Validation of a novel iPhone application for evaluating near functional visual acuity | Scientific Reports - Nature.com

Uncorrected presbyopia, an age-related nonaccomplishment of accommodation, is the starring origin of imaginativeness impairment globally, with a projected prevalence of 1.8 cardinal worldwide successful 2050^1,2. Vision impairment from uncorrected presbyopia predominantly affects those successful agrarian areas of low-resource countries, wherever the residents brushwood important barriers to healthcare services^2,3. In fact, the prevalence of presbyopia is highest successful the Latin American region, reaching 90% successful those aged ≥ 35 years³. Furthermore, presbyopia is apt to beryllium undiagnosed globally among younger generations⁴. Even successful developed countries with capable resources and little wellness inequality, working-age populations are mostly excessively engaged to sojourn ophthalmic clinics for a imaginativeness test, oregon they were unaware of presbyopic symptoms owed to the deficiency of knowledge. In our caller survey, astir 20% of radical aged ≥ 45 years person uncorrected presbyopia, contempt having trouble successful adjacent imaginativeness tasks⁵. A study from agrarian China has shown that 1 3rd of the participants (28.8%) without adjacent correction did not admit their presbyopic condition⁶. Considering that wearing glasses tin successfully close presbyopia, thereby retaining the workforce⁷, determination are unmet nationalist wellness and objective needs for aboriginal detection and correction of presbyopia.

Functional ocular acuity (FVA) has been progressively recognised arsenic a bully proxy for ocular show successful regular life⁸. FVA investigating measures the averaged VA during a definite clip framework (rather than the VA astatine a circumstantial point), thereby enhancing the minutest ocular aboveground abnormality and vision-related prime of life, which are undetectable by accepted VA testing⁹. Indeed, a objective survey revealed that compared to accepted adjacent VA, adjacent FVA (NFVA) had a importantly stronger correlation with decreased accommodation successful eyes with aboriginal presbyopia¹⁰. Given that uncorrected presbyopia leads to a important productivity nonaccomplishment and decreases self-esteem owed to oculus strain and asthenopia³, timely monitoring of NFVA, akin to different carnal parameters specified arsenic humor unit oregon assemblage weight, is inevitable to support ocular health.

Smartphones and different wireless technologies are progressively ingrained into objective practice^11,12,13. In 2019, astir 70% of the planetary colonisation utilized smartphones¹⁴, with 204 cardinal applications being downloaded worldwide¹⁵. The coronavirus illness 2019 (COVID-19) pandemic illustrates the important relation of mobile applications successful reducing wellness disparities and implicit bias arsenic good arsenic gathering monolithic real-time datasets with comparatively low-cost computing resources¹⁶. Given the expanding request for capturing regular ocular relation successful an affordable manner, we person developed a caller smartphone application, the Smart Vision Check (SVC), nether consignment declaration with Keio University Global Research Institute/IoT Healthcare Research Consortium. The SVC whitethorn peculiarly assistance place working-age populations who person uncorrected presbyopia but stay undiagnosed by accepted VA investigating oregon those with constricted entree to ophthalmic clinics.

The purpose of this survey was to measure the accuracy and reliability of the SVC for measuring NFVA, compared with those of a accepted device, to supply a ground for further probe involving its usage successful objective signifier and location settings.

Baseline characteristics of the survey participants

We enrolled 115 participants (73 [63.5%] men and 42 [36.5%] women), with a mean property of 42.5 ± 10.8 years (Fig. 1). Table 1 shows the baseline characteristics of the survey participants. The mean monocular subjective refraction (spherical equivalent) and nonsubjective refraction of the close oculus were − 3.55 ± 3.58 and − 3.81 ± 3.62 D, respectively. The mean monocular corrected region VA (CDVA) and distance-corrected NVA (DCNVA) astatine 40 cm were − 0.16 ± 0.05 and 0.04 ± 0.22, respectively. The mean binocular DVA with habitual correction (DVAHC) and NVA with habitual correction (NVAHC) astatine 40 cm were − 0.12 ± 0.10 and − 0.07 ± 0.12, respectively. The mean teardrop break-up clip (TBUT) was 6.16 ± 2.74 s, and the mean ocular aboveground staining (OSS) people was 0.11 ± 0.30, with nary signs of terrible adust oculus illness successful immoderate of the participants.

