Telemedicine for Screening and Follow-Up of Glaucoma: A Descriptive Study

Abstract

Introduction:

Glaucoma is a leading cause of irreversible blindness. It is a prevalent disease worldwide, affecting ∼70 million people and expected to reach up to 112 million by 2040.

Purpose:

The aim of this study is to describe the implementation and initial experience of a telemedicine program to monitor glaucoma and glaucoma suspect patients in a large, integrated health care system during the COVID-19 pandemic.

Methods:

A retrospective chart review of established glaucoma or glaucoma suspect patients who participated in a telemedicine evaluation at the ophthalmic center of a large, Colombian health care system between June 2020 and April 2023 was conducted. Clinical and sociodemographic variables were analyzed. Generated clinical orders for additional testing, surgical procedures, follow-ups, and referrals, as well as changes in medical treatment, were evaluated.

Results:

A total of 11,034 telemedicine consults were included. The mean ± standard deviation age of this group was 63 ± 17.2 years and 67% were female. Of the patients who attended teleconsults, 49% were glaucoma suspects and 38.5% were followed with a diagnosis of open-angle glaucoma. After the consult, 25% of patients were referred to a glaucoma specialist, 40% had additional testing ordered, and 8% had a surgical procedure ordered, mainly laser iridotomy (409 cases). Almost a third of patients returned for subsequent telemedicine visits after the initial encounter. Despite some technical difficulties, 99.8% of patients attended and completed their scheduled telemedicine appointments.

Conclusions:

A telemedicine program aimed to monitor established glaucoma patients can be successfully implemented. Established patients within an integrated health care system have high adherence to the virtual model. Further research by health care institutions and government agencies will be key to expand coverage to additional populations.

Clinical Trial Registration Number: CEIFUS 1026-24

Introduction

Glaucoma is a leading cause of irreversible blindness. It is a prevalent disease worldwide, affecting ∼70 million people and expected to reach up to 112 million by 2040.¹ Glaucoma detection is challenging and it is often underdiagnosed; this causes significant disease burden that leads to disabling visual loss and higher costs for the health care system, namely medication, surgery, laser treatment, visit, and ancillary testing costs.²

Telemedicine can be defined as health care delivery over distance through any type of electronic device.³ When employed in eye health (teleophthalmology), it can provide access to eye specialists in remote regions, improve screening and monitoring for ophthalmic diseases, provide timely diagnosis, and aid in early treatment and educational programs for health care providers and patients.⁴

Modalities of telemedicine include the synchronous modality, which involves real-time interaction between the provider and the patient, and asynchronous modality, in which data collection takes place and data are subsequently forwarded for remote evaluation by the provider; the latter method enables acquisition of digital images from multiple testing sources such as slit-lamp photos, optical coherence tomography (OCT), and visual field (VF) testing.⁵

A hybrid telehealth service incorporates elements of asynchronous data collection and live consultation. For example, a patient visits a health care facility for intraocular pressure (IOP) measurement, OCT, VF testing, and optic disc photography, after which the collected data are transmitted to a glaucoma specialist who, after reviewing it, contacts the patient for additional medical history and synchronous discussion of the results, which tends to be similar to a typical in-person clinical interaction.^3,5

The global health landscape was significantly impacted by the COVID-19 pandemic, which demanded development of alternative health care models that prioritize safety and reliability of health care.⁶ In this context, telemedicine has emerged as an effective solution to overcome geographical barriers and enhance access to medical services.

Given the nature of glaucoma disease, the use of telemedicine seems to be of particular suitability both for early diagnosis and long-term monitoring. It is feasible to perform a reasonable evaluation and make clinical decisions, including the need for an in-office examination, using data obtained from fundus photography, IOP measurement, visual acuity testing, VF testing, OCT, and patient questionnaires indicating sudden changes in vision or new side effects of medications.^6,7

Glaucoma screening can be especially effective in identifying the disease at its early stages among high-risk populations and in underserved areas. Glaucoma management can be optimized with remote monitoring through virtual clinics, where traditional in-person visits are substituted with synchronous data collection conducted by nonophthalmologists and subsequent asynchronous review by ophthalmologists for decision-making purposes.

