Taking a deeper look at several imaging technology which have advanced optical imaging.
New York—These days, it’s commonplace to use optical coherence tomography (OCT) to measure retinal nerve fiber layer (RNFL) thinning with optic nerve injury, due to glaucoma, optic neuritis, ischemic optic neuropathy, and to determine disease progression and the effects of therapy.
At the 2014 American Academy of Ophthalmology meeting, Mark J. Kupersmith, MD, delivered the 2014 Hoyt Lecture, concentrating on some of his earlier findings in optical imaging studies. Dr. Kupersmith discussed his interest in neuro-ophthalmology, and how far imaging has come since his resident days.
Other methods of optical imaging, polarimetry and applied optics, are either less commonly used or in development.
These and other techniques “can show injury to peripapillary retinal axons and ganglion cells before the RNFL is thinned and can be used to increase the intensity of therapy or serve as an objective outcome or biomarker in treatment trials,” said Dr. Kupersmith, director of neuro-ophthalmology, Institute of Neurology and Neurosurgery, at Mount Sinai, New York, and the chief of service of neuro-ophthalmology at New York Eye and Ear. “Like most neuro-ophthalmologists and glaucoma specialists, I am always interested in identifying changes in the optic nerve that can be used to monitor the effects of treatment, so-called biomarkers, or those that might suggest permanent injury that would not improve with an intensive or invasive therapy.
Dr. Kupersmith, through his work with many collaborators, looked at diseases that cause optic nerve injury, including optic neuritis related to multiple sclerosis, or ischemic optic neuropathy, or optic nerve damage from chronic papilledema, among others.
“All of those disorders result in either one-time or progressive visual loss,” Dr. Kupersmith said. “We're looking at therapies to try to prevent the subsequent vision loss when someone presents, or try to reverse the visual loss.”
To date, no neuroprotective drug has been proven efficacious in humans. “But when they are available, the question is, how are you going to study it?” he asked, and answers, “Imaging.”
As early as 1972, studies (red free photography) showed axonal loss in the RNFL despite visual recovery in optic neuritis, Dr. Kupersmith said.