Advances in Ocular Imaging Technology
Improvements on many fronts are creating a more unified picture
BY DIANE DONOFRIO ANGELUCCI
As the old saying goes, a picture is worth a thousand words. Today, there are more ocularimaging device options available than ever before — devices that acquire high-quality images that help provide patients with optimal care. Learn what experts are saying about just some of the latest devices.
OCT is probably the most recognized and utilized type of ocular imaging device. Time domain OCT started the trend, but spectral domain OCT has taken imaging to another level by offering better resolution, faster acquisition speeds, and the potential for earlier diagnosis and monitoring of disease.
"OCT technology is very helpful to anyone who provides ophthalmic care because it offers a very accurate representation, or measurement, of retinal anatomy, nerve fiber layer anatomy, and optic disc topography," says Joseph Sowka, OD, professor of optometry and director of the glaucoma service, Nova Southeastern University College of Optometry, Ft. Lauderdale, Fla. "So it's a very good diagnostic tool for retinal disease and glaucoma. It's probably used more for retinal disease than glaucoma, but it's very effective in glaucoma, and spectral domain is more reproducible, with finer detail organization than the original time domain technologies."
Michael Rothschild, OD, chief executive officer of West Georgia Eye Care, Carrollton, Ga., and founder of LeadershipOD.com, explains how OCT allows optometrists to assess patients more precisely. "Before this technology, we would see a defect in the macula or some swelling but we didn't know exactly what layer it was on. Now we're able to determine if it's something that's threatening the fovea, something we can monitor, or something we need to refer immediately," he says.
Because the location of his practice is 1 hour from Atlanta and the nearest retina specialists, Dr. Rothschild has found the technology to be particularly useful. "If we have patients with active bleeding near the macula or in the retina or with fluid buildup, with this technology, we can actually take an image and transmit it to the retina specialist. They can see the image and tell us whether it warrants an immediate referral or if it's something we can monitor while working closely with them," he says. "By having this technology, we're able to better communicate the situation to retina specialists and save the patient time and traveling."
Linking Your Images Effectively
By Sean McKinney, Contributing EditorAs you plan for future uses of ocular imaging, consider how the images you capture will integrate with your electronic medical records (EMR) and electronic health records (EHR). Will you be able to access images away from your instruments?
Connectivity software and the functionality of an image management system will determine how well you achieve your goals.
Kim Castleberry, OD, of Plano, Tex., and Lorie Lippiatt, OD, of Salem, Ohio, recommend that you research image management systems carefully before buying one. What works now may be of diminishing value in 2011, when the 2009 Health Information Technology and Clinical Health Act (HITECH) begins providing eligible doctors with up to $44,000 in extra Medicare payments for adopting qualified EHR and EMR systems.
"To qualify for this funding, you will need interoperability — the ability to communicate images and data electronically with other providers or facilities outside of your office," says Dr. Lippiatt, noting that EHR systems provide interoperability, while EMR systems provide interconnectivity within in your office.
"You can buy something now that provides interconectivity among your instruments inside your office," says Dr. Castleberry. "But it won't be what you want or need beginning in 2011 if it doesn't provide interoperability."
Two methods of linking imagesEven if you choose a system that provides interoperability, you still have to choose a method of accessing images on a network. Consider these two approaches:
Direct access. You can auto-populate your medical records with data from your diagnostic instruments, gaining direct access to patient images through your EMR or EHR system.
Indirect access. You can view, control, or manipulate diagnostic data within your instruments, using a system that provides indirect access through your EMR or EHR system. The indirect system doesn't allow access while someone else is using the instrument, however. To circumvent this limitation, you can use workstation review software, available for many instruments. This allows you to load the software onto exam room computers, providing access to diagnostic data while a staff member or colleague is using the instrument on a different patient.
Alternative work-aroundAnother work-around for an indirect access system is to create a remote-controlled computer that allows you to access data on a server at any time without affecting the use of your instruments. Each doctor can have a remotely controlled computer assigned to him or her, permitting access to all data through the configuration of remote desktop connection software on exam room PCs.
"I prefer this approach because it doesn't require that you maintain review software for each computer in each exam room," says retinal specialist Vincent R. Vann, MD, PhD, of Edinburg, Tex. Dr. Vann operates a Mac-based network but uses Microsoft Remote Desktop Connection Client 2.0 software to interact with his PC-based instruments. He plans to use iTap software on the iPad to access data produced by OCT, perimetry, ultrasonography, fundus photography, and angiography while he's out of the office.
Below is an overview of systems for linking images and diagnostic data, based on information provided by the companies that sell the systems. Consultation with independent and knowledgeable experts is recommended.
Carl Zeiss Meditec (FORUM)FORUM, a data management system, integrates data from Zeiss and non-Zeiss instruments to produce a complete, centralized and paperless record. FORUM complements EMR systems by providing a robust platform for viewing clinical images and reports. It makes clinical data instantaneously available in your office and off-site.
Connectivity is established through an optional EMR license, which creates a seamless link between FORUM and an existing EMR system. The interface enables transfer of diagnostic images and reports from FORUM to the EMR system. Patient demographic data also can be transferred from the EMR system back to the instrument.