This approach can be particularly beneficial for low-risk patients with early-stage glaucoma, streamlining health care logistics, minimizing the need for face-to-face consultations, and saving time and costs.^4,8

In Colombia as well as the Latin-American region, there are multiple barriers to health care that persist due to the geography, socioeconomic resources, and centralization of specialized care in major cities. Due to limited availability of ophthalmology in-office visits, patients who require immediate attention can be lost among those with stable conditions attending follow-up or screening visits.

Therefore, teleophthalmology provides a unique opportunity for general ophthalmologists and glaucoma specialists to optimize care for those patients with advanced or severe glaucoma who may need timely surgical treatment or stricter monitoring, minimizing the risk of irreversible visual loss from the disease.^2,3

In recent years, additional technological advances such as artificial intelligence (AI), machine learning, and deep learning (DL) have gained significance regarding teleophthalmology use and advances in eye care centers for various diseases, including glaucoma, diabetic retinopathy, age-related macular degeneration, and anterior segment disease such as keratoconus.^7,9

–13

In glaucoma, researchers worldwide have developed increasingly complex artificial neural networks that analyze fundus images, optic nerve OCT, and clinical data, aiming to optimize care. These AI-based tools can permit better screening, diagnosis, follow-up, and decision-making related to changes in management plans in glaucoma care.^7,9,11,14,15

The primary objective of this article is to provide a description of the telemedicine services offered by a Colombian center amid the COVID-19 pandemic. More specifically, it aims to emphasize the implementation of a virtual model tailored for glaucoma patients. The article intends to shed light on both the advantages and challenges encountered within this particular population.

Methods

This was a descriptive cross-sectional study and part of a broader telemedicine study ongoing since the COVID-19 pandemic.¹⁶

Medical data were obtained from adult patients with diagnosis of glaucoma or glaucoma suspect who attended a telemedicine evaluation at an ophthalmic center in Bogotá between April 2020 and June 2023. Implementation of the virtual care was hastened by disruption of routine medical services due to isolation mandates implemented in response to the COVID-19 pandemic in our country.

This ophthalmic center is part of a large, integrated health company that includes several clinics and ambulatory care units; all the facilities within this company use a single electronic medical record (EMR) system, Avicenna 7.6.0.

Inclusion criteria were patients who received a telemedicine consultation for glaucoma pathologies and who had accepted the virtual consultation model. Patients who did not have complete information in the EMR were excluded.

A hybrid model of telemedicine was selected for the virtual care process. Virtual care begins with the asynchronous element: patients with known diagnosis of glaucoma or glaucoma suspect, who attend a regular in-person visit as part of chronic management of their disease, are offered a virtual follow-up consultation for ancillary imaging review and discussion of results. If the patient agrees, the virtual consultation is scheduled. In-person testing is performed within the next few days. After that the synchronous element follows through a video call. The virtual platform used is Avicenna software.

On the day of the virtual encounter, an online link previously sent is used by the patient to access the platform. Once the patient is in the system, they must consent to the teleconsult evaluation by signing an online form. The physician then connects with the patient and each participant has a video window and audio that allows real interaction. If the patient does not have access to a camera, the virtual encounter proceeds with audio only.

During the encounter, the physician completes the medical history, reviews available data such as IOP measurement and digital images of the ordered tests, discusses results, and generates a treatment plan. All medical orders generated through the consult are sent to the patient's registered e-mail. An online medical assistant is dedicated to assist the virtual medical encounters when urgent procedures/follow-ups are requested.

DATA COLLECTION STORAGE

The medical records of patients with glaucoma or glaucoma suspect diagnosis that assisted a telemedicine consultation were reviewed. The collected data were stored using an Excel spreadsheet with exclusive access by the investigators and thus the principle of confidentiality was maintained.

