Visual acuity measured with a smartphone app is more accurate than Snellen testing by emergency department providers

Assessment of visual function using mobile Apps

With the advances in smartphone and tablet screens, as well as their processing power and software, mobile apps have been developed reporting to assess visual function. This review assessed those mobile apps that have been evaluated in the scientific literature to measure visual acuity, reading metrics, contrast sensitivity, stereoacuity, colour vision and visual fields; these constitute just a small percentage of the total number of mobile apps reporting to measure these metrics available for tablets and smartphones. In general, research suggests that most of the mobile apps evaluated can accurately mimic most traditionally paper-based tests of visual function, benefitting from more even illumination from the backlit screen and aspects such as multiple tests and versions (to minimise memorisation) being available on the same equipment. Some also utilise the in-built device sensors to monitor aspects such as working distance and screen tilt. As the consequences of incorrectly recording visual function and using this to inform clinical management are serious, clinicians must check on the validity of a mobile app before adopting it as part of clinical practice.

Evaluating the precision of an online visual acuity test tool

OBJECTIVE

The aim of this study was to assess the precision of a web-based tool in measuring visual acuity (VA) in ophthalmic patients, comparing it to the traditional in-clinic evaluation using a Snellen chart, considered the gold standard.

METHODS

We conducted a prospective and in-clinic validation comparing the Eyecare Visual Acuity Test® to the standard Snellen chart, with patients undergoing both tests sequentially. Patients wore their standard spectacles as needed for both tests. Inclusion criteria involved individuals above 18 years with VA equal to or better than +1 logMar (20/200) in each eye. VA measurements were converted from Snellen to logMAR, and statistical analyses included Bland-Altman and descriptive statistics.

RESULTS

The study, encompassing 322 patients and 644 eyes, compared Eyecare Visual Acuity Test® to conventional methods, revealing a statistically insignificant mean difference (0.01 logMAR, P = 0.1517). Bland-Altman analysis showed a narrow 95% limit of agreement (0.22 to -0.23 logMAR), indicating concordance, supported by a significant Pearson correlation (r = 0.61, P < 0.001) between the two assessments.

CONCLUSION

The Eyecare Visual Acuity Test® demonstrates accuracy and reliability, with the potential to facilitate home monitoring, triage, and remote consultation. In future research, it is important to validate the Eyecare Visual Acuity Test® accuracy across varied age cohorts, including pediatric and geriatric populations, as well as among individuals presenting with specific comorbidities like cataract, uveitis, keratoconus, age-related macular disease, and amblyopia.

Painful Eyes in Neurology Clinic: A Guide for Neurologists

Eye pain is a common complaint among patients presenting to the neurology clinic. It can be related to neurologic diseases, but it can also be a localized eye condition. Such disorders can be misleading, as their benign appearance might mask more grave underlying conditions, potentially leading to misdiagnoses or delayed treatment. Clinicians should be aware of the specific neurologic or systemic disorders (eg, demyelinating diseases or vascular abnormalities) that might first manifest as eye pain. Formal ophthalmic consultation is recommended for patients presenting with eye pain as the predominant complaint especially when red flags for more serious pathology are present.

Effect of different screen brightness and devices on online visual acuity test

PURPOSE

This study aimed to study the difference in test results of online visual acuity (VA) test under different devices and screen brightness conditions and to compare online VA test with Early Treatment Diabetic Retinopathy Study (ETDRS).

METHODS

Healthy volunteers with the best corrected VA of 0.0 LogMAR or higher were recruited. VAs under ETDRS were tested first, and then online VA test (the Stanford Acuity Test, StAT) visual acuities using iPad Air2 and Microsoft Surface pro4 under 50% and 100% screen brightness were performed. The VA results and the testing times were compared between different devices and screen brightness conditions.

RESULTS

A total of 101 eyes were included in this study. The VA results measured by the StAT were better than those of ETDRS. The VA results measured at 100% screen brightness were better than those of 50% brightness (mean difference, 0.013 logMAR at most, less than 1 letter); the VA results measured by iPad Air2 were better than those of Surface pro4 (mean difference, -0.009 logMAR at most, less than 1 letter). Significantly less time was spent on VA testing under StAT than that under ETDRS.

CONCLUSION

The impact of screen brightness and the device on the VA results generated by online VA tests was clinically insignificant. In addition, online VA tests are found to be reliable and more time efficient than ETDRS.

Design and Validation of a Novel Smartphone-Based Visual Acuity Test: The K-VA Test

INTRODUCTION

Visual acuity (VA) testing is a critical screening examination for the assessment of visual function. This study describes the development and validation of a smartphone-based VA test: the K-VA test.

METHODS

A total of 171 patients with various ocular diseases were examined in our outpatient unit at Aristotle University of Thessaloniki, School of Medicine in Greece. Participants underwent VA examination using the standard Early Treatment Diabetic Retinopathy Study (ETDRS) charts and the K-VA smartphone-based test. The K-VA test was performed by participants themselves. The Bland-Altman method was employed to assess the agreement between the ETDRS charts and the new test for the examination of VA at 1 m and 40 cm. Test-retest reliability was also calculated. A questionnaire regarding the participants' feedback on the K-VA test was completed.

