An Assessment of the Fidelity of Two Different Interventions to Improve Adherence to Glaucoma Treatment in Patients of African Descent

poster abstractGlaucoma is a chronic eye disease, which is asymptomatic and can slowly lead to blindness if left untreated. Glaucoma is caused by damage to the optic nerve and can lead to irreversible loss of sight. The overall objective of this MURI study was to determine the impact of two different interventions on compliance to glaucoma medication in patients of African descent with open-angle glaucoma. Two types of intervention were used – Education and Motivational Interviewing (MI). The educational intervention involved sharing knowledge with patients about glaucoma, its causes, and its treatments, to help patients better understand glaucoma and the importance of adhering to the daily medication regimen. The MI intervention involved communicating with the patients and encouraging them to identify strategies that would help them better adhere to their medications. These sessions were video-recorded and the content of each video was transcribed verbatim. The transcripts were then scored to assess the fidelity of each session with the intervention type that was given; this was done to ensure that each patient in the MI group received intervention consistent with MI, and that each patient in the Education group received an intervention free of MI. The standard Motivational Interviewing Treatment Integrity 3.0 coding sheet was used to code the MI and Education sessions. Global ratings were given for empathy, direction, collaboration, evocation and autonomy/support on a scale ranging from 1 (Low) to 5 (High). The following behaviors were counted within each transcript: giving information, MI adherent (asking permission, affirm, emphasize control, support), MI Non-adherent (advise, confront, direct), questions (closed questions, open questions), and reflections (simple, complex). We expect that the MI interventions would have significantly higher scores on MI adherent behaviors and significantly lower on MI-non-adherent behaviors compared to the Education session

Determining the Impact of Demographic Factors on Adherence to Glaucoma Treatment in Patients of African Descent

poster abstractPrimary open-angle glaucoma (POAG) affects approximately 2.5 million Americans. Elevated intraocular pressure (IOP) is the only treatable risk factor to slow the progression of the disease and prevent blindness. Topical ocular hypotensive medications, dispensed in the form of eye drops, are the first line of treatment to reduce IOP. Patients are required to use their eye drops once or twice daily throughout the rest of their lives. Patients of African descent are more vulnerable to this chronic disease, with a prevalence six times higher than patients of European descent. They also have worse adherence to the treatment regimen in general. The main purpose of this study was to determine the impact of education, age, gender, household income, marital status, employment and number of prescribed medications on the adherence to the glaucoma treatment. Twenty-one patients were included and adherence was measured using Medication Event Monitoring System caps, which electronically record every time a patient uses their eye drops. After 4 weeks, patients returned with the caps and the compliance level was recorded. During the initial interview, patients answered a questionnaire about the different factors tested in this study. There was a positive correlation between the compliance percentage and age, with patients who are 70 years or older having the highest compliance levels (82% compared to 62% in the 50s and 60s category). Education also affected compliance, with patients who have a high school degree having a lower compliance at 62% compared to the patients with some college or a bachelor’s degree with compliance of 81%. The employment status was another contributor, with higher compliance in full-time employed patients compared to other employment types. The remaining factors did not contribute to the adherence levels. Overall, education, age, and employment status were the only factors that impacted adherence levels

Retinal thickness estimation from SD-OCT macular scans

Glaucoma, a leading cause of blindness worldwide, can be detected using retinal thicknesses from spectral-domain optical coherence tomography (SD-OCT) scans of the macula. We calculate the desired thickness maps as the distance between the inner-limiting membrane (ILM) and retinal pigmented epithelium (RPE) of the retina. To delineate these two layers, we use a set of two deformable open surfaces that are driven by intensity contrast, while preserving their shape and topology properties, i.e. local surface smoothness and inter-surface distance smoothness. To evaluate our method, qualified graders manually segmented 30 random sections from 20 OCT image stacks, in triplicate; we make comparisons with obtained ground-truth and the clinically tested Heidelberg Spectralis segmentation. We show the superiority of our method with respect to accuracy and average execution time (~7 secs), validating it as a clinical tool

Comparison of retinal nerve fiber layer and macular thickness for discriminating primary open-angle glaucoma and normal-tension glaucoma using optical coherence tomography

