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  • 2018 Academy Online Package

    Contains 150 Product(s) 3 new product(s) added recently

    This content package represents several years of education, accessible in 2018 and early 2019.

    This content represents several years of education, accessible in 2018 and early 2019.

  • 2018 Student Fellowship Orientation

    Contains 2 Component(s)

    This session is a requirement for students participating in the Student Fellowship program at Academy 2018 San Antonio, November 7-10, 2018. You must login with your Academy credentials to view the orientation video and complete the required quiz at the end.

    This session is a requirement for students participating in the Student Fellowship program at Academy 2018 San Antonio, November 7-10, 2018.

    Instructions

    1. You must login with your Academy credentials.
    2. Watch the 2018 Student Fellowship Orientation video (link to the right).
    3. Once you have completed watching the orientation video, please select "Required Quiz" to the right.

  • iPoster: Phenotyping Slc4a11 Knock-Out Mouse Model of Congenital Hereditary Endothelial Dystrophy (CHED)

    Contains 2 Component(s)

    In this study, we examined homozygous Slc4a11 knock-out (KO) C57BL/6 mice with a targeted deletion of exons 9 to 13 of the murine Slc4a11 gene as a model for Congenital Hereditary Endothelial Dystrophy. Slc4a11 KO mouse recapitulates diffuse corneal edema seen in CHED, with ground glass appearance under light microscopy and with progression monitored longitudinally via AS-OCT. Histologically, edematous corneal stroma, uniformly thickened Descemet’s membrane with increased auto-fluorescence and vacuolated corneal endothelium are all present in Slc4a11 KO mouse cornea.

    Purpose: Congenital Hereditary Endothelial Dystrophy (CHED) is characterized by presentation at or soon after birth of diffuse corneal edema with bilateral involvement, and without other significant developmental abnormalities of the anterior segment. CHED can either be progressive or non-progressive. CHED is recognized as an anomalous development of neural crest origin corneal endothelium during or after fifth month of gestation. Histologically, the diffusely edematous corneal stroma accounts for the marked increase in corneal thickness observed clinically. Uniform thickening of Descemet’s membrane and vacuolation of corneal endothelium are characteristic histological findings of CHED. Additionally, marked epithelium thinning with variability of cell layer numbers, focal loss of polarity and intracellular edema especially at the base of epithelium were considered secondary in nature. The genetic loci for CHED has been mapped to 20p13 and SLC4A11 mutations were reported to cause CHED. Since then, 74 mutations in 17 of the 19 coding exons of SLC4A11 have been identified thus far. In this study, we examined homozygous Slc4a11 knock-out (KO) C57BL/6 mice with a targeted deletion of exons 9 to 13 of the murine Slc4a11 gene as a model for CHED.

    Method: Mouse cornea edema was monitored by light microscopy and anterior segment optical coherent tomography (AS-OCT, iVue) at 12 weeks and 40 weeks. Histological cornea sections (40 weeks) were stained with hematoxylin and eosin (H&E) and imaged with AxioImager M1 microscope (Zeiss).

    Results: Slc4a11 KO mouse recapitulates diffuse corneal edema seen in CHED, with ground glass appearance under light microscopy and with progression monitored longitudinally via AS-OCT. Histologically, edematous corneal stroma, uniformly thickened Descemet’s membrane with increased auto-fluorescence and vacuolated corneal endothelium are all present in Slc4a11 KO mouse cornea. Furthermore, secondary corneal epithelium changes are also present, which include various degrees of epithelium thinning with loss of superficial squamous cells, basal epithelial cell edema and loss of polarity accompanied with focal epithelial hyperplasia.

    Conclusion: In summary, Slc4a11 KO C57BL/6 mouse provides a good animal model for CHED.

    Wenlin Zhang, MD, PhD

    Postdoctoral Fellow, Jules Stein Eye Institute, UCLA

    Dr. Wenlin Zhang, received her PhD from Indiana University School of Optometry Vision Science program (2016), is currently continuing her work with SLC4A11 and Congenital Hereditary Endothelial Dystrophy in Jules Stein Eye Institute, UCLA. Dr. Zhang was a recipient of 2016 William C. Ezell Fellowship and is a fellow of American Academy of Optometry.

