Diagnostic test accuracy of Spot and Plusoptix photoscreeners in detecting amblyogenic risk factors in children: a systemic review and meta-analysis

Evaluation of cycloplegic and noncycloplegic performance of spot vision screener in detection of amblyopia risk factors using 2021 AAPOS guidelines

PURPOSE

This research evaluates the effectiveness of the Spot Vision Screener (SVS) before and after cycloplegia to detect amblyogenic refractive errors in children.

METHODS

Children ages 3 to 10 years old were screened by the SVS before and after cycloplegia. Sensitivity, specificity, positive and negative predictive value, paired t-test, Bland-Altman plot and receiver operating characteristic area under the curve were evaluated by comparing the results of the SVS (v3.0.05) measurements with the results of the cycloplegic Topcon autorefractometer according to the 2021 guidelines of the American Association for Pediatric Ophthalmology and Strabismus.

RESULTS

Both eyes of 211 patients aged 3 to 10 years old were included. Regarding the amblyopia risk factors, the noncycloplegic SVS had 65.7 % sensitivity, 94.9 % specificity, 81.2 % positive predictive value and 89.3 % negative predictive value. The SVS's sensitivity increased from 65.7 % to 81.9 % with cycloplegia compared to noncycloplegic SVS results. The sensitivity detection of hyperopia was improved from 4.2 % to 100 % after cycloplegia. Areas under the receiver operator characteristic curve for noncycloplegic SVS and cycloplegic SVS were 0.506 (95 % CI, 0.395 to 0.646, p = 0737) and 0.905 (95 % CI, 0.915 to 0.971, p < 0.001) for hyperopia, respectively. Using the +1.64 D revised cutoff criteria for hyperopia increased sensitivity from 4.2 % to 78 %.

CONCLUSION

Noncycloplegic SVS measurements showed relatively high specificity in detecting amblyopia risk factors. The fact that noncycloplegic measurements have a very low sensitivity for hyperopia is an important weakness of the SVS, especially because hyperopia is the most frequently encountered refractive error in very young children. It should be noted that amblyogenic hyperopia may be overlooked by an SVS without cycloplegia.

Developing a Novel Pediatric Eye Chart Assessing Visual Acuity by Minimum Separable Threshold

The purpose of this study was to develop a new pediatric acuity chart that can assess the minimum separation threshold by incorporating the minimum separation threshold into the picture. To overcome the design limitations of the Landolt ring, two designs of highly versatile minimum separable thresholds that can be easily incorporated into a picture were created: a black, filled circle (the "Circle") and a segment (the "Square"), both with the same break as in the Landolt ring. The three designs-the Landolt ring, Circle, and Square-were used to evaluate and compare the differences in the visual acuity of 21 healthy adults. No significant differences were observed between the results of the visual acuity tested with the Landolt ring, Circle, and Square (Landolt ring vs. Circle: p = 0.92, Landolt ring vs. Square: p = 0.31, Circle vs. Square: p = 0.40). The Bland-Altman analysis revealed no fixed errors between the Landolt ring and Circle and between the Landolt ring and Square (95% CI: -0.09-0.08, -0.09-0.12). Proportional errors were also not observed (p = 0.68, p = 0.41). The Landolt ring, Circle, and Square designs obtained equal results in visual acuity, thus achieving the successful development of a novel pediatric visual acuity chart using these designs.

Automatic Refractive Error Estimation Using Deep Learning-Based Analysis of Red Reflex Images

Purpose/Background: We evaluate how a deep learning model can be applied to extract refractive error metrics from pupillary red reflex images taken by a low-cost handheld fundus camera. This could potentially provide a rapid and economical vision-screening method, allowing for early intervention to prevent myopic progression and reduce the socioeconomic burden associated with vision impairment in the later stages of life. Methods: Infrared and color images of pupillary crescents were extracted from eccentric photorefraction images of participants from Choithram Hospital in India and Dargaville Medical Center in New Zealand. The pre-processed images were then used to train different convolutional neural networks to predict refractive error in terms of spherical power and cylindrical power metrics. Results: The best-performing trained model achieved an overall accuracy of 75% for predicting spherical power using infrared images and a multiclass classifier. Conclusions: Even though the model's performance is not superior, the proposed method showed good usability of using red reflex images in estimating refractive error. Such an approach has never been experimented with before and can help guide researchers, especially when the future of eye care is moving towards highly portable and smartphone-based devices.

