- Email: [email protected]
Evaluation of the Spot Vision Screener in young children in Costa Rica
Evaluation of the Spot Vision Screener in young children in Costa Rica Maricela Arana Mendez, MD,a Leslie Arguello, MSc, MD,a Joaquin Martinez, MD,a Marisela Salas Vargas, MD,b Ana Maria Alvarado Rodriguez, OD,b Carrie E. Papa, BS,c Carolyn M. Peterseim, BA,c Mauricio Otarola Vıquez, MD,d Rupal H. Trivedi, MD,c and Mae Millicent W. Peterseim, MDc BACKGROUND
The Spot Vision Screener has demonstrated good sensitivity and specificity in the pediatric ophthalmology clinic setting. We sought to evaluate the updated Spot (version 2.0.16) in a general pediatric population through a collaboration of the Storm Eye Institute of the Medical University of South Carolina, the Clinica Dr Clorito Picado, and National Children’s Hospital of Costa Rica. We compared results of screening with the Spot and pediatric ophthalmologic examination and determined sensitivity and specificity of the Spot in detecting amblyogenic risk factors (ARFs) according to the 2013 AAPOS Vision Screening Committee guidelines for automated vision screeners.
METHODS
Children were screened with the Spot followed by a pediatric ophthalmologic examination. Cycloplegic refraction and motility findings were analyzed by age group to determine ARFs. A total of 219 subjects, averaging 60 months of age (range, 20-119 mo) were included. The prevalence of ARFs in our population was 12.3% (27/219). The most common risk factor was astigmatism, with a prevalence of 8.7% (19/219). The Spot referred 43 children (19.6%). Sensitivity of the Spot was 92.6%; specificity, 90.6%. The positive predictive value was 58.1%; the negative predictive value, 98.9%. The Spot demonstrated good sensitivity and specificity in detecting amblyopia risk factors in this general pediatric population. ( J AAPOS 2015;19:441-444)
RESULTS
CONCLUSIONS
T
he American Academy of Pediatrics has recommended automated vision screeners as an acceptable alternative to traditional vision screening in children 3-5 years old.1 The Spot Vision Screener2 (Welch Allyn, Skaneateles Falls, NY), introduced in October 2011, has been evaluated in pediatric ophthalmology offices and demonstrated good sensitivity and specificity in these enriched populations.3-6 As part of a collaboration between the Storm Eye Institute of the Medical University of South Carolina and the Clinica Dr Clorito Picado and ophthalmologists of the National Children’s Hospital of Costa Rica, we sought to evaluate the updated Spot
Author affiliations: aDepartment of Ophthalmology, National Children’s Hospital of Costa Rica, San Jose, Costa Rica; bClinica Ophthalmologica, San Jose, Costa Rica; cMiles Center for Pediatric Ophthalmology, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina; dDepartment of Pediatrics, Clinica Dr. Clorito Picado, San Jose, Costa Rica Supported in part by Research to Prevent Blindness, New York, NY. Submitted March 20, 2015. Revision accepted August 12, 2015. Correspondence: Mae Millicent W. Peterseim, MD, MUSC, Storm Eye Institute, 167 Ashley Avenue, Charleston, SC 29425-5536 (email: [email protected]). Copyright Ó 2015 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2015.08.002
Journal of AAPOS
(version 2.0.16) in a general pediatric population. We compared Spot screening and a pediatric ophthalmologic examination to determine the sensitivity and specificity of the Spot screener in detecting amblyopia risk factors (ARFs) according to the 2013 American Association of Pediatric Ophthalmology and Strabismus (AAPOS) Vision Screening Committee guidelines for automated vision screeners.7
Subjects and Methods This prospective study was approved by the Institutional Review Board for Human Research of the Medical University of South Carolina and the Comite Local de Bioethica, Centro de Desarrollo Estrategico e Informacion en Salud y Seguridad, Caja Costarricense de Seguro Social (Local Bioethics Committee, Center of Strategic Development and Information on Health and Insurance, Costa Rican Department of Social Security) and adhered to the US Health Insurance Portability and Accountability Act of 1996. Patients 2-9 years of age underwent a Spot vision screening and examination by one of three pediatric ophthalmologists (MAM, LCA, MMP) from March to June 2014. Patients were seen on the day of their pediatric visit or scheduled by Clinica Dr Clorito Picado (San Jose Costa Rica) scheduling staff from a computer-generated list of patients seen recently for well-
