Article

Tele-glaucoma: The Next Frontier

How this technology can help improve care for many patients

Web-based communication, data analysis filters, wearable technology, and artificial intelligence are all being applied in telemedicine. Tele-glaucoma is an integral part of tele-ophthalmology and, perhaps, one of its most challenging fields, because glaucoma may not lend itself as well as other eye diseases, such as cataract and diabetic retinopathy, to telemedicine. Glaucoma is often slow and elusive, requiring both structural and functional testing. We know that IOP, which is widely investigated and used for screening, is not optimal for screening or detection.

Although telemedicine has evolved in various disciplines over the past two decades, the advances in tele-glaucoma have not been as clearly visible. As a comparator, the American Telemedicine Association has a landmark publication delineating standards for telemedicine for diabetic retinopathy.1 The VA healthcare system also applies tele-ophthalmology to screening and referring diabetic patients. Due to the complexities of detecting glaucoma, tele-glaucoma doesn’t have similar current standards, such as those in place for diabetic eye disease. Establishing standards for tele-glaucoma are necessary for the field to evolve and improve.

Validating and Comparing Tele-glaucoma to Standard of Care

Perhaps the first step toward establishing standards is to validate tele-glaucoma models. In a systematic review,2 tele-glaucoma was found to accurately discriminate between screening test results with greater odds for positive cases. In that review, tele-glaucoma detected more cases of glaucoma than an in-person examination. The advantages included early detection, reduction in wait and travel time for patients, improved specialist referral rates, and possible cost savings, specifically for remote and underserved communities.2

The Philadelphia Telemedicine Glaucoma Detection and Follow-up Study3 examined a protocol for detection of vision-threatening diseases, including glaucoma. The NJ Health Foundation Tele-Glaucoma Study is an ongoing trial that compares tele-glaucoma to standard of care clinical evaluation.4 It includes more than 100 subjects with confirmed glaucoma who were evaluated through a tele-glaucoma protocol and then underwent a comprehensive clinical glaucoma evaluation. The outcomes were highly correlated for several clinical measures, including IOP and optic nerve examination, as well as for diagnostic accuracy and treatment recommendations.

It was evident from the NJ tele-glaucoma study that OCT was an essential diagnostic tool. The versatility of OCT was apparent in the ability to acquire useful data, even when media opacity precluded quality imaging and limited the clinical exam (Figure 1).

Figure 1. Using tele-glaucoma, OCT can acquire data even when digital imaging is hindered by media opacity.

Another lesson learned from the study was the power of combining multiple imaging tools to improve the diagnostic capabilities of tele-glaucoma. It is known that splinter hemorrhages are less likely to be missed on an optic nerve image than on clinical exam. This was noted with the NJ tele-glaucoma study, in which imaging picked up subtle hemorrhages, wedge retinal nerve fiber layer defects, and posterior segment pathology that were sometimes missed during clinical evaluation. Of course, clinical evaluation remains the standard of care and was superior in confirming or precluding pathology that was detected during tele-glaucoma (higher false positive rates on optic nerve and angle assessment with OCT). Media opacity also significantly affects tele-glaucoma fundus imaging through smaller pupils and in patients with cataracts, whereas slit lamp biomicroscopy is less hindered by those barriers.

Tele-presence and Tele-glaucoma

It is also known that patients would often fail to return for an eye evaluation after being identified during screening. This perhaps remains one of the most significant shortcomings of community screening for glaucoma and other diseases.

Tele-presence allows subjects to be screened while a remotely placed physician has access to the individual’s data through a secure web connection or other cloud-based solution. Tele-presence has the potential to be performed through an efficient capture-and-forward technology, or more effectively through live, real-time streaming. This reduces the need for the subject to come in for an appointment.

Tele-presence can be applied to glaucoma and other vision-threatening diseases and may rectify the issue of individuals having limited access to eye care. With tele-presence, patients can have their ocular data and images analyzed remotely by a trained ophthalmologist. This can be vital for diseases, such as glaucoma, where up to half of the population with the vision-threatening disease may not be aware of their condition.