Diagnostic performance of the Spot vision photoscreener for the detection of exodeviation in preschool-aged children

PURPOSE

To evaluate the diagnostic performance of the Welch Allyn Spot Vision photoscreener in preschool children for detecting exotropia, the most prevalent type of strabismus among Asian children.

METHODS

Children aged 3-6 years were screened using the Spot Vision photoscreener and then underwent a complete ophthalmologic examination on the same day. A child with exodeviation ≥8 Δ in the primary position using the cover-uncover test and the alternate prism cover test was confirmed to have exotropia. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the photoscreener in detecting exotropia were calculated. Subgroup analyses were performed according to the angle of deviation (≥25 Δ vs. <25 Δ) and fusional control (good/fair vs. poor).

RESULTS

Two hundred and ten children were included in this study. Among 80 exotropia-confirmed children, 23 needed referrals for exodeviation (screening-positive) and 57 were proven to be screening-negatives with the photoscreener. The overall sensitivity, specificity, PPV and NPV of the photoscreener for detecting exotropia were 28.8%, 95.4%, 79.3% and 68.5%, respectively. The positive and negative likelihood ratios were 6.26 and 0.75, respectively. Compared with the 57 children with false-negatives (71.3%), those with true-positive results with the photoscreener had significantly larger angles of exodeviation (p = 0.02) and a higher proportion of poor fusional control (p = 0.004). The photoscreener had low sensitivity even in detecting exotropia ≥25 Δ or those with poor fusional control (35.2% and 43.6%, respectively). Approximately 65% (42 out of 64) of the children with a significant exodeviation which needed strabismus surgery were not identified by the Spot Vision Photoscreener.

CONCLUSIONS

The Spot Vision photoscreener has low sensitivity for detecting exodeviation. It should not be used alone for assessing exotropia in preschool-aged children.

Positive predictive value of dual-modality vision screening in school children 4-7 years of age-a retrospective review in Queensland, Australia

PURPOSE

To report the outcomes and positive predictive value (PPV) of vision screening in schoolchildren 4-7 years of age through the Primary School Nurse Health Readiness Program (PSNHRP) in Queensland, Australia.

METHODS

A retrospective review of schoolchildren who underwent vision screening between January 2017 and December 2020 was conducted. Vision screening was performed through a dual-examination method, using the Parr 4m letter-matching vision test with crowding bars and the Spot photoscreener. Children were referred to an optometrist or ophthalmologist for review as required and if they failed either screening modality. PPVs were calculated based on whether a visual abnormality was confirmed by an ophthalmologist or optometrist.

RESULTS

Of 185,685 eligible children, 176,164 (94.9%) consented to vision screening, 164,890 (93.6%) consented children underwent vision screening, and of those 12,148 (7.4%) were referred for an eye assessment. Of the 8,659 children with a known outcome (71.3% of referred), 6,011 (69.4% of known outcomes) had a confirmed visual abnormality and 2,648 (30.6%) children did not. The PPV was 0.73 when a referral was indicated by the photoscreener result, 0.76 when indicated by visual acuity testing, and 0.91 when indicated by both the photoscreener and visual acuity testing.

CONCLUSIONS

The PSNHRP vision screening program showed a high uptake, and the dual screening method was effective in identifying visual abnormalities, with higher PPV when both visual acuity and photoscreener results indicated a need for referral.

Detection of Significant Hyperopia in Preschool Children Using Two Automated Vision Screeners

SIGNIFICANCE

Moderate to high uncorrected hyperopia in preschool children is associated with amblyopia, strabismus, reduced visual function, and reduced literacy. Detecting significant hyperopia during screening is important to allow children to be followed for development of amblyopia or strabismus and implementation of any needed ophthalmic or educational interventions.

PURPOSE

This study aimed to compare the sensitivity and specificity of two automated screening devices to identify preschool children with moderate to high hyperopia.

