Current Research Projects
The Association of Retinal Neural and Vascular Function in Patients with Diabetes
Principal Investigator: Dr. Jason Ng
Co-Investigators: Drs. Justin Kwan and Patrick Yoshinaga
Significance: Diabetes has become an epidemic in the United States. About 8% of the US population has diabetes (~26 million; of these ~1/3 are undiagnosed), and another 80 million pre-diabetic. Diabetes is the leading cause of new cases of blindness among adults aged 20-74 years, due to the fact that of those with diabetes, roughly 30% have some form of diabetic retinopathy (e.g., retinal changes such as hemorrhages). The goals of the study are to further investigate markers of retinal health that can be used to identify patients at high-risk for developing further diabetic eye disease or used as markers to monitor patient health during the evaluation of new treatments for diabetic retinopathy.
Description: The study is primarily evaluating the association between retinal nerve function and retinal lesions in diabetic retinopathy. Patients with or without diabetes, between 20 and 70 years of age, will be enrolled and various vision functions are measured (e.g., visual acuity, electroretinograms, macular pigment density) in addition to taking retinal photographs.
Status: Actively enrolling.
The Concordance (Agreement) and Evaluation of Color Vision Tests
Principal Investigators: Drs. Jason Ng and James Bailey
Significance: Color vision defects overwhelmingly affect males, at a rate of approximately 8% of the US male population. Color vision testing and management is frequently neglected, yet is critical to the success of individuals with regard to the education system and future fields of occupation. The goals of the study are to better understand how test results from a given color vision test transfer to other tests as well as to evaluate and validate new color vision tests.
Description: The study is evaluating the relationship between several color vision tests as well as evaluating new color vision tests. Patients between 18 and 100 years of age, with or without known color vision problems are being recruited. Collaborations are being developed with California State University, Fullerton; University of Washington; and the University of New South Wales to conduct some parts of the studies.
Status: Actively enrolling.
Developing a Normative Database for a New Optical Coherence Tomographer (iVue)
Principal Investigator: Dr. George Comer
Significance: Retinal imaging devices provide structural information that can aid in the diagnosis and management of numerous ocular pathologies. The Optical Coherence Tomographer (OCT) has become the most widely used scanning laser instrument in clinical practice. OptoVue has developed an advanced version of the Fourier Domain OCT, the iVue, that allows faster imaging with improved resolution compared to older OCT devices.
Description: The purpose of this study is to collect iVue OCT data in healthy individuals. Data from the normal, healthy eyes will be used to establish normal ranges in order to create an appropriate normative database (NDB). This study involves three sites, with a total enrollment among sites of approximately 360 subjects. This site, Southern California College of Optometry (SCCO), is expected to enroll 120 normal subjects, from age 18 year with no known ocular conditions.
Status: Currently enrolling.
Using Accommodative Lag to Diagnose Accommodative (Mis-Focus) Disorders
Investigators: Drs. Eric Borsting and Lawrence Stark; and Dr. Christopher Chase at Western University of Health Sciences
Significance: This is a National Institute of Health funded project. This is the second phase of a long-term collaboration between Dr. Eric Borsting and Dr. Christopher Chase. The first phase of the project was funded by the National Institute of Health while Dr. Chase was a professor at Claremont McKenna College.
This project studies accommodative function, the ability to focus while doing near work. Visual discomfort symptoms, such as headaches, sore eyes, and blurred vision are commonly associated with prolonged reading or other near work. Researchers have long suspected accommodative dysfunction was involved but most clinical studies have failed to establish a relationship between weak accommodation and symptoms or reading impairments. Recent research, however, has found that clinical measures overestimate accommodative function and encourage the use of objective, autorefraction methods to measure and study accommodative weakness.
Description: This project will accomplish three goals. First, using autorefraction, objective and reliable procedures will be developed for measuring accommodative lag, the difference between the target location and where the eye is focused. Second, experiments will measure in real-time the impact of accommodative lag on reading fluency and visual discomfort. Third, studies will explore the role of the slow adaptive component in accommodative weakness. This work will lead to better methods for diagnosing and treating accommodative disorders.
Status: Recruiting subjects at Western University of Health Sciences.