Software Solutions and Artificial Intelligence

Digital images can be separated into components to enhance the appearance of pathology and improve detection. For example, red, green, blue separation is a well-recognized technique that has the ability to enhance the appearance of the retinal layer. Particularly, the blue and green wavelength channels can enhance pathology in the retina and nerve fiber layer, which can prove invaluable for detection of retinal nerve fiber layer (RNFL) defects.

Splinter hemorrhages tend to appear with enhanced clarity on green channels, even when very subtle on a color image. Red channels are optimal for deeper pathology, such as AMD. Embossing techniques highlight pixel coordinates and can be applied to digital images to enhance RNFL defects (and the elevations/depressions in the retina that are seen in diabetic retinopathy and macular degeneration).

All of these software enhancements can make pathology more readily visible and correlate well with OCT findings (Figure 2). Although, as glaucoma physicians, we may be more focused on glaucoma detection, any tele-medicine protocol will have to optimize detection of various vision-threatening diseases (e.g., macular degeneration and diabetic retinopathy).

Figure 2. Digital filters during tele-glaucoma enhance retinal nerve fiber layer defect that is detected on OCT (A: Color image, B: Blue channel, C: Emboss filter, D: OCT RNFL defect, E: OCT posterior pole ganglion cell loss).

Most recently, artificial intelligence (AI) has had various novel applications in medicine. Computers can gather information and analyze it to emulate the decision-making processes of human cognition.

The integration and analysis of a large database can be used to enhance and streamline patterns of detection. There are AI applications that assist in analyzing optic nerve appearance as well as retinal pathology. Such technology will undoubtedly continue to evolve in the coming years. The application of AI and big data in tele-glaucoma is promising, and research in this area will shed light on its role, as well as its limitations.

Current Applications in Community Outreach and Education

Tele-glaucoma can be applied to allow patients access to care that would otherwise not be available. For example, tele-glaucoma programs that provide remote specialized care already exist in Canada and Australia.5

The community outreach program at New Jersey Medical School employs tele-glaucoma to provide access to specialized ophthalmology to subjects in homeless shelters, soup kitchens, and community centers in New Jersey. This program also provides medical students with an excellent opportunity to serve the community while gaining exposure to technology. Translational research opportunities for students, residents, and faculty help bridge the gap in the literature on existing tele-glaucoma standards for protocols and practice.

Tele-glaucoma for consultation also can be applied across healthcare networks, particularly in the emergency room setting where the need surely exists. Other applications in education and training can be used to provide feedback to physicians in training. The impact on quality of training and patient care can be significant.

Evolving Technology

Tele-glaucoma as a field lends itself very well to the advances in hardware, software, and digital tele-communication. The applications of tele-glaucoma within healthcare, research, and education will undoubtedly continue to evolve. A collaborative effort by various societies will help set the standards that are needed for tele-glaucoma. GP

References

  1. Cavallerano J, Lawrence MG, Zimmer-Galler I, et al. Telehealth practice recommendations for diabetic retinopathy. Telemed J E Health. 2004;10(4):469-482.
  2. Thomas SM, Jeyaraman MM, Hodge WG, Hutnik C, Costella J, Malvankar-Mehta MS. The effectiveness of teleglaucoma versus in-patient examination for glaucoma screening: A systematic review and meta-analysis. PLoS One. 2014;9(12):e113779.
  3. Hark LA, Katz LJ, Myers JS, et al. Philadelphia telemedicine glaucoma detection and follow-up study: Methods and screening results. Am J Ophthalmol. 2017;181:114-124.
  4. Mendez N, Kommana S, Szirth B, Khouri A. Glaucoma telemedicine versus conventional care: New Jersey Health Foundation prospective clinical trial. Paper presented during the AAO Annual Meeting; Oct. 16-18, 2016; Chicago, IL.
  5. Kassam F, Yogesan K, Sogbesan E, Pasquale LR, Damji KF. Teleglaucoma: improving access and efficiency for glaucoma care. Middle East Afr J Ophthalmol. 2013;20(2):142-149.