Telemedicine in ophthalmology - Wiley Online Library

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Technical problems have not been significant, but many open questions ... specialists, or between ophthalmological .... computer vision algorithms may provide.
ACTA OPHTHALMOLOGICA SCANDINAVICA 2003

Review Article Telemedicine in ophthalmology Heikki Lamminen,1,2 Ville Voipio,3 Keijo Ruohonen4 and Hannu Uusitalo5 1

Department of Ophthalmology, Tampere University Hospital, Finland Primary Health Care Centre, Ikaalinen, Finland 3 Novametor Oy, Helsinki, Finland 4 Department of Mathematics, Tampere University of Technology, Finland 5 Department of Ophthalmology Kuopio University Hospital, University of Kuopio, Finland 2

ABSTRACT. Objectives: To give an overview of telemedical applications in ophthalmology and to provide background information on new tele-ophthalmological applications. Methods: We carried out a literature review, a database search and an Internet search. Results: According to published research, the cost-efficiency of telemedicine in ophthalmology has not been established. It has been found to have educational benefits and patients have been satisfied with the possibility of obtaining specialist care without having to travel. Conclusions: Most studies have been pilot studies and telemedicine is still seldom the primary mode of operation. Technical problems have not been significant, but many open questions about organizational and operational issues remain. Further studies should be directed towards solving these problems and establishing technical standards. Key words: telemedicine – tele-ophthalmology

Acta Ophthalmol. Scand. 2003: 81: 105–109 Copyright # Acta Ophthalmol Scand 2003. ISSN 1395-3907

Introduction Telemedicine is regarded as a way of delivering health care and exchanging health information across distances. It covers all medical activities, including making diagnoses, treatment, prevention, education and research. It makes the practice of medicine independent of location or time. One important facility of telemedicine is its ability to expand the range of medical services available to remote locations. Telemedicine is not actually a separate field of medicine, but rather a new tool in medicine.

The health care system in industrialized countries faces several new challenges. Ageing populations need more health care services and their medical care is more demanding. The development of medical technology sets new requirements for the personnel involved. New technology may also be more expensive to acquire and use. These factors mean that the cost of health care is increasing. Telemedicine has been regarded as one solution by which necessary health care services can be provided to everybody at a reasonable cost. However, it should

remembered that it is useful only if it either improves the quality of treatment or decreases costs without compromising quality of treatment. Economic savings alone do not provide an acceptable justification for the use of telemedicine if the quality of the health care provided deteriorates. When economic evaluations of telemedicine are being carried out, all economic parameters, including indirect effects, should ideally be taken into consideration. A large proportion of the financial savings associated with telemedicine are not necessarily directly visible in the health care system itself; significant economic impact may be made by, for example, savings in time and travel expenses, thereby contributing to society only indirectly. For the past 30 years the development of telemedicine has in general followed closely behind that of general informatics. New communication technology, such as cellular phones and the Internet, tends to be adopted quickly by consumers. According to Moore’s Law, semiconductor capacity doubles every 18 months. The capacity of fibre optic communication channels increases even faster, with some estimates claiming a 6-monthly doubling pace. This allows for very fast technology development with low equipment costs. Thus the main obstacles in adopting telemedicine seem to be organizational rather than technological. In a broad sense, even a telephone discussion can be regarded as a

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ACTA OPHTHALMOLOGICA SCANDINAVICA 2003 teleconsultation. However, this article focuses on digital visual teleconsultation. There are essentially two different approaches to the visual teleconsultation. Videoteleconferencing (VTC) employs a two-way real time video connection offering a real time consultation. Storeand-forward (SF) teleconsultation is a somewhat lighter solution. The data is first captured and then sent forward as an email attachment. Both these methods have become more widely available in recent years, as the advent of video and mobile technology has opened new possibilities for real time telemedicine. Moreover, inexpensive and high quality digital camera technology, along with the Internet, has made SF teleconsultation available to virtually everyone at very low cost. However, the use of a public network requires additional security measures, necessitating special attention.

camera that allows for still photography is sufficient. On the other hand, eye examinations leading to more complicated diagnoses such as iridocyclitis require specialized instruments and personnel who are trained to use them. These factors limit the applicability of sophisticated tele-ophthalmology to a certain extent. Based on our own experience (Lamminen et al. 1999, 2001), videoconsultations using standard low cost equipment can be used in consultations between primary health care personnel and specialists. This type of consultation provides a reliable method of fulfilling the needs of GPs and can improve their diagnostic accuracy (Lamminen et al. 1999, 2001). However, clinical decision making is never 100% accurate, and it must be borne in mind that teleconsultation cannot surpass face-to-face examination in terms of accuracy.