The following sociodemographic variables were included: age, sex, city of residence, clinical variables such as comorbidities and type of glaucoma, and variables related to the virtual appointment type such as ophthalmology specialty and attendance. Outcome variables included generated orders for testing, surgery, referrals or follow-up, and findings related to care.

DATA ANALYSIS

Collected data were reviewed by investigators to verify information related to the definition and type of variable, corresponding unit, and coding if applicable. For categorical variables, the distribution of frequencies and percentages is reported. For continuous variables, mean (standard deviation) values are reported. The statistical software, STATA, version 17, was used for data analysis.

ETHICAL CONSIDERATIONS

This study followed the tenets of the Declaration of Helsinki for research on human subjects and was approved by the Research Committee and the Research Ethics Committee of the Fundación Universitaria Sanitas without requiring informed consent. This retrospective study involved no more than minimal risk to the participants and did not adversely affect their rights and welfare.

Results

A total of 11,034 teleglaucoma consults were made between April 2020 and June 2023. The mean age of patients was 63 ± 17.2 years and 67% were female. Approximately 95% of patients reside in Colombia's capital city, Bogota, and its metropolitan area. Other patients come from nearby departments (geographical regions), with 1.5% attending from Cundinamarca (Table 1 and Fig. 1).

Fig. 1.

Distribution of virtual visits in Colombia by city between April 2020 and June 2023.

Table 1.

Clinical and Sociodemographic Characteristics of the Patients

VARIABLE	MEAN (SD) or n (%)
Age, years	63.02 (17.2)
Sex
Female	7,461 (67.6)
Patient residency department
Bogotá D.C.	9,948 (95.1)
Cundinamarca	170 (1.5)
Tolima	30 (0.3)
Others	38 (0.3)
Comorbidities
Arterial hypertension	5,231 (47.4)
Chronic renal disease	2,485 (22.5)
Diabetes mellitus	2,044 (18.5)
Cancer	1,030 (9.3)
Chronic obstructive pulmonary disease	245 (2.2)

SD, standard deviation.

Systemic comorbidities were analyzed. Of the patients who received teleglaucoma care, the most frequent comorbidity was arterial hypertension (47.4%), followed by chronic renal disease (22.5%) and diabetes mellitus (18.5%) (Table 1).

Regarding the outcomes of the teleglaucoma attention, 99.8% of visits were carried out and 18 (0.12%) were canceled. The duration of the consults was 20 min in 89.5% of cases, which corresponds to the time allotted. In 10.4% of cases, the appointment lasted 15 min. Eighteen patients (0.2%) required a consult of more than 30 min. The specialists who conducted the teleglaucoma consult were, for the most part, general ophthalmologists (63.1%) and glaucoma specialists (36.4%). Nonetheless, cornea and retina specialists also provided these consultations, representing 0.4% and 0.2% of the attention, respectively (Table 2).

Table 2.

Characteristics and Outcomes of Telemedicine Attention

VARIABLE	n (%)
Type of consultation
Assigned	11,034 (100)
Canceled	18 (0.2)
Unattended	0 (0)
Duration, min
20	9,873 (89.5)
≤5	1,143 (10.4)
>30	18 (0.2)
Specialty area^a
Comprehensive ophthalmology	6,658 (60.3)
Glaucoma	4,315 (39.1)
Cornea	43 (0.4)
Retina	18 (0.2)

Ophthalmology residents performed 6.13% of consults.

The primary diagnosis for the teleglaucoma consults included glaucoma suspect in 49.0% of cases, primary open-angle glaucoma in 38.5% of cases, primary angle closure glaucoma in 4.5% of cases, glaucoma secondary to inflammatory diseases in 2.4% of cases, and unspecified glaucoma or other diagnosis in 2.9% and 2.7% of cases, respectively (Table 3).

Table 3.