Amblyopia Treatment Study (ATS) 15: Increasing Patching for Amblyopia in Children 3 to <8 Years Old
Investigators: Drs. Susan Cotter, Carmen Barnhardt, Angela Chen, Raymond Chu, Catherine Heyman, Kristine Huang, Reena Patel
Significance: Amblyopia is the most common cause of monocular visual impairment in both children and young and middle-aged adults. Both patching and atropine are accepted treatment modalities for the management of moderate amblyopia in children. Many practitioners prescribe 2 hours daily patching as initial therapy for amblyopia. However, not all children achieve normal visual acuity in the amblyopic eye with this regimen. When visual acuity improvement with initial therapy stops and amblyopia is still present, treatment options include increasing the dosage of current treatment, switching to another treatment, maintaining the same treatment and dosage for additional months, or combining treatments. Many eye care providers increase the dosage of the current treatment, in part because families have become comfortable with that particular mode of treatment. However, it is unknown whether increasing occlusion dosage will improve amblyopic eye visual acuity in these patients. The primary objective of this study is to determine if increasing patching dosage will improve visual acuity in patients with amblyopia still present after visual acuity has stabilized with initial treatment.
Description: This study, funded by the National Eye Institute, is a multi-center randomized clinical trial designed to evaluate the effectiveness of increasing patching treatment from 2 to 6 hours daily after visual acuity has stabilized with initial treatment and amblyopia is still present. Children ages 3 to < 8 years with visual acuity of 20/50 to 20/400 in the amblyopic eye will be enrolled in a run-in phase with 2 hours daily patching until no improvement, followed by randomization of eligible patients to patching 2 hours daily versus an average of 6 hours daily (42 hours per week). Further details can be found at the NEI webpage and clinical trials.gov.
Amblyopia Treatment Study (ATS) 16: Augmenting Atropine Treatment for Amblyopia in Children 3 to <8 Years Old
Investigators: Drs. Susan Cotter, Carmen Barnhardt, Angela Chen, Raymond Chu, Catherine Heyman, Kristine Huang, Reena Patel
Significance: Amblyopia is the most common cause of monocular visual impairment in both children and young and middle-aged adults. Atropine is an accepted treatment modality for the management of moderate amblyopia in children. Eye care providers often prescribe weekend atropine as initial therapy for amblyopia. However, not all children obtain normal visual acuity in the amblyopic eye after treatment with atropine. When visual acuity improvement stops after initial therapy and amblyopia is still present, many clinicians will add a plano lens over the sound eye to the atropine treatment. This option is limited to children with hypermetropia in the sound eye. However, it is unknown whether adding a plano lens over the sound eye will improve amblyopic eye visual acuity more than continuing atropine alone in patients who have shown no further improvement after initial treatment with atropine.
Description: This study is designed to evaluate the effectiveness of adding a plano lens to weekend atropine after visual acuity has stabilized with weekend atropine but amblyopia is still present. Children ages 3 to < 8 years with visual acuity of 20/50 to 20/400 in the amblyopic eye will be enrolled in a run-in phase with weekend atropine until no improvement, followed by randomization of eligible patients to weekend atropine treatment with a plano lens over the sound eye versus without a plano lens over the sound eye.
Intermittent Exotropia Trial (IXT) 2: Observation Versus Occlusion Therapy for Intermittent Exotropia
Investigators: Drs. Susan Cotter, Carmen Barnhardt, Angela Chen, Raymond Chu, Catherine Heyman, Kristine Huang, Reena Patel; Dr. George Cotter is the Protocol Chair for this multicenter study.
Significance: Intermittent exotropia is the most common form of childhood-onset exotropia, which can lead to learning and visual functioning problems. Although occlusion treatment for IXT treatment is widely used, there have been no randomized clinical trials evaluating its effectiveness. Understanding the degree of effectiveness of occlusion treatment for IXT and the natural history of IXT has important public health implications. Successful restoration of binocular alignment and normal binocular function with occlusion therapy, or spontaneous improvement, will reduce the proportion of children undergoing surgery. Defining the rate of success with either occlusion or observation is therefore important in planning treatment for children with IXT. Alternatively, evidence of low treatment effectiveness with occlusion will help avoid unnecessary treatment.