    Diego G. Ogando, PhD

    Research Associate, Indiana University School of Optometry

    Dr. Diego Ogando received his M.S. in Biology from the University of Buenos Aires (1996) and Ph.D in Biology from the University of Buenos Aires (2002). Dr. Ogando is currently working as a Research Associate in molecular mechanisms of corneal dystrophies in School of Optometry, Indiana Universty. Dr Ogando is a member of Association for Research in Vision and Ophthalmology and a member of the American Physiological Society.

    Joseph A Bonanno, OD, PhD, FAAO

    Professor and Dean, Indiana University School of Optometry

    Dr. Joseph Bonanno received his B.A in Biology from the University of Pennsylvania (1975), M.S. in Molecular Biology (1977), O.D. (1981), and Ph.D. in Physiological Optics (1987) from the University of California, Berkeley.  Dr. Bonanno is a fellow of the American Academy of Optometry, a member of the Association for Research in Vision and Ophthalmology, and a member of the American Physiological Society. Dr. Bonanno was appointed dean of the School of Optometry in October 2010.

  • iPoster: Diopsys® NOVA pattern electroretinogram characteristics associated with glaucoma progression

    Contains 2 Component(s)

    A retrospective cohort study to identify characteristics of the pattern electroretinogram (PERG) associated with glaucoma progression in patients receiving normal clinical care of their glaucoma.

    Purpose: To identify characteristics of the pattern electroretinogram (PERG) associated with glaucoma progression in patients receiving normal clinical care of their glaucoma. 

    Methods: Clinical records from a single glaucoma subspecialty practice were reviewed to identify patients that had undergone at least one PERG exam using the contrast sensitivity fixed protocol of the Diopsys NOVA device. Inclusion criteria included adults with any form of glaucoma, one or more PERG reports available for review, and a sufficient number of perimetry exams using the Humphrey Visual Field Analyzer to assess disease progression. Guided progression analysis trend analysis of the visual field data of qualifying patients was used to determine whether statistically significant (p < 5%) disease progression had occurred. Demographic and clinical variables were analyzed for association with disease progression. Areas under the receiver operating characteristic curves (AUC) were calculated to evaluate classifier accuracy of the parameters.

    Results: 44 eyes of 26 patients were included in the analysis. Of these, 33 eyes demonstrated stability and 11 eyes experienced progression during the observation period, which ranged from 3-8yrs (mean: 5.8 ±1.5) and comprised 3-17 (mean: 11.9 ±3.8) visual field examinations. There was no significant difference in age or intraocular pressure between stable and progressing eyes. A higher proportion of men experienced progression than women (46% versus 16%, p =0.04). Eyes suffering progression tended to have a lower Mag D (stable: 0.63±0.25 μv; prog: 0.40±0.20 μv; p < 0.01) and a lower Mag D/Mag ratio (stable: 0.59±0.20; prog: 0.42±0.15; p = 0.01) under high contrast conditions than stable eyes. In addition, average RNFL thickness was significantly different between the two groups (stable: 78.75±19.51 μm; prog: 60.39±22.28 μm; p = 0.03). Receiver operating characteristic analysis reveals that each of these parameters offers good ability to discriminate between stable and progressing glaucoma patients.

    Conclusion: Diopsys NOVA PERG measurements were associated with glaucoma progression in a diverse cohort of well-managed glaucoma patients.

    David Wesley Juett

    3rd Year Student at the UIW Rosenburg School of Optometry

    Wesley is currently studying at The UIW Rosenberg School of Optometry located in San Antonio, Texas. He was the first student from RSO to deliver a stage presentation at an Academy meeting and is a student fellow of the American Academy of Optometry. Following graduation, he is interested in pursuing a residency in ocular disease. He would like to one day run a private practice somewhere in the Mountain West. He has an interest in research and intends to incorporate it into his practice. 