The system is compatible with Mac and Microsoft Operating Systems. FORUM also eliminates the need to key patient demographic data into each instrument, preventing charting errors. The Archive component links your instruments, diagnostic images, reports, and raw data for synchronization, remote access, and data backup. The DICOM-compliant design of FORUM allows integration of instruments into a single digital data flow that can be seamlessly extended — even into the OR.
The Forum Viewer, a Web-based application, provides immediate remote access to diagnostic data from any computer within your network.
Chace and Associates Technologies, LLC (iViews)iViews is a premier informatics system for eye care. It allows advanced diagnostic review of images and text via any desktop, wherever the imaging, electronic reports, and data are needed for review. The system integrates more than 160 instruments for viewing. iViews works with MS Terminal Services, Citrix, and all mobile devices, such as iPad.
Once processed through the iViews Imaging System into Digital Imaging and Communications in Medicine (DICOM) files, all images and e-PDFs are available for viewing in iViews. The system allows user-customized viewing options, multiple visit dates, serial analysis, side-by-side views, and device-specific viewing. Buttons in the viewer can be used to simplify the viewing experience. Once exams are retrieved, users can display, annotate, and print images and maps.
Instrument databases can be located on the image server and manipulated by review software. You can create buttons for custom grouping, layout, and appearance at any time. Custom summary sheets are ready for discrete data tracking. This data can be presented graphically to track changes to data, such as intraocular pressure, nerve fiber layer thickness, central macular thickness, or other measurements. iViews can be launched from within most EMRs with preselected patient information.
Kowa (DigiVersal)All image formats can be stored in the DigiVersal image and data management system, regardless of their platform. The software compresses images, but not to the point of interfering with DICOM compliance. The system, which interfaces with medical records and non-Kowa instruments, processes slit-lamp, retinal, and OCT images.
The system comes with a series of annotation tools, including a feature that lets you mark a copy of an image while maintaining a pristine original version of the image. You can measure cup-to-disc ratio or the distance of a lesion from the macula. The software also provides image-processing capabilities, including a filtering system that allows viewing of the original image and three other filters (red, green, and blue) at the same time. Filtered images are linked so you can view the same section of multiple images simultaneously.
The DigiVersal system allows you to search through a patient's records by diagnosis, a series of diagnoses, or by type of image capture. For example, you can search by slit-lamp only or visual fields only or look at all central images for glaucoma. The system has a Flex option for multiple locations, allowing images to be stored on one central database.
OIS (Symphony Web)OIS Symphony takes data captured by a variety of manufacturers' instruments and integrates the data into one format, enabling you to view all of a patient's information on a screen from anywhere instantly. The system, providing access through Web functionality, links with EMR software. Once patient data is entered into the EMR, it flows into the image management system and attaches to each new image that is added to the database. There's no need to input patient information into the instruments, which provide images to the system at full resolution.
To ensure efficiency, images and diagnostic reports are stored separately from the EMR on a server. You can review history, images, and diagnostic reports for a patient and, using an instrument's native viewing software, analyze 3-D data. The PerfectView feature combines images from multiple retinal viewing technologies, such as fluorescein angiography and optic nerve head photography, or serial images from the same technology over time. With AutoHistory, you can page through multiple diagnostic reports. The Montage feature combines fundus images into a single color image. The system also lets you search and sort through all images associated with each patient. You can also download images to a computer hard-drive for email communication of patient data.
TOPCON (EyeRoute)The EyeRoute system lets you view, compare, organize, annotate, and transmit patient images from more than 100 instruments manufactured by Topcon and by other companies. Data from the instruments flow into the Capture Station Gateway (CSG), which sends the information to the EyeRoute host server. The server makes the images available quickly via a Web browser, allowing you to view them on a desktop computer, laptop, iPhone, or iPad. The browser also can provide data to an EMR system.
The system's AutoSync technology automatically imports exam data from remote locations with 7-point data validation to prevent database errors. You can drag and drop images into referral letters, emails, and presentations. Other characteristics include redundant, fail-safe servers that eliminate down time; HIPAA compliance; encryption; latest firewall protection; and usage tracking. EyeRoute's Flash networking software permits instant remote access to all stored information. Work flow centers around an exam screen list from which you can select types of images, dates of image captures, and patient histories. The screen displays selected images in one window and lets you enlarge images and use measuring tools. With the AnyUp feature, you can compare and enlarge specific images from varying instruments in the same window. EyeRoute also features a diabetic retinopathy telemedicine reading module, iReports, PDF report, and other modules to enhance workflow. OM
OCT Update● Cirrus HD-OCT (Carl Zeiss Meditec) With resolution of 5 microns and repeatability of 2.5 microns, Cirrus HD-OCT captures a full cube of retinal scans in just 2.4 seconds. Precise registration and proprietary algorithms provide 2D and 3D images, layer segmentation, and optical biopsies for assessment of retinal conditions and changes. Designed for efficiency, Cirrus HD-OCT offers easy and fast scan acquisition, a small footprint, and a modern integrated design that fits in the corner of a room. New Optic Nerve Head Analysis software provides automated identification of the optic disc and cup boundaries. The analysis is generated using the existing Optic Disc 200x200 data cube and a new proprietary ZEISS algorithm. This algorithm is designed to precisely measure the neuro-retinal rim, while accounting for tilted discs, disruptions to the RPE, and other challenging pathology. Guided Progression Analysis (GPA) compares RNFL thickness measurements from the Optic Disc Cube scan over time and determines if statistically significant change has occurred. The results show event analysis, trend analysis, and a quantified rate of progression. Anterior segment imaging requires no additional add-on lens and provides visualization of the angle and central corneal thickness measurement.
