Comprehensive Primary Eye Care: A Comparison Between an In-Person Eye Exam and a Tele-Eye Care Exam

Introduction

Proper access to primary eye care is essential in addressing vision impairment, and tele-eye care examinations are a promising solution that could facilitate this access in many rural or remote areas. Even though remote eye exams are becoming increasingly frequent, comprehensive tele-eye care exams are still limited by the lack of published data. The aim of this study is to compare a comprehensive tele-eye care exam with a gold standard in-person primary eye care exam with an emphasis on refractive measurements, ocular health assessment, confidence level of the eye care providers and patient satisfaction.

Methods

Sixty-six participants underwent two comprehensive eye exams performed by two eye care providers. One was a gold standard in-person exam, while the other was a remote exam performed by an eye care provider through videoconference. An overall patient satisfaction survey and a questionnaire for visual comfort with a trial frame from each modality were completed and the eye care providers scored their confidence level for each test. Exam results and diagnoses were compared between both modalities.

Results

Tele-refraction has a good to excellent agreement with in-person subjective refraction in terms of sphero-cylindrical power and best corrected visual acuity. There was no statistically significant difference for visual comfort between both modalities. The agreement between in-person and remote exams for ocular health assessment ranged from fair to almost perfect, but there was a low prevalence of ocular pathologies within the study sample. The confidence level of the eye care providers and patient satisfaction were statistically higher in-person.

Conclusion

Tele-eye care appears to be statistically and clinically non-inferior to in-person eye exams, especially for refraction, but the low prevalence of ocular pathologies somewhat limits the comparison of its efficacy for ocular health assessment. More studies on comprehensive tele-eye care exams are needed.

Ordering Eyeglasses Using 3D Head Scan Technology versus Established Online and Storefront Clinic Methods

SIGNIFICANCE

This study investigates how a new smartphone scanning technology compares with established online and storefront vendors in providing remote measurement and adjustment of prescription eyeglasses.

PURPOSE

This study aimed to evaluate a new technology for ordering prescription eyeglasses online.

METHODS

Thirty participants with 2.00 to 2.75 D of presbyopia (aged 49 to 74 years) were asked to order eyeglasses with progressive addition lenses from four vendors: one online vendor using a new head scan technology (Topology, San Francisco, CA), two established Web site-based vendors (vendors A and B), and one storefront vendor: Université de Montréal's Vision Clinic (UMVC). The resulting measurements were compared with those of opticians. Participant-reported preferences on visual and physical comfort of eyeglasses were collected after 15-minute trials of eyeglasses from each vendor.

RESULTS

Pupillary half-distance measured with Topology matched optician measurements, but online vendors A and B diverged (mean difference, - 0.80 mm [ Z = -2.79; P = .005]). Topology and vendor B segment addition heights were similar to optician measurements, but vendor A diverged (mean, -1.40 mm [ Z = -2.58; P = .01]). The personalization parameter values obtained with Topology were different from optician measurements for pantoscopic angle (-5.30° [ Z = -4.12; P < .001]) and face wrap angle (+1.25° [ Z = -2.94; P = .003]). The UMVC eyeglasses scored best for adjustment (8.71/10 [ Z = -5.53; P < .001]), with Topology coming second (7.23/10). Topology scores were equivalent to UMVC scores for all eight items of patient-reported preferences (nonparametric Friedman analysis of variance, P < .05).

CONCLUSIONS

Basic lens centration measurements obtained with Topology compare well with those of opticians, but some aspects of the methodology for measuring personalization parameters could be improved. In comparison with two established online vendors, resulting measurements with Topology are more consistent. Initial wearer satisfaction with Topology eyeglasses was also better.

Tele-refraction in tele-eye care settings

Refraction is an important part of a comprehensive eye examination, and when performed remotely through information and communication technology or when its results are transmitted for remote analysis, this procedure is called tele-refraction. Uncorrected refractive errors are the main reason for consultation in primary eye care, and an increasing number of eye care providers offer tele-refraction services in response to the global demand. Even so, very little literature exists on how the correction of refractive errors can be managed through tele-eye care. The objectives of this review are to examine the integration of tele-refraction in different eye care models and to report the existing findings regarding patient satisfaction towards tele-refraction and the efficacy of tele-refraction. Searches were undertaken on Medline, Embase, EBM Reviews, CINAHL and Web of Science to identify relevant articles. All original studies describing a clinical tele-refraction service and its outcomes were included. Out of 1322 articles, 15 were retained for analysis and have shown that tele-refraction has been provided for general eye care (n = 10; 67%), refractive-only examinations (n = 3; 20%) or disease-specific screening (n = 2; 13%). Ten (67%) had a hybrid telemedicine modality. Given the small number of included studies and the lack of outcomes comparing refractive errors between face-to-face and remote refraction, it is concluded that the current scientific literature does not reflect the increasing availability of tele-refraction in clinical practice. More studies on remote refraction should be conducted to better understand its efficacy, cost-effectiveness and impacts on patient satisfaction and management.

Comparing the Netra smartphone refractor to subjective refraction

BACKGROUND

Among technologies targeting mobile eye care, EyeNetra is a smartphone-based subjective refraction system. This study compared the results from this system with those of professional subjective refraction. Participant visual comfort and preference of results were also measured.

METHODS

Thirty-six optometry-naïve participants (n = 36 eyes, aged 18-35 years), were randomly subjected to three refraction methods: professional subjective refraction, unassisted Netra (participants alone) and refined Netra (sphere results refined by a practitioner). Using a randomised, double-blind design, refraction results were mounted in a trial frame and distance logMAR visual acuities were measured. Subjective appreciation and visual comfort were assessed by questionnaire. Overall preference was ranked.