RESULTS

No significant bias was observed between the gold standard ETDRS charts and the K-VA test measurements. The mean difference (95% limits of agreement, LoA) between the K-VA test at 1 m and the ETDRS chart at 4 m was -0.006 (95% LoA -0.129 to 0.117) logarithm of the minimal angle of resolution (logMAR). The agreement of the K-VA test at 40 cm with the near ETDRS chart was also high with a mean difference of -0.007 (95% LoA -0.105 to 0.090) logMAR. Test-retest reliability was found to be high with a mean difference of 0.003 (95% LoA -0.045 to 0.033) logMAR and 0.005 (95% LoA -0.065 to 0.076) logMAR for the K-VA test at 1 m and 40 cm, respectively. A total of 97 participants answered the questionnaire and 71 (73.2%) stated that the test was easy to very easy to use for self-performance.

CONCLUSIONS

The study demonstrated that the K-VA application performed well compared with the ETDRS charts and provides reliable and repeatable measurements of VA across a wide range of VA.

Is your vision blurry? A systematic review of home-based visual acuity for telemedicine

INTRODUCTION

Visual acuity (VA) testing is a vital screening tool for the assessment of ocular function. The coronavirus 2019 pandemic has caused an immediate need for synchronous telemedicine in all specialties, including ophthalmology. While a plethora of mobile VA applications exist, there is no consensus as to what technology can accurately and reproducibly measure a patient's vision at home.

METHODS

A systematic literature search was performed in April 2020 using PubMed, Embase and Medline, identifying English publications from 2010 to 2020 on remote VA tests: 4338 articles were identified and 14 were ultimately included in the review.

RESULTS

Of those 14, the highest quality studies, best reproducibility and correlation with in-clinic acuities measured were found using the Peek Acuity application. The studies included patients throughout the world aged 3-97, with and without correction, with known ocular pathology.The Peek Acuity studies measured distance vision on a Samsung Galaxy S3 with a mean difference of 0.055 Logarithm of the Minimum Angle of Resolution (LogMAR) for home testing compared with the Early Treatment Diabetic Retinopathy Study (ETDRS). Test-retest variability was ±0.029 LogMAR for 95% confidence interval limits.

DISCUSSION

There can be one or more lines of variability in vision testing in a clinical setting using reference standard ETDRS and clinical standard Snellen charts. Test-retest reliability is not perfect even on standard clinical charts (variation up to 0.48 LogMAR). Of the technologies reviewed, Peek Acuity home testing had the greatest correlation with ETDRS clinical vision and high test-retest reliability. Peek Acuity performed no worse than Snellen and ETDRS charts.

Augmentation of telemedicine post-operative follow-up after oculofacial plastic surgery with a self-guided patient tool

PURPOSE

This study evaluates a web-based tool designed to augment telemedicine post-operative visits after periocular surgery.

METHODS

Adult, English-speaking patients undergoing periocular surgery with telemedicine follow-up were studied prospectively in this interventional case series. Participants submitted visual acuity measurements and photographs via a web-based tool prior to routine telemedicine post-operative visits. An after-visit survey assessed patient perceptions. Surgeons rated photographs and live video for quality and blurriness; external raters also evaluated photographs. Images were analyzed for facial centration, resolution, and algorithmically detected blur. Complications were recorded and graded for severity and relation to telemedicine.

RESULTS

Seventy-nine patients were recruited. Surgeons requested an in-person assessment for six patients (7.6%) due to inadequate evaluation by telemedicine. Surgeons rated patient-provided photographs to be of higher quality than live video at the time of the post-operative visit (p < 0.001). Image blur and resolution had moderate and weak correlation with photograph quality, respectively. A photograph blur detection algorithm demonstrated sensitivity of 85.5% and specificity of 75.1%. One patient experienced a wound dehiscence with a possible relationship to inadequate evaluation during telemedicine follow-up. Patients rated the telemedicine experience and their comfort with the structure of the visit highly.

CONCLUSIONS

Augmented telemedicine follow-up after oculofacial plastic surgery is associated with high patient satisfaction, rare conversion to clinic evaluation, and few related post-operative complications. Automated detection of image resolution and blur may play a role in screening photographs for subsequent iterations of the web-based tool.

Validation of Home Visual Acuity Tests for Telehealth in the COVID-19 Era

Importance

Visual acuity (VA) is one of the most important clinical data points in ophthalmology. However, few options for validated at-home VA assessments are currently available.

Objective

To validate 3 at-home visual acuity tests in comparison with in-office visual acuity.

Design, Setting, and Participants

Between July 2020 and April 2021, eligible participants with VA of 20/200 or better were recruited from 4 university-based ophthalmology clinics (comprehensive, cornea, glaucoma, and retina clinics). Participants were prospectively randomized to self-administer 2 of 3 at-home VA tests (printed chart, mobile phone app, and website) within 3 days before their standard-of-care clinic visit. Participants completed a survey assessing usability of the at-home tests. At the clinic visit, best-corrected Snellen distance acuity was measured as the reference standard.

