"Can spectroscopic OCT improve the early diagnosis of diseases such as glaucoma,diabetic retinopathy, and age-related macular degeneration?"
Patients with glaucoma are not aware that they have the disease, mainly because current screening methods detect cellular and axonal loss in the retina and optic nerve head after years of disease progression, often after significant and permanent vision loss.
A period of metabolic stress, potentially reversible through treatments or interventions, is thought to precede neuronal death and vision loss in glaucoma, presenting a “window of opportunity” for appropriate treatments. Importantly, oxygen metabolism supports the energetic requirements of neuronal activity and active transport in the inner retina, which have been shown to be impaired in early glaucoma before structural changes occur. However, no current test can measure such metabolic dysfunction on an immediate time scale to adequately diagnose, monitor, or predict disease progression.
The purpose of this research is to investigate a new noncontact optical method, called spectroscopic optical coherence tomography (OCT), to measure the oxygen saturation in retinal blood vessels. Spectroscopic OCT may enable the assessment of retinal vessel oxygenation which could improve the early diagnosis of diseases such as glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD).
This study requires
Eye scans We expect that the duration for consent, set-up of the experiment, and data acquisition will not take more than 2 hours.
Who can participate?
Inclusion criteria: Adults with no history or evidence of intraocular surgery or laser, no history or evidence of retinal pathology or glaucoma, best corrected visual acuity 20/40 or better, intraocular pressure (IOP) 21 mm Hg or lower, normal appearing optic nerve and Humphrey visual field (if available). These criteria would be determined based on the last previous ophthalmic or optometric exam.
Exclusion Criteria: Subjects will be excluded from the study if their fundus is not visible, their media are opaque, or if they are unwilling or unable to participate in the study. Subjects will be excluded if they have a history of heart disease or pulmonary disease. Individuals who cannot speak English, provide consent, and those who are not yet adults will not be included in this study. Pregnant women and prisoners will not be included in this study either.
Benefits and risks of participating
We cannot promise any benefits to you or others from your taking part in this research. We believe that if this technology is effective, we could detect ocular diseases in a much earlier state. Therefore, your participation may help others.
Light Exposure to the Eye: The risks of the procedure are very low. You will be asked to look at a fixation point. OCT imaging will then be performed by directing and scanning a beam of low power light into the eye (>10x lower power than commercially available laser pointers). The light exposure is well within documented safe limits set by the American National Standards Institute (ANSI) for visible light exposure. Since these measurements are being performed optically, no contact with the eye will be required at any time during the measurement. Similar OCT instruments are in use in the ophthalmology clinic. There is no known risk associated with this procedure. If you experience any discomfort or eye strain as you are fixating during the study, you may take a break. You may also leave the research at any time during the study should you wish. Infection Risk: Since the imaging procedure is non-contact, there is minimal infection risk. The forehead rest and chin rest are cleaned with alcohol before each imaging session. Disposable tissue paper (which is discarded after each imaging session) is placed under your chin during the imaging procedure to further guard against infection. Electrical Hazard: The instrument does not make any electrical connections to you. Therefore, the risk of electrical contact or shock is extremely low. Breach of confidentiality: As with all research, there is a chance that confidentiality could be compromised; however, we are taking precautions to minimize this risk.
UC Davis IRB: 827153
Study duration and period
One visit, that will last approximately two hours
From March 22, 2016
Department of Biomedical Engineering
451 Health Science Drive GBSF Room 2303 Davis, CA 95616