    Richard C Trevino, OD, FAAO

    Associate Professor at the Rosenberg School of Optometry

    Richard Trevino is an Associate Professor at the Rosenberg School of Optometry, where he has taught since 2010. He serves as Director of Residency Programs and Chief of the Ocular Health Service. In 2014, RSO launched a Glaucoma Center of Excellence under the direction of Dr Trevino, funded, in part, by a grant from Capital One, to provide glaucoma care, research and education. The grant enables the clinic to care for indigent patients who otherwise would be unable to afford treatment of their glaucoma. Dr Trevino practiced in the Veterans Administration for 13 years. He is a graduate of the Illinois College of Optometry and completed a residency in Primary Care Optometry at the Pennsylvania College of Optometry. He has held faculty and adjunct appointments at the University of Waterloo, State University of New York, and the New England College of Optometry.

    Carolyn Majcher, OD, FAAO

    Assistant Professor and Chief of the Retina Clinic at the Rosenburg School of Optometry University of the Incarnate Word

    Carolyn Majcher is a Doctor of Optometry and a Fellow of the American Academy of Optometry. She received her Doctorate of Optometry from the Pennsylvania College of Optometry at Salus University in 2011 and graduated Summa Cum Laude with advanced retinal competencies. In 2012, Dr. Majcher completed a primary care residency at the Eye Institute of the Pennsylvania College of Optometry concentrated in ocular disease management. She was one of four recipients awarded an Optometry Residency Matching Service Scholarship given to residents with the highest cumulative scores on all three parts of the National Board Examinations. Following completion of her residency, Dr. Majcher became and remains a full-time faculty member at the University of the Incarnate Word Rosenberg School of Optometry where she is an Assistant Clinical Professor and Director of Externship Programs. She is involved in didactic instruction of the 2nd and 3rd year glaucoma, posterior segment disease, and neuro-ophthalmic disease courses. She also participates in clinical instruction of 4th year students in the Ocular Disease Clinics and serves as chief of the Retina Service. Dr. Majcher’s research interests include ocular disease and retinal imaging

    Elizabeth Dosch

    3rd Year Student at the UIW Rosenburg School of Optometry

    N/A

    William Sponsel, MD, FAAO

    UIW Rosenberg School of Optometry

    N/A

  • iPoster: Suppression on the Worth 4 dot test and its relationship to stereo acuity

    Contains 2 Component(s)

    Binocular status in clinical setting is routinely investigated in the clinic using the Worth 4 dot (W4DT) test and stereopsis measures. We investigated the relationship between W4DT responses and stereopsis tests in patients with amblyopia. We find that W4DT can only partially predict abnormal or absent stereopsis in amblyopia.

    Purpose: The Worth 4Dot test (W4DT) is routinely used to evaluate binocular sensory status. In this study we investigated whether two possible W4DT outcomes, suppression or fusion, relate to clinical measures of stereopsis in individuals with amblyopia.

    Methods: 131 patients with amblyopia (69 adults [18-65yrs], 62 children [7-17 yrs]) completed the W4DT at distance (6 m) and near (33 cm) subtending visual angles of 1° and 6° respectively the Randot Preschool Stereoacuity test and the Titmus Stereo Fly test as part of a baseline assessment for a randomized clinical trial of amblyopia treatment (the BRAVO study). For each stereotest, normal stereoacuity was defined as ≤60 sec arc.

    Results: For the Randot test, 128 (98%) patients had reduced stereopsis and 90 (69%) had nil stereopsis. For the Titimus test 109 (83%) had reduced stereopsis and 30 (23%) had nil stereopsis. Log stereoacuity thresholds were statistically significantly correlated between the two tests (rs = 0.65, P < .001). Only 21% of those with abnormal stereopsis on the Randot test exhibited suppression on the near W4DT. This increased to 52% for the distance W4DT. A similar trend was present when considering patients with nil stereopsis on the Randot test. 28% of these patients exhibited W4DT suppression at near and 57% exhibited suppression at distance.

    Conclusions: The Worth 4 dot percept of suppression does not consistently predict reduced stereopsis in amblyopia. The relationship is improved when imagery does not exceed 1°. This is consistent with the gradient of strong central suppression to weaker peripheral suppression that we have previously observed in patients with amblyopia.

    Raiju Babu, BSOptom, PhD, FAAO

    Research Associate

    Completed undergraduate degree in Optometry from the Elite School of Optometry, India and following which completed Doctoral degree at the University of Waterloo, Canada. My post doctoral work was at McGill University. Currently involved in a clinical trial where a new binocular video game treatment of amblyopia is tested. My interests are in amblyopia, eye movements and binocular vision.