Tele-ophthalmology The importance of visual information in ophthalmology makes it obvious that telemedicine, with its facility to transmit live or still pictures, will offer benefits in terms of ophthalmological consultations. Tele-ophthalmology can be practised, for example, between primary health care practitioners and specialists, or between ophthalmological units, either in real time through videoconferencing or as SF by email, depending on the needs of the users. Telemedicine is especially suitable for diagnosing and treating eye diseases, as ophthalmologists are well versed in making diagnoses, prescribing therapy and designing treatment plans on the basis of visual information obtained from the eyes of patients. For the purposes of tele-ophthalmology, it is also important that examination and diagnosis of the most common eye diseases seen in general practice does not require specialized equipment. According to Sheldrick et al. (1993), the most common conditions presenting in general practice are infective and allergic conjunctivitis, dry eyes, cataract, blepharitis and chalazion. The diagnoses most often confused by general practitioners (GPs) all concerned external eye diseases, for which diagnosis requires no specialized diagnostic equipment. Thus, tele-ophthlamological equipment requirements are relatively modest. In most cases, a digital video

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Research projects in teleophthalmology There have been several research projects in tele-ophthalmology in Europe. The OPHTEL project used SF email systems and real time videoconferencing for collaborative ophthalmology consultations in diabetes (Mertz et al. 1997) Based on the results and experiences of the OPHTEL project, a new project, Tele-Ophthalmological ServicesCitizen-Centred Application (TOSCA), was started. TOSCA aims to reduce the incidence of blindness caused by diabetic retinopathy and glaucoma. The EUREKA project involved visual electrodiagnosis and transmission of colour fundus photographs, pictures of fluorescein angiography, video clips permitting assessment of eye position and mobility, and videoconference facilities for live discussion between experts in cases of diagnostic ambiguity (Papakostopoulos et al. 1997). Slit-lamp studies

In the early 1990s, digital slit-lamp images were transferred between optometrists and remote ophthalmologists (Garden et al. 1990, 1991). More recently, patients have been examined by trained ophthalmic nurses on the first postoperative day after cataract, trabeculectomy and combined proce-

dures and consulted by using video slit-lamp images (Murdoch et al. 2000). Real time slit-lamp images obtained through integrated services digital network (ISDN) lines (at 384 kilobits per second) have offered sufficiently satisfactory visual resolution of the ocular surface for the diagnosis and follow-up of ocular surface and corneal disease (Shimmura et al. 1998). Although the studies concerning slit-lamp image transfer are as yet limited, they show the potential of telemedical consultations for many purposes (Pickard 1998; Shanit et al. 1998; Hariprasad et al. 1999). However, the slit-lamp is slightly more complicated to use than standard video consultation equipment and thus requires trained personnel. Fundus imaging and screening studies

Fundus imaging has its roots in space technology; NASA began remote monitoring of astronauts in the early 1960s (Link 1965). Interestingly, in 1987 retinal vessels were monitored during space flights using a new digital fluorescein angiography system (Feldman 1987; Hunter et al. 1993). The importance of screening for diabetic retinopathy has been established, but the best method of doing so has not yet been determined. Telescreening for diabetic retinopathy by an assessment of two-field, 50-degree, non-stereo digital images is a valid screening method. However, detection of clinically significant macular oedema by biomicroscopy is superior to that by digital or standard non-stereo photographs (Liesenfeld et al. 2000). Viewing digitally reconstructed photographic images of the retina on a video display caused doctors to lose confidence in their ability to make a diagnosis before they lost accuracy (Briggs et al. 1998). This loss of confidence has also been noted in other specialties, and serves as a safety factor in the process of the teleconsultation. Despite the small pupil cameras, dilating the pupils of patients over 55 years of age has positive effects on the quality of photographs in screenings (Heaven et al. 1993; Schachat et al. 1993). Constable et al. (2000) have elaborated on the potential of digital screening for eye diseases. Tele-ophthalmological consultations have also been performed in photorefractive surgery (Maldonado et al. 1997), corneal transplants (Shimmura

ACTA OPHTHALMOLOGICA SCANDINAVICA 2003 et al. 1998), macular diseases (Berger & Shin 1999), glaucoma (Tang et al. 1977; Beauregard et al. 2000), strabismus (Cheung et al. 2000; Jason et al. 2000) and diabetes (Klein et al. 1985; Yogesan et al. 2000). The possibility of making computer-assisted diagnoses by using computer vision algorithms may provide interesting alternatives (Garden et al. 1996; Williamson & Keating 1998; Madjarov & Berger 2000; Teng et al. 2002).

Economic aspects The main purpose of the healtheconomic analysis is to provide information on cost efficiency to decision makers. The principle challenges facing the economic evaluation of telemedicine concern constantly changing technology, the lack of appropriate study design to manage frequently inadequate sample sizes, the inappropriateness of conventional techniques of economic evaluation and the evaluation of health and non-health outcomes, such as length of waiting time, travel expenses, time to diagnosis, improved education and confirmation of diagnoses (i.e second opinions) (McIntosh & Cairns 1997). It is known that the costs of telemedicine are closely related to the number of patients concerned (Lobley 1997). The available literature leads us to conclude that it is premature for any statements to be made, whether positive or negative, regarding the cost effectiveness of telemedicine in general (Whitten et al. 2000). This does not indicate economic inefficiency, as telemedicine is already seen to be cost effective in certain circumstances (Lamminen et al. 2001).