Outcomes of Telemedicine Attention

PRIMARY DIAGNOSIS
Glaucoma suspect	5,406 (49.0)
Primary open-angle glaucoma	4,247 (38.5)
Primary angle-closure glaucoma	499 (4.5)
Glaucoma, unspecified	316 (2.9)
Glaucoma secondary to inflammatory disorders	260 (2.4)

The management plan following teleglaucoma included follow-ups and ordering of tests, referrals, or surgical procedures. Referrals and follow-up appointments included glaucoma specialist (25.6% of orders), general ophthalmology (16.9%), and optometry (1.6%). Testing orders included VF examination in 18.7%, OCT in 16.5%, and pachymetry in 5.3% of cases.

The most frequent surgical procedure ordered was laser iridotomy in 409 cases (3.7% of procedures), followed by cataract surgery (1.3%), selective laser trabeculoplasty (1.3%), and laser iridoplasty (0.4%). Other procedures included laser capsulotomy (1.0%) and glaucoma drainage device insertion (0.4%). Additionally, pterygium surgery (0.2%) and argon laser retinal photocoagulation (0.2%) were also ordered (Table 4).

Table 4.

Postconsultation Plan

ORDERED SERVICES
Glaucoma control	2,821 (25.6)
Visual field study	2,067 (18.7)
Ophthalmology consult	1,864 (16.9)
Posterior segment optical tomography	1,825 (16.5)
Pachymetry	595 (5.4)
Optometry consult	174 (1.6)

PROCEDURE REQUESTED
Laser iridotomy	409 (3.7)
Clear lens extraction/cataract surgery	279 (2.5)
Laser trabeculoplasty	139 (1.3)
Laser capsulotomy	109 (1.0)
Laser iridoplasty	47 (0.4)
Glaucoma drainage device insertion	41 (0.4)

Of the patients who received this modality of attention, 69.1% only had one teleconsult. Of the resultant 30.9% (3,411 patients), 72.0% had two virtual appointments, 20.2% received three appointments, and 7.8% had more than three appointments (Table 5).

Table 5.

Number of Teleophthalmology Visits per Patient

VARIABLE	n (%)
Number of visits per patient
Single virtual visit	7,623 (69.1)
Multiple virtual visits	3,411 (30.9)
Total	11,034
Patients with multiple virtual visits
2 Visits	2,457 (72.0)
3 Visits	688 (20.2)
>3 Visits	266 (7.8)
Total	3,411 (30.9)

While technical difficulties with the video component were reported during the teleglaucoma care (Table 6), physicians were able to complete the medical attention through a phone call, and no appointments were canceled.

Table 6.

Technical Errors Reported During the Telemedicine Visits

NOTED PROBLEMS
Phone call is requested due to no internet access and is in urgent need of medication.
No e-mail is provided and requests a phone call.
No e-mail is provided and is unable to receive help from others
Patient does not have a smartphone or internet access, but is able to receive phone calls

Discussion

The presented study shows the successful integration of teleglaucoma in the treatment of an established population of glaucoma patients and their ongoing clinical management, including medication adjustments, recommendations, and even scheduling surgery. This approach has proven to be effective, leading to decisive consults and receiving positive feedback from both patients and physicians.

Even before the COVID-19 pandemic, our ophthalmic center has faced considerable challenges in providing timely outpatient care for glaucoma patients who often require strict follow-up to prevent blindness due to tardiness. Studies, including those by Gan et al. and Zanotto et al., demonstrated that diagnostic tests can be effectively evaluated remotely, reducing the need for in-person visits, and the implementation of this modality has shown high patient satisfaction rates.^17
–19

Since the early 2010s, various studies have been designed to evaluate effectiveness and cost-efficiency in the use of teleglaucoma, showing significant reduction in costs in long-term projections.^20,21 Given recent events in human history, namely the SARS-COV2 pandemic in 2019, the use of teleglaucoma has granted the medical community the chance to further expand their knowledge and expertise by continuing with the use of these tools for the benefit of patients.^17,21

–24

A main interest of several teleglaucoma studies is the focus on detection of glaucoma suspects, screening in the general population, or improving adherence to treatment with the help of a virtual care model.^25

–28 However, few studies report on the clinical outcomes of virtual models integrated in the ongoing care of a established cohort of glaucoma patients such as ours, mainly in the Latin-American scene.