    Rajkumar Raveendran, BSOptom, MSc

    PhD Candidate at the University of Waterloo

    Rajkumar Raveendran (Raj) studies the stability and characteristics of fixational eye movements as a platform to understand the sensory deficits associated with amblyopia. Amblyopic eyes exhibit abnormal fixational eye movements that may play an important role in the visual deficits associated with amblyopia. Raj’s research findings will advance our understanding of mechanisms underlying abnormal amblyopic eye fixational eye movements and will also provide insights into effective treatment strategies of amblyopia.

  • iPoster: Accommodative lag and near heterophoria in children

    Contains 2 Component(s)

    To examine the relationship between accommodative lag and near heterophoria in a non-clinic-based population of children.

    Purpose: To examine the relationship between accommodative lag and near heterophoria in a non-clinic-based population of children.

    Methods: Children (Age 3-13 years, n = 68) with emmetropia and corrected myopia (−4.00 to +0.95 D) were recruited at the Center or Science and Industry (COSI) in Columbus, Ohio. Refractive error and accommodative lag (monocular, 4.0-D stimulus) were measured with an autorefractor. Horizontal near heterophoria was measured using the Modified Thorington technique. The relationship between heterophoria and accommodative lag was determined with a generalized linear model.

    Results: The magnitude of near exophoria increased with accommodative lag (β = -5.1, p = 0.02) and age (β = -1.2, p = 0.02). There was a significant, positive interaction between age and accommodative lag (β = 0.7, p = 0.004). Gender and refractive error were not significantly associated with heterophoria in the model.

    Conclusion: Exophoria at near in children was associated with increasing accommodative lag. It is possible that accommodative ability may have impacted the heterophoria measurement or that children with exophoria avoid near work, leading to a larger accommodative lag. When evaluating children clinically, accommodative ability should be considered along with heterophoria in order to determine the most accurate binocular vision/accommodative diagnosis and treatment plan.

    Erin Rueff, OD, MS, FAAO

    The Ohio State University College of Optometry

    Melissa Bailey, OD, PhD, FAAO

    Associate Professor at The Ohio State University College of Optometry

    Melissa Bailey, OD, PhD is an associate professor at The Ohio State University (OSU) College of Optometry. Her laboratory, Lab4Eyes, is devoted to helping children and adults see and read better. Dr. Bailey has an active research program, studying ciliary muscle development and how it relates to myopia, accommodative function, and academic achievement. She is also working to develop and commercialize new devices that will allow healthcare providers to make more accurate eye measurements and improve access to vision care for patients around the world. She has trained numerous graduate students and teaches introductory contact lens fitting and optics at OSU. Dr. Bailey has been a Fellow of the American Academy of Optometry since 2002, and she is the former Membership Committee Chair. She was the 2012 Irvin M. and Beatrice Borish Outstanding Young Research Awardee and a past recipient of two William C. Ezell Fellowships. In addition, she is an Ezell Club Member and a President’s Circle Gold Member.

  • iPoster: The Management of Relative Amblyopia: A Case Series Confounded by Optic Nerve Hypoplasia

    Contains 2 Component(s)

    Relative amblyopia is the development of amblyopia in conjunction with vision loss from coexisting pathology, quite commonly optic nerve hypoplasia.  Visual prognosis can be difficult to determine, so amblyopia treatment should be initiated to maximize visual potential. Amblyopic patients that do not improve as expected need to be fully evaluated for co-existing pathology including neuro involvement.

    Introduction: Relative amblyopia occurs when an amblyogenic risk in the presence of pathology causes additional vision loss. Management is challenging if the cause for pathologic loss isn’t easily identifiable or doesn’t have predictable acuity. Two cases, one where pathogenic cause was determined during amblyopia treatment and another who underwent amblyopia therapy despite obvious optic nerve hypoplasia are discussed.

    Case Report: A 5 year old healthy female, presented with BCVA of 20/300 OD, 20/20 OS. She had nearly constant 35 PD right exotropia with constant suppression but unremarkable ocular health and refractive error. She was diagnosed with strabismic amblyopia and patched (6 hrs/day) with excellent compliance for 37 weeks, but plateaued at BCVA of 20/200 OD. MRI was performed and found optic nerve hypoplasia OD and atrophic posterior pituitary. Referral for strabismus surgery and growth hormone evaluation was made. She continued to patch post-surgery with no improvement.