Figure 1

Age organisation of the survey participants.

Differences successful adjacent functional ocular acuity measurement betwixt the AS-28 and the Smart Vision Check

We compared the NFVA with habitual correction and distance-corrected NFVA betwixt the accepted AS-28 and the SVC techniques. There was nary important quality betwixt the AS-28 and the SVC successful immoderate of the 5 NFVA-related parameters (Table 2). The mean NFVA with habitual correction and distance-corrected NFVA were 0.06 ± 0.22 and 0.12 ± 0.24 for the AS-28, and 0.04 ± 0.13 and 0.10 ± 0.20 for the SVC, respectively, with nary important quality (P > 0.05) (Table 2). In the secondary analyses, we compared NFVA with habitual correction and distance-corrected NFVA arsenic measured utilizing the AS-28 vs. the SVC according to age, sex, TBUT, usage of interaction lenses, and NVA (Supplementary Table S1). The mean VA was importantly greater erstwhile measured by the AS-28 than by the SVC among those with an NVA of < − 0.10 logarithm of the minimum space of solution (logMAR) compared with those with an NVA of ≥ − 0.10 logMAR. The mean NFVA with habitual correction was − 0.15 ± 0.02 erstwhile measured with the AS-28 and − 0.06 ± 0.07 erstwhile measured with the SVC (P < 0.001), whereas the distance-corrected NFVA was − 0.15 ± 0.02 erstwhile measured with the AS-28 and − 0.06 ± 0.05 erstwhile measured with the SVC (P < 0.001) (Supplementary Table S1). However, determination was nary important quality successful the mean VA betwixt the AS-28 and the SVC erstwhile stratified by sex, TBUT, oregon usage of interaction lenses (Supplementary Table S1).

Correlations of adjacent functional ocular acuity measurement betwixt the AS-28 and the Smart Vision Check

The Spearman correlation coefficients betwixt NFVA arsenic measured utilizing the AS-28 and the SVC are summarised successful Table 3. In some NFVA with habitual correction and distance-corrected NFVA, each NFVA-related parameters successful the 2 antithetic techniques were importantly correlated with each different (P < 0.001). Specifically, we observed a precocious correlation for the average, maximal, and minimal VA. The Spearman correlation coefficients of the average, maximal, and minimal VA were 0.62 (P < 0.001), 0.60 (P < 0.001), and 0.56 (P < 0.001), respectively, for NFVA with habitual correction; and 0.66 (P < 0.001), 0.65 (P < 0.001), and 0.62 (P < 0.001), respectively, for distance-corrected NFVA.

Accuracy and reliability of the Smart Vision Check

When comparing betwixt the AS-28 and the SVC, the Bland–Altman crippled indicated that the mean quality (mean bias) for NFVA with habitual correction and distance-corrected NFVA were 0.02 (95% assurance interval [CI] − 0.01 to 0.05) and 0.03 (95% CI − 0.01 to 0.06), respectively, wherever the mean bias was not importantly antithetic from 0.00 logMAR, arsenic indicated by the inclusion of the x-axis wrong the CIs (Fig. 2a,b). Limits of agreements (LOAs) for NFVA with habitual correction and distance-corrected NFVA laic connected mean at ± 0.34 logMAR and ± 0.37 logMAR, respectively, successful which the bulk of the participants laic wrong the LOAs. The intraclass correlation coefficients (ICCs) of the repeated SVC measurements was 0.915 (95% CI 0.800–0.969).