441
442
Arana Mendez et al
Volume 19 Number 5 / October 2015
Table 1. Performance metrics for the Spot, version 2.0.16, by age group Groups Children 31-48 months Spot referral/positive Spot pass/negative Children 48-137 months Spot referral/positive Spot pass/negative All children Spot referral/positive Spot pass/negative
ARF1
ARF
10 1
7 75
15 1
7 91
25 2
18 174
Sensitivity (95% CI)
Specificity (95% CI)
PPV (95% CI)
NPV (95% CI)
90.9 (58.7-98.5)
91.5 (83.2-96.5)
58.8 (33.0-81.5)
98.7 (92.9-99.8)
93.8 (69.7-99.0)
92.9 (85.9-97.1)
68.2 (45.1-86.1)
98.9 (94.1-99.8)
92.6 (75.7-98.9)
90.6 (85.6-94.4)
58.1 (42.1-73.0)
98.9 (96.0-99.8)
ARF, amblyopia risk factors; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value. child visits or minor illness in the pediatric clinic, with no knowledge of eye complaints. In addition, children in three day care centers (Guarderias Centro Modelo, La Libertad, and Montesori Los Angeles of the Fundacion Humanitaria) were screened and examined through the Christian Medical Clinic in La Carpio, San Jose, Costa Rica. Approved written informed consent was obtained (in Spanish) from parents or guardians prior to the examination.
Statistical Analysis
Testing
A total of 219 children (115 females [53%]) were tested; 98% were Hispanic and 2% were African American. Patients were from the general pediatric practice of Clinica Dr Clorito Picado (150) and local preschools (69). The average age was 60 months (range, 20-119 months). Our sample included only 12 patients in group 1 (12-30 months), which we believed too few for separate analysis. Therefore, we analyzed results only for group 2 (93 children) and group 3 (114). ARFs as determined by the ophthalmologist examination in our population were found in 27 subjects (12.3%). The most common ARF was astigmatism, with a prevalence of 19 of 219 (8.7%). The Spot referred 43 children (19.6%). The Spot did not obtain a result after repeated attempts in 3 children, who were 30, 35, and 38 months of age and found not to have ARFs on ophthalmological examination. The sensitivity of the Spot to detect ARFs was 92.6%; the specificity was 90.6%. The positive predictive value (PPV) was 58.1% and the negative predictive value (NPV) was 98.9% (Table 1). The Spot referred 31 children for astigmatism, 3 for anisometropia, 3 for hyperopia, and 3 for myopia. Some children were referred for more than one reason. Of the 31 children referred for astigmatism, 19 were found on examination to meet AAPOS criteria for astigmatism and 12 were false positives. There were no children meeting AAPOS criteria for astigmatism on examination who were missed using the Spot. The false positive rate for astigmatism (false positives/false positives 1 true negatives) was 6% for group 2and 4% for group 3. In group 2 the sensitivity of the Spot to detect ARFs was 90.9%, and the specificity was 91.5%. The PPV was 58.8%; the NPV, 96.7%.
4,6
The Spot device has been described elsewhere. Spot software version 2.0.16 was employed in this study. Initially 30 patients were screened by the ophthalmologists prior to the examination, following manufacturer guidelines. Subsequent patients were screened by one of two trained lay personnel, following manufacturer guidelines (AMAR, 120 children; CMP, 69 children). Spot screening and examinations were performed in a separate room. Ophthalmological examination included cover-uncover ocular motility testing and examination of the anterior segment. Cycloplegic retinoscopy and dilated fundus examination were performed after 30 minutes after instillation of 1-2 drops each of tropicamide 0.5% with phenylephrine 5% and cyclopentolate 1%.
