Special Skills and Techniques

Gretchen Beal Van Boemel, PhD, COMT, has worked in the field of ophthalmology since 1982. She received her undergraduate defree from California State University, Long Beach in the field of research psychology. After 1 year of working as a research assistant in the Department of Cardiology at the University of Southern California, Gretchen started working for the Doheny Eye Institute. She started out as a trainee in electrophysiology under the direction of Thomas E. Ogden, MD, PhD. Within several years, she was teaching electrophysiology courses to University of Southern California medical students and ophthalmology residents. She taught her first JCAHPO course on electrophysiology in 1985, and has taught various courses to ophthalmic technicians and registered nurses since that time. After 5 years she began teaching the practical aspects of ocular electrophysiology and psychophysiology to ophthalmology and psychology fellows (including foreign fellows). After several years of working at Doheny, she found that she was fascinated by the other facets of the field of ophthalmology. She first studied for her COT, and received it in 1985. Later she went on for her COMT certification, which she received in 1991. While at the Doheny Eye Institute, Gretchen also conducted original research in the areas of the usefulness of electrophysiology in the evaluation of the traumatized eye, and VER testing for unexplained vision loss. While conducting the later study, she became intrigued with what appeared to be psychogenic blindness in certain refugee women. With the assistance of a colleague specializing in psychology, Gretchen embarked on a research agenda that included investigating the consequences of severe trauma as the likely cause of psychogenic blindness in a group of older Cambodian women. That work resulted in national and international attention with appearances on ABC’s 20/20 news program, and CNN evening news segment, British and German equivalents of 20/20, as well as being featured in numerous newspaper articles, including a feature story in the New York Times Magazine. As a result, Gretchen felt it necessary to continue her education, and she went back to graduate school while maintaining a full-time position as director of the electrophysiology and psychophysiology department at Doheny. She received her doctorate in Social Ecology with an emphasis in Health Psychology from the University of California, Irvine, in 1995. Since receiving her doctorate, Gretchen has continued to work as director of the electrophysiology and psychophysiology department, but has taken on new responsibilities, as well. She was asked to create a multidisciplinary low vision rehabilitation program that she currently heads. She is also the director of the Continuing Medical Education program at the Doheny Eye Institute. She has coordinated a grant on why preventable blindness occurs in diabetes and is currently investigating barriers to low vision care. Additionally, she has been a principal investigator on a Social Security Administration project aimed at assisting low income blind and visually impaired individuals in receiving appropriate benefits. She continues teaching JCAHPO courses, as well as courses at USA and California State University, Long Beach in the Health Science Department. Gretchen truly loves the field of ophthalmology. It is her sincere hope that many of you will develop a greater appreciation of the field after reading this book. The areas covered are often considered tedious to get through, she hopes that the care examples she has provided with allow these subjects to "come alive."

• Contents Dedication Acknowledgements About the Author Introduction The Study Icons Part I. Advanced Tests and Techniques Chapter 1. Diagnostic Testing Exophthalmometry Pachymetry The Photokeratoscope Corneal Topography Pupillometry Pupillography Ophthalmoscopy Chapter 2. Psychophysical Testing Overview of Psychophysical Testing Advanced Color Vision Testing Dark Adaptometry Testing The Macular Photostress Test The Potential Acuity Meter The Glare Test and the Brightness Acuity Test Contrast Sensitivity Chapter 3. Microbiology Overview Ocular Microbiology Identification of the Infectious Antigen The Immune System Part II. Biometry and Echography Chapter 4. Axial Eye Length A-Scans and Intraocular Lens Calculations Axial Eye Length Techniques of Axial Eye Length A-Scans Brief Review Probe Placement Calculating Axial Eye Lengths with the A-scan Echo Patterns Conducting an Axial Eye Length Examination IOL Power Calculations Chapter 5. Diagnostic A- and B- Scan Ultrasonography Basic Principles Standardized Echography Examination Techniques B-Scan Examination A- and B- Scan Used Together Indications Part III. Electrophysiology Testing Chapter 6. Electroretinography Introduction to the Electroretinogram The Full-Field ERG Materials Needed for Recording the ERG Recording a Full-Field ERG According to International Standards Recording a Dark-Adapted ERG Recording a Light-Adapted ERG Concluding the ERG Testing Session Results of ERG Testing The Clinical Usefulness of the ERG Case Histories - Basic Waveform Abnormalities Case Histories - Disorders Suggesting Cone Photoreceptor Cell Abnormality Case Histories - Disorders Suggesting Rod Photoreceptor Cell Abnormality Case Histories - The ERG in Unexplained Vision Loss Chapter 7. Electro-Oculography Introduction to the Electro-Oculogram Preparing the Patient for an EOG Recording the EOG Evaluating the EOG Clinical Usefulness of the EOG Case Histories Chapter 8. Visual Evoked Response Introduction to the Visual Evoked Response Stimuli Averaging VER Testing Evaluating Test Results The Clinical Usefulness of Flash and Pattern VER Testing Case Histories Appendix A. Disability Determination: Who Qualifies and Who Doesn’t Impairment and Disability Definitions of Vision Loss Importance of Determining Level of Impairment and Disability Assessing and Documenting Vision Loss Other Visual System Abnormalities Affecting Disability Determination Appendix B. Universal Precautions Protecting Patients from Exposure Protecting Staff and Physicians from Exposure Exposure Index