Purpose
To report the outcomes of full ophthalmic examination for preschool children in LA County who failed screening with the Retinomax Autorefractor.
Design
Retrospective, cross-sectional study.
Methods
Between August 2012 and May 2013, the University of California Los Angeles (UCLA) preschool vision program screened 11 260 preschool children aged 3–5 years in Los Angeles County using the Retinomax Autorefractor only. Of those, 1007 children who failed the screening were examined by an ophthalmologist on the UCLA Mobile Eye Clinic. Data from the eye examination were recorded for all children. 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.
Results
Glasses were prescribed for 740 (74%) of those examined. Uncorrected visual acuity for all examined children was 0.4 ± 0.2 (logMAR mean ± SD), and BCVA was 0.2 ± 0.1. Of the 88% who underwent cycloplegia, 58% had hyperopia (spherical equivalent [SE] ≥+0.50 diopter [D]), mean of +2.50 D, and 21% had myopia (SE ≤−0.50 D), mean of −1.40 D. A total of 69% had astigmatism ≥1.50 D, mean of 1.97 D (range 0–5.75). Spherical and cylindrical anisometropia ≥1.00 D were each found in 26% of those examined. Refractive amblyopia was found in 9% of those examined, or 0.8% of the original population. Of the amblyopic subjects, 77% were unilateral.
Conclusions
Screening of preschoolers with the Retinomax led to diagnosis and early treatment of uncorrected refractive errors and amblyopia. By treating children early, amblyopia may be prevented, quality of life improved, and academic achievements enhanced.
Preschool vision screening allows for early diagnosis and treatment of visual impairment and disease such as refractive error, strabismus, and amblyopia. Significant refractive errors are the most prevalent and treatable vision problems in preschool children. Unlike strabismus, which will generally prompt a referral to an eye doctor, refractive errors in children causing severe decrease in visual acuity of 1 eye or both eyes can go unnoticed for years because children rarely complain about their vision, especially if the problem is unilateral. Children with high refractive errors and/or amblyopia can be detected by screening programs, thus the recommendation of the United States Preventive Services Task Force (USPSTF) for vision screening of all children at least once between the ages of 3 and 5 years. Early treatment of refractive errors in children can greatly improve their quality of life and their academic achievements, and can reduce the prevalence of refractive amblyopia in the population. Refractive amblyopia is among the most common causes of amblyopia and includes bilateral high hyperopia, high myopia, high astigmatism, and anisometropia. Recent large population-based studies have confirmed that the prevalence of amblyopia in childhood is approximately 1%–2%. Early detection of amblyopia and early initiation of treatment has been shown to improve visual acuity (VA) outcomes for children with amblyopia. A previous study revealed that the prevalence of amblyopia at age 7 years was reduced by 45% in children who had received preschool screening by age 37 months. One of the most sensitive and specific methods for screening preschool children, as shown recently in the Vision in Preschoolers Study (VIP), is the Retinomax Autorefractor. The hand-held Retinomax Autorefractor requires minimum training for examiners and allows easy and quick measurements of refractive errors, thus making it an excellent method for screening children. Current recommendations state that handheld autorefraction may be used as an alternative to traditional vision screening methods using VA charts in 3- to 5-year-olds.
The University of California Los Angeles (UCLA) preschool vision program (UPVP), modeled after the University of California San Diego “EyeMobile for Children” program, is a community outreach program that has been set up to screen children attending preschool programs in Los Angeles County for refractive errors and amblyopia risk factors, to examine those who fail the screening, to prescribe and deliver glasses to those who need them, and to refer those children for further follow-up; these are provided as free services. In this study, we report the refractive errors, visual acuity, and refractive amblyopia found in children examined during the first year of our program.
Methods
This study was approved by the UCLA Institutional Review Board and conformed to the requirements of the United States Health Insurance Portability and Accountability Act. The data reported in this study are from the 2012–2013 school year. The children were aged 3–5 years, attending subsidized preschools within Los Angeles County.