Data Collection Patient data collected included age, sex, race, Spot refraction estimate, screener recommendation using Spot “out of the box” manufacturer criteria (“complete eye exam recommended” or “all measurements in range”), reason for referral, and results of ophthalmologist’s examination, including presence of strabismus and cycloplegic refraction and diagnosis of ocular pathology. Ophthalmologists’ findings were added to the Spot-generated Excel database for analysis.
Analysis All patients who entered the study were included, even those on whom a reading was not obtained. Children were divided into age groups to determine gold standard results (ARF1/ARF ), according to the AAPOS guidelines: group 1, 12-30 months; group 2, 31-48 months, and group 3, .48 months. Patients were considered to have ARFs on the comprehensive examination on the basis of the physician’s diagnosis and 2013 AAPOS guidelines.7
Descriptive statistics were calculated. Sensitivity, specificity, positive and negative predictive values of the Spot in detecting ARF1 conditions were calculated. The 3 children for whom the Spot was unable to obtain a result were included as automatic referrals and included as test positives.
Results
Journal of AAPOS
Volume 19 Number 5 / October 2015 In group 3, the sensitivity of the Spot to detect ARFs was 93.8 %; the specificity, 92.9%. The PPV was 68.2%; the NPV, 98.9%. Of the 3 children referred by the Spot for “gaze,” 2 had strabismus meeting AAPOS criteria (manifest heterotropia of .8D)—one exotropic and the other hypertropic. The third child was not found to have strabismus.
Discussion Improved automated screening tools help reach the almost 40% of children who do not receive recommended preschool vision screening.8 Early detection improves visual acuity outcomes.9,10 This study compared the newest version of the Spot vision screener to pediatric ophthalmologic examination in a population of young children in Costa Rica. Previous reports of the Spot as a screening tool in the general pediatric population noted poor follow-up.11 We were able to complete ophthalmologic examinations on all children tested. Costa Rica has a successful centralized health system by many measures.12 Babies eyes are routinely tested using red reflex testing in the nursery, and parents receive information about childhood development that includes signs of visual problems. While many primary care public clinics perform vision screening between the ages of 5 and 6, there is not a standardized system for testing vision in young children. Our population prevalence of ARFs of 12.3% is between estimates of ARFs in the general pediatric population of 20%7,13,14 and the amblyopia prevalence of 1.6% to 3.6%.15 It is slightly less than the 14% found by Matta and Silbert16 in an older pediatric population in Honduras. Using the manufacturer’s referral criteria, we found excellent sensitivity and specificity of the Spot in the general pediatric population studied. Compared with results reported by Silbert and Matta16 using the Plusoptix and SureSight screeners in Honduras, we found slightly lower sensitivity and specificity than plusoptiX S04 and higher sensitivity and specificity than plusoptiX A09 and Suresight.17 Compared to previous validation studies of the Spot screener used in pediatric ophthalmology populations, which found a sensitivity of 80% to 89% and a specificity 74% to 88%,4-6 our results found improved sensitivity (92.6%) and specificity (90.6%) in the general population. A weakness of the present study is that, due to early staffing issues, our ophthalmologists conducted the screening for the first approximately 30 patients, allowing the potential for the ophthalmologists to be influenced by the screener results. However, the examination was carried out independently and confidence was placed in the doctors findings as the gold standard. In addition, a larger sample size and further testing would improve confidence intervals. Our findings in a Costa Rican population may differ from those found in other countries. Our high rate of astigmatism may be related to our Hispanic population18 and is reflected in the high referral rate
Journal of AAPOS
Arana Mendez et al
443
