and RA were used and from 9% to 17% when CSP MS and RA were used. With the DSF model, the median prediction errors ranged from 6% to 11% when SAP MS and RA were used and from 7% to 16% when CSP MS and RA were used. CONCLUSIONS: The DSF model had consistently lower prediction errors than simple linear regression. The lower test-retest variability of CSP in glaucomatous defects did not, however, result in lower prediction error.
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    Racial differences in correlations between optic nerve head morphology and ocular blood flow in healthy eyes
    (Office of the Vice Chancellor for Research, 2016-04-08) Ramezani, Koosha; Harris, Alon; Siesky, Brent A; Olinde, Carine; WuDunn, Darrell; Kaskan, Betül; Eikenberry, Jennifer; Tobe, Leslie A.; Racette, Lyne
    Purpose: To assess differences in the relationship between optic nerve head (ONH) morphology and ocular blood flow between persons of African descent (AD) and European descent (ED) with healthy eyes. Methods: 46 participants (20 AD, 26 ED) with normal fundoscopic exam and intraocular pressure were included. Each participant was assessed for disc area (DA), rim area (RA), linear cup to disc ratio (CDR), mean retinal nerve fiber layer (RNFL) thickness by Heidelberg retina tomograph. Retrobulbar blood flow was assessed by color Doppler imaging in the ophthalmic (OA), central retinal (CRA), nasal short posterior ciliary (NPCA) and temporal short posterior ciliary (TPCA) arteries. Peak systolic velocity (PSV), end diastolic velocity (EDV) and the resistive index (RI) were assessed in each artery. Mean retinal capillary blood flow and % of the area with no blood flow in both hemifields were measured with Heidelberg retinal flowmeter. Correlations between ONH morphology and ocular blood flow were derived using Pearson correlations. Differences between the correlations in the AD and ED groups were assessed using the Fisher r-to-z transformation method. Results: Age, gender, IOP and blood pressure were not significantly different between groups. Significant differences in correlations were observed between groups in the CRA. In this artery, PSV and DA were positively correlated in AD (r=0.43) and negatively correlated in ED (r=-0.35) (Δr=0.78; p=0.01). A similar finding was observed for PSV and RA (AD: r=0.39; ED: r=-0.22; Δr=0.61; p=0.04). Significant negative correlations between RI and CDR were observed in all arteries in the ED group (r coefficients range=-0.48 to -0.39), but not in the AD group (r coefficients range=-0.14 to 0.17). No significant differences were observed in the correlations of ONH morphology and capillary blood flow. Conclusion: ONH morphology and ocular blood flow relationship was significantly different in the healthy eyes of AD compared to ED.
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    Structure-­Function Associations in Healthy and Glaucoma Eyes
    (Office of the Vice Chancellor for Research, 2016-04-08) Chu, Fang-I; Marin‐Franch, Iván; Ramezani, Koosha; Racette, Lyne
    Purpose: To determine whether differences exist in the structure--‐function associations between healthy and glaucoma eyes. Methods: Structure--‐function associations were assessed in three different datasets. First, in the Diagnostic Innovation and Glaucoma Study and African Descent and Glaucoma Evaluation Study, associations between rim area (RA) (Heidelberg Retina Tomography II) and both mean sensitivity (MS) and mean deviation (MD) from conventional automated perimetry (CAP) were assessed in 698 healthy subjects and 1036 glaucoma patients. Associations between retinal nerve fiber layer thickness (RNFLT) from the Spectralis optical coherence tomography (OCT) (Heidelberg Engineering) and MS or MD from CAP were assessed in 198 healthy subjects and 634 glaucoma patients. Second, in the dataset used in Swanson et al (2014), the association between RNFLT from the Stratus OCT (Heidelberg Engineering) and MD from CAP, measures from contrast sensitivity perimetry (CSP--‐2), and from frequency--‐doubling perimetry (FDP) in the superior temporal (ST) and inferior temporal (IT) optic disc sectors were assessed in 62 healthy subjects and 51 glaucoma patients. Third, in a dataset obtained from Iowa University, association between RNFLT and relative field sensitivity was assessed in 79 healthy subjects. All associations were assessed with the generalized estimating equation (GEE) procedure, linear mixed effect model (LMM), and the Pearson, Spearman and Kendall correlations. Age was included to adjust for its confounding effect in all GEE and LMM models. Results: For healthy eyes, no significant structure--‐function association was found using GEE, Pearson, Spearman and Kendall correlations. With LMM, a significant association was found between RNFLT and both MS and MD. For glaucoma eyes, significant associations were found with all methods. Conclusion: Significant structure--‐function associations were identified in glaucoma eyes but not in healthy ones. This suggests that the structure--‐function associations should be considered separately in healthy and glaucoma eyes because of the different nature of the associations. Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis IN, US. Departamento de Óptica. Facultad de Física. Universitat de València, Burjassot, Valencia, Spain. Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis IN, US. Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis IN, US. Acknowledgement: This project was supported in part by the BrightFocus Foundation grant G2014096, IUPUI DRIVE grant, and by an unrestricted grant from Research to Prevent Blindness. The DIGS and ADAGES studies were supported by National Institutes of Health grants P30EY022589, EY021818, EY11008, U10EY14267, EY019869, and by the Eyesight Foundation of Alabama, Alcon Laboratories, Inc., Allergan, Inc;, Pfizer, Inc., Merck, Inc., Santen, Inc., the Edith C. Blum Research Fund of the New York Glaucoma Research Institute (New York, NY), and by an unrestricted grant from Research to Prevent Blindness. The study reported in Swanson et al (2014) was supported by National Institutes of Health grants R01EY007716 (Swanson) and 5P30EY019008 (Indiana University School of Optometry). One of the authors (RM) received a portion of his funding from the Department of Health’s NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology. We thank Michael Wall and Randy Kardon for providing the control data for healthy eyes collected at University of Iowa Hospitals and Clinics.