This study included a review and discussion of diagnostic testing results during the virtual consult summarized in a medical plan, and 10% of virtual visits generated orders for surgical procedures, most of them being laser treatments.

Our own telemedicine hybrid mode included the review and discussion of diagnostic testing results during the virtual consult summarized in a medical plan; in 10% of visits, the generated orders included a surgical procedure that could be scheduled virtually as well. Most of these procedures were laser treatments, while less than 1% were scheduled for a glaucoma filtering surgery. This reflects the preference of our physicians to discuss major intraocular surgery in person given the risk profile involved.

To the best of our knowledge, this is one of the few studies describing the use of teleglaucoma specifically and the largest reported to date. In Chile, a 10-week, synchronous telemedicine program for the ophthalmological attention pilot program that was implemented during the COVID-19 pandemic resulted in 291 consults, the majority of which were related to ocular and adnexal inflammatory diseases (43.3% and 36.1%, respectively).

No information regarding glaucoma was available in this research. Additionally, no information regarding adherence to consultations was available.²⁹ A study in Peru, including 308 patients who received synchronous teleorientation by ophthalmologists, described that 19% of patients had a glaucoma-related diagnosis and 2 patients were referred to in-office visits with suspicion of acute angle closure.

It is specified that 389 patients were originally included in the study and 78 were excluded due to incomplete information and filling errors, yet no information is available regarding adherence to visits, cancelations, or other technical difficulties.³⁰ In Mexico City, a similar study described the experience of synchronous teleophthalmological orientation in early 2020, 7.3% of consults being related to glaucoma. No information related to patient adherence was included.³¹

These studies offer insight into the efficiency of teleophthalmology, with resolution of patient's main concerns reported being more than 80%.^29
–31 Additionally, all authors conclude that the overall experience, both for patients and doctors, was positive; however, no information regarding adherence to visits was discussed.

Screening and diagnostic tests such as fundus photography are low-cost and easily implemented tools that have already been incorporated into teleophthalmology programs.^7,32 Nonetheless, several challenges remain as obstacles for widespread implementation in this type of care. Technical challenges include the need for complex data management systems⁴ and the cost associated with infrastructure, which includes imaging equipment, hardware, storage, and labor costs encompassing staff time and training.^8,33

Challenges related to the health care system involve clearer regulation by government agencies and medical entities, practitioners' acceptance of telemedicine, and further research establishing its cost-effectiveness and safety.^3
–5 Population-based screening for glaucoma case detection remains low and the elderly or individuals with disabilities may encounter challenges when attempting to use telemedicine services due to lack of familiarity with the technology or physical limitations.^4,8,15,34,35

As was mentioned, this study is the first to describe patient adherence to teleophthalmology and teleglaucoma care, with excellent results. Good adherence to telemedicine programs for glaucoma has been previously described.^24,35,36 Despite technical difficulties experienced by some patients, it is notable that 99.83% of patients in the telemedicine program were able to attend virtual visits, including 31% who had multiple virtual visits.

This outstanding result was achieved using various instruments: physicians were instructed to make multiple attempts to contact patients and use all available resources (phone or video), and those who were unable to attend the virtual consultation were ultimately reassigned to a later date by a technician who was exclusively dedicated to this task.

Most of our patients belonged to a higher socioeconomic level, thus having the means to undergo the virtual consultation. Additionally, the majority of our patients benefit from better insurance coverage as they are affiliated with the contributory health care system in Colombia, which comprises predominantly employed individuals with higher socioeconomic status. This demographic has the financial means to make virtual consultations.