    A 10 year old male presented with optic nerve hypoplasia and posterior staphyloma of the right eye. He had been patching one hour/day for the past 3-4 years with poor compliance. BCVA was 20/160 OD, 20/32 OS and he had significant myopic anisometropia: -10.50-2.50x030 OD and -2.75-1.25x180 OS. Posterior segment findings were confirmed and he was educated on proper patching (6 hrs/day), fit in contact lenses with eye protection and followed every 2 months. BCVA improved to 20/60 OD.

    Conclusion: It’s common for patients with optic nerve hypoplasia to develop relative amblyopia and isn’t always easy to determine if retrobulbar cause for visual loss is present in patients with an amblyogenic risk. Management of amblyopia should involve close monitoring and if improvement isn’t as expected, brain imaging should be performed. If potential acuity cannot be determined based on the pathogenic cause, it is recommended to attempt amblyopia treatment to reach potential acuity.

    Katie Connolly, OD, FAAO

    Assistant Clinical Professor, Indiana University School of Optometry

    Katie Connolly, O.D. graduated from the Michigan College of Optometry at Ferris State University in 2014 and completed a residency in Pediatric Optometry at Indiana University School of Optometry (IUSO) in 2015. Dr. Connolly joined IUSO as an assistant clinical professor immediately following her residency. She currently serves as the chief of pediatrics/binocular vision, director of the school screening program, coordinator of the pediatric optometry residency at IU and is president of her local optometric society. She teaches courses on non strabismic binocular vision and optometric coding and billing. Her special interests include amblyopia and strabismus. She is fellow of the American Academy of Optometry and is an active member of the American Optometric Association.

  • iPoster: Lay Observers Ability to Detect Strabismus and the Role of Model and Observer Ethnicity

    Contains 2 Component(s)

    This study examines the magnitude of strabismus detectable by lay observers and the influence of model and observer ethnicity.

    Purpose: The magnitude when strabismus becomes socially significant is unclear. Previous publications suggest exotropia is easier to detect in Black and Caucasian models, but the reverse may be true for Asian models. The role that observer ethnicity plays in the detection of strabismus has never been investigated. This study examines the magnitude of strabismus detectable by lay observers and the influence of model and observer ethnicity. 

    Methods:  Through photo-manipulation, 8 ethnically diverse models (2 Black, 2 Caucasian, 2 Asian) were simulated to have strabismus (21pd esotropia to 21pd exotropia including orthophoria). Images were presented to 126 non-health care professional observers (42 Black, 42 Caucasian, 42 Asian) who were asked if strabismus was present. A bi-linear fit was applied to find the 70% detection threshold and bootstrap method was used to construct a 95% confidence interval. 

    Results:  For all models combined, the 70% detection threshold was higher for esotropia (18.93pd (95% CI, 18.34pd to 19.50pd)) than exotropia (15.94pd (95% CI, 15.50pd to 16.44pd)). This trend was consistent for Black and Caucasian, but not Asian models where no difference between esotropia (16.50pd (95% CI 15.70pd to 17.47pd)) and exotropia (17.56pd (95% CI, 16.73pd to 18.50pd)) was found. The false positive rate was significantly lower for Black (16.55% (95% CI, 12.18% to 20.92%)) compared to Caucasian (37.41% (95% CI, 31.72% to 43.10%)) and Asian models (34.53%(95% CI, 28.94% to 40.12%)). There were no significant differences when observers viewed models of similar ethnicities compared to observers viewing models of different ethnicities. 

    Conclusion:  Overall, exotropia was easier to detect than esotropia. Ethnic differences existed for models, but not observers. This information supports previous research and further adds to our understanding of what influences the cosmetic appearance of strabismus and may be valuable in the management of patients with strabismus. 

    Erik Weissberg, OD, FAAO

    New England College of Optometry

    Dr. Weissberg, the director of clinical education, is a professor of optometry in the Department of Specialty and Advanced Care and has been a faculty member at the college since 1998. He is the instructor of record for the course Strabismus and Amblyopia and is also a clinical instructor at the South End Community Health Center and the South Boston Community Health Center.

