Teleophthalmology is a branch of telemedicine that delivers eye care through digital medical equipment and telecommunications technology. Today, applications of teleophthalmology encompass access to eye specialists for patients in remote areas, ophthalmic disease screening, diagnosis and monitoring; as well as distant learning. [1]
Teleophthalmology (also known as tele-retina) offers several advantages. It eliminates the need for patients to travel to major medical centers or endure long wait times for specialist appointments. Instead, trained technicians or nurses can acquire eye images, typically fundus photographs and optical coherence tomography (OCT) scans, and transmit them securely online to ophthalmologists for review. This allows for efficient triage, identifying patients requiring in-person examinations and determining the urgency of their needs. Teleophthalmology provides a cost-effective diagnostic method, particularly beneficial in reaching remote populations and screening individuals at higher risk of eye diseases, such as those with diabetes [2] .
Although ocular photography has been present since the early 1980s, the transfer of digital images from one location to another for assessment is a relatively recent phenomenon. The rise of digital imaging in the early 1990s allowed ophthalmologists and optometrists to capture images and store them on computers for future assessment. The advent of the Internet allowed for the digital transfer of these ocular images from one location to another.
Current teleophthalmological solutions are generally focused on a particular eye problem, such as diabetic retinopathy, [3] retinopathy of prematurity, [4] macular degeneration, strabismus [5] and adnexal eye diseases. [6] Less common conditions that can be revealed using retinal images are arterial and vein occlusions, chorioretinitis, congenital anomalies, and tapetoretinal abitrophy. Several population-based studies have used retinal imaging to relate ophthalmic abnormalities to general conditions, including hypertension, renal dysfunction, cardiovascular mortality, subclinical and clinical stroke, and cognitive impairment. [7]
Mobile applications are widely available in ophthalmology and optometry as tools for eye tests (visual acuity, colour test, and viewing eye images) and for educational purposes. [8] Technological advancements in digital ocular imaging devices are perceived by many as key drivers for teleophthalmology. Recently, emerging retinal imaging modalities such as optical coherence tomography are capable of producing digital images of the retina with a micrometer resolution, which can be transmitted for research or diagnostic purposes. Along with systems designed for health care professionals, patient-centred systems such as Eye-File Archived 2022-03-14 at the Wayback Machine for use by the general public are emerging.
Fundus photography is performed by a fundus camera, [9] which basically consists of a specialized low power microscope with an attached camera.
Teleophthalmology services can be provided primarily in two ways synchronously or asynchronously:
Images of the eye can be captured non-invasively through various methods, generally by a technician or non-physician health care professional.
Mydriasis (pupil dilation, e.g. using tropicamide) may be required to obtain an image of sufficient quality. [11] Stereoscopy may be used to detect retinal thickening. [12] The image can then be transferred, over the Internet or dedicated network to a physician for immediate examination, or for storage and later review. Ideally, the image is encrypted or anonymized for transmission, to protect patient confidentiality. Between image capture and viewing, image processing may be done, including compression, enhancement and edge-detection. [13] Image evaluation, to detect various pathologies in the case of asynchronous evaluation, is often done by an ophthalmologist, optometrist or primary care physician, though it is also performed by specially trained staff. [14] Image evaluation may also be automated to provide pathology detection or grading.
Computer software applications have been tasked with the automated assessment of retinal images to recognize lesions associated with an ocular disease of interest. [15] The clinical process entails initially discriminating retinal lesions from non-factor artifacts, subsequently distinguishing lesions associated with the disease in question from other types of lesions, and finally grading the disease according to guideline-endorsed severity scales set by medical authorities.
Dedicated research in artificial intelligence drives the underlying technology in automated image recognition. Specific approaches involve pattern recognition using trained artificial neural networks; feature extraction using edge-detection and region-growing techniques; and content-based comparison with previously adjudicated samples. [16] [17]
A 100-case audit of retinal screening by optometrists was performed in the remote areas of Western Australia. Projects are now being started base on this pilot experience.
A number of teleophthalmology programs exist in Canada, including those in the provinces of Alberta, British Columbia, Manitoba, Newfoundland, Ontario, and Quebec. [3]
The cost of taking the images and of the ophthalmologist to interpret the images is covered by public-funded health care insurance. Typically a registered nurse or registered practical nurse is trained to dilate the patient's pupils and take the images.
Key challenges to providing teleophthalmology services in Canada are likely: 1) the high staff turnover in remote areas; 2) the lack of an inexpensive mobile imaging device that takes diagnostic quality images; and 3) the difficulty securing public funds where the costs are incurred and savings are realized from separate funding envelopes.