Although elderly patients may not be usually adept at using electronic devices, it is possible that the shift to remote activities during the COVID-19 pandemic meant a higher availability of assistance with such devices from someone within their household or nearby area, allowing them to complete the encounter.^37,38 It is also worth noting that in Colombia, during the peak of the COVID-19 pandemic, strict at-home quarantine was mandatory, therefore attendance was almost guaranteed.

The main strength of this study is the size of the population included, which to our knowledge is the largest telemedicine experience in glaucoma patients reported to date. Limitations of this study were inherent to its retrospective design. The population was based on a single ophthalmic unit in a metropolitan area, affecting the generalizability to different health care systems. An interruption in medical data storage for 3 months due to a malware attack resulted in missing data during this period.

Conclusions

Our experience with telemedicine these past few years has demonstrated that teleglaucoma is a useful tool for patient education, screening, follow-up, and management of established glaucoma patients. Reduced volume of outpatient visits in health care facilities can help prioritize patient care through remote monitoring. This is why teleophthalmology provides a unique opportunity for physicians to optimize care for those patients with advanced or severe glaucoma who need timely surgical treatment and strict monitoring, minimizing the risk of irreversible visual loss.

Integration of telemedicine and AI in glaucoma clinics holds immense potential for optimizing patient care.^36,37 This advanced approach facilitates various aspects of glaucoma management, including diagnosis, treatment adjustment, and follow-up.³⁸ By incorporating AI analysis of fundus photos in virtual consultations, telemedicine eliminates geographic barriers and enhances accessibility.³⁹ Furthermore, the implementation of DL and AI algorithms improves the accuracy of screening and diagnostic tools, aiding in early detection and decision-making for patients.

We must be aware that our present and future lie in the combination of telemedicine and all the advantages that our specialty offers to harness AI, keeping in mind that in-person interaction is still crucial for the doctor–patient relationship, which will ultimately reflect in a successful outcome.

Further investment and research regarding telemedicine in Colombia, as well as other Latin-American countries, must be prioritized by health care institutions and government agencies to expand coverage and promote inclusivity.

Footnotes

Disclosure Statement

No competing financial interests exist.

Funding Information

This study did not receive external funding. It was developed with the researchers' own resources.

References

Tham

, Li

, Wong

, et al. Global prevalence of glaucoma and projections of glaucoma burden through 2040: A systematic review and meta-analysis. Ophthalmology, 2014; 121(11):2081–2090; doi: 10.1016/j.ophtha.2014.05.013

Allison

, Patel

, Alabi

. Epidemiology of glaucoma: The past, present, and predictions for the future. Cureus, 2020; 12(11):e11686; doi: 10.7759/cureus.11686

Parikh

, Armstrong

, Liou

, et al. Advances in telemedicine in ophthalmology. Semin Ophthalmol, 2020; 35(4):210–215. Doi:10.1080/08820538.2020.1789675

Brandão-de-Resende

, Alcântara

LAR

, Vasconcelos-Santos

, et al. Glaucoma and telemedicine. J Glaucoma, 2023; 32(5):327–332; doi: 10.1097/IJG.000000000000220

Ertel

, Kahook

, Capitena Young

. The future is now: Incorporating telemedicine into glaucoma care. Curr Ophthalmol Rep, 2021; 9(3):88–95; doi: 10.1007/s40135-021-00269-x

Saleem

, Pasquale

, Sidoti

, et al. Virtual ophthalmology: Telemedicine in a COVID-19 era. Am J Ophthalmol, 2020; 216:237–242; doi: 10.1016/j.ajo.2020.04.029

Medeiros

, Jammal

, Thompson

. From machine to machine: An OCT-trained deep learning algorithm for objective quantification of glaucomatous damage in fundus photographs. Ophthalmology, 2019; 126:513–521; doi: 10.1016/j.ophtha.2018.12.033

Thomas

, Jeyaraman

, Hodge

, et al. The effectiveness of teleglaucoma versus in-patient examination for glaucoma screening: A systematic review and meta-analysis. PLoS One, 2014; 9(12):e113779.