Technical aspects The main choice to be made in terms of the technology used concerns that between SF and VTC systems. Storeand-forward systems are very lightweight and inexpensive to implement. They also enable the transfer of very high quality digital photographs because resolution is not limited by the communication medium. The number of pixels provided by a modern digital still camera is over 10 times that provided by a VTC system. However, SF systems are not well suited for

interactive communications that require real time discussion. Videoteleconferencing systems offer much more limited technology. This is not always a disadvantage, because using a telephone-based VTC system is similar to using an ordinary telephone, and is thus familiar to all participants. Moreover, using the telephone network resolves issues of data security. In the future, there will most likely be a move towards Internet-based VTC/ SF hybrid solutions where the videoteleconference is transmitted over the Internet. This will reduce costs significantly and allow for long distance conferences. However, the use of the Internet requires the resolution of several data security issues, because the Internet can be described as a hostile environment. In addition, the actual computer technology involved in this solution is more complicated, and thus requires a great deal of user education and technical support at the outset. All new telemedical systems should be based on open standards where applicable. This is important because today’s technology will be old tomorrow and obsolete the day afterwards. For example, if a camera system is built around a proprietary camera, replacing the camera with a better one will be very expensive. If, instead, standard components are used, replacing them is inexpensive. Using open and clearly defined interfaces between different components will also make upgrading and maintenance easier. It is a common misconception to think that proprietary systems are safer because they are not publicly known. In practice, a highly secure system has to be based on publicly known and verified security concepts rather than on what are often unsafe proprietary systems. The use of ordinary office equipment (digital cameras, desktop scanners, standard email facilities) should also be encouraged. These may not be reliable enough in critical applications, but the cost savings are very significant in non-emergency use. In addition, the technology used in office equipment is often more up-to-date than that used in proprietary equipment.

Conclusions At present, tele-ophthalmology already provides a real possibility for consulta-

tions either between GPs and ophthalmologists or between two or more ophthalmological units. The lessons learned so far indicate that the people involved in telemedicine must be aware of the technologies used (Jennett et al. 1995; Nitzkin et al. 1997). The benefits for medical staff in terms of skills acquisition and education are also evident. Tele-ophthalmology in primary care appears to be reliable and is likely to be valuable in rural areas, where the distance to an ophthalmologist can be a significant obstacle to satisfactory diagnosis and treatment (Blomdahl et al. 2001). Telemedicine can support the use of real time surgical telementoring to teach complex ophthalmological procedures (Camara & Rodriguez 1998). Tele-ophthalmology can provide secondary specialist advice in the diagnosis and treatment of difficult ophthalmology cases (Kennedy et al. 2001). Telemedical services must be understood as a complete process of medical care on the basis of modern communication technologies, a premise that influences the management of the process. Most telemedicine studies concentrate on the diagnostic accuracy of telemedicine. In this respect, there have been very few total failures. However, the economic evaluation of telemedicine is still very incomplete, and as the cost of technology is decreasing, all evaluations tend to be outdated by the time they are published. The same applies to technology, as almost all quantitative figures relating to IT or data communication quickly become obsolete. Data security represents another aspect of the process which is rather often overlooked. Few articles describe the actual steps taken to ensure data security. Whilst the achievement of a good level of data security is usually fairly straightforward, it requires a certain amount of IT and cryptography knowledge. Telemedicine has had and continues to have many promising applications. At present, it seems that the diagnostic accuracy and economic efficiency of telemedicine depend more on education of personnel and organizational strategy than on the technology itself. In the future, lightweight SF telemedical systems will be so inexpensive that almost all practitioners will have access to such systems. This will shift the emphasis

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ACTA OPHTHALMOLOGICA SCANDINAVICA 2003 more towards strategic decisions, as the cost of technology will become negligible in simple applications. On the other hand, high-end solutions will start to provide diagnostic aids by using sophisticated image processing. Ophthalmology will be one of the first fields to take advantage of this as retinal diseases are routinely diagnosed from standard retinal photographs. It seems evident that computerized diagnostic aids will come into routine use in almost all visual medical disciplines, as they help to remove interobserver variation in quantified parameters. These diagnostic systems will not replace specialists but they help in follow-up, screening and other routine work. (This has already happened to a certain extent in radiology, especially in mammography.) At present, there are very few established standards concerning teleophthalmology. There should be comprehensive standards on technical aspects as well as guidelines on good clinical practice. Such standards exist in radiology and could be used as models for their ophthalmic equivalents. Standards should not concentrate on actual technical performance figures, such as resolution, but on the process of tele-ophthalmology. An important aspect of this issue concerns the implementation of quality control in telemedical applications (Mertz et al. 1997).

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Received on September 9th, 2002. Accepted on December 9th, 2002. Correspondence: Heikki Lamminen Department of Ophthalmology Tampere University Hospital

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