for astigmatism of the Spot screener. However, the number of false positive referrals for astigmatism suggests an adjustment in the manufacturer’s criteria may improve specificity. In conclusion, we found that the newest version of the Spot offered very good specificity and sensitivity in this general pediatric patient population. Our findings compare favorably with those of other automated screeners.3,17,19 Evaluation of automated screener performance is important, as national panels make specific recommendations about new technology to detect amblyopia risk factors and to prevent or treat amblyopia.20,21 References 1. Miller JM, Lessin HR, American Academy of Pediatrics Section on Ophthalmology, Committee on Practice and Ambulatory Medicine, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, American Association of Certified Orthoptists. Instrument-Based Pediatric Vision Screening Policy Statement. Pediatrics 2012;130:983-6. 2. Spot Vision Screener, 2014 Welch Allyn. http://www.welchallyn.com/ en/products/categories/physical-exam/eye-exam/vision-screeners/spotvision-screener.html. Accessed 10/16/2014. 3. Arnold RW, Arnold AW, Armitage MD, Shen JM, Hepler TE, Woodard TL. Pediatric Photoscreeners in High Risk Patients 2012: A Comparison Study of Plusoptix, iScreen and SPOT. Binocul Vis Strabolog Q Simms Romano 2013;28:20. 4. Silbert DI, Matta N. Performance of the Spot vision screener for the detection of amblyopia risk factors in children. J AAPOS 2014;18: 169-72. 5. Garry GA, Donahue S. Validation of Spot screening device for amblyopia risk factors. J AAPOS 2014;18:476-80. 6. Peterseim MMP, Papa CE, Wilson ME, et al. The effectiveness of the Spot Vision Screener in detecting amblyopia risk factors. J AAPOS 2014;18:539-42. 7. Donahue SP, Arthur B, Neely DE, Arnold RW, Silbert D, Ruben JB. AAPOS Vision Screening Committee. Guidelines for automated preschool vision screening: a 10-year, evidence-based update. J AAPOS 2013;17:4-8. 8. Kemper AR, Wallace DK, Patel N, Crews JE. Preschool vision testing by health providers in the United States: findings from the 2006-2007 Medical Expenditure Panel Survey. J AAPOS 2011;15:480-83. 9. Holmes JM, Lazar E, Melia BM, , et al. Pediatric Eye Disease Investigator Group. Effect of age on response to amblyopia treatment in children. Arch Ophthalmol 2011;129:1451-7. 10. Teed RG, Bui C, Morrison DG, Estes RL, Donahue SP. Amblyopia therapy in children identified by photoscreening. Ophthalmology 2010;117:159-62. 11. Ransbarger KM, Dunbar J, Choi SE, Khazaeni LM. Results of a community vision-screening program using the Spot photoscreener. J AAPOS 2013;17:516-20. 12. World Health Organization. Global Health Data Repository. Life Expectancy Data by Country. http://apps.who.int/gho/data/node. main.3?lang5en. 2014. Accessed 10/16/2014. 13. Arnold RW. Amblyopia risk factor prevalence. J Pediatr Ophthalmol Strabismus 2013;50:213-17. 14. Varma R. Author reply on behalf of the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Investigators. Ophthalmology 2012;119:1283-4. 15. Simon K. Amblyopia characterization, treatment, and prophylaxis. Surv Ophthalmol 2005;50:123-65. 16. Matta NS, Singman EL, McCarus C, Matta E, Silbert DI. Screening for amblyogenic risk factors using the PlusoptiX S04 Photoscreener
444
Arana Mendez et al
on the indigent population of Honduras. Ophthalmology 2010;117: 1848-50. 17. Silbert DI, Matta N, Amanda L, Ely AL. Comparison of SureSight autorefractor and plusoptiX A09 photoscreener for vision screening in rural Honduras. J AAPOS 2014;18:42-4. 18. Ying GS, Maguire MG, Cyert LA, , et al. Vision In Preschoolers (VIP) Study Group. Prevalence of vision disorders by racial and ethnic group among children participating in head start. Ophthalmology 2014;121:630-36.
Volume 19 Number 5 / October 2015 19. Arthur BW, Riyaz R, Rodriguez S, Wong J. Field testing of the plusoptiX S04 photoscreener. J AAPOS 2009;13:51-7. 20. Nicolella L. Vision screening for children 1 to 5 years of age: US Preventive Services Task Force Recommendation Statement. Pediatrics 2011;127:1-7. 21. Cotter SA, Cyert LA, Miller JM, Quinn GE. National Expert Panel to the National Center for Children’s Vision and Eye Health. Vision screening for children 36 to \72 months: recommended practices. Optom Vis Sci 2014;92:6-16.