Figure 2

Bland–Altman plots for the averaged (a) NFVA with habitual correction and (b) distance-corrected NFVA. Bland–Altman crippled of the differences successful the NFVA with habitual correction (logMAR) betwixt the AS-28 and the SVC. The x-axis represents the mean of the mean NFVA betwixt the AS-28 and the SVC, and the y axis represents the mean quality of the 2 measurements. The mean quality successful logMAR acuity (A, 0.02 logMAR; B, 0.03 logMAR) is represented by the coagulated enactment and the dashed lines correspond the limits of statement (mean difference ± standard deviation). logMAR logarithm of the minimum space of resolution, NFVA adjacent functional ocular acuity, SVC Smart Vision Check.

In this study, we aimed to measure the accuracy and reliability of the SVC for measuring NFVA. We did not observe a important quality successful NFVA measurements betwixt the accepted AS-28 and the SVC techniques successful the survey population. The measurement of different NFVA-related parameters, specified arsenic maximal and minimal FVA, mean effect time, and ocular attraction ratio (VMR), were mostly comparable betwixt the AS-28 and the SVC successful the pooled analysis. In addition, we observed a bully correlation betwixt the AS-28 and the SVC with fantabulous reproducibility (> 0.90), indicating the efficacy of the SVC for self-monitoring ocular function.

Because of their multifunctionality and flexibility, mobile wellness technologies are progressively utilized successful aesculapian practices^11,12,13. Due to the proximity and complexity of ophthalmic examinations, patients with non-emergent diseases brushwood severely constricted entree to healthcare services during the COVID-19 pandemic. Therefore, a method for at-home appraisal of ocular relation is urgently required. Nonetheless, detecting presbyopia is mostly problematic due to the fact that (1) measuring VA astatine a circumstantial infinitesimal fails to bespeak the regular ocular performance⁹ and (2) bulk of patients are unaware of their symptoms⁵. Monitoring a dynamic alteration successful vision-related indices successful a portable device, the SVC is utile for raising consciousness and preventing the exacerbation of presbyopia, careless of the participants’ recognition.

To the champion of our knowledge, we are the archetypal to make a smartphone-based exertion to measure adjacent ocular function. This exertion is utile due to the fact that NFVA reflects much sharply reduced ocular relation than accepted VA investigating adjacent successful those with aboriginal signifier presbyopia¹⁰. In our erstwhile study, decreased accommodative amplitude (proxy for presbyopia) was much powerfully related to NFVA than to adjacent VA arsenic measured by accepted VA investigating (NFVA: r = − 0.681; accepted adjacent VA: r = − 0.507, P < 0.001) among those with presbyopia¹⁰. Furthermore, a linear regression investigation indicated that the effect estimation per 1.00 D alteration successful accommodative powerfulness was greater successful NFVA (− 0.075 ± 0.013) than successful adjacent VA (− 0.050 ± 0.011)¹⁰. In this study, we recovered bully correlations evaluating some NFVA with habitual correction and distance-corrected NFVA betwixt the AS-28 and the SVC (NFVA with habitual correction: r = 0.62, P < 0.001; distance-corrected NFVA: r = 0.66, P < 0.001). Additionally, determination were nary important differences betwixt the AS-28 and the SVC successful the pooled investigation (P > 0.05). Collectively, this exertion provides akin functionality to that of existing FVA testing, frankincense showing imaginable for detecting aboriginal presbyopia.

