The effectiveness of teleglaucoma versus in-patient examination for glaucoma screening: a systematic review and meta-analysis

Methodological quality of the review: High confidence

Authors: Thomas SM, Jeyaraman M, Hodge WG, Hutnik C, Costella J, Malvankar-Mehta MS

Region: Europe, Asia, Africa and USA

Sector: Glaucoma

Sub-sector: Screening

Equity focus: None specified

Review type: Other review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background:

Glaucoma is the leading cause of irreversible visual impairment in the world affecting 60.5 million people worldwide in 2010, which is expected to increase to approximately 79.6 million by 2020. Therefore, glaucoma screening is important to detect, diagnose, and treat patients at the earlier stages to prevent disease progression and vision loss. Teleglaucoma uses stereoscopic digital imaging to take ocular images, which are transmitted electronically to an ocular specialist.

Objectives:

The purpose is to synthesize literature to evaluate teleglaucoma, its diagnostic accuracy, healthcare system benefits, and cost-effectiveness.

Main findings:

The authors included a total of 45 studies. The results indicated that 17 articles were high quality, 13 were moderate quality, and 15 articles were graded as low quality of evidence. Despite the quality of evidence, all articles were included in the analysis. Seven studies each were conducted in the USA and Canada, three each in Germany, Spain and India, four in Australia and one each in Indonesia, Finland, Greece, Taiwan, Netherlands, New Zealand, Tasmania rural Africa and Alberta. One study did not report study location.

Their results indicated that teleglaucoma is more specific and less sensitive than in-person examination. The pooled estimate of sensitivity was 0.832 [95% CI 0.770, 0.881] and specificity was 0.790 [95% CI 0.668, 0.876]. The relative odds of a positive screen test in glaucoma cases are 18.7 times more likely than a negative screen test in a non-glaucoma cases. Additionally, the mean cost for every case of glaucoma detected was $1098.67 US and of teleglaucoma per patient screened was $922.77 US.

The authors concluded that teleglaucoma can accurately discriminate between screen test results with greater odds for positive cases. It detects more cases of glaucoma than in-person examination. Both patients and the healthcare systems benefit from early detection, reduction in wait and travel times, increased specialist referral rates, and cost savings. Teleglaucoma is an effective screening tool for glaucoma specifically for remote and under-serviced communities.

Methodology: 

Research databases and conference meeting abstracts were searched for articles published from 1999 to current, and included MEDLINE (OVID and PubMed), Cochrane Library (Wiley), BIOSIS (Thomson-Reuters), CINAHL (EBSCO), Web of Science (Thomson-Reuters), and EMBASE (OVID). The grey literature was explored by searching Dissertations and Theses (ProQuest), the Canadian Health Research Collection (Ebrary), as well as the annual meeting abstracts of the European Society of Ophthalmology, Canadian Society of Ophthalmology (CSO), Association for Research in Vision and Ophthalmology (ARVO), and American Academy of Ophthalmology (AAO). The Conference Proceedings Citation Index was also included as part of the Web of Science search. Hand searches of ARVO’s Investigative Ophthalmology & Visual Science journal and Canadian Journal of Ophthalmology associated with CSO were performed. The search strategies employed database specific subject headings and keywords for glaucoma, tele-screening, detection, and their synonyms.

Articles included were from any country, all in English, published from 1999 to current, and were research articles. The articles included study population that are adults in the general population or populations at risk of glaucoma. The study population included those with or without glaucoma. Articles on teleglaucoma intervention for glaucoma screening were included, both in-comparison to in person screening and analyzing teleglaucoma on its own. Outcome measures of teleglaucoma articles selected contained efficiency measures, specificity, sensitivity, and its ability to detect glaucoma, as well as patient benefits and cost data. Economic evaluations such as cost-effectiveness analysis and studies with costing data were also included. Articles were assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines for publication bias, risk of bias, imprecision, inconsistency, and indirectness

Two reviewers independently screened studies for inclusion. One reviewer extracted data using an excel template. The authors were emailed to obtain missing relevant information.

Applicability/external validity:

The authors note that teleglaucoma is beneficial to offering services in underserviced regions and rural areas. It considerably reduces patient access times and cycle times.

Geographic focus:

Authors do not discuss applicability of findings to low- and middle- income countries.

Summary of quality assessment:

Overall, there is high confidence in the conclusions about the effects of this study. The authors used appropriate methods to search for literature avoiding biases. One minor limitation was identified, as only one of the reviewers extracted data of included studies.