Seeing Is Believing The truth is that Braille fought his entire life to convince others that his system was a meaningful contribution to the blind. Many times he despaired that his system, though obviously superior to any other method, would ever be used by anyone outside the walls of his school, and sometimes, by anyone but himself. When Braille died in 1852, at the age of 43, he was practically unknown. —Andrew Lam, Saving Sight (Bokeelia, Fla.: Irie Books, 2013), 177.
Journal of AAPOS
The Spot Vision Screener has demonstrated good sensitivity and specificity in the pediatric ophthalmology clinic setting. We sought to evaluate the updated Spot (version 2.0.16) in a general pediatric population through a collaboration of the Storm Eye Institute of the Medical University of South Carolina, the Clinica Dr Clorito Picado, and National Children’s Hospital of Costa Rica. We compared results of screening with the Spot and pediatric ophthalmologic examination and determined sensitivity and specificity of the Spot in detecting amblyogenic risk factors (ARFs) according to the 2013 AAPOS Vision Screening Committee guidelines for automated vision screeners.
METHODS
Children were screened with the Spot followed by a pediatric ophthalmologic examination. Cycloplegic refraction and motility findings were analyzed by age group to determine ARFs. A total of 219 subjects, averaging 60 months of age (range, 20-119 mo) were included. The prevalence of ARFs in our population was 12.3% (27/219). The most common risk factor was astigmatism, with a prevalence of 8.7% (19/219). The Spot referred 43 children (19.6%). Sensitivity of the Spot was 92.6%; specificity, 90.6%. The positive predictive value was 58.1%; the negative predictive value, 98.9%. The Spot demonstrated good sensitivity and specificity in detecting amblyopia risk factors in this general pediatric population. ( J AAPOS 2015;19:441-444)
RESULTS
CONCLUSIONS
T
he American Academy of Pediatrics has recommended automated vision screeners as an acceptable alternative to traditional vision screening in children 3-5 years old.1 The Spot Vision Screener2 (Welch Allyn, Skaneateles Falls, NY), introduced in October 2011, has been evaluated in pediatric ophthalmology offices and demonstrated good sensitivity and specificity in these enriched populations.3-6 As part of a collaboration between the Storm Eye Institute of the Medical University of South Carolina and the Clinica Dr Clorito Picado and ophthalmologists of the National Children’s Hospital of Costa Rica, we sought to evaluate the updated Spot
Author affiliations: aDepartment of Ophthalmology, National Children’s Hospital of Costa Rica, San Jose, Costa Rica; bClinica Ophthalmologica, San Jose, Costa Rica; cMiles Center for Pediatric Ophthalmology, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina; dDepartment of Pediatrics, Clinica Dr. Clorito Picado, San Jose, Costa Rica Supported in part by Research to Prevent Blindness, New York, NY. Submitted March 20, 2015. Revision accepted August 12, 2015. Correspondence: Mae Millicent W. Peterseim, MD, MUSC, Storm Eye Institute, 167 Ashley Avenue, Charleston, SC 29425-5536 (email: [email protected]). Copyright Ó 2015 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2015.08.002
Journal of AAPOS
(version 2.0.16) in a general pediatric population. We compared Spot screening and a pediatric ophthalmologic examination to determine the sensitivity and specificity of the Spot screener in detecting amblyopia risk factors (ARFs) according to the 2013 American Association of Pediatric Ophthalmology and Strabismus (AAPOS) Vision Screening Committee guidelines for automated vision screeners.7
Subjects and Methods This prospective study was approved by the Institutional Review Board for Human Research of the Medical University of South Carolina and the Comite Local de Bioethica, Centro de Desarrollo Estrategico e Informacion en Salud y Seguridad, Caja Costarricense de Seguro Social (Local Bioethics Committee, Center of Strategic Development and Information on Health and Insurance, Costa Rican Department of Social Security) and adhered to the US Health Insurance Portability and Accountability Act of 1996. Patients 2-9 years of age underwent a Spot vision screening and examination by one of three pediatric ophthalmologists (MAM, LCA, MMP) from March to June 2014. Patients were seen on the day of their pediatric visit or scheduled by Clinica Dr Clorito Picado (San Jose Costa Rica) scheduling staff from a computer-generated list of patients seen recently for well-