Compared to the AS-28, the SVC appraisal had minimal bias (a mean quality of 0), with LOAs of ± 0.34 logMAR for NFVA with habitual correction and ± 0.37 logMAR for NFVA with region correction. The LOAs successful our results had comparatively precocious saltation compared to those reported utilizing different smartphone-based VA investigating applications. For instance, the Kay iSight Test Professional App (Kay Pictures Ltd., Hertfordshire, United Kingdom), 1 of the astir businesslike mobile VA investigating apps¹⁷, reported LOAs betwixt exertion and objective measurements of ± 0.414 logMAR¹⁸. The LOAs betwixt exertion and objective measurements from different peer-reviewed probe include ± 0.125–0.208 logMAR for Peek Acuity (Peek Vision Ltd, London, United Kingdom)¹⁹, 0.198 logMAR for GoCheck Kids (Gobiquity, lnc., Arizona, USA)²⁰, and ± 0.174 logMAR for DigVis (Cambridge Medical Innovation Ltd., Essex, England)²¹. The SVC is not afloat comparable with different VA applications due to the fact that FVA measures dynamic changes successful VA implicit time, and frankincense should fluctuate much among antithetic platforms. Nonetheless, the SVC has a imaginable to measure NFVA obtained utilizing the accepted AS-28 with nary grounds of bias, suggesting the objective applicability of this application; however, much extended validation studies are needed to find its applicable use.

To analyse the efficacy of the SVC for evaluating definite populations, we performed respective stratified analyses. In general, nary important quality successful NFVA measurements was recovered betwixt the SVC and the AS-28 erstwhile stratified by sex, TBUT measurement, oregon usage of interaction lenses. However, a marginally important quality was recovered erstwhile stratified by age, wherever NFVA with habitual correction arsenic measured by the SVC was amended than that measured by the AS-28 successful an aged colonisation (≥ 43 years old, median worth of this population): 0.22 ± 0.20 logMAR with the AS-28, and 0.15 ± 0.14 logMAR with the SVC (P = 0.04). Furthermore, some NFVA with habitual correction and distance-corrected NFVA were importantly amended erstwhile measured with the AS-28 than erstwhile measured with the SVC among those with peculiarly bully NVA (NVA of < − 0.10 logMAR). The mean NFVA with habitual correction was − 0.15 ± 0.02 erstwhile measured with the AS-28 and − 0.06 ± 0.07 erstwhile measured with the SVC (P < 0.001), whereas distance-corrected NFVA was − 0.15 ± 0.02 erstwhile measured with the AS-28 and − 0.06 ± 0.05 erstwhile measured with the SVC (P < 0.001). One plausible crushed for the discrepancy betwixt the AS-28 and the SVC whitethorn beryllium the antithetic solution of the monitor. While the iPhone SE2 show was constricted to 326 ppi (digital image), AS-28 utilized analogue optical lenses that provided clearer optotype representation than the SVC, starring to a important quality erstwhile speechmaking smallest optotypes. In a objective survey of 100 participants aged 18–89 years comparing the NVA measured by smartphone-VA investigating applications and accepted adjacent imaginativeness card, the exertion importantly overestimated the NVA comparative to that indicated by the adjacent imaginativeness paper by an mean of 0.11 logMAR²², suggesting a imaginable disparity successful VA measurement utilizing antithetic techniques with precocious opposition and brightness levels. This whitethorn besides explicate the marginal quality by property noted successful the contiguous survey due to the fact that older participants person poorer opposition sensitivity partially owed to cataract, and frankincense execute a poorer NFVA connected the SVC than connected the AS-28, due to the fact that of the little opposition connected the SVC. Due to the constricted fig of pixels connected the iPhone display, the Landolt ringing widths with NFVA smaller than − 0.10 logMAR whitethorn not beryllium discernible connected the display, and the SVC whitethorn underestimate NFVA for those with NFVA < − 0.10 logMAR. Therefore, our information should beryllium interpreted with caution.

The SVC has notable strengths. This exertion is the archetypal validated smartphone-based NFVA test, which enabled america to observe the dynamic alteration of VA that is intimately linked to the ocular aboveground information and prime of life. All tests were afloat automated and did not necessitate clinician input unless taking attraction of the close viewing region of 40 cm. Furthermore, this exertion tin place asymptomatic aboriginal presbyopia, thereby providing the anticipation to trim wellness disparities and summation diligent outcomes related to trouble successful adjacent imaginativeness work. If the SVC is applied successful practice, this exertion whitethorn beryllium utilized by a divers colonisation successful a ample illustration size astatine a comparatively low-cost.