Description: This study, funded by the National Eye Institute, is a multicenter randomized clinical trial designed to assess the natural history of intermittent exotropia and to establish the effectiveness of part-time occlusion in its treatment. More than 500 children aged 12 months to < 11years with previously untreated intermittent exotropia will be randomly assigned to 3 hours of daily occlusion for at least 5 months or observation only. For more information, please go to: http://clinicaltrials.gov/ct2/show/NCT01032330.
Surround Propinquity (Awareness of Nearness) and Dark Focus of Accommodation
Investigator: Dr. Lawrence Stark
Significance: Tonic accommodation is recognized as a component of the normal accommodation response. However, some authors have questioned whether it is possible to obtain a valid measure of tonic accommodation, uncontaminated by the individual’s knowledge of the nearness of objects (propinquity). Therefore, this study will quantify the effect of surround propinquity on dark focus of accommodation, and from this relationship obtain and investigate the fulcrum of the propinquity stimulus–response function (in dark conditions) as a potential new measure of "tonic accommodation."
Description: Ocular accommodation will be measured with an autorefractor while subjects are seated at various distances from a wall in a completely dark room. Thirty young adults will be recruited for the study.
Status: Preparing equipment.
Accommodative Performance in Children
Investigators: Drs. Susan Cotter and Angela Chen
Significance: Amblyopia is relatively common in school-age children, as are accommodative (focusing) difficulties. The goal of this study is to determine the accuracy of the focusing system of children with amblyopia and to identify the ways in which it is different from children with normal vision. Ultimately, it is possible that we might improve amblyopia treatment with glasses if we know more about the focusing system of children with amblyopia.
Description: The goal of this NEI-funded study is to investigate the accommodative ability of children with amblyopia. Approximately 200 children < 17 years, both with amblyopia and without amblyopia, will be enrolled at our clinic and at the following 3 clinics: Children’s Hospital of Los Angeles (CHLA); the Indiana University Department of Ophthalmology in Indianapolis, Indiana; and the Indiana University School of Optometry in Bloomington, Indiana. For more information, please go to: http://www.opt.indiana.edu/people/faculty/candy/our_research.html
A Single-Center, Masked, Randomized Study Comparing Bepreve (bepotastine besilate) 1.5% - H1 Specific Antihistamine vs. Alrex (loteprednol etabonate) 0.2% - Corticosteroid in Subjects with Moderate to Severe Allergic Conjunctivitis
Principal Investigator: Dr. Judy Tong
Co-Investigators: Drs. Mark Sawamura, Justin Kwan, Jerry Paugh
Significance: Allergic conjunctivitis (AC) afflicts approximately 15-20% of the US population. Typically, patients manifest symptoms in the spring, summer and fall, when airborne allergens are at their peak. Signs and symptoms of allergic conjunctivitis are conjunctival hyperemia (redness), ocular itching, conjunctival and eyelid edema, papillary hypertrophy, tearing and burning. While the newer steroids used to treat AC offer advantages over older, ketone-based steroids, they still have adverse effects such as delaying healing of the anterior segment, elevation of intraocular pressure and/or propagation of opportunistic infections. The primary objective of this study is to evaluate the efficacy of bepotastine besilate 1.5% ophthalmic solution, a selective H1 receptor antagonist with few side effects, compared to loteprednol etabonate 0.2% in the treatment of moderate to severe allergic conjunctivitis.
Description: Subjects over age 18 with moderate to severe allergic conjunctivitis will be randomized to either Bepreve or Alrex. Individual subject participation will be approximately 14 days in duration and the study is anticipated to last 4 months. Assessments will include novel grading charts for ocular redness, and objective chromaticity (redness) measurements using a photometer.
Dry Eye and Reading
Investigators: Drs. Eric Borsting, Annie Chang, William Ridder, Jerry Paugh
Significance: Dry eye impacts several features of sufferer’s quality of life, including ocular pain, loss of normal activities due to light sensitivity, and frequently disturbance of visual performance. The study is evaulating the impact of dry eye on quality of life related to reading performance.
Description: The purpose of this study is three fold. First, we are investigating the specific complaints when reading or doing close work in adults with clinically significant dry eye using the Convergence Insufficiency Symptom Score (CISS). Second, we are looking at associations between the Ocular Surface Disease Index (OSDI), a dry eye symptom questionnaire and the CISS in a group of patients with significant dry eye. Third, we are developing and pilot testing techniques to assess reading rate under low and high stress conditions in adults with dry eye. This study in sponsored by an unrestricted grant from Allergan.