Main Outcomes and Measures

The at-home VA test results were compared with the in-office VA test results using paired and unpaired t tests, Pearson correlation coefficients, analysis of variance, χ2 tests, and Cohen κ agreement. The sensitivity, specificity, positive predictive value, and negative predictive value of each at-home test were calculated to detect significant VA changes (≥0.2 logMAR) from the in-office baseline.

Results

A total of 121 participants with a mean (SD) age of 63.8 (13.0) years completed the study. The mean in-office VA was 0.11 logMAR (Snellen equivalent 20/25) with similar numbers of participants from the 4 clinics. Mean difference (logMAR) between the at-home test and in-office acuity was -0.07 (95% CI, -0.10 to -0.04) for the printed chart, -0.12 (95% CI, -0.15 to -0.09) for the mobile phone app, and -0.13 (95% CI, -0.16 to -0.10) for the website test. The Pearson correlation coefficient for the printed chart was 0.72 (95% CI, 0.62-0.79), mobile phone app was 0.58 (95% CI, 0.46-0.69), and website test was 0.64 (95% CI, 0.53-0.73).

Conclusions and Relevance

The 3 at-home VA test results (printed chart, mobile phone app, and website) appeared comparable within 1 line to in-office VA measurements. Older participants were more likely to have limited access to digital tools. Further development and validation of at-home VA testing modalities is needed with the expansion of teleophthalmology care.

Development and validation of a new method for visual acuity assesment on tablet in pediatric population: eMOVA test

BACKGROUND

Amblyopia is a major public health concern. Its screening and management require reliable methods of visual acuity assessment. New technologies offer nowadays many tests available on different app stores for smartphone or tablet but most of them often lack of scientific validation for a medical use. The aim of our study was to attempt validating a tablet-based near visual acuity test adapted to the pediatric population: the eMOVA test (electronic Measurement Of Visual Acuity) by comparing visual acuity measured with more conventional test.

METHODS

A cohort of 100 children aged 3 to 8 attending the ophthalmic-pediatric for eye examination between September 2016 and June 2017 were included in the study. Near visual acuity was assessed on participants using both the eMOVA test and a Standard test (Rossano-Weiss test). Duration of each test, its comprehension, its acceptability and the attention of the child during the test was also investigated.

RESULTS

The eMOVA test overestimated near visual acuity by 0.06 logMAR. This difference, statistically significant, was not clinically relevant. The duration of the eMOVA test was longer than the reference test, but less discomfort and preferred by children and their parents compared to standard tests.

CONCLUSION

The eMOVA test appears as a reliable test to assess near visual acuity in children. By its portability and efficiency, this application proved to be a relevant tool to be used for children eye examination in daily routine at the hospital.

Use of Mobile Apps for Visual Acuity Assessment: Systematic Review and Meta-analysis

Background

Vision impairments (VIs) and blindness are major global public health issues. A visual acuity (VA) test is one of the most crucial standard psychophysical tests of visual function and has been widely used in a broad range of health care domains, especially in many clinical settings. In recent years, there has been increasing research on mobile app–based VA assessment designed to allow people to test their VA at any time and any location.

Objective

The goal of the review was to assess the accuracy and reliability of using mobile VA measurement apps.

Methods

We searched PubMed, Embase, Cochrane Library, and Google Scholar for relevant articles on mobile apps for VA assessment published between January 1, 2008, and July 1, 2020. Two researchers independently inspected and selected relevant studies. Eventually, we included 22 studies that assessed tablet or smartphone apps for VA measurement. We then analyzed sensitivity, specificity, and accuracy in the 6 papers we found through a meta-analysis.

Results

Most of the 22 selected studies can be considered of high quality based on the Quality Assessment of Diagnostic Accuracy Studies–2. In a meta-analysis of 6 studies involving 24,284 participants, we categorized the studies based on the age groups of the study participants (ie, aged 3-5 years, aged 6-22 years, and aged 55 years and older), examiner (ie, professional and nonprofessional examiners), and the type of mobile devices (ie, smartphone, iPad). In the group aged 3 to 5 years, the pooled sensitivity for VA app tests versus clinical VA tests was 0.87 (95% CI 0.79-0.93; P=.39), and the pooled specificity was 0.78 (95% CI 0.70-0.85; P=.37). In the group aged 6 to 22 years, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86 (95% CI 0.84-0.87; P<.001), and the pooled specificity for VA app tests versus clinical VA tests was 0.91 (95% CI 0.90-0.91; P=.27). In the group aged 55 years and older, the pooled sensitivity for VA app tests versus clinical VA tests was 0.85 (95% CI 0.55-0.98), and the pooled specificity for VA app tests versus clinical VA tests was 0.98 (95% CI 0.95-0.99). We found that the nonprofessional examiner group (AUC 0.93) had higher accuracy than the professional examiner group (AUC 0.87). In the iPad-based group, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86, and the pooled specificity was 0.79. In the smartphone-based group, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86 (P<.001), and the pooled specificity for VA app tests versus clinical VA tests was 0.91 (P<.001).