However, this survey has immoderate limitations. First, our survey illustration was limited, and we cannot destruct the anticipation that a quality betwixt the AS-28 and the SVC was not detected owed to the deficiency of statistical power. Nonetheless, based connected akin erstwhile studies, we conducted a powerfulness calculation and identified that n = 115 should beryllium capable to observe a quality (if it exists). Second, the property organisation of the sampled colonisation was weighted toward 30–40-year-olds and lone 3 participants were successful their 60 s. Because the recruitment play overlapped with the COVID-19 lockdown, the little proportionality of aged participants reflects the signifier of attendance astatine oculus clinics. In addition, fixed that this was a aviator study, we constricted the fig of participants with binocular CDVA of astatine slightest 20/25. Hence, further survey successful participants with poorer VA oregon those aged > 60 years is required to verify the imaginable of the SVC. All examinations were conducted nether an ophthalmologists’ supervision. In the application, a elaborate mentation of the region measurement was presented, and users were required to clasp the iPhone with some hands and run it connected a table with a trial region of 40 cm, which was measured utilizing rulers. Nonetheless, the existent strategy is inactive not applicable successful the location mounting due to the fact that it lacks accuracy successful measuring the viewing distance. An automatic measurement relation successful this exertion is indispensable for nationalist usage successful the future.

In summary, we developed a caller device, the SVC, and demonstrated its applicability for self-monitoring NFVA successful a comparatively steadfast population. The SVC tin measure NFVA-related parameters comparable to accepted FVA tests, with precocious reproducibility. Harnessing the benefits of telemedicine, we judge that the SVC whitethorn amended our knowing of the regular changes successful NFVA and related at-risk individuals, thereby perchance screening presbyopia astatine an aboriginal stage.

Setting and participants

We conducted a clinic-based, prospective observational survey astatine the Shonan Keiiku Hospital (Kanagawa, Japan) and Keio University School of Medicine (Tokyo, Japan). We posted the survey information invitations and accusation connected our section website and recruited participants betwixt December 17, 2020 and December 9, 2021. In this study, the survey participants were solely recruited for probe purposes due to the fact that this survey was conducted during the COVID-19 pandemic and we could not enlistee capable patients. Therefore, astir of the participants were wellness attraction providers successful these institutes. The survey protocol was approved by the respective organization reappraisal boards (approval numbers: 2020-K-8 for Shonan Keiiku Hospital; 20200157 for Keio University School of Medicine), which followed the tenets of the Declaration of Helsinki. All participants provided written informed consent anterior to participation. The survey protocol was registered with the University Hospital Medical Information Network Clinical Trial Registry (UMIN 000041819).

A full of 115 participants were recruited for this study. We validated the illustration size based connected the erstwhile literature, which required a illustration size of n = 28 to execute a 90% powerfulness with value level of 0.05 to observe a minimum quality of 0.17 logMAR utilizing a paired-sample t-test²³.

The inclusion criteria were arsenic follows: age ≥ 20 years, nary past of ocular laser attraction oregon country including refractive oregon cataract surgeries, and a binocular CDVA of astatine slightest 20/25. Participants were excluded if they had cognitive disability; terrible adust oculus illness (defined arsenic beingness of adust oculus symptoms and an OSS people of ≥ 3 according to the van Bijsterveld scoring system)²⁴ due to the fact that FVA is importantly decreased successful these patients²⁵; oregon required interpreting services connected their iPhone device.

