Abstract
E-ophthalmology can be defined as the use of information and telecommunications technologies (ICT) to provide or support a group of activities related to ophthalmic care. E-ophthalmology-based models of assistance can be useful resources to compensate for the increased demand for medical care foreseeable in the near future due to aging of the population and lack of medical specialists. The authors present in detail the models proposed for three important health problems in ophthalmology as screening for diabetic retinopathy and follow-up of glaucoma and age-related macular degeneration (AMD). Furthermore, the main advantages of these models and the technologic requirements needed for their implementation are described. Finally, future trends in e-ophthalmology are also addressed.
TopCurrent Status
eOphthalmology can be defined as the use of information and communication technology to provide or support a diverse group of activities related to ophthalmic care (Kumar, 2005). eOphthalmology can cover different areas of medical practice such as diagnosis of disease, treatment, prevention, education, and research. eOphthalmology makes medical practice more independent of time and place, allows specialists to better organize their time, and medical services to become more accessible to patients.
The implementation of systems of eOphthalmology requires peripheral equipment to capture, store, and transmit information and images, electronic medical records to manage the results, and protocols to organize medical attention (Tang, 2005). eOphthalmology can be applied to screening of diabetic retinopathy, examination of the anterior segment of the eye, screening for glaucoma, consultations for poor vision, or even to provide support from a remote location during surgery. These systems can be used in real time, for example, during surgery or in a store-and-forward mode, as in the case of screening for diabetic retinopathy. The use of the system in real time is more expensive, requiring more sophisticated technology and a greater bandwidth to transmit information.
Key Terms in this Chapter
Optic Disc: This is the point at which the optic nerve enters the eye passing through the sclerotic membrane, the choroid layer, and finally the retina. The optic disc, a red disc found in the posterior of the eye, has a mean diameter between 2 x 1.5 mm. There are no photoreceptors in the optic disc, and for this reason it is also known as the blind spot.
Nonmydriatic Retinography: This is a diagnostic tool used to obtain digital photographs of the retina (retinographies) without dilation of the pupils (mydriasis). This technique is used mainly in screening for diabetic retinopathy
Picture Archiving and Communication Systems (PACS): This system manages storage, access, distribution, interpretation, and representation of image files. Normally, PACS work closely with the DICOM format.
eOphthalmology: This term refers to the use of information and communications technology to provide or support activities related to ophthalmology, such as diagnosis, treatments, prevention, education, and research.
Chronic Glaucoma: This is a chronic optic neuropathy in adults in whom IOP and other currently unknown factors contribute to damage and in which there is a characteristic acquired atrophy of the optic nerve and loss of retinal ganglion cells and axons. This is associated with an anterior chamber angle that is open by gonioscopic vision.
Optical Coherence Tomography (OCT): This is a non-invasive technique used to image intraocular tissues by measuring the echo time delay and intensity of back-reflected light. The resulting image provides high-resolution, cross-sectional representation of structure with near-histological detail.
Age-Related Macular Degeneration (AMD): Even though there is no universally accepted definition, AMD can be defined as a condition characterized by alterations of the retinal pigment epithelium (the outer retinal layer), drusen (yellow excrescences at the level of the basement membrane of the retinal pigment epithelium), and fundus abnormalities associated with the development of choroidal neovascularisation (new vessels originating from the choroid that spread under the retina). AMD generally occurs in persons over 65 years old in whom the VA may vary from normal to severely impair.
Digital Imaging and Communication in Medicine (DICOM): This is the standard recognized worldwide for the exchange and management of medical images between equipment from different manufacturers.
Ophthalmologic Information System (OIS): This system helps manage patients in ophthalmology practice. The principal services rendered are follow-up of patients and scheduling appointments.
Digital Image Processing: The application of mathematical algorithms to digital images is of great interest in improving the quality and detection of edge, segmentation, recognition of patterns, and classification. Digital imaging processing definitively shows the possibility of developing tools that help in diagnosis and complement the studies carried out by medical specialists.
Diabetic retinopathy: This is a disorder of the retinal vasculature that eventually develops to some degree in nearly all patients with long-standing diabetes mellitus. Early clinical manifestations of retinopathy include microaneurysms, haemorrhages, retinal capillary no perfusion, cotton-wool spots, and intraretinal micro vascular abnormalities. Finally, increasing no perfusion can lead to closure of retinal vessels and pathologic proliferation of retinal vessels and increased vasopermeability resulting in retinal thickening (edema). Visual loss occurs as a result of macular edema, macular capillary no perfusion, vitreous haemorrhage, and retinal distortion or traction detachment.
Visual Field: This is the space that the eye captures when looking at a fixed point. To carry out an examination of the visual field, the patient sits before a concave screen and gazes at a centrally placed object. A computer program emits small lights of variable intensity at different sites of the screen and the patient presses a button as soon as the light is perceived. The patient responses are compared to a control group of subjects of equivalent age to determine the presence of visual field defects.