RESULTS

Unassisted Netra yielded a median myopic overcorrection of 0.60 D (interquartile range [IQR] 0.25 to 0.94) compared to professional subjective refraction. Median equivalent sphere with unassisted Netra (-1.40 D, IQR -3.10 to -0.90) was significantly more myopic than refined Netra (-0.70 D, IQR -1.60 to -0.30) and then subjective refraction (-0.80 D, IQR -1.60 to -0.30) (all p-values < 0.01). Median visual acuity with professional subjective refraction (-0.16, IQR -0.22 to -0.09) was superior than unassisted Netra (-0.08, IQR -0.20 to 0.03) (p < 0.01). Subjective refraction was ranked first in preference of trial framed results by 72 per cent of participants; median preference rank favoured professional subjective refraction to both Netra results (all p < 0.01). For all questionnaire items, visual comfort was higher with subjective refraction than with unassisted Netra (all p < 0.04).

CONCLUSION

The Netra device - especially when used without professional assistance and compared to subjective refraction - induces significant myopic overcorrection and lower levels of visual acuity, subjective preference and visual comfort.

Myopes Show Greater Visually Induced Postural Responses Than Emmetropes

PURPOSE

The literature already establishes that vision plays a crucial role in postural control and that this visual dependence shows intra- and interindividual variability. However, does ametropia also have an effect on postural control? This question leads to our study, which aims primarily to determine if myopes and emmetropes behave differently in terms of postural control when subjected to visual stimulation, and secondarily, if this difference persists in the presence of barrel and pincushion distortions. The results could lead, among other things, to improved lens design.

METHODS

Twenty-four subjects (12 myopes of -2.00 to -9.00 diopters [D] and 12 emmetropes of -0.50 to +0.50 D), between 19 and 35 years of age, participated in the study after comprehensive eye examinations were carried out. Of the 12 myopes, the preferred type of correction was divided equally within the group. While standing in front of a projection system and fixating on an immobile point, a checkerboard stimulus was displayed in their peripheral visual field, in either a static or dynamic state. Three conditions of optical distortion (plan, pincushion, and barrel distortions) were presented to the subjects. Their postural response was measured and recorded using a system of infrared cameras and optical sensors positioned on a helmet.

RESULTS

The results show that postural instability induced by a dynamic peripheral stimulus is higher for myopes compared with emmetropes (ANOVA Refractive Error, F1,22 = 5.92, P = 0.0235). When exposed to optical distortions, the two groups also have significant differences in postural behaviors (ANOVA Refractive Error*Optical Distortion, F2,44 = 5.67, P = 0.0064).

CONCLUSIONS

These results suggest that refractive error could be a factor in explaining individual variations of the role of vision in postural control.

Postural hypo-reactivity in autism is contingent on development and visual environment: a fully immersive virtual reality study

Although atypical motor behaviors have been associated with autism, investigations regarding their possible origins are scarce. This study assessed the visual and vestibular components involved in atypical postural reactivity in autism. Postural reactivity and stability were measured for younger (12-15 years) and older (16-33 years) autistic participants in response to a virtual tunnel oscillating at different frequencies. At the highest oscillation frequency, younger autistic participants showed significantly less instability compared to younger typically-developing participants; no such group differences were evidenced for older participants. Additionally, no significant differences in postural behavior were found between all 4 groups when presented with static or without visual information. Results confirm that postural hypo-reactivity to visual information is present in autism, but is contingent on both visual environment and development.

Effect of visual field locus and oscillation frequencies on posture control in an ecological environment

To examine the respective roles of central and peripheral vision in the control of posture, body sway amplitude (BSA) and postural perturbations (given by velocity root mean square or vRMS) were calculated in a group of 19 healthy young adults. The stimulus was a 3D tunnel, either static or moving sinusoidally in the anterior-posterior direction. There were nine visual field conditions: four central conditions (4, 7, 15, and 30 degrees); four peripheral conditions (central occlusions of 4, 7, 15, and 30 degrees); and a full visual field condition (FF). The virtual tunnel respected all the aspects of a real physical tunnel (i.e., stereoscopy and size increase with proximity). The results show that, under static conditions, central and peripheral visual fields appear to have equal importance for the control of stance. In the presence of an optic flow, peripheral vision plays a crucial role in the control of stance, since it is responsible for a compensatory sway, whereas central vision has an accessory role that seems to be related to spatial orientation.

Development of visually driven postural reactivity: a fully immersive virtual reality study

The objective of this study was to investigate the development of visually driven postural regulation in typically developing children of different ages. Thirty-two typically developing participants from 5 age groups (5-7 years, 8-11 years, 12-15 years, 16-19 years, or 20-25 years) were asked to stand within a virtual tunnel that oscillated in an anterior-posterior fashion at three different frequencies (0.125, 0.25, and 0.5 Hz). Body sway (BS) and postural perturbations (as measured by velocity root mean squared or vRMS) were measured. Most of the 5- to 7-year-old participants (67%) were unable to remain standing during the dynamic conditions. For older participants, BS decreased significantly with age for all frequencies. Moreover, vRMS decreased significantly from the 8- to 11- through 16- to 19-years age groups (greatest decreases for 0.5 Hz, followed by 0.25-Hz and 0.125-Hz conditions). No difference of frequency or instability was found between the 16- to 19- and 20- to 25-year-old groups for most conditions. Results suggest an over-reliance on visual input relative to proprioceptive and vestibular inputs on postural regulation at young ages (5-7 years). The finding that vRMS decreased significantly with age before stabilizing between 16 and 19 years suggests an important transitory period for sensorimotor development within this age range.