COMMENTARY

Looking Back on an Innovative Year in Ophthalmology

Ronald C. Gentile, MD; Tal Raviv, MD; Joseph F. Panarelli, MD; Richard B. Rosen, MD

Disclosures

December 29, 2014

In This Article

Retinal Prosthesis for the Blind

In the past, patients who were blind from retinitis pigmentosa or other hereditary photoreceptor diseases had very few options. The Argus® II Retinal Prosthesis System (Second Sight Medical Products Inc.; Sylmar, California) is the first of the next-generation solutions to this problem. After approval by the FDA in 2013,[12] the first nonstudy device was implanted in the United States in January 2014.

The retinal prosthesis is 3 × 5 mm and is installed surgically onto the surface of the retina, where it acts to replace the function of the degenerated photoreceptor cells.[13] The current-generation implant contains 60 electrodes that stimulate the retina with electrical impulses created by a video processing device. That device transforms images from the video camera mounted in a pair of eyeglasses into electronic information that is wirelessly transmitted to the retinal prosthesis.

This implant, also referred to as a "bionic eye," has been implanted in approximately a dozen patients in the United States, and its use is expected to increase as patient experiences are shared and reimbursement solutions become standardized.

Noninvasive Retinal Imaging

Optical coherence tomography (OCT) has fundamentally altered the way in which ophthalmologists approach the eye, and it promises to continue to deliver better anatomical information and lead the way to functional imaging.

This became immediately evident with the recent introduction of OCT angiographic images produced without injection of extraneous dye. OCT is able to reveal detailed images of large retinal vessels and capillary networks in seconds using a strategy called "motion contrast," as opposed to the minutes required in conventional fluorescein angiography. These images are uniquely three-dimensional and allow isolated study of individual capillary beds at different depths of the retina.

Although concerns have been raised about loss of the ability to image leakage (owing to the short recording interval), the need to recognize motion artifacts, and the small fields of view, new strategies are being developed to compensate for these limitations. OCT angiography will greatly expand upon the clinician's ability to noninvasively recognize the subtle progressive vascular changes in diabetic patients that precede macular decompensation and edema.[14]

Adaptive optics is an imaging technology that offers 10 times better resolution than the current generation of clinical systems. Although it is still in the early stages of commercial availability, its use promises to propel retinal imaging to the next level of detail, providing images of individual photoreceptor cells and microvascular structures, including capillaries and microaneurysms.[15]

Clinical insights using these noninvasive imaging tools have the potential to radically expand the understanding of ocular diseases and treatment responses.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....