METHODS

Children in the Vision in Preschoolers (VIP) study were screened with the Retinomax Autorefractor (Nikon, Inc., Melville, NY) and Plusoptix Power Refractor II (Plusoptix, Nuremberg, Germany) and examined by masked eye care professionals to detect the targeted conditions of amblyopia, strabismus, or significant refractive error, and reduced visual acuity. Significant hyperopia (American Association for Pediatric Ophthalmology and Strabismus definition of hyperopia as an amblyopia risk factor), based on cycloplegic retinoscopy, was >4.00 D for age 36 to 48 months and >3.50 D for age older than 48 months. Referral criteria from VIP for each device and from a distributor (PediaVision) for the Power Refractor II were applied to screening results.

RESULTS

Among 1430 children, 132 children had significant hyperopia in at least one eye. Using the VIP referral criteria, sensitivities for significant hyperopia were 80.3% for the Retinomax and 69.7% for the Power Refractor II (difference, 10.6%; 95% confidence interval, 7.0 to 20.5%; P = .04); specificities relative to any targeted condition were 89.9 and 89.1%, respectively. Using the PediaVision referral criteria for the Power Refractor, sensitivity for significant hyperopia was 84.9%; however, specificity relative to any targeted condition was 78.3%, 11.6% lower than the specificity for the Retinomax. Analyses using the VIP definition of significant hyperopia yielded results similar to when the American Association for Pediatric Ophthalmology and Strabismus definition was used.

DISCUSSION

When implementing vision screening programs for preschool children, the potential for automated devices that use eccentric photorefraction to either miss detecting significant hyperopia or increase false-positive referrals must be taken into consideration.

Instrument Referral Criteria for PlusoptiX, SPOT and 2WIN Targeting 2021 AAPOS Guidelines

Background

Methods

Results

Conclusion

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The UCI EyeMobile Preschool Vision Screening Program: Refractive Error and Amblyopia Results from the 2019-2020 School Year

Purpose

To introduce the University of California Irvine (UCI) EyeMobile for Children preschool vision screening program and describe the ophthalmic examination results of children who failed screening with the PlusoptiX S12C photoscreener during one school year.

Patients and Methods

Children aged 30-72 months were screened with the PlusoptiX using ROC mode 3 during the 2019-2020 school year. Children who failed screening were referred for comprehensive eye examination on the EyeMobile mobile clinic. Presence of amblyopia risk factors (ARFs), amblyopia, and refractive error was determined via retrospective review of records. Amblyopia was defined as unilateral if there was ≥ 2-line interocular difference in the best-corrected visual acuity (BCVA) and as bilateral if BCVA was < 20/50 for children < 4 years old and < 20/40 for children ≥ 4 years old. ARFs were defined using 2021 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) instrument-based screening guidelines.

Results

5226 children were screened during the study period. Of the 546 children who failed screening, 350 (64%) obtained consent and were examined. Mean age of examined children was 4.45 years. Amblyopia was found in 8% of examined children, with unilateral amblyopia seen in 79% of amblyopic subjects. Glasses were prescribed to 246 (70.3%) children. Of the 240 children who received cycloplegic examinations, 43% had hyperopia and 30% had myopia. The positive predictive value (PPV) of the PlusoptiX screening for ARFs in children who received cycloplegic examinations was 70.4%.

Conclusion

A significant proportion of Orange County preschoolers with refractive errors and amblyopia have unmet refractive correction needs. The PlusoptiX S12C photoscreener is an adequate screening device for the UCI EyeMobile for Children program, although modification of device referral criteria may lead to increased PPV. Further research is necessary to understand and overcome the barriers to childhood vision care in our community.

Effectiveness of Kanna photoscreener in detecting amblyopia risk factors

Purpose:

Amblyopia is a significant public health problem. Photoscreeners have been shown to have significant potential for screening; however, most are limited by cost and display low accuracy. The purpose of this study was validate a novel artificial intelligence (AI) and machine learning–based facial photoscreener “Kanna,” and to determine its effectiveness in detecting amblyopia risk factors.

Methods:

A prospective study that included 654 patients aged below 18 years was conducted in our outpatient clinic. Using an android smartphone, three images of each the participants’ face were captured by trained optometrists in dark and ambient light conditions and uploaded onto Kanna. Deep learning was used to create an amblyopia risk score based on our previous study. The algorithm generates a risk dashboard consisting of six values: five normalized risk scores for ptosis, strabismus, hyperopia, myopia and media opacities; and one binary value denoting if a child is “at-risk” or “not at-risk.” The presence of amblyopia risk factors (ARF) as determined on the ophthalmic examination was compared with the Kanna photoscreener.