Status: Still recruiting subjects for investigating association between the OSDI and the CISS.
Spatial Light Modulation to Investigate Wavefront Vergence Detection for Accommodation.
Investigators: Drs. Philip Kruger and Klarissa Cum, SUNY Optometry; and Dr. Lawrence Stark, SCCO.
Significance: Several avenues of research suggest that the visual system detects optical vergence to guide accommodation (eye focusing), emmetropization (coordinated growth of eye) and depth perception. The long-term aim is to identify optical signals that specify the sign (positive or negative) of defocus of the eye
Description: This study will test the hypothesis that reflex accommodation responds to optical vergence as a modulation of light across the pupil in conjunction with modulation of light across the retina (defocus-blur), and that a comparison of phase across pupil and retina provides the sign of defocus. In simple terms, we will test the idea that the visual system learns about defocus by watching the ‘with’ and ‘against’ skiascopic motions in the exit pupil, as viewed from the retina.
Status: Data collection is ongoing.
Contact: Dr. Philip Kruger, SUNY Optometry
Visual Effects of Artificial Tear Supplements on Contrast Sensitivity
Principal Investigator: Dr. William Ridder
Significance: Understanding the influence of topical ocular formulations on vision is crucial to understanding the efficacy of supplements such as artificial tears and lubricants. Dr. Ridder uses psychophysical methods (rigorous means to test vision) and newer approaches such as measurement of the eyes’ aberrations to assess the effect on visual performance.
Description: In a series of studies visual effects of topical formulations have been investigated in normals and in dry eye subjects. These studies include the systematic evaluation of the effect (magnitude and length of time of the defect) of different artificial tears on contrast sensitivity. Viscosity appears to play a major role in influencing the decrease in visual performance observed with certain formulations.
Investigating the Visual System of Genetically Altered Mice with Electroretinograms (ERGs) and Visual Evoked Potentials (VEPs)
Principal Investigator: Dr. William Ridder
Significance: Conditions impacting vision such as multiple sclerosis, retinitis pigmentosa, or Leber’s congenital amaurosis are not common, but have devastating effects on visual functioning and sufferers’ quality of life. Mouse models similar to these pathologies are currently available and allow study using the specialized methods of electrophysiology. These studies are designed to investigate the origin of these diseases and potential treatments.
Description: In a series of investigations, faculty member William Ridder, O.D., Ph.D., has been collaborating with researchers at University of California-Los Angeles in measuring ERGs and VEPs in genetically altered mice to further knowledge of the electrophysiological characteristics of these mice.
Recently Completed Research at the Southern California College of Optometry
Epithelial Barrier Function and Contact Lens Solution Bio-Incompatibilities: Four Separate Studies:
Investigators: Former Research Fellows, Drs. Justin Webb and Daniel Krall; Former Contact Lens Resident, Dr. Gloria Chiu; Dr. Jerry R. Paugh
Significance: There is currently significant controversy regarding whether superficial, solution-induced corneal staining is a meaningful complication of modern contact lens wear.
Results: In this series of randomized, controlled studies, using fluorometry to objectively measure fluorescein dye diffusion through human anterior segments, we have found: 1) significant correlation of corneal staining scores with increased dye diffusion through the epithelium; 2) increased corneal (stromal) fluorescein accumulation with increased cornea staining; and 3) increased anterior chamber (the front chamber of the eye) dye concentrations with increased corneal staining. These studies prove that corneal staining is real, and denotes transient, yet significant changes in the barrier properties of the human cornea.
Status: Current studies completed; new Masters thesis project beginning to examine the effect of preservatives on corneal barrier function.
Multiple Rod Signaling Pathways in the Mammalian Retina
Faculty Member, Dr. William Ridder in collaboration with researchers at the University of California, Los Angeles Medical School, are using the electroretinogram to investigate multiple pathways for rod information flow through the retina. These studies are designed to understand the visual processing in a normal retina so that appropriate test can be designed to further understand retinal disease.