Purpose The aim of this study was to evaluate the discrimination capabilities of macular and peripapillary retinal nerve fiber layer (pRNFL) thickness parameters as measured using spectral domain optical coherence tomography (SD-OCT) between primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). Methods A total of 90 subjects were enrolled: 30 healthy subjects, 30 subjects with POAG and 30 subjects with NTG, consecutively. Retinal nerve fiber layer thickness, macular thickness and volume measurements were obtained with circular and radial SD-OCT scans. All parameters were compared between groups using an analysis of variance test. Areas under receiver-operating characteristic (AROC) curves with sensitivities at specificities greater than or equal to 90 per cent were generated to compare discrimination capabilities of various parameters between POAG and NTG. Results Macular thickness and volume measurements were the highest in normal subjects, followed by NTG and POAG (p < 0.05). Average retinal nerve fiber layer thickness had perfect discrimination for normal-POAG (AROC: 1.000; sensitivity: 100 per cent) and near perfect discrimination for normal-NTG (AROC: 0.979; sensitivity: 93 per cent) as well as NTG-POAG pairs (AROC: 0.900; sensitivity: 60 per cent). Inferior outer macular thickness (IOMT) and total volume were the best macular thickness and volume parameters having similar AROCs and sensitivities between normal and POAG (IOMT, AROC: 0.987; sensitivity: 92 per cent and total volume, AROC: 0.997; sensitivity: 97 per cent), normal and NTG (IOMT, AROC: 0.862, sensitivity: 47 per cent and total volume, AROC: 0.898, sensitivity: 67 per cent) and also between NTG and POAG (IOMT, AROC: 0.910, sensitivity: 53 per cent and total volume, AROC: 0.922, sensitivity: 77 per cent). In each comparison group, there was no statistically significant difference in AROCs between average retinal nerve fiber layer and inferior outer macular thickness, as well as total volume. Conclusions The macular parameters offer comparable performance to pRNFL parameters for the discrimination of NTG and POAG. Average retinal nerve fiber layer thickness, total macular volume and inferior outer macular thickness were the best SD-OCT parameters with superior discriminating capabilities

Structure-­Function Associations in Healthy and Glaucoma Eyes

poster abstractPurpose: 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

The joint structure–function dynamics of glaucoma progression

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

Does Knowledge of the Causes of Glaucoma Impact Adherence?

poster abstractPurpose: Glaucoma is informally known as loss of sight due to the deterioration or damage to the optic nerve; some scientists claim to have identified the genes related to these causes. The most prevalent risk factor includes those of African descendant. We tested the hypothesis that the adherence level is higher in patients with more knowledge of their condition than those with none. Methods: A dataset of the first visit from a clinical diagnosis of open-angle glaucoma was retrieved, in which all the patients administered once-daily prostaglandin analog eye drops themselves. Participants were on average 60.38±9.93yrs of age and identified as African descendants; of the 29 patients, 16 self-identified as male and the rest female. Participants were specifically asked to “Please list in rank-order the three most important factors that you believe caused your illness”. We grouped the results into three different conditions: (1) those with at least on “true” (current factors that are widely accepted scientifically) risk factors vs those with none, (2) those who included race as a risk factor vs those who did not, and (3) those who listed any risk factors vs those with none. We compared the adherence within each condition using two-tailed t-test to calculate the “level of significance”. Results: Our results did not agree with our hypothesis. The values returned were: (1) 0.1244, (2) 0.3744, and (3) 0.2516. Because all three results were ≥ 0.05, our data displayed that there were no relationship between the groups. It meant that our outcomes were most likely a consequence of chance with no significance. Conclusions: Though our results were not consistent with our hypothesis, we were still able to come to a different deduction: whether or not individuals are educated on the causes of their conditions, their adherence will only improve if they decide it so

Prediction Accuracy of the Dynamic Structure-Function Model for Glaucoma Progression Using Contrast Sensitivity Perimetry and Confocal Scanning Laser Ophthalmoscopy

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

Estimation of the Co-prevalence of Age-related macular degeneration and Glaucoma

poster abstractPurpose: 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

Differences in Ocular Blood Flow Between People of African and European Descent With Healthy Eyes

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