Paycha

, Paycha

. The assisted-diagnosis by identification program, an expert system for acquired ocular hypertension in adults [in French]. J Fr Ophtalmol, 1986; 9(6–7):485–491.

10.

Choi

, Coyner

, Kalpathy-Cramer

, et al. Introduction to machine learning, neural networks, and deep learning. Transl Vis Sci Technol, 2020; 9(2):14; doi: 10.1167/tvst.9.2.14

11.

Ting

DSJ

, Foo

, Yang

LWY

, et al. Artificial intelligence for anterior segment diseases: Emerging applications in ophthalmology. Br J Ophthalmol, 2021; 105(2):158–168; doi: 10.1136/bjophthalmol-2019-315651

12.

Ting

DSW

, Pasquale

, Peng

, et al. Artificial intelligence and deep learning in ophthalmology. Br J Ophthalmol, 2019; 103(2):167–175; doi: 10.1136/bjophthalmol-2018-313173

13.

Ferro Desideri

, Rutigliani

, Corazza

, et al. The upcoming role of Artificial Intelligence (AI) for retinal and glaucomatous diseases. J Optom, 2022; 15(Suppl 1):S50–S57; doi: 10.1016/j.optom.2022.08.001

14.

Abràmoff

, Lavin

, Birch

, et al. Pivotal trial of an autonomous AI-based diagnostic system for detection of diabetic retinopathy in primary care offices. NPJ Digit Med, 2018; 1:39; doi: 10.1038/s41746-018-0040-6

15.

Kim

, Cho

, Oh

. Development of machine learning models for diagnosis of glaucoma. PLoS One, 2017; 12(5):e0177726; doi: 10.1371/journal.pone.0177726

16.

Caycedo

, Serrano

, Ucrós

. Telemedicine and ophthalmology amidst covid-19: A descriptive study. Univ Med, 2022; 63:1–9.

17.

Gan

, Liu

, Stagg

, et al. Telemedicine for glaucoma: Guidelines and recommendations. Telemed J E Health, 2020; 26(4):551–555; doi: 10.1089/tmj.2020.0009

18.

Zanotto

, Etges

APBDS

, Siqueira

, et al. Economic evaluation of a telemedicine service to expand primary health care in Rio Grande do Sul: TeleOftalmo's microcosting analysis. Cien Saude Colet, 2020; 25(4):1349–1360; doi: 10.1590/1413-81232020254.28992019

19.

Rhodes

, Huisingh

, McGwin

, et al. Glaucoma patient knowledge, perceptions, and predispositions for telemedicine. J Glaucoma, 2019; 28(6):481–486; doi: 10.1097/IJG.0000000000001238

20.

Lam

, Chow

, Lai

JSM

, et al. A review on the use of telemedicine in glaucoma and possible roles in COVID-19 outbreak. Surv Ophthalmol, 2021; 66(6):999–1008; doi: 10.1016/j.survophthal.2021.03.008

21.

Thomas

, Hodge

, Malvankar-Mehta

. The cost-effectiveness analysis of teleglaucoma screening device. PLoS One, 2015; 10(9):e0137913; doi: 10.1371/journal.pone.0137913

22.

Nikolaidou

, Tsaousis

. Teleophthalmology and artificial intelligence as game changers in ophthalmic care after the COVID-19 pandemic. Cureus, 2021; 13(7):e16392; doi: 10.7759/cureus

23.

Vinod

, Sidoti

. How glaucoma care changed for the better after the pandemic. Curr Opin Ophthalmol, 2022; 33(2):59–66; doi: 10.1097/ICU.0000000000000812

24.

Sundararajan

, Schallhorn

, Doan

, et al. Changes to ophthalmic clinical care during the coronavirus disease 2019 pandemic. Curr Opin Ophthalmol, 2021; 32(6):561–566; doi: 10.1097/ICU.0000000000000797

25.