441
442
Arana Mendez et al
Volume 19 Number 5 / October 2015
Table 1. Performance metrics for the Spot, version 2.0.16, by age group Groups Children 31-48 months Spot referral/positive Spot pass/negative Children 48-137 months Spot referral/positive Spot pass/negative All children Spot referral/positive Spot pass/negative
ARF1
ARF
10 1
7 75
15 1
7 91
25 2
18 174
Sensitivity (95% CI)
Specificity (95% CI)
PPV (95% CI)
NPV (95% CI)
90.9 (58.7-98.5)
91.5 (83.2-96.5)
58.8 (33.0-81.5)
98.7 (92.9-99.8)
93.8 (69.7-99.0)
92.9 (85.9-97.1)
68.2 (45.1-86.1)
98.9 (94.1-99.8)
92.6 (75.7-98.9)
90.6 (85.6-94.4)
58.1 (42.1-73.0)
98.9 (96.0-99.8)
ARF, amblyopia risk factors; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value. child visits or minor illness in the pediatric clinic, with no knowledge of eye complaints. In addition, children in three day care centers (Guarderias Centro Modelo, La Libertad, and Montesori Los Angeles of the Fundacion Humanitaria) were screened and examined through the Christian Medical Clinic in La Carpio, San Jose, Costa Rica. Approved written informed consent was obtained (in Spanish) from parents or guardians prior to the examination.
Statistical Analysis
Testing
A total of 219 children (115 females [53%]) were tested; 98% were Hispanic and 2% were African American. Patients were from the general pediatric practice of Clinica Dr Clorito Picado (150) and local preschools (69). The average age was 60 months (range, 20-119 months). Our sample included only 12 patients in group 1 (12-30 months), which we believed too few for separate analysis. Therefore, we analyzed results only for group 2 (93 children) and group 3 (114). ARFs as determined by the ophthalmologist examination in our population were found in 27 subjects (12.3%). The most common ARF was astigmatism, with a prevalence of 19 of 219 (8.7%). The Spot referred 43 children (19.6%). The Spot did not obtain a result after repeated attempts in 3 children, who were 30, 35, and 38 months of age and found not to have ARFs on ophthalmological examination. The sensitivity of the Spot to detect ARFs was 92.6%; the specificity was 90.6%. The positive predictive value (PPV) was 58.1% and the negative predictive value (NPV) was 98.9% (Table 1). The Spot referred 31 children for astigmatism, 3 for anisometropia, 3 for hyperopia, and 3 for myopia. Some children were referred for more than one reason. Of the 31 children referred for astigmatism, 19 were found on examination to meet AAPOS criteria for astigmatism and 12 were false positives. There were no children meeting AAPOS criteria for astigmatism on examination who were missed using the Spot. The false positive rate for astigmatism (false positives/false positives 1 true negatives) was 6% for group 2and 4% for group 3. In group 2 the sensitivity of the Spot to detect ARFs was 90.9%, and the specificity was 91.5%. The PPV was 58.8%; the NPV, 96.7%.
4,6
The Spot device has been described elsewhere. Spot software version 2.0.16 was employed in this study. Initially 30 patients were screened by the ophthalmologists prior to the examination, following manufacturer guidelines. Subsequent patients were screened by one of two trained lay personnel, following manufacturer guidelines (AMAR, 120 children; CMP, 69 children). Spot screening and examinations were performed in a separate room. Ophthalmological examination included cover-uncover ocular motility testing and examination of the anterior segment. Cycloplegic retinoscopy and dilated fundus examination were performed after 30 minutes after instillation of 1-2 drops each of tropicamide 0.5% with phenylephrine 5% and cyclopentolate 1%.
Data Collection Patient data collected included age, sex, race, Spot refraction estimate, screener recommendation using Spot “out of the box” manufacturer criteria (“complete eye exam recommended” or “all measurements in range”), reason for referral, and results of ophthalmologist’s examination, including presence of strabismus and cycloplegic refraction and diagnosis of ocular pathology. Ophthalmologists’ findings were added to the Spot-generated Excel database for analysis.