Conclusions

In this study, we conducted a comprehensive review of the research on existing mobile apps for VA tests to investigate their diagnostic value and limitations. Evidence gained from this study suggests that mobile app–based VA tests can be useful for on-demand VI detection.

Digital Tools for the Self-Assessment of Visual Acuity: A Systematic Review

INTRODUCTION

Numerous digital tools to self-assess visual acuity have been introduced. The recent COVID-19 pandemic underlined the need for high-quality remote care. This review gives a current overview of digital tools for remotely assessing visual function and reports on their accuracy.

METHODS

We searched the databases of Embase and Pubmed, and systematically reviewed the literature, conforming to PRISMA guidelines. Two preliminary papers were added from medRxiv.org. The main outcome was the agreement of the digital tools with conventional clinical charts, as expressed by mean differences and 95% limits of agreement (95% LoA).

RESULTS

Seventeen publications included studies reported on 13 different digital tools. Most of the tools focus on distance visual acuity. The mean differences of the digital tools ranged from - 0.08 to 0.10 logMAR, when compared to traditional clinical assessments. The 95% LoA differed considerably between studies: from ± 0.08 logMAR to ± 0.47 logMAR, though the variability was less pronounced for higher visual acuities.

CONCLUSION

The low mean differences between digital visual acuity assessments and reference charts suggest clinical equivalence, though the wide 95% LoA identify a lower precision of digital self-assessments. This effect diminishes in individuals with better visual acuities, which is a common feature of visual acuity assessments. There is great potential for the digital tools to increase access to eye care and we expect the accuracy of the current tools to improve with every iteration in technology development.

Validation of Digital Applications for Evaluation of Visual Parameters: A Narrative Review

The current review aimed to collect and critically analyze the scientific peer-reviewed literature that is available about the use of digital applications for evaluation of visual parameters in electronic devices (tablets and smartphones), confirming if there are studies calibrating and validating each of these applications. Three bibliographic search engines (using the search equation described in the paper) and the Mendeley reference manager search engine were used to complete the analysis. Only articles written in English and that are evaluating the use of tests in healthy patients to measure or characterize any visual function aspects using tablets or smartphones were included. Articles using electronic visual tests to assess the results of surgical procedures or are conducted in pathological conditions were excluded. A total of 19 articles meeting these inclusion and exclusion criteria were finally analyzed. One critical point of all these studies is that there was no mention of the characterization (spatial and/or colorimetrical) of screens and the stimuli used in most of them. Only two studies described some level of calibration of the digital device before the beginning of the study. Most revised articles described non-controlled comparatives studies (73.7%), reporting some level of scientific evidence on the validation of tools, although more consistent studies are needed.

Enabling teleophthalmology during the COVID-19 pandemic in the Province of Trento, Italy: Design and implementation of a mHealth solution

BACKGROUND

Due to the many restrictions imposed during the COVID-19 emergency, the normal clinical activities have been stopped abruptly in view of limiting the circulation of the virus. The extraordinary containment measures have had a dramatic impact on the undertaking and follow-up of ophthalmic outpatients.

OBJECTIVE

In order to guarantee proper monitoring and routine care, the Pediatric Ophthalmology equipe of Rovereto Hospital (North-East of Italy) supported by the Competence Center on Digital Health TrentinoSalute4.0, designed and implemented a digital platform, TreC Oculistica, enabling teleophthalmology. We report our innovative-albeit restricted-experience aiming at testing and maximizing the efficacy of remote ophthalmic and orthoptic visits.

METHODS

A multidisciplinary team created the TreC Oculistica platform and defined a teleophthalmology protocol. The system consists of a clinician web interface and a patient mobile application. Clinicians can prescribe outpatients with the App and some preliminary measurements to be self-collected before the televisit. The App conveys the clinician's requests (i.e. measurements) and eases the share of the collected information in a secure digital environment, promoting a new health care workflow.

RESULTS

Four clinicians took part in the testing phase (2 ophthalmologists and 2 orthoptists) and recruited 37 patients (mostly pediatric) in 3 months. Thanks to a continuous feedback between the testing and the technical implementation, it has been possible to identify pros and cons of the implemented functionalities, considering possible improvements. Digital solutions such as TreC Oculistica advance the digitalization of the Italian health care system, promoting a structured and effective reorganization of the workload supported by digital systems.

CONCLUSIONS

The study tested an innovative digital solution in the teleophthalmology context and represented the first experience within the Italian healthcare system. This solution opens up new possibilities and scenarios that can be effective not only during the pandemic, but also in the traditional management of public health services.