Results:

Correlated patient data for 654 participants were analyzed. The mean age of the study population was 7.87 years. The algorithm had an F-score, 85.9%; accuracy, 90.8%; sensitivity, 83.6%; specificity, 94.5%; positive predictive value, 88.4%; and negative predictive value, 91.9% in identifying amblyopia risk factors. The P value for the amblyopia risk calculation was 8.5 × 10⁻¹⁴² implying strong statistical significance.

Conclusion:

The Kanna photo-based screener that uses deep learning to analyze photographs is an effective alternative for screening children for amblyopia risk factors.

Prevalence of primary open angle glaucoma in the last 20 years: a meta-analysis and systematic review

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness in the world and is influenced by various sociodemographic factors. This meta-analysis aims to determine the worldwide prevalence of POAG in the adult general population for the last 20 years, and explore variation in prevalence by age, gender and geographical location. An electronic literature search was performed using the PubMed, Embase, and Web of Science databases. Population-based cross-sectional or cohort studies published in the last 20 years (2000–2020) that reported prevalence of POAG were recruited. Relevant studies meeting defined eligibility criteria were selected and reviewed systematically by meta-analysis. The prevalence of POAG was analyzed according to various risk factors. A random effect model was used for the meta-analysis. Fifty publications with a total of 198,259 subjects were included in this meta-analysis. The worldwide overall prevalence of POAG was 2.4% (95% CI 2.0 ~ 2.8%). The prevalence increases with age. Men are found to be more susceptible to POAG than women (RR 1.28, p < 0.01). Africa is found to have the highest prevalence of POAG (4.0%) among all continents. The current estimated global population of POAG is 68.56 million (95% CI 59.99 ~ 79.98). POAG is a worldwide vision threatening disease with high prevalence for the last 20 years. The population-based prevalence of POAG varies widely across individual studies, due to variations in risk factors of age, gender, and population geographic location.

Drive-by Photoscreening: Plusoptix, 2WIN and Blinq Amblyopia Detection During the COVID-19 Pandemic

Background

Community photoscreening for amblyopia had successfully been adopted by many communities, however many clinics curtailed screening as a result of the COVID-19 pandemic. We modified three conventional devices and tested them for outdoor, drive-by socially distanced photoscreening and refraction.

Methods

External frames that provide luminance control and focus distance were fashioned for plusoptiX S12 (Nuremberg, Germany), Adaptica 2WIN in Kaleidos case (Padova, Italy) and the Rebion blinq (Boston, USA). Children were screened by each device and then Retinomax (Righton, Japan) before AAPOS guideline validation.

Results

Eighty-eight children average age 8±7 years had precise refraction and alignment from which 69% AAPOS 2003 risk factors were determined. The sensitivity/specificity/inconclusive rate for plusoptiX was 85%/96%/16%, for 2WIN 79%/89%/5% and for blinq 43%/74%/8%. Blinq improved to 54%/70% when screening for amblyopia ± strabismus. Bland Altman analysis of spherical equivalent showed plusoptiX and 2WIN with less over-minus than Retinomax and J0 and J45 vectors highly reliable for astigmatism determination.

Conclusion

The infrared photorefractors in modified cases reliably screened amblyopia risk factors and refraction. The birefringent scanner provided drive-by results but less reliably with wire-frame opaque case than without the case in a dimly lit room. Modified drive-by photoscreeners could help reduce amblyopia and provide socially distanced refraction during an extended pandemic.

Does the Accuracy and Repeatability of Refractive Error Estimates Depend on the Measurement Principle of Autorefractors?

Purpose

The purpose of this study was to determine the accuracy and repeatability of refractive errors obtained using three autorefractors based on different measurement principles, vis-à-vis, gold-standard retinoscopy.

Methodology

Accuracy of noncycloplegic, sphero-cylindrical refractive error of 234 eyes was obtained using the rotary prism-based RM-8900 closed-field autorefractor, photorefraction based Spot vision screener, wavefront aberrometry based E-see, and streak retinoscopy by four different examiners, masked to the results of each other. Intersession repeatability of autorefractors was determined by repeat measurements in a subset of 40 subjects.