Modjtahedi

, Chu

, Luong

, et al. Two-year outcomes of a pilot glaucoma suspect telemedicine monitoring program. Clin Ophthalmol, 2018; 12:2095–2102; doi: 10.2147/OPTH.S171263

26.

Hark

, Katz

, Myers

, et al. Philadelphia telemedicine glaucoma detection and follow-up study: Methods and screening results. Am J Ophthalmol, 2017; 181:114–124; doi: 10.1016/j.ajo.2017.06.024

27.

Giorgis

, Alemu

, Arora

, et al. Results from the first teleglaucoma pilot project in Addis Ababa, Ethiopia. J Glaucoma, 2019; 28(8):701–707; doi: 10.1097/IJG.0000000000001271

28.

Rhodes

, Huisingh

, McGwin

Jr ., et al. Eye Care Quality and Accessibility Improvement in the Community (EQUALITY): Impact of an eye health education program on patient knowledge about glaucoma and attitudes about eye care. Patient Relat Outcome Meas, 2016; 7:37–48; doi: 10.2147/PROM.S98686

29.

Arntz

, Khaliliyeh

, Cruzat

, et al. Open-care telemedicine in ophthalmology during the COVID-19 pandemic: A pilot study. Arch Soc Esp Oftalmol (Engl Ed), 2020; 95(12):586–590; doi: 10.1016/j.oftal.2020.09.005

30.

Huancahuari

, Roman-Benate

J-F

, Hernandez

, et al. Teleorientation in the ophthalmology service in a public hospital from May to August 2020 during the COVID-19 pandemic in Peru. Act Med, 2022; 39(2):120–127.

31.

Avalos-Lara

, Antonio-Aguirre

, Vázquez-Quezadas

, et al. Teleophthalmology implementation during COVID-19 pandemic: Experience in Mexico City. Acta Sci Ophthalmol, 2021; 4(7):38–43.

32.

Mirzania

, Thompson

, Muir

. Applications of deep learning in detection of glaucoma: A systematic review. Eur J Ophthalmol, 2021; 31(4):1618–1642; doi: 10.1177/1120672120977346

33.

, Liu

, Ting

DSJ

, et al. Digital technology, tele-medicine and artificial intelligence in ophthalmology: A global perspective. Prog Retin Eye Res, 2021; 82:100900; doi: 10.1016/j.preteyeres.2020.100900

34.

Chen

, Andoh

, Nwanyanwu

. Socioeconomic and demographic disparities in the use of telemedicine for ophthalmic care during the COVID-19 pandemic. Ophthalmology, 2022; 129(1):15–25; doi: 10.1016/j.ophtha.2021.07.003

35.

Fatehi

, Jahedi

, Tay-Kearney

, et al. Teleophthalmology for the elderly population: A review of the literature. Int J Med Inform, 2020; 136:104089; doi: 10.1016/j.ijmedinf.2020.104089

36.

Hogarty

, Mackey

, Hewitt

. Current state and future prospects of artificial intelligence in ophthalmology: A review. Clin Exp Ophthalmol, 2019; 47(1):128–139; doi: 10.1111/ceo.13381

37.

Arora

, Rudnisky

, Damji

. Improved access and cycle time with an “in-house” patient-centered teleglaucoma program versus traditional in-person assessment. Telemed J E Health, 2014; 20(5):439–445; doi: 10.1089/tmj.2013.0241

38.

Zedan

MJM

, Zulkifley

, Ibrahim

, et al. Automated glaucoma screening and diagnosis based on retinal fundus images using deep learning approaches: A comprehensive review. Diagnostics (Basel), 2023; 13(13):2180; doi: 10.3390/diagnostics13132180

39.

Tan

NYQ

, Friedman

, Stalmans

, et al. Glaucoma screening: Where are we and where do we need to go?. Curr Opin Ophthalmol, 2020; 31(2):91–100; doi: 10.1097/ICU.0000000000000649