Applying normal PedEyeQ thresholds to define reduced quality of life

Patient-reported outcome measures such as the Pediatric Eye Questionnaire (PedEyeQ) are increasingly recognized as important in healthcare assessment. Defining normal PedEyeQ thresholds would allow classification of individual children as having reduced versus normal domain scores. We prospectively enrolled visually normal children (aged 0-17 years; n = 310) to calculate normal PedEyeQ domain thresholds. In addition, 48 children with bilateral visual impairment (VI; best-eye acuity worse than 20/70 or 20/70 or better with limited visual fields) were enrolled for validation. The Child PedEyeQ (four domains) was completed by 5- to 17-year-olds. Parents completed Proxy (five domains) and Parent PedEyeQ (four domains). Each domain was Rasch scored (converted to 0-100); normal thresholds were defined as the 5th percentile of scores in visually normal controls. For Child 5-11 PedEyeQ, 39%-78% of VI children had reduced domain scores, and 88%-100% for 12- to 17-year-olds. For Proxy PedEyeQ, proportions ranged from 55% to 100% and for Parent PedEyeQ ≥83% had reduced scores. High prevalence of reduced PedEyeQ domain scores in the VI cohort, validates the use of normal thresholds. Nevertheless, variability in child self-reporting creates challenges for identifying individual 5- to 11-year-olds with reduced scores.

Smartphone applications in ophthalmology: A quantitative analysis

Purpose:

There is limited information in literature about the scope and usability of Smartphone Applications (Apps) in ophthalmology. Eye care professionals are therefore skeptical about the benefits of smartphone Apps and are reluctant to adopt it in their day to day practice. The purpose of this study was to provide an updated overview of all Apps exclusive to ophthalmology.

Methods:

This study was a quantitative analysis of Smartphone Apps exclusively designed for ophthalmic care. The Apple iPhone and Google play store were searched for eye care themed Apps. Any App related to eye treatment and management such as visual acuity screening, eye education, calculators, eBooks, Low Vision Aids were included in the study. Data on the purpose of the Apps, target end-users, validation, App usage, user ratings, and App developer qualifications were documented.

Results:

As of March 2020, a total of 131 Apps exclusively dedicated for eye care were identified. 53% (69/131) were available in iPhones, 44% (58/131) in Android smartphones, and 3% in both. 32% (41/131) Apps were designed for visual acuity (VA) screening, 13% (17/131) for eye relaxation exercises, 12% (15/131) for professional education, and the remaining for Apps detecting color blindness, low vision aids, and assistance and patient education. Among the 131 Apps, 6 (4.5%) Apps are claimed by the developers as validated.

Conclusion:

This study unveils a wide range of smartphone Apps exclusive to ophthalmology and suggests guidelines to choose an appropriate App. The study also highlights the importance of interdisciplinary collaboration in the design, development, and validation of such Apps.

Saving space: Comparing mini - logMAR with standard logMAR visual acuity

Purpose:

Assessing visual acuity (VA) is the cornerstone of an ophthalmic workup and needs VA charts in a four or six meters space. The objective of this study was to compare the performance of distant VA (DVA) on one meter mini-logMAR (MLM) with a standard six meter logMAR (SLM) chart.

Methods:

We developed a MLM chart to be used at 1 m with +1.0 D spectacles, by reducing the SLM chart designed for 6 meters, to 1/6^th its size, using AutoCAD version 2014. On an initial cohort, we obtained DVA on the two charts by optometrist trainees, masked to the outcomes on the different tests. We performed regression and checked agreement between the two measurements. Subsequently, on a new cohort, we validated the performance of the MLM.

Results:

Of the 56 initial subjects, mean DVA with SLM was 0.44 ± 0.13 and with MLM was 0.45 ± 0.13; mean difference of -0.01 ± 0.02, 95%CI: 0.007 to 0.018; P < 0.0001 on paired t-test. There was a significant correlation: r = 0.99; r² = 0.98, P < 0.0001. On an average, DVA with MLM was less than a letter worse than with SLM. The regression formula obtained: SLM DVA = -0.1312 + 1.0014 x (MLM DVA). The validation study revealed no significant difference (P = 0.29) between the predicted standard DVA calculated by the regression formula and the actual standard.

Conclusion:

We suggest that we can deduce distance logMAR VA from a mini-logMAR chart as devised and used by us. This will take less space, be portable and allow congenial interaction with patients.

Utility of teleconsultation in accessing eye care in a developing country during COVID-19 pandemic

OBJECTIVE

To evaluate the utility of teleconsultation in the provision of eye care services during the COVID-19 lockdown. Disparities in the consultation burden of sub-specialities and socio-demographic differences in teleconsultation utilization were also assessed.

METHODS

Al-Shifa Trust Eye Hospital Rawalpindi began audio and video teleconsultation using broadband telecommunication services during the lockdown. Patients' and consultations' data gathered during the first three weeks after the commencement of this programme were compared with data from the four weeks prior to lockdown. The weekly consultation ratio and overall consultation burden of sub-specialities were measured. Chi-Square tests of association determined the relationship between different variables (socioeconomic status and consultation characteristics) and consultation modality (on-site vs online).

RESULTS

In total, 17507 on-site consultations (4377/week) were conducted compared to 1431 teleconsultations (477/week), which maintained 10.89% of the weekly pre-lockdown eye care services. The post-lockdown teleconsultation programme saw a relatively higher percentage of service utility among female (47.09% vs 44.71%), younger-age (31.33±19.45 vs 41.25±23.32 years) and higher-socioeconomic-status (32.21% vs 0.30%) patients compared to pre-lockdown on-site consultations. The most common indication for teleconsultation was red-eye (16.70%). While cornea and glaucoma clinics maintained most of the pre-lockdown services (30.42% and 29% respectively), the highest dropout was seen in optometric and vitreoretinal services supporting only 5.54% and 8.28% of pre-lockdown services, respectively.