Results

Retinoscopy values of M, J₀, and J₄₅ power vectors for the cohort ranged from -10.2 to 8 D, -1.4 to 1.8 D, and -0.9 to 1.2 D, respectively. Across autorefractors, the interequipment bias of M and J₀ power vectors were statistically insignificant (< ±0.5 D; P > 0.05) but the corresponding limits of agreement were ±2.5 and ±1 D, respectively, without any trend across instruments or the patient's age (P > 0.5). Repeatability of M and J₀ power vectors were ±0.75 D and ±0.40 D, respectively, across autorefractors. The range of J₄₅ power vector was too narrow for any meaningful analysis.

Conclusions

Refractive errors measured using autorefractors operating on different principles show minimal bias and good short-term repeatability but relatively large agreement limits, vis-à-vis, retinoscopy. Among them, the wavefront aberrometry based E-see autorefractor performs relatively better in all measurement parameters evaluated here.

Translational Relevance

Although autorefractor estimates of noncycloplegic refractive error appears independent of their measurement principle, their relatively poor agreement with gold-standard retinoscopy warrants caution while used for screening and quantification of refractive errors.

Prevalence of Primary Angle Closure Glaucoma in the Last 20 Years: A Meta-Analysis and Systematic Review

Purpose: This meta-analysis aims to investigate the worldwide prevalence of primary angle-closure glaucoma (PACG) and its risk factors in the last 20 years.

Methods: We conducted a systematic review and meta-analysis of 37 population-based studies and 144,354 subjects. PubMed, Embase, and Web of Science databases were searched for cross-sectional or cohort studies published in the last 20 years (2000–2020) that reported the prevalence of PACG. The prevalence of PACG was analyzed according to various risk factors. A random-effects model was used for the meta-analysis.

Results: The global pooled prevalence of PACG was 0.6% [95% confidence interval (CI) = 0.5–0.8%] for the last 20 years. The prevalence of PACG increases with age. Men are found less likely to have PACG than women (risk ratio = 0.71, 95% CI = 0.53–0.93, p < 0.01). Asia is found to have the highest prevalence of PACG (0.7%, 95% CI = 0.6–1.0%). The current estimated population with PACG is 17.14 million (95% CI = 14.28–22.85) for people older than 40 years old worldwide, with 12.30 million (95% CI = 10.54–17.57) in Asia. It is estimated that by 2050, the global population with PACG will be 26.26 million, with 18.47 million in Asia.

Conclusion: PACG affects more than 17 million people worldwide, especially leading a huge burden to Asia. The prevalence of PACG varies widely across different ages, sex, and population geographic variation. Asian, female sex, and age are risk factors of PACG.

Performance of Plusoptix A09 Photo Screener in Refractive Error Screening in School Children Aged between 5 and 15 Years in the Southern Part of India

Purpose:

To evaluate the performance of Plusoptix A09 in detecting ametropia, warranted against frequently-used technique of retinoscopy in children attending school (5–15 years) and its probability as a screening tool.

Methods:

This study was the subset of a larger epidemiological study visual acuity refractive error squint conducted in schools to determine the prevalence of ocular morbidity among the 5–15 years' school children population. Every 7^th student in the class (each school had mean value of 100 students) was randomly selected for this study after ascertaining their eligibility as per the inclusion criteria. A cohort of a total of 150 children within the age group of 5–15 (mean, 10.21 ± 2.83) years were recruited from 11 schools of Udupi district. Students with best corrected visual acuity of 20/20, refractive error within ±5.00 diopter (D), without any eccentric fixation, and no history of ocular pathology or seizures were recruited. Refractive error was tested by Plusoptix photorefractor followed by non-cycloplegic and cycloplegic retinoscopic techniques. The examiners performing these tests were masked and unware of the findings. Bland Altman plotted the agreement between the techniques, followed by the receiver operating characteristic curve (ROC), and sensitivity of Plusoptix.