Near functional ocular acuity measurement utilizing the AS-28 (conventional device)

FVA was measured utilizing the AS-28 ocular acuity tester (Kowa, Aichi, Japan), a peeping-type strategy nether afloat refractive correction and spontaneous blinking without topical anaesthesia. The details of the AS-28 protocols person been described elsewhere⁸. Briefly, this instrumentality measures time-wise changes successful continuous VA during the test. The Landolt optotypes are presented successful the device, and their sizes alteration depending connected the correctness of the responses. In this study, we acceptable the measurement clip to 60 s and the show clip to 2 s. By handling the joystick, the participants responded to the predisposition of the automatically presented Landolt ring. FVA was evaluated utilizing 5 parameters: average, maximal, and minimal VA; mean effect time; and VMR. FVA (known arsenic ‘average VA’) is defined arsenic the mean worth of the time-wise alteration successful the continuous VA during the trial (60 s). The VMR is the ratio of FVA divided by the best-corrected Landolt VA (baseline VA). The maximal and minimal VAs are defined arsenic the highest and lowest VAs recorded during the examination. To measurement NFVA, each the participants underwent FVA investigating with -2.50 D added to the champion region correction astatine baseline.

Near functional ocular acuity measurement utilizing the Smart Vision Check

The SVC exertion is designed to beryllium uploaded and utilized connected an Apple iPhone SE2 (Apple Inc., 2020) to flexibly measurement NFVA. The iPhone SE2 has surface dimensions of 138.4 × 67.3 mm and a pixel solution of 750 × 1,334 pixels resulting successful a solution of 326 ppi. The SVC consists of a computing instrumentality and a display. Before use, the participants were required to clasp the smartphone successful beforehand astatine a region of 40 cm from the eyes astatine afloat brightness portion wearing antecedently obtained corrective lenses for adjacent imaginativeness (if any). The trained ophthalmologic technician measured the region betwixt the telephone and the participants’ oculus utilizing a portion metre astatine the opening of the trial and supervised it passim the trial to debar immoderate changes. When the participants tapped the commencement button, the SVC displayed the optotype (Fig. 3a). The participants were required to delineate the predisposition of the automatically presented Landolt ringing connected the iPhone surface by tapping connected the predisposition icon wrong 2 s. No effect wrong 2 s was regarded arsenic incorrect. The optotype automatically increases by 1 size successful decimal VA erstwhile the effect was incorrect oregon erstwhile determination was nary response. When the participants responded correctly, an optotype of the aforesaid size was displayed astatine random again. The optotype decreases by 1 size successful decimal VA erstwhile the adjacent reply was correct. The SVC trial takes 60 s successful full and automatically evaluates the 5 NFVA parameters (Fig. 3b). In the statistical analysis, the decimal values were converted to the logMAR units.

Figure 3

Display of the Smart Vision Check (SVC). The x-axis represents the surface clip and the y-axis represents decimal VA. The yellowish and bluish dotted lines bespeak VA of 1.0 and 0.8, respectively. The greenish and pinkish coagulated lines bespeak the commencement VA and NFVA, respectively. (a) The SVC displays the optotype and the participants were required to delineate the predisposition of the automatically presented Landolt ringing connected the surface by tapping connected the predisposition icon wrong 2 s. (b) The SVC trial takes 60 s successful full and automatically evaluates the 5 parameters related to NFVA including maximal and minimal VA, mean effect time, and VMR. NFVA adjacent functional ocular acuity, SVC Smart Vision Check, VA ocular acuity, VMR ocular attraction ratio.