CONCLUSION

Digital initiatives could partially maintain eye care services during the lockdown. Focused strategies to improve teleconsultation utilization are required during the pandemic and beyond.

Eliminating Visual Acuity and Dilated Fundus Examinations Improves Cost Efficiency of Performing Optical Coherence Tomogrpahy-Guided Intravitreal Injections

Purpose

The clinic efficiency and cost savings achieved by eliminating formal visual acuity (VA) and dilated fundus examinations (DFEs) were assessed for established patients receiving optical coherence tomography (OCT)–guided intravitreal injections.

Design

Comparative cost analysis.

Methods

Two different treatment models were evaluated. The first model included patients undergoing routine VA assessment, DFEs, OCT imaging, and intravitreal injections. The second model eliminated the routine VA assessment and DFE while using OCT imaging through an undilated pupil followed by the intravitreal injection. The 2 models incorporated both bevacizumab and aflibercept. The number of patients per clinic day, the cost per visit, and the daily revenues were compared between the 2 models.

Results

Optimized schedules with and without VA assessments and DFEs allowed for 48 and 96 patients to be injected per day, respectively. Excluding drug costs, the cost per encounter for the visits with and without a DFE were $39.33 and $22.63, respectively. Including the drug costs, the costs per encounter for the visits with and without a DFE were $85.55 and $68.85 for bevacizumab and $1787.58 and $17770.88 for aflibercept, respectively. Once the reimbursements for each visit type were included, the clinics that eliminated the VA and DFEs were more cost efficient.

Conclusion

Eliminating both VA assessments and DFEs for patients undergoing OCT-guided retreatment with intravitreal injections resulted in decreased exposure times between patients and clinic staff, decreased cost per encounter, and increased patient volumes per clinic day, resulting in improved clinic efficiency and safety while seeing more patients in a clinic day.

A mobile vision testing application based on dynamic distance determination from the human corneal limbus

Here we present a mobile application that accurately determines the distance between an optical sensor and the human corneal limbus for visual acuity assessment. The application uses digital image processing and randomized circle detection to locate the cornea. Then, a reference scaling measurement is employed to calculate distance from the sensor to a user. To determine accuracy and generalizability, testing was conducted both with 200 static images, 25 images each of males and females for four ethnic groups from a facial image database, and live image streams from a test subject. Average absolute corneal radius error over 10 trials for the static images was 6.36%, while average absolute distance error for the live image streams was less than 1%. Subsequently, distance measurements were used to scale letter sizes for a Snellen Chart-based visual acuity assessment. This system enables monitoring of chronic retinal diseases, as patients can quickly and accurately measure their visual acuity through the mobile eye exam suite.

Validation of the visual acuity iPad app Eye Chart Pro compared to the standard Early Treatment Diabetic Retinopathy Study chart in a low-vision population

INTRODUCTION

A low-vision assessment (LVA) is central to developing a vision rehabilitation plan. However, access to LVAs is often limited by the quantity and geographic distribution of low-vision providers, as well as patient-centred transportation challenges. A tablet-based LVA tool kit, delivered virtually, has the potential to overcome many of these barriers. The purpose of this research was to validate a key component of the tablet-based tool kit - a commercially available iPad visual acuity (VA) test (Eye Chart Pro) iPad app - in a low-vision population.

METHODS

Participants with low vision (n = 26) and those who were normally sighted (n = 25) underwent VA testing with both the iPad VA test application and the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The VA data were compared using a t-test, linear regression and Bland-Altman analysis.

RESULTS

There was no significant difference in the mean absolute difference in VA (log of minimum angle of resolution (logMAR)=0.11; p = 0.82). Eye Chart Pro and Standard ETDRS Chart measures were also not significantly different (p = 0.98). However, there were significant differences between test methods in the low-vision group and the normally sighted group (p > 0.0001 and p = 0.007, respectively). The Bland-Altman analysis showed a mean bias (difference) of -0.0005 logMAR between methods, and 95% limits of agreement of 0.298 and -0.299 logMAR.

DISCUSSION

The ETDRS chart function on the Eye Chart Pro application can reliably measure VA across a range, from normally sighted patients to those with low vision.

A new visual acuity test on touchpad for vision screening in children

AIM

To validate a visual acuity (VA) test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.

METHODS

A cohort of 101 patients, 44 girls and 57 boys with a median of 6.5 years old (3-10 years of age), presenting for eye examinations in Ophthalmology Department (Strasbourg, France) between November 1^st, 2018, and February 1^st, 2019 were enrolled. Monocular and binocular VA testing was performed on the subject using both a standard test and the touchpad application (Monoyer, "E" or, Pigassou depending of children's capacities). Patients were excluded if they were physically or mentally unable to use the touchpad. The duration of each tests, the painfulness, the comprehension, the attention of children during the test and test's preferences were also evaluated.