Visual Discomfort and Reading
This research has been a collaborative effort between Drs. Eric Borsting and William Ridder at SCCO and Dr. Christopher Chase at Claremont Mckenna College and has been funded by a grant from the National Institute of Health. The purpose of the project is to investigate possible causes of visual discomfort in college students. The research has assessed the type and frequency of visual discomfort in college students and investigated sensory and oculomotor etiologies of discomfort symptoms. The initial results have shown that oculomotor functions are most associated with visual discomfort.
Therapy for Improving Reading Performance in Children with Symptomatic Convergence Insufficiency: A Prospective Study
Investigators: Drs. Eric Borsting, Susan Cotter, Carmen Barnhardt, Raymond Chu
Convergence insufficiency (CI) is a common condition in school children and is often associated with symptoms such as frequent loss of place, loss of concentration, having to re-read, reading slowly, trouble remembering what was read, sleepiness, blurred vision, diplopia, headaches, and/or eyestrain. A recently completed randomized clinical trial demonstrated that a 12-week program of office-based vergence/accommodative therapy (OBVAT ) is an effective treatment for symptomatic CI in children 9 to 17 years of age. The question that requires additional investigation is whether these changes lead to an improvement in reading performance. The proposed study is designed to provide pilot data about the association between CI and reading, attention, quality of life and the effectiveness of OBVAT in improving reading performance of children with symptomatic CI.
Amblyopia Treatment Studies
As members of the Pediatric Eye Disease Investigator Group, Drs. Susan Cotter, Carmen Barnhardt, Raymond Chu, Kristine Huang, and Huey-Fen Song have participated in a number of studies funded by the National Eye Institute relating to the treatment of amblyopia in children. A description of each study and a brief summary of the major results can be found at the link.
- Occlusion vs. Pharmacologic Therapy for Moderate Amblyopia (ATS1)
- Assessment of Home Visual Activities While Patching (ATS2PS)
- A Randomized Trial Comparing Part-time vs. Full-time Patching for Severe Amblyopia (ATS2A)
- A Randomized Trial Comparing Part-time vs. Minimal-time Patching for Moderate Amblyopia (ATS2B)
- An Observational Study on Recurrence of Amblyopia after Discontinuation of Treatment (ATS2C)
- A Pilot Study to Assess the Effectiveness of Amblyopia Treatment in 10 to 19 Year Olds (ATS3PS)
- An Evaluation of Treatment of Amblyopia in 7 to <18 Year Olds (ATS3)
- A Randomized Trial Comparing Daily Atropine vs. Weekend Atropine for Moderate Amblyopia (ATS4)
- A Randomized Trial to Evaluate 2 Hours of Daily Patching for Amblyopia in Children 3 to < 7 Years Old (ATS5)
- A Randomized Trial Comparing Near Versus Distance Activities While Patching for Amblyopia in Children 3 to < 7 Years Old (ATS6)
- Bilateral Refractive Amblyopia Treatment Study (ATS7)
- A Randomized Trial Comparing Atropine to Atropine Plus a Plano Lens for the Sound Eye as Prescribed Treatments for Amblyopia in Children 3 to < 7 Years old (ATS8)
- A Randomized Trial Comparing Patching vs. Atropine for Amblyopia in 7 to < 13 Year Olds (ATS9)
- A Randomized Trial of Full-time Bangerter Filters vs. Part-time Daily Patching for the Treatment of Moderate Amblyopia in Children (ATS10)
- A Randomized Trial to Evaluate Combined Patching-Atropine for Residual Amblyopia (ATS11)
- An Observational Study of Optical Correction for Strabismic Amblyopia in Children 3 to < 7 Years Old (ATS13)
Correction of Myopia Evaluation Trial 2 (COMET2)
COMET is a multicenter randomized clinical trial to determine if progressive addition lenses (PALs) versus single vision lenses (SVLs) slow the progression of low myopia in children with poor accommodative responses (i.e., large accommodative lags) and near esophoria. The study is funded by the National Eye Institute; further information can be found at: http://clinicaltrials.gov/ct2/show/NCT00320593?term=PALs&rank=2.
Opportunities to Make a Difference in Research at SCCO
It is difficult to procure some of the big ticket items required to maintain SCCO at the forefront of eye research from normal operating funds. Several opportunities exist to support key equipment that would greatly further research at the College. The list and supporting rationale for each can be found by clicking on the following link: Opportunities for Giving, Research.
Revised: October 29, 2012