Repeat Retinomax screening changes positive predictive value

UCI EyeMobile Exam Findings from School Children Following on-Site Screening

Purpose

Uncorrected refractive errors (REs) and amblyopia can lead to visual impairment with deleterious effects on quality of life and academic performance. Early detection and treatment by community vision care programs, such as the UCI EyeMobile for Children, can aid in addressing preventable vision loss.

Methods

A total of 5074 children between the ages of 3 and 10 years were screened at 153 locations, including preschools, head start programs, and elementary schools within Orange County (OC), California (CA). Subsequently, 1024 children presented for comprehensive eye examinations. A retrospective analysis of all examined children was conducted, determining the frequency and severity of REs and amblyopia and the spectacle prescription rate by age. Propensity score matching analysis evaluated the effect of median household income on RE and amblyopia frequency.

Results

Among those who failed initial screening and were subsequently examined, significant rates of REs and amblyopia were detected: myopia (24.4%), hyperopia (35.4%), astigmatism (71.8%), anisometropia (8.9%), amblyopia (7.0%), and amblyopia risk (14.4%). A majority (65.0%) of those examined received prescription spectacles from UCI EyeMobile, with around a third requiring a new or updated prescription. The frequency of REs and amblyopia and the spectacle prescription rate were uniform across OC congressional districts. Myopia and amblyopia risk was positively and negatively associated with household income, respectively.

Conclusion

The UCI EyeMobile for Children serves as a vital vision care program, providing free vision screening, comprehensive eye examinations, and spectacles. A significant number of children required examination, and a high frequency of REs and amblyopia were detected in examined children, with subsequent provision of prescription spectacles to most children.

Comparability of the Retinomax K-plus 3 handheld autorefractometer in quick mode versus on-table autorefractometer in standard mode

INTRODUCTION

This study analyzes the comparability of measurements taken by a Retinomax K-plus 3 handheld autorefractometer in Quick mode and a Topcon KR-800 on-table autorefractometer in standard mode on the pediatric population, and establishes their correlation.

METHODS

It is a retrospective comparative study. Spherical diopter power (SPH), cylindrical diopter power (CYL), angle of cylindrical axis (AX), and spherical equivalent (SE) were measured with the Retinomax in Quick mode and with the Topcon in standard mode. Each patient was evaluated in cycloplegic and non-cycloplegic conditions by both autorefractometers. Student's t-test was performed between the two instruments for SPH, CYL, and SE. The Pearson correlation coefficient was calculated and the dispersion was represented using Bland-Altman graphs, also evaluating the subgroup of patients under 4 years of age. A descriptive analysis of the percentages of measures that differed was performed.

RESULTS

It included 98 eyes of 49 subjects (age range: 3-16 years). The data for HPS without cycloplegia are virtually identical, whereas with cycloplegia there is a hyperopic bias of +0.5 diopters measured with Retinomax. CYL results are very similar with and without cycloplegia. There is a high Pearson correlation for both instruments (>0.91) and a low degree of dispersion in the Bland-Altman plots under cycloplegia.

CONCLUSION

The Retinomax data were consistent with those obtained by Topcon. The Retinomax is a useful instrument for detecting refractive errors in children between 3 and 16 years of age.

A population-level post-screening treatment cost framework to help inform vision screening choices for children under the age of seven

PURPOSE/BACKGROUND

Visual acuity (VA) screening in children primarily detects low VA and amblyopia between 3 and 6 years of age. Photoscreening is a low-cost, lower-expertise alternative which can be carried out on younger children and looks instead for refractive amblyopia risk factors so that early glasses may prevent or mitigate the conditions. The long-term benefits and costs of providing many children with glasses in an attempt to avoid development of amblyopia for some of them needs clarification. This paper presents a framework for modeling potential post-referral costs of different screening models once referred children reach specialist services.

METHODS

The EUSCREEN Screening Cost-Effectiveness Model was used together with published literature to estimate referral rates and case mix of referrals from different screening modalities (photoscreening and VA screening at 2, 3-4 years and 4-5 years). UK 2019-20 published National Health Service (NHS) costings were used across all scenarios to model the comparative post-referral costs to the point of discharge from specialist services. Potential costs were compared between a) orthoptist, b) state funded ophthalmologist and c) private ophthalmologist care.

RESULTS

Earlier VA screening and photoscreening yield higher numbers of referrals because of lower sensitivity and specificity for disease, and a different case mix, compared to later VA screening. Photoscreening referrals are a mixture of reduced VA caused by amblyopia and refractive error, and children with amblyopia risk factors, most of which are treated with glasses. Costs relate mainly to the secondary care providers and the number of visits per child. Treatment by an ophthalmologist of a referral at 2 years of age can be more than x10 more expensive than an orthoptist service receiving referrals at 5 years, but outcomes can still be good from referrals aged 5.

CONCLUSIONS

All children should be screened for amblyopia and low vision before the age of 6. Very early detection of amblyopia refractive risk factors may prevent or mitigate amblyopia for some affected children, but population-level outcomes from a single high-quality VA screening at 4-5 years can also be very good. Total patient-journey costs incurred by earlier detection and treatment are much higher than if screening is carried out later because younger children need more professional input before discharge, so early screening is less cost-effective in the long term. Population coverage, local healthcare models, local case-mix, public health awareness, training, data monitoring and audit are critical factors to consider when planning, evaluating, or changing any screening programme.

Scope and costs of autorefraction and photoscreening for childhood amblyopia-a systematic narrative review in relation to the EUSCREEN project data

Background

Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally.

Methods

A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality.

Results

Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably.

Discussion

Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.

Evaluation of patient visual comfort and repeatability of refractive values in non-presbyopic healthy eyes

AIM

To evaluate the intra-operator repeatability in healthy subjects using the WAM-5500 auto-kerato/refractometer and the iTrace aberrometer, to compare the refractive values and the subjective refraction obtained with both devices and to determine which of these three spherocylindrical corrections allows the subject to achieve the best visual comfort.

METHODS

Forty-two non-presbyopic healthy eyes of 42 subjects were enrolled in this prospective study. Refractive values were compared, evaluating the repeatability, the relationship between the methods and the best visual comfort obtained.

RESULTS

Sphere, cylinder and axis results showed good intraclass correlation coefficients (ICC); the highest ICC was obtained using the spherical refraction with the autorefractometer and the aberrometer, achieving levels of 0.999 and 0.998, respectively. The power vector (PV) was calculated for each refraction method, and the results indicated that there were no statistically significant differences between them (P>0.05). Direct comparison of PV measurements using the three methods showed that aberrometer refraction gave the highest values, followed by the subjective values; the autorefractometer gave the lowest values. The subjective method correction was most frequently chosen as the first selection. Equal values were found for the autorefractometer and the aberrometer as the second selection.

CONCLUSION

The iTrace aberrometer and the WAM-5500 auto-kerato/refractometer showed high levels of repeatability in healthy eyes. Refractive corrections with the aberrometer, the autorefractometer and subjective methods presented similar results, but spherocylindrical subjective correction was the most frequently selected option. These technologies can be used as complements in refractive evaluation, but they should not replace subjective refraction.