RESULTS

There was a good linear correlation and intra-class correlation coefficient [ICC=0.50 (0.34, 0.64) for binocular acuity, 0.74 (0.64, 0.82) for right eyes and 0.525 (0.37, 0.66) for left eye]. The standard errors of measurement were very low (0.08, 0.05, 0.08 for binocular VA, right eyes VA and left eyes VA, respectively). There was no difference between two tests for right eye (P=0.126), left eye (P=0.098) and binocular acuity (P=0.085). Non inferiority was proved for all binocular [-0.06 (-0.09, -0.03)], right eye [-0.04 (-0.07, -0.01)] and left eye [-0.06 (-0.09, -0.02)] VA. The sensitivity and specificity, which correspond to the ability for our app to detect amblyopia, were 92% and 80% respectively.

CONCLUSION

Our touchpad application represents an efficient and valid test of VA in children with a high specificity to detect visual impairment.

Smart phone apps every ophthalmologist should know about

We are living in a mobile world, where the number of medical apps is surging in recent years. Over 320 000 healthcare apps are now available as shown in the latest research. The major function and potential of these apps vary, from assisting the learning and practice of clinicians as well as achieving better outcomes of patients to preventing eye diseases through the education of healthy individuals. However, based on the various features, ophthalmology apps nowadays contain a wide range of subjects and focus on different stakeholders in the ophthalmic practice, including but not limited to doctors, patients, and researchers. Here, we review special and advanced apps that ophthalmologists will find useful in their clinical practice.

Does the EyeChart App for iPhones Give Comparable Measurements to Traditional Visual Acuity Charts?

Aim

To investigate if the EyeChart app gives accurate visual acuity (VA) measurements that are comparable to those achieved using traditional VA charts.

Method

Twenty-four participants (aged 18-27 years, mean 20.13 ± 1.78 years) with VA of 6/60 Snellen or better regardless of any strabismus, amblyopia, or ocular pathology volunteered for this prospective study. The best-corrected monocular VA of each participant's right eye was measured on the Snellen chart at 6 m, the ETDRS chart at 3 m, and the EyeChart app presented on an iPhone SE at 1.2 m (4ft).

Results

The mean VA scores obtained were: -0.13 ± 0.08 logMAR on the Snellen chart, -0.11 ± 0.08 logMAR on the ETDRS chart, and -0.09 ± 0.07 logMAR on the EyeChart app. After Bonferroni Correction adjustments were applied, a significant difference was found between the EyeChart app and the Snellen chart (t = -3.756, p = 0.003), however the difference between the EyeChart app and the ETDRS chart did not reach statistical significance (t = -2.391, p = 0.076). The EyeChart app had a strong correlation with both the Snellen (r = 0.79, p < 0.01) and ETDRS charts (r = 0.88, p < 0.01). The Coefficients of Agreement revealed a variation of less than one logMAR line between the EyeChart app and the traditional VA charts (Snellen: 0.09 logMAR; ETDRS: 0.08 logMAR).

Conclusion

This study found that the EyeChart app gives accurate VA scores that are comparable to those achieved using the gold-standard ETDRS chart in a healthy young adult population. However, the accuracy and repeatability of the EyeChart app when testing a patient population must be investigated before it can be integrated into clinical practice.

Development and validation of a machine learning, smartphone-based tonometer

BACKGROUND/AIMS

To compare intraocular pressure (IOP) measurements using a prototype smartphone tonometer with other tonometers used in clinical practice.

METHODS

Patients from an academic glaucoma practice were recruited. The smartphone tonometer uses fixed force applanation and in conjunction with a machine-learning computer algorithm is able to calculate the IOP. IOP was also measured using Goldmann applanation tonometry (GAT) in all subjects. A subset of patients were also measured using ICare, pneumotonometry (upright and supine positions) and Tono-Pen (upright and supine positions) and the results were compared.

RESULTS

92 eyes of 81 subjects were successfully measured. The mean difference (in mm Hg) for IOP measurements of the smartphone tonometer versus other devices was +0.24 mm Hg for GAT, -1.39 mm Hg for ICare, -3.71 mm Hg for pneumotonometry and -1.30 mm Hg for Tono-Pen. The 95% limits of agreement for the smartphone tonometer versus other devices was -4.35 to 4.83 mm Hg for GAT, -6.48 to 3.70 mm Hg for ICare, -7.66 to -0.15 mm Hg for pneumotonometry and -5.72 to 3.12 mm Hg for Tono-Pen. Overall, the smartphone tonometer results correlated best with GAT (R²=0.67, p<0.001). Of the 92 videos, 90 (97.8%) were within ±5 mm Hg of GAT and 58 (63.0%) were within ±2 mm Hg of GAT.

CONCLUSIONS

Preliminary IOP measurements using a prototype smartphone-based tonometer was grossly equivalent to the reference standard.

Development and Validation of a Smartphone-Based Visual Acuity Test (Vision at Home)

Purpose

To describe the development and validation of a smartphone-based visual acuity (VA) test called Vision at home (V@home).