  • iPoster: The Relationship Between Corneal Nerve Density and Refractive Error

    Contains 2 Component(s)

    Previously our group evaluated corneal nerve density in a group of high myopes, low myopes and hyperopes. We found that the high myopes had lower corneal nerve density than their counterparts in the other groups. Here we follow up on that study and add more subjects by more closely evaluating corneal nerve density in a group of low and high myopes along with additional measurements of eye in these patients.

    Purpose: Previously our group evaluated corneal nerve density in a group of high myopes, low myopes and hyperopes. We found that the high myopes had lower corneal nerve density than their counterparts in the other groups. Here we follow up on that study and add more subjects by more closely evaluating corneal nerve density in a group of low and high myopes along with additional measurements of eye in these patients.

    Methods: 30 new young healthy subjects between the ages of 21-40 participated in this phase of the study. Almost all the subjects were contact lens wearers (90%) and general prescription information was gathered from each subject. There were 15 low myopes (-5.50 and below) and 15 high myopes (-5.50 and above).  An autorefraction, a scan, keratometry reading and 3 corneal nerve scans were done for each eye and one eye was selected for analysis. Corneal nerves were imaged over the central cornea with a Nidek CS4 confocal microscope (460x345 um field). Nerves were evaluated using the Neuron J program for density calculation.  Comparisons between groups were made with T-tests but relationships between factors were evaluated with regression analysis.  Data was analyzed for this phase of the project separately and also along with the 30 subjects from the previous pilot. One subject was removed from the analysis as an outlier.

    Results: As expected there was a significant difference between the two group in a scan value (24.22 vs 26.21; p< 0.001) and age of first Rx (14.88 vs 11.50 years; p = 0.006). There was no difference in keratometry readings or corneal thickness between the groups (p=0.12). Also as expected there was a strong relationship between autorefraction and axial length (p

    Conclusion:  There does appear to be a relationship between central corneal nerve density and refractive error in young health patients. However, there is a lot of scatter in these measures that still needs to be accounted for in this data.  A larger group of hyperopic patients is needed to complete this study.  In addition, we may want to further consider other health factors which may alter corneal nerve health in these patients. 

    Christine Shukis, OD

    Resident at Cincinnati VA

    Liz Hundelt, BS

    Midwestern University

    Celine Gabai, BS

    Midwestern University

    Galina Vardanyan, OD

    Optometrist

    Galina Vardanyan is a graduate of Arizona College of Optometry, where she received a Doctor of Optometry (O.D.) in 2017. She completed her Bachelor of Science degree in Biochemistry at California State University, Los Angeles in 2011. Before optometry school, Dr. Vardanyan taught math and science to foster kids in South Los Angeles. Dr. Vardanyan fluently speaks Armenian, Russian and English. Her dream is to open a Vision Therapy practice in Los Angeles. In her free time, she loves playing with her daughter and travelling with her family.

    Wendy Harrison, OD, PhD, FAAO

    Assistant Professor at the Arizona College of Optometry, Midwestern University

    Wendy Harrison, OD, PhD, FAAO, is a graduate from the Indiana University (IU) School of Optometry. She was the first person to earn a joint OD, MS degree in four years. She completed her residency in Cornea, Contact Lenses at IU and a PhD in Vision Science in 2011 from University of California, Berkeley. Dr. Harrison is an assistant professor at the Arizona College of Optometry, Midwestern University where her clinical and research interest involves electrophysiology in retinal disease. She teaches coursework in the areas of epidemiology, ocular anatomy and physiology, and contact lenses. Dr. Harrison is the current chair of the ARVO diversity issues committee. She serves the AAO on the executive committee of the Fellows Doing Research SIG and as an Education Quality Assurance Monitor. She is an AAOF President's Circle Member and two time recipient of the Foundation's prestigious William C. Ezell Fellowship and was also honored to receive the George Mertz Contact Lens Research Award.