Teleophthalmology has been provided in Alberta since 2003, and is supported by Alberta Health Services, using their proprietary teleophthalmology software Secure Diagnostic Imaging. Approximately six ophthalmologists from the University of Alberta review the images. As of January 2014, approximately 15,000 patients had been screened for diabetic retinopathy, across 15 community-hospital-based stationary locations, 44 First Nations communities and five primary care practices. Approximately 130 patients are screened per month across these locations. The teleophthalmology program also facilitates approximately 55 optometrist-to-ophthalmologist referrals per month.
Teleophthalmology is provided by ophthalmologists from the University of British Columbia, and is supported by Alberta Health Service's proprietary Secure Diagnostic Imaging [ permanent dead link ] software.
In Manitoba, teleophthalmology is provided by ophthalmologists at the University of Manitoba, and is supported using Alberta Health Service's proprietary Secure Diagnostic Imaging [ permanent dead link ] software.
A teleophthalmology program was started in the Eastern Health Region of Newfoundland, under one of four regional health authorities. This program was started in May 2012 and is supported by an ophthalmologist in St. John's. The program uses Synergy software by TopCon Canada Inc.
Thirteen teleophthalmology programs currently exist in Ontario. Two of the programs facilitate ophthalmology support for premature infants, screening for retinopathy of prematurity (RoP), using ophthalmologists at Sick Kids and McMaster University Medical Centre.
The other eleven of these teleophthalmology programs primarily screen for diabetic retinopathy in diabetic patients who have limited access to eye care professionals, or who for various reasons do not seek regular eye care. Ten of these eleven programs use the Ontario Telemedicine Network teleophthalmology (TOP) service to transmit images to an ophthalmologist for evaluation. OTN uses Merge Healthcare teleophthalmology software to provide this service. Some of these locations use a fundus camera, others use both fundus and optical coherence tomography (OCT) imaging devices, and all programs dilate their patients' eyes before screening. Since 2009, and as of January 2014, more than 4600 diabetic patients have been screened, finding pathology in approximately 25-35% of screens. Approximately 120 patients are screened per month, by five reading ophthalmologists.
In Ontario, the implementation of teleophthalmology has reduced the average wait time from six months to four weeks, for some diabetic patients to obtain retinal screening from a specialist. [19]
There are a number of teleophthalmology programs in Quebec, following on a feasibility study completed by the institut national d'excellence en santé et en service sociaux, entitled Dépistage de la rétinopathie diabétique au Québec Archived 2014-02-27 at archive.today .
Between 2006 and 2008, a large scale teleretinal screening project using mobile units was implemented in China. [20]
The OPHDIAT Network supports diabetic retinal screening across 34 sites and has screened over 13,000 patients since 2004. [21]
The teleophthalmology program provided in Chennai, India by Sankara Nethralaya has reached more than 450,000 patients since its inception in October, 2003.
The Karnataka Internet Assisted Diagnosis of Retinopathy of Prematurity (KIDROP) program, started in 2008, uses teleophthalmology to screen for retinopathy of prematurity. They are India's first, and the world's largest, program of this kind. [22] They have performed more than 6339 imaging sessions of 1601 infants in rural and remote areas, preventing blindness and finding that non-physician experts can be trained to accurately grade the images. [23]
In 2011, the Health Service Executive announced the development of a diabetic retinopathy screening programme. The Diabetic RetinaScreen programme was rolled out in 2013. [24]
The PEEK (Portable Eye Examination Kit) program has screened 2500 people in Kenya, and incorporates geo-tagging to facilitate follow-up treatment and demographic research. [25]
Since 2001, more than 30,000 people with diabetes have been screened since 2001 as part of a project called EyeCheck [26] in the Netherlands.
In the United Kingdom, more than 1.7 million people with diabetes were screened using digital fundus photography in 2010 and 2011. [27] A pilot project with telemedicine transmission of retinal OCT images from community optometry care to hospital eye services improved the triage of macular patients and swifter care of urgent cases. The project was led by Consultant Ophthalmologist Simon P Kelly, Royal Bolton Hospital and Ian Wallwork, Optometrist, and undertaken in Salford. The project was recognized in an award from the Clinical Leaders Network. [28] [29] In Scotland, NHS Forth Valley has introduced teleophthalmology in standard practice, to link ophthalmologists and emergency services. The technology has been developed in collaboration with the University of Strathclyde, and is currently being piloted in other Scottish health boards. [30]
The United States Department of Veterans Health Affairs was one of the first organizations to deploy a large-scale teleretinal imaging program starting in 1999. In 2006, this program was expanded and received further funding for a nationwide program. As of 2010, more than 120,000 patients have been screened through the program. [31]
Teleophthalmology relies on a standard for the representation, storage, and transmission of medical images known as Digital Imaging and Communications in Medicine (DICOM). The medical imaging standard is managed by the Medical Imaging & Technology Alliance (MITA), which is a division of the Virginia-based National Electrical Manufacturers Association (NEMA).