Methods

Three study populations (elderly Chinese, adolescent Chinese, and Australian groups) underwent distance and near VA testing using standard Early Treatment Diabetic Retinopathy Study (ETDRS) charts and the V@home device; all VA tests used tumbling E optotypes. VA tests were repeated with one eye, selected randomly. Distance VA was measured monocularly at 2 m, and near VA was measured binocularly at 40 cm. Participants also completed a questionnaire about their satisfaction with the device. V@home VA (logMAR) was compared to VA for ETDRS charts at distance and near and test-retest reliability.

Results

The mean difference between V@home and ETDRS distance VA across all groups ranged from -0.010 to -0.100 logMAR. Tolerant weighted kappa (TWK) agreement ranged from substantial (0.742) in the Australian group to almost perfect (0.950) in the adolescent Chinese group. There was high agreement of V@home with near ETDRS VA across all groups, with a mean difference of -0.092 to -0.042 logMAR and a TWK of 0.736 to 0.837. Test-retest reliability was also high (difference: -0.018 to 0.026) for both distance and near VA tests (95% limits of agreement: -0.289 to 0.258 for distance and -0.235 to 0.199 for near). The majority of participants were satisfied with V@home.

Conclusions

V@home could accurately and reliably measure both distance and near VA and is well accepted by participants.

Translational Relevance

The V@home system could potentially serve as a useful tool to improve eye care accessibility, especially in underdeveloped areas with limited eye care personnel and resources.

House Calls Are Reaching the Tipping Point - Now We Need the Workforce

Home-based primary care (HBPC) improves the lives of high-cost, frail, homebound patients and their caregivers while reducing costs by keeping patients at home and reducing the use of hospitals and nursing homes. Several forces are behind the resurgence of HBPC, including the rapidly aging population, advancements in portable medical technology, evidence showing the value of HBPC, and improved payments for HBPC. There are 2 million to 4 million patients who could benefit from HBPC, but only 12% are receiving it. The number of these patients is expected to double over the next two decades. This requires a larger and better prepared HBPC workforce, making St. Clair and colleagues' article published within this same issue very timely. They showed residents exposed to HBPC had increased interests in providing HBPC in the future. They also found HBPC training fulfilled all 6 Accreditation Council of Graduate Medical Education core competencies and at least 16 of the 22 Family Medicine Milestone Project subcompetencies. Such medical education curricula are necessary to sufficiently develop a future workforce capable of appropriately providing HBPC to an increasing number of patients.

Android mobile applications in eye care

Google Play Store was used to search for eye care-related applications the android simulator using various general terms related to eye care to review and categorize various interactive eye care-related applications in android platform from the details available in the application website. Data collected from application description and application developer's webpage include target audience, category of apps, estimated number of downloads, average user rating, involvement of eye care professionals in developing the application, and cost of the app. All these data were collected only from the details provided in the application website considering on online user perspective and the developers were not contacted to collect any other details. In total, 475 applications were identified and grouped into 13 categories depending on the type of service the application provide. Out of which, only 107 (22.53%) applications had mentioned about the eye care professional involvement in their design or development of the application. The applications were also stratified according to the target audience, and many had no user rating with very few downloads. The lack of evidence-based principles and standardization of application development should be taken into consideration to avoid its negative impact on the community, especially in eye care.

Validation of Peek Acuity application in pediatric screening programs in Paraguay

AIM

To validate the Peek Acuity mobile phone application in pediatric populations and compare its utility, both economic and diagnostic, against conventional screening methods using a pediatric ophthalmologist examination as the gold standard.

METHODS

A cohort of 393 subjects from Fernando de la Mora, Paraguay (ages 6-16y) were enrolled in the study. Subjects were randomly assigned a starting screening modality among: Peek Acuity, a single line of tumbling E optotypes set at 20/40, and Spot Vision Screener. Once completing the first screening modality, the subjects completed the two remaining techniques. Referral criteria were established based on the most current American Association of Pediatric Ophthalmology and Strabismus (AAPOS) recommendations: 20/40 for Peek Acuity and the tumbling E, and refractive error detection for the Spot Vision Screener. Subjects that failed to achieve the cut-off for any of the three screening techniques or subjects that passed the screening but were randomly selected to perform a comprehensive eye exam to determine the false negative rate, were evaluated by a pediatric ophthalmologist. This evaluation was considered the gold standard, and included vision assessment by a Snellen chart, strabismus evaluation, and cycloplegic refraction with dilated fundoscopy.

RESULTS

We obtained 48% sensitivity, 83% specificity, 43% positive predictive value, and 86% negative predictive value for Peek Acuity's ability to refer compared to evaluation by a pediatric ophthalmologist, failing to achieve a desired sensitivity for implementation. Peek Acuity trended to overestimate the subject's visual acuity, providing a higher visual acuity that would not indicate referral for a comprehensive eye examination. However, its high specificity accurately predicted a significant number of children who did not need further evaluation. When comparing the three screening methods, no single screening modality outperformed the others. Peek Acuity represented a technology that was economically feasible compared to other screening modalities in low income settings, due to the prevalence of cell phone use.

CONCLUSION

Peek Acuity represents an efficient tool that has potential for implementation in school screenings with different strategies aimed at pediatric populations due to its low cost and high specificity. An increase in sensitivity would improve detection of children with refractive errors.