    Nicole Putnam, MS, PhD

    Assistant Professor at the Arizona College of Optometry, Midwestern University

    Nicole M. Putnam is an Assistant Professor at the Arizona College of Optometry, Midwestern University with a PhD in Vision Science from UC Berkeley. She is the course and laboratory director for the Geometrical and Physical Optics I and II courses and the Visual Optics course. Her research focuses on the optical investigation of the structure and function of normal and diseased visual systems. This includes the development and use of novel optical techniques for imaging the eye, using optical imaging and testing to better understand visual function and performance, image processing, and applications of clinical imaging and ophthalmic instrumentation.

  • iPoster: Measurement of Fluorescein concentration in the tear film by image analysis and tear sampling

    Contains 2 Component(s)

    Two methods to estimate the concentration of fluorescein in the inferior meniscus. Knowledge of this will serve as a surrogate to estimate the concentration of salt molecules dissolved in the tear film which is considered to increase with an increase in evaporation during TBU.

    Purpose: The purpose of this study was to develop methods to measure fluorescein (FL) concentration by image analysis of the inferior meniscus and by direct measurement of small tear samples.

    Methods: An eye meniscus model was constructed to mimic the inferior meniscus. Five microliters of various FL concentrations were imaged on a slit lamp biomicroscope. Images were converted to grayscale and pixel intensity measured by a custom MATLAB program. To calibrate tear sample data, fluorescence intensity of 10 microliter samples of known concentrations were measured on an RT- PCR (Real time polymerase chain reaction). Following instillation of 2% FL, the same methods as above were used to image the inferior meniscus of one eye of 8 human subjects. FL concentrations were calculated and compared to concentrations measured spifrom tear samples. 

    Results: Fluorescence intensity measured by the slit lamp biomicroscope image analysis reached its maximum at the 0.07% concentration and then rapidly decreased due to concentration self-quenching. A similar pattern was reached with PCR data, with a maximum at 0.07%FL. FL concentrations of 0.6%, 0.4%, 0.3%, 0.14 and 0.07%, yielded average pixel intensity values of 9.00, 18.20, 35.40, 74.38 and 102.15 (image analysis) and Rpre (Initial fluorescence from pre-read) values of, 3762, 5487, 9369, 20461 and 23027. For human tear measures, there was a high correlation in FL concentrations between the two methods (r=0.87, Pearson’s). 

    Conclusions: These methods showed high agreement and thus have potential for measuring FL concentrations in the tear film from the inferior meniscus. During TBU, as visualized via tear film fluorescence, both FL concentration and tear film thickness are unknown. Knowledge of FL concentration within the tear film before TBU begins allows better estimation of relative tear film thickness changes during TBU. 

    Deborah Antwi

    PhD Student at Indiana University, School of Optometry

    I am Deborah Antwi, the 5th born of seven children of my parents. I was born in Sunyani in the Brong Ahafo Region of Ghana and trained as an Optometrist at the Kwame Nkrumah University of Science and Technology (Ghana). I worked as an Optometrist for one year during with most of our patients presented with complains of dry eye. With majority of our patients suffering from dry eye disease, I developed an interest to join, teach and lead future efforts to understand the causes of dry eye related pathology, and to develop methods for improved diagnosis and treatment.

    Ashley Ryckman, BSc

    Indiana University School of Optometry

    Jenna Troiani, BSc

    Indiana University School of Optometry

    Ziwei Wu, PhD

    Indiana University School of Optometry

    Carolyn Begley, OD, MS, FAAO

    Indiana University School of Optometry

    Dr. Carolyn Begley’s clinical research has spanned a wide variety of topics in the area of cornea, contact lenses, and allergy, although her main focus in the last 12 years has been dry eye. Her training includes immunology and cell biology (NEI post-doc, 1988-89) and substantial research experience in tear film and ocular surface imaging, optics and vision, psychophysics, symptom questionnaires and sensory measures, measurement of blink rate and velocity, and fluorescence measures of the tear film. She has received numerous awards, including the Garland M. Clay Award from the American Academy of Optometry for her most cited paper, Characteristics of corneal staining in hydrogel contact lens wearers. She has served as a consultant and received numerous research grants from the major optical and pharmaceutical companies in the vision care field. She is currently funded by the National Eye Institute for a project examining tear instability as a unifying mechanism for dry eye symptoms. Dr. Begley has lectured around the world and published numerous papers and book chapters in the field of dry eye, keratoconus, ocular allergy, and contact lenses.