Various regulations exist on national levels that govern the use of teleophthalmological solutions. Some of them are listed below:
Emerging techniques for eye image capture include ophthalmoscopes that can be combined with mobile devices, increasing portability and accessibility to the general public. The introduction of full auto focusing retinal cameras has the potential to reduce the need for operators.
Telehealth networks are growing in number, and advancements are being made in automated detection methods for diseases such as diabetic retinopathy. Teleophthalmology has the potential to improve access to screening and early treatment for a number of ocular conditions. It serves to identify patients who are at risk of various types of retinopathy and allows further evaluation and early management resulting in considerable economic benefit. [32]
A recent Cochrane review notes that no randomized controlled trials or controlled clinical trials have been published evaluating whether there are any benefits or harms to telerehabilitation, over inpatient care for improving vision outcomes. [33] The authors note that the lack of published research in teleopthalmology may compromise possible funding or support for these services. [33]
Despite ongoing research and advancement in digital photography, digital imaging techniques still face certain barriers, including low sensitivity and specificity, [34] as well as lack of stereopsis (impression of depth). [12] As such, teleophthalmology cannot be a true substitute for comprehensive eye examinations using traditional binocular observation with standard 7-field stereoscopic fundus photography.
Automated image recognition algorithms are gaining in clinical adoption. While they perform at a level nearly equivalent to humans in ascertaining low and high risk states, diagnosis and grading performance is still insufficient for clinical acceptance. [15]
Ophthalmology is a clinical and surgical specialty within medicine that deals with the diagnosis and treatment of eye disorders. A former term is oculism.
Retinopathy is any damage to the retina of the eyes, which may cause vision impairment. Retinopathy often refers to retinal vascular disease, or damage to the retina caused by abnormal blood flow. Age-related macular degeneration is technically included under the umbrella term retinopathy but is often discussed as a separate entity. Retinopathy, or retinal vascular disease, can be broadly categorized into proliferative and non-proliferative types. Frequently, retinopathy is an ocular manifestation of systemic disease as seen in diabetes or hypertension. Diabetes is the most common cause of retinopathy in the U.S. as of 2008. Diabetic retinopathy is the leading cause of blindness in working-aged people. It accounts for about 5% of blindness worldwide and is designated a priority eye disease by the World Health Organization.
Diabetic retinopathy, is a medical condition in which damage occurs to the retina due to diabetes. It is a leading cause of blindness in developed countries and one of the lead causes of sight loss in the world, even though there are many new therapies and improved treatments for helping people live with diabetes.
The National Eye Institute (NEI) is part of the U.S. National Institutes of Health (NIH), an agency of the U.S. Department of Health and Human Services. The mission of NEI is "to eliminate vision loss and improve quality of life through vision research." NEI consists of two major branches for research: an extramural branch that funds studies outside NIH and an intramural branch that funds research on the NIH campus in Bethesda, Maryland. Most of the NEI budget funds extramural research.
Orthoptics is a profession allied to the eye care profession. Orthoptists are the experts in diagnosing and treating defects in eye movements and problems with how the eyes work together, called binocular vision. These can be caused by issues with the muscles around the eyes or defects in the nerves enabling the brain to communicate with the eyes. Orthoptists are responsible for the diagnosis and non-surgical management of strabismus (cross-eyed), amblyopia and eye movement disorders. The word orthoptics comes from the Greek words ὀρθός orthos, "straight" and ὀπτικός optikοs, "relating to sight" and much of the practice of orthoptists concerns disorders of binocular vision and defects of eye movement. Orthoptists are trained professionals who specialize in orthoptic treatment, such as eye patches, eye exercises, prisms or glasses. They commonly work with paediatric patients and also adult patients with neurological conditions such as stroke, brain tumours or multiple sclerosis. With specific training, in some countries orthoptists may be involved in monitoring of some forms of eye disease, such as glaucoma, cataract screening and diabetic retinopathy.
Fluorescein angiography (FA), fluorescent angiography (FAG), or fundus fluorescein angiography (FFA) is a technique for examining the circulation of the retina and choroid using a fluorescent dye and a specialized camera. Sodium fluorescein is added into the systemic circulation, the retina is illuminated with blue-green light at a wavelength of 490 nanometers, and an angiogram is obtained by photographing the fluorescent green light that is emitted by the dye. The fluorescein is administered intravenously in intravenous fluorescein angiography (IVFA) and orally in oral fluorescein angiography (OFA). The test is a dye tracing method.