Screening was performed by screeners using the Retinomax Autorefractor, a handheld auto-refractometer (Retinomax 3; Righton, Tokyo, Japan) set for reporting the refractive error in minus cylinder form. The criteria for failing the screening were: sphere ≤−3.25 diopters (D) or ≥+1.75 D, cylinder ≥1.50 D, or an interocular difference of ≥2.00 D in spherical error (≥1.50 D if antimetropic) or ≥1.00 D cylinder error, revised from the VIP trials. Children who failed the screening were given a full examination by an ophthalmologist with the UCLA mobile eye clinic on a different date after receiving parental consent for a full dilated eye examination.
The comprehensive examination consisted of VA for distance and near tested with Allen pictures, color vision, stereoacuity with the titmus fly test, ocular motility, ocular alignment performed with cover test, slit-lamp examination, cycloplegic retinoscopy, and indirect ophthalmoscopy. Cycloplegia was attained after topical instillation of a mixture of cyclopentolate 1%, tropicamide 0.25%, phenylephrine 0.4%, and proparacaine .04% drops. Cycloplegic refraction was performed at least 30 minutes after instillation of the drops. Best-corrected visual acuity (BCVA) was assessed with the cycloplegic refraction. Glasses were prescribed according to accepted pediatric ophthalmology guidelines. Children who needed glasses were fitted with frames and received their glasses a few weeks later. Parents were instructed to take their children for further follow-up with an eye care professional. The follow-up interval and type of eye care professional recommended depended on the child’s diagnosis.
For analysis of the results, hyperopia and myopia were calculated as spherical equivalent (SE). SE was calculated as the sum of the spherical plus half the cylindrical error. Snellen VA format was converted to logMAR in order to facilitate the calculations. Anisometropia was calculated as ≥1.50 D and ≥1.00 D difference in spherical or cylindrical error. Amblyopia was defined as unilateral if there was a ≥2 line interocular difference in the BCVA, with at least 1 refractive risk factor (anisohyperopia SE ≥1.00 D, anisoastigmatism ≥0.50, or anisomyopia ≥2.00), and bilateral if BCVA in each eye was <20/50 for children <4 years old and <20/40 for children ≥4 years old with at least 1 refractive risk factor (hyperopia >4.00 D for 3-year-olds and >3.50 D for 4- to 5-year-olds, astigmatism of >2.00 D for 3-year-olds and >1.50 D for 4- to 5-year-olds, myopia >−3.00 D for 3-year-olds and >−1.50 D for 4- to 5-year-olds, based on new recommendations ). Unilateral amblyopia was further categorized as mild (≥20/30), moderate (20/40–20/80), and severe (≤20/100) based on BCVA. If a child had both unilateral and bilateral amblyopia, he was counted once for the total amblyopia patients and was classified in the results table as bilateral amblyopia.
Amblyopia risk factors were calculated according to the 2013 AAPOS referral criteria. Criteria in children <4 years old, criteria were hyperopia >4.00 D, myopia >−3.00 D, astigmatism >2.00 D, anisometropia >2.00 D. In children ≥4 years old, criteria were hyperopia >3.50 D, myopia >−1.50 D, astigmatism >1.50 D, anisometropia >1.50 D.
Statistical analyses were performed with SAS version 9.4 (SAS Institute, Cary, North Carolina, USA). The difference in continuous variables among multiple subgroups was assessed using analysis of variance (ANOVA), and the difference in categorical variables among multiple subgroups was evaluated using χ 2 tests. P < .05 was considered statistically significant.
Results
Between August 2012 and May 2013, 11 260 children were screened. Of those screened, 1761 (16%) failed, including 207 already under care with an eye care provider. The 1554 children who failed screening and were not already under care were referred for a full ophthalmic examination. Of those referred, 1007 children (65%) arrived for their appointment with parental consent and were given an ophthalmic examination. A total of 740 (74% of children examined) were prescribed glasses for the first time. Altogether, at least 8% (n = 914, including another 174 children who were already under care and wearing glasses) of the population screened required glasses. Among the children who failed screening criteria, 117 children (12%) did not need glasses per the ophthalmologist’s clinical judgment based on VA and dry Retinomax readings and were thus not given cycloplegic examinations. Of the children examined, 89% were Hispanic, mean age was 4.3 years, and 51% were female. Results for the right and left eyes were comparable; thus we report results for the right eye