Change analysis to monitor disease progression and therapeutic outcomes is available for retina. Macular Change Analysis provides visual and quantitative comparison of two exams. Post-acquisition registration and the Fovea Finder function ensure the accuracy and precise repeatability of macular thickness measurements. CZM soon will introduce software to help quantify the area and volume of drusen, and area of geographic atrophy. The Advanced RPE Analysis module will make use of an algorithm developed by Giovanni Gregori, PhD, at Bascom Palmer to create a map showing elevations in the RPE corresponding to drusen. The package will provide images of geographic atrophy, along with an automated segmentation developed by Zeiss.
● Heidelberg Engineering offers seven distinct models of its Spectralis Tracking OCT product line with up to 6 imaging modes, including the competitively priced SPECTRALIS OCT, which sells for less than half the price of the original Spectralis HRA+OCT model. Designed with general practitioners in mind, the Spectralis OCT simultaneously captures infrared fundus and SD-OCT images. It has a user interface designed for fast, easy scanning, and like all Spectralis models, it's built with TruTrack Active Eye Tracking. All Heidelberg SD-OCT systems capture OCT images at 40,000 A-scans per second and use the proprietary TruTrack eye-tracking technology that recognizes, locks onto, and follows the patient's retina during scanning, and automatically positions follow-up scans (AutoRescan) to ensure accurate monitoring of disease progression and treatment. TruTrack also enables the proprietary Heidelberg Noise Reduction feature, which produces scans that show retinal layers and detail never seen before, according to the company.
● Bioptigen offers a handheld SD-OCT device particularly adept at capturing pediatric images. Its portability means that it can go from the clinic to the operating room, and also enables OCT images to be obtained regardless of patient posture. Bioptigen's handheld OCT can acquire and display high-resolution B-scans at 17 fps, the company says. A wide array of add-on probes and scanners are available for greater flexibility.
● The RTVue and iVue, designed and manufactured by Optovue, Inc., are high-resolution, high-speed, full Spectral/Fourier-Domain OCT instruments with 5-micron resolution and 26,000 A-scan/second scan speed. The systems offer imaging capabilities of both the anterior and posterior poles as standard. High-resolution B-scans and retinal thickness mapping aid eye-care professionals in identifying and tracking retinal disease. RNFL thickness mapping and TSNIT analysis help to identify RNFL loss. Full 6x6 mm pachymetry mapping, plus visualization and measurement of the angle, provide the tools to aid in anterior segment assessment. The iVue is very compact, weighing less than 30 pounds, while providing goldstandard tools for retinal, RNFL, and anterior segment assessment. Optovue's exclusive Ganglion Cell Complex (GCC) Analysis is offered on the RTVue platform. Furthermore, RTVue provides 3D posterior and anterior segment imaging capabilities as well as optic disc parameters for added confidence in clinical assessment and monitoring disease progression.
● The Topcon 3D OCT-2000 system is the first Spectral Domain OCT system to incorporate a high-resolution fundus camera and a user-friendly, color touch-screen display in a compact, space-saving design. The intuitive FastMap software enables dynamic viewing of the OCT data, providing 3D, 2D and fundus images simultaneously. Pin-Point Registration properly indicates the location of the OCT image within the fundus image. In addition, the compare function allows users to view serial exams in a comparison view and use different analytical tools. Seamless integration of the 3D OCT-2000 with Topcon's EyeRoute Image Management System provides true connectivity and access to images anywhere, anytime.
● Opko/OTI's Spectral OCT/SLO combines optical coherence tomography with a scanning laser ophthalmoscope, and allows anterior segment scans with an optional add-on lens. The device can also capture "microperimetry" data that can be overlaid onto OCT or SLO scans to correlate objective and subjective findings. Images are captured at resolutions of 5 to 6 microns and can be viewed in several different modes onscreen; software aids analysis of change over time.
● Canon's SPOCT-HR, licensed from Optopol, is expected to receive FDA approval later this year. The company says it will offer 3-micron resolution, ultra-high scanning speed (up to 52,000 A-scans per second), and software packages for glaucoma and retinal disease.
● Tomey offers an anterior segment OCT system that uses swept-source OCT, also called optical frequency domain imaging. It is an alternative implementation of Fourier Domain-OCT in which the wavelength of the light source is tuned in rapid cycles. The company says its system provides both high resolution and wide area measurements. It offers a penetration depth of 6 mm.