The optic disc or optic nerve head is the point of exit for ganglion cell axons leaving the eye. Because there are no rods or cones overlying the optic disc, it corresponds to a small blind spot in each eye.
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope. It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor.
Retinal hemorrhage is a disorder of the eye in which bleeding occurs in the retina, the light sensitive tissue, located on the back wall of the eye. There are photoreceptor cells in the retina called rods and cones, which transduce light energy into nerve signals that can be processed by the brain to form visual images. Retinal hemorrhage is strongly associated with child abuse in infants and young children and often leaves such abused infants permanently blind. In older children and adults, retinal hemorrhage can be caused by several medical conditions such as hypertension, retinal vein occlusion, anemia, leukemia or diabetes.
Electroretinography measures the electrical responses of various cell types in the retina, including the photoreceptors, inner retinal cells, and the ganglion cells. Electrodes are placed on the surface of the cornea or on the skin beneath the eye to measure retinal responses. Retinal pigment epithelium (RPE) responses are measured with an EOG test with skin-contact electrodes placed near the canthi. During a recording, the patient's eyes are exposed to standardized stimuli and the resulting signal is displayed showing the time course of the signal's amplitude (voltage). Signals are very small, and typically are measured in microvolts or nanovolts. The ERG is composed of electrical potentials contributed by different cell types within the retina, and the stimulus conditions can elicit stronger response from certain components.
An eye care professional is an individual who provides a service related to the eyes or vision. It is any healthcare worker involved in eye care, from one with a small amount of post-secondary training to practitioners with a doctoral level of education.
Progressive outer retinal necrosis (PORN) syndrome is a form of chorioretinitis, an infection in the retina, the back of the eye. The disease is most commonly caused by the varicella zoster virus and is found almost exclusively in patients with HIV/AIDS. Progressive outer retinal necrosis is the second most common opportunistic retinal infection in North America among people with AIDS. The reason this disease process is considered opportunistic is precisely because it only presents in patients with AIDS, a disease that attacks and weakens the immune system, making space for other infections, like Varicella zoster virus (VZV) and Herpes simplex virus (HSV), to attack the body.
Dilated fundus examination (DFE) is a diagnostic procedure that uses mydriatic eye drops to dilate or enlarge the pupil in order to obtain a better view of the fundus of the eye. Once the pupil is dilated, examiners use ophthalmoscopy to view the eye's interior, which makes it easier to assess the retina, optic nerve head, blood vessels, and other important features. DFE has been found to be a more effective method for evaluating eye health when compared to non-dilated examination, and is the best method of evaluating structures behind the iris. It is frequently performed by ophthalmologists and optometrists as part of an eye examination.
Fundus photography involves photographing the rear of an eye, also known as the fundus. Specialized fundus cameras consisting of an intricate microscope attached to a flash enabled camera are used in fundus photography. The main structures that can be visualized on a fundus photo are the central and peripheral retina, optic disc and macula. Fundus photography can be performed with colored filters, or with specialized dyes including fluorescein and indocyanine green.
Bascom Palmer Eye Institute is the University of Miami School of Medicine's ophthalmic care, research, and education center. The institute is based in the Health District of Miami, Florida, and has been ranked consistently as the best eye hospital and vision research center in the nation.
Chloroquine retinopathy is a form of toxic retinopathy caused by the drugs chloroquine or hydroxychloroquine, which are sometimes used in the treatment of autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus. This eye toxicity limits long-term use of the drugs.
Michael David Abràmoff is an American neuroscientist, ophthalmologist, vitreoretinal surgeon, computer engineer, and entrepreneur. He is the Watzke Professor of Ophthalmology and Visual Sciences at the Roy J. and Lucille A. Carver College of Medicine at the University of Iowa.
Noemi Lois is a Clinical Professor of Ophthalmology at Queen's University Belfast and an Honorary Consultant Ophthalmologist and Vitreoretinal Surgeon at the Belfast Health and Social Care Trust.
Sickle cell retinopathy can be defined as retinal changes due to blood vessel damage in the eye of a person with a background of sickle cell disease. It can likely progress to loss of vision in late stages due to vitreous hemorrhage or retinal detachment. Sickle cell disease is a structural red blood cell disorder leading to consequences in multiple systems. It is characterized by chronic red blood cell destruction, vascular injury, and tissue ischemia causing damage to the brain, eyes, heart, lungs, kidneys, spleen, and musculoskeletal system.
AEYE Health is an American technology company specializing in artificial intelligence-based diagnostics for retinal imaging. The company has offices in New York and Tel Aviv.