Analysis All patients who entered the study were included, even those on whom a reading was not obtained. Children were divided into age groups to determine gold standard results (ARF1/ARF ), according to the AAPOS guidelines: group 1, 12-30 months; group 2, 31-48 months, and group 3, .48 months. Patients were considered to have ARFs on the comprehensive examination on the basis of the physician’s diagnosis and 2013 AAPOS guidelines.7
Descriptive statistics were calculated. Sensitivity, specificity, positive and negative predictive values of the Spot in detecting ARF1 conditions were calculated. The 3 children for whom the Spot was unable to obtain a result were included as automatic referrals and included as test positives.
Results
Journal of AAPOS
Volume 19 Number 5 / October 2015 In group 3, the sensitivity of the Spot to detect ARFs was 93.8 %; the specificity, 92.9%. The PPV was 68.2%; the NPV, 98.9%. Of the 3 children referred by the Spot for “gaze,” 2 had strabismus meeting AAPOS criteria (manifest heterotropia of .8D)—one exotropic and the other hypertropic. The third child was not found to have strabismus.
Discussion Improved automated screening tools help reach the almost 40% of children who do not receive recommended preschool vision screening.8 Early detection improves visual acuity outcomes.9,10 This study compared the newest version of the Spot vision screener to pediatric ophthalmologic examination in a population of young children in Costa Rica. Previous reports of the Spot as a screening tool in the general pediatric population noted poor follow-up.11 We were able to complete ophthalmologic examinations on all children tested. Costa Rica has a successful centralized health system by many measures.12 Babies eyes are routinely tested using red reflex testing in the nursery, and parents receive information about childhood development that includes signs of visual problems. While many primary care public clinics perform vision screening between the ages of 5 and 6, there is not a standardized system for testing vision in young children. Our population prevalence of ARFs of 12.3% is between estimates of ARFs in the general pediatric population of 20%7,13,14 and the amblyopia prevalence of 1.6% to 3.6%.15 It is slightly less than the 14% found by Matta and Silbert16 in an older pediatric population in Honduras. Using the manufacturer’s referral criteria, we found excellent sensitivity and specificity of the Spot in the general pediatric population studied. Compared with results reported by Silbert and Matta16 using the Plusoptix and SureSight screeners in Honduras, we found slightly lower sensitivity and specificity than plusoptiX S04 and higher sensitivity and specificity than plusoptiX A09 and Suresight.17 Compared to previous validation studies of the Spot screener used in pediatric ophthalmology populations, which found a sensitivity of 80% to 89% and a specificity 74% to 88%,4-6 our results found improved sensitivity (92.6%) and specificity (90.6%) in the general population. A weakness of the present study is that, due to early staffing issues, our ophthalmologists conducted the screening for the first approximately 30 patients, allowing the potential for the ophthalmologists to be influenced by the screener results. However, the examination was carried out independently and confidence was placed in the doctors findings as the gold standard. In addition, a larger sample size and further testing would improve confidence intervals. Our findings in a Costa Rican population may differ from those found in other countries. Our high rate of astigmatism may be related to our Hispanic population18 and is reflected in the high referral rate
Journal of AAPOS
Arana Mendez et al
443