Results:

One-way analysis of variance calculated statistical differences among Plusoptix, objective retinoscopy, and cycloplegic retinoscopy for mean spherical value (1.12 ± 1.16 D, 0.65 ± 0.69 D, and 0.8 ± 0.82 D), cylindrical value (−0.83 D ± 1.27, −0.32 D ± 0.86, and −0.34 D ± −0.93), and spherical equivalent value (0.71 D ± 1.06, 0.45 D ± 0.7, and 0.61 D ± 0.81), with P = 0.0001, 0.0001, and 0.097, respectively. Bland Altman plots showed good agreement for spherical equivalent values of Plusoptix and objective retinoscopy. However, the area under the ROC curve (0.386) suggests that lower diagnostic ability of this device in this age group population in comparison to retinoscopy (0.575) with the sensitivity and specificity of Plusoptix was 69.2% and 84.8%.

Conclusions:

This study fails to report ideal sensitivity mandated for a screening tool, although good specificity and agreement are observed. Along with retinoscopy, this tool will be effective in screening a children's population aged between the age group of 5 and 15 years.

School-based epidemiology study of myopia in Tianjin, China

PURPOSE

To study the epidemiology of myopia in school-aged children in Tianjin and the relationship between visual acuity-based screening and refraction-based screening.

METHOD

This school-based prospective cohort study was performed on children from 42 elementary schools and 17 middle schools in Tianjin, China. Totally 14,551 children, ages ranging from 5 to 16 years, were included in this study. Uncorrected visual acuity (UCVA) was determined by logarithmic tumbling E chart. Non-cycloplegic photorefraction was examined by the Spot (v2.1.4) photoscreener. The relationship between the UCVA and refractive error was investigated for different age groups.

RESULTS

The overall prevalence of myopia at this school based screen is 78.2%, ranged from 10% at age of 5 to 95% at age of 16. The most dramatic increase in prevalence is from age of 6 (14.8%) to age of 7 (38.5%). The overall prevalence of high myopia is 2.5%. UCVA is found corresponding to spherical equivalent refraction (SER) in a manner of normal distribution and is significantly affected by age. When using UCVA to estimate the prevalence of myopia, the overall sensitivity and specificity are 0.824 and 0.820, respectively. Age-dependent optimal cutoff points and 95% confident intervals of such estimation are reported.

CONCLUSIONS

Myopia is heavily affecting school-aged children in Tianjin, China. The refraction screening is preferable for myopia screening, whereas the UCVA screening results need to be interpreted in an age-dependent manner for myopia estimation.

Systematic Review and Meta-Analysis of Comparing Phacoemulsification Combined with goniosynechialysis to other mainstream procedures in treating patients with angle-closure glaucoma

BACKGROUND

The aim of this meta-analysis is to compare the efficacy and safety of combined phacoemulsification (Phaco) with goniosynechialysis (GSL) to either Phaco or to Phaco combined with trabeculectomy or trabeculectomy alone in patients with angle closure glaucoma (ACG).

METHODS

Five main electronic databases were searched for the eligible studies. Intraocular pressure (IOP) decrease was set as the primary outcome, while anti-glaucomatous medication decrease, changes of anterior chamber depth (ACD), range of peripheral anterior synechia (PAS), and complication occurrence were the secondary outcomes. Standard mean difference (SMD) and relative risk (RR) were the size effects for continuous and binomial data, respectively. Either fixed-effects model or random-effects model was chosen to pool the data based on the heterogeneities.

RESULTS

A total of 7 eligible studies were included. The combined data showed the IOP decreased more significantly after Phaco-GSL than that after Phaco alone (SMD = -0.42,95%CI: -0.70 - 0.14, I = 17.6%, Z = 2.90, P = .004). However, there were no distinct differences regarding medication decrease (SMD =  -0.25,95%CI: -0.70 - 0.21, I = 0%, Z = 1.06, P = 0.29), ACD, the range of PAS and complication occurrence rate when compared Phaco-GSL to Phaco. Moreover, Phaco-GSL was comparable to Phaco-trabeculectomy/trabeculectomy in decreasing IOP (SMD =  -0.08, 95%CI = -0.32 - 0.15, I = 0%, Z = 0.70, P = .49).

CONCLUSIONS

Phaco-GSL might be an optimal procedure to treat ACG with concomitant cataract due to its bleb-less nature, and its capacity for lowering IOP seems superior to Phaco alone and comparable to Phaco-trabeculectomy/trabeculectomy.