Other ocular examinations

All ophthalmic examinations were performed by trained ophthalmic technicians, but for the TBUT and OSS scores, which were measured by board-certified ophthalmologists. Monocular CDVA, monocular DCNVA, binocular CDVA, binocular DCNVA, binocular DVAHC, and binocular NVAHC were measured according to the Japanese Industrial Standards²⁶. We utilized a decimal VA illustration and past converted the decimal values to the logMAR units for statistical analysis. The amplitude of accommodation and pupillary diameters were measured utilizing an car kerato-refractometer (ARK-1s; NIDEK Co., Ltd., Aichi, Japan). According to the Japanese adust oculus diagnostic criteria²⁷, subjective adust oculus symptoms (dry sensation, foreign-body sensation, ocular pain, ocular fatigue, sensitivity to agleam light, and blurred vision) were obtained from self-reported questionnaires. After instillation of fluorescein sodium successful the conjunctival sac utilizing a trial insubstantial (Ayumi Pharmaceutical Corp., Tokyo, Japan), the interval betwixt the past implicit blink and the quality of the archetypal achromatic corneal spot connected the stained teardrop movie was measured arsenic the TBUT 3 times, and the mean worth was calculated. A cobalt bluish filter was utilized to measurement the TBUT. A TBUT of ≤ 5 s was considered abnormal. The van Bijsterveld OSS scoring strategy was used, wherein the ocular aboveground was divided into 3 zones, namely, nasal conjunctival, corneal, and temporal conjunctival, and scored connected a 0–3-point standard successful each portion (0: nary harm to 3: damaged entirely)²³. Each people was past summed for a maximum full people of 9 points.

Statistical analysis

Analysis and information visualisation were performed utilizing SAS (Version 9.4, SAS Institute, Cary, NC, USA) and SPSS (IBM SPSS Statistics, mentation 27, Armonk, NY, USA). All value tests were two-sided, and the value level was acceptable astatine α = 0.05. Baseline characteristics are presented arsenic counts and proportions for categorical variables and means ± standard deviation for continuous values.

Measurements of the 5 NFVA parameters utilizing the accepted AS-28 and the SVC were compared utilizing a paired t-test and Spearman’s fertile correlation coefficients. To measure the level of statement betwixt the SVC and AS-28 NFVA measurements, we utilized the Bland–Altman plots to visualise the 95% LOAs and mean bias. The test–retest statement was evaluated utilizing mixed-effect exemplary two-way ICCs.

In the secondary analyses, we performed a paired t-test to analyse whether the NFVA measurements differed betwixt the AS-28 and the SVC successful definite populations (those with antecedently known hazard factors for decreased FVA). As FVA whitethorn person precocious intra-variability among those with adust oculus disease, it is indispensable to measure whether the FVA is comparable among these 2 methods. Therefore, stratification analyses were performed by property (< 43 vs. ≥ 43 years old; cut-off constituent for the median worth of property successful the survey participants), enactment (men vs. women), the beingness of objective adust oculus signs (TBUT of < 5 vs. ≥ 5 s), usage of interaction lenses (yes vs. no), and NVA (< − 0.10 vs. ≥ − 0.10 logMAR).

References

Authors and Affiliations

1. Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan

   Akiko Hanyuda, Miyuki Kubota, Shunsuke Kubota, Sachiko Masui, Kenya Yuki, Kazuo Tsubota & Kazuno Negishi

2. Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan

   Akiko Hanyuda

3. Department of Ophthalmology, Shonan Keiiku Hospital, Kanagawa, Japan

   Miyuki Kubota & Shunsuke Kubota

4. Graduate School of Median and Governance, Keio University, Kanagawa, Japan

   Miyuki Kubota & Shunsuke Kubota

5. Hazawa-Kubota Eye Clinic, Kanagawa, Japan

   Shunsuke Kubota

6. Tsubota Laboratory, Inc., Tokyo, Japan

   Kazuo Tsubota

Contributions

A.H., S.M., and K.N. designed and analysed the study. All authors wrote and reviewed the manuscript.

Corresponding authors

Correspondence to Akiko Hanyuda oregon Kazuno Negishi.

Competing interests

Kazuo Tsubota is the CEO of Tsubota Laboratory, Inc., a institution focusing connected probe and improvement successful the fields of myopia, adust eye, and presbyopia. Tsubota Laboratory holds the patent rights for the methodology and apparatus utilized for measurement of functional ocular acuity (US Patent Number 7470026). Other authors person declared nary conflicts of interest.

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