for astigmatism of the Spot screener. However, the number of false positive referrals for astigmatism suggests an adjustment in the manufacturer’s criteria may improve specificity. In conclusion, we found that the newest version of the Spot offered very good specificity and sensitivity in this general pediatric patient population. Our findings compare favorably with those of other automated screeners.3,17,19 Evaluation of automated screener performance is important, as national panels make specific recommendations about new technology to detect amblyopia risk factors and to prevent or treat amblyopia.20,21 References 1. Miller JM, Lessin HR, American Academy of Pediatrics Section on Ophthalmology, Committee on Practice and Ambulatory Medicine, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus, American Association of Certified Orthoptists. Instrument-Based Pediatric Vision Screening Policy Statement. Pediatrics 2012;130:983-6. 2. Spot Vision Screener, 2014 Welch Allyn. http://www.welchallyn.com/ en/products/categories/physical-exam/eye-exam/vision-screeners/spotvision-screener.html. Accessed 10/16/2014. 3. Arnold RW, Arnold AW, Armitage MD, Shen JM, Hepler TE, Woodard TL. Pediatric Photoscreeners in High Risk Patients 2012: A Comparison Study of Plusoptix, iScreen and SPOT. Binocul Vis Strabolog Q Simms Romano 2013;28:20. 4. Silbert DI, Matta N. Performance of the Spot vision screener for the detection of amblyopia risk factors in children. J AAPOS 2014;18: 169-72. 5. Garry GA, Donahue S. Validation of Spot screening device for amblyopia risk factors. J AAPOS 2014;18:476-80. 6. Peterseim MMP, Papa CE, Wilson ME, et al. The effectiveness of the Spot Vision Screener in detecting amblyopia risk factors. J AAPOS 2014;18:539-42. 7. Donahue SP, Arthur B, Neely DE, Arnold RW, Silbert D, Ruben JB. AAPOS Vision Screening Committee. Guidelines for automated preschool vision screening: a 10-year, evidence-based update. J AAPOS 2013;17:4-8. 8. Kemper AR, Wallace DK, Patel N, Crews JE. Preschool vision testing by health providers in the United States: findings from the 2006-2007 Medical Expenditure Panel Survey. J AAPOS 2011;15:480-83. 9. Holmes JM, Lazar E, Melia BM, , et al. Pediatric Eye Disease Investigator Group. Effect of age on response to amblyopia treatment in children. Arch Ophthalmol 2011;129:1451-7. 10. Teed RG, Bui C, Morrison DG, Estes RL, Donahue SP. Amblyopia therapy in children identified by photoscreening. Ophthalmology 2010;117:159-62. 11. Ransbarger KM, Dunbar J, Choi SE, Khazaeni LM. Results of a community vision-screening program using the Spot photoscreener. J AAPOS 2013;17:516-20. 12. World Health Organization. Global Health Data Repository. Life Expectancy Data by Country. http://apps.who.int/gho/data/node. main.3?lang5en. 2014. Accessed 10/16/2014. 13. Arnold RW. Amblyopia risk factor prevalence. J Pediatr Ophthalmol Strabismus 2013;50:213-17. 14. Varma R. Author reply on behalf of the Multi-Ethnic Pediatric Eye Disease Study and the Baltimore Pediatric Eye Disease Study Investigators. Ophthalmology 2012;119:1283-4. 15. Simon K. Amblyopia characterization, treatment, and prophylaxis. Surv Ophthalmol 2005;50:123-65. 16. Matta NS, Singman EL, McCarus C, Matta E, Silbert DI. Screening for amblyogenic risk factors using the PlusoptiX S04 Photoscreener
444
Arana Mendez et al
on the indigent population of Honduras. Ophthalmology 2010;117: 1848-50. 17. Silbert DI, Matta N, Amanda L, Ely AL. Comparison of SureSight autorefractor and plusoptiX A09 photoscreener for vision screening in rural Honduras. J AAPOS 2014;18:42-4. 18. Ying GS, Maguire MG, Cyert LA, , et al. Vision In Preschoolers (VIP) Study Group. Prevalence of vision disorders by racial and ethnic group among children participating in head start. Ophthalmology 2014;121:630-36.
Volume 19 Number 5 / October 2015 19. Arthur BW, Riyaz R, Rodriguez S, Wong J. Field testing of the plusoptiX S04 photoscreener. J AAPOS 2009;13:51-7. 20. Nicolella L. Vision screening for children 1 to 5 years of age: US Preventive Services Task Force Recommendation Statement. Pediatrics 2011;127:1-7. 21. Cotter SA, Cyert LA, Miller JM, Quinn GE. National Expert Panel to the National Center for Children’s Vision and Eye Health. Vision screening for children 36 to \72 months: recommended practices. Optom Vis Sci 2014;92:6-16.
Seeing Is Believing The truth is that Braille fought his entire life to convince others that his system was a meaningful contribution to the blind. Many times he despaired that his system, though obviously superior to any other method, would ever be used by anyone outside the walls of his school, and sometimes, by anyone but himself. When Braille died in 1852, at the age of 43, he was practically unknown. —Andrew Lam, Saving Sight (Bokeelia, Fla.: Irie Books, 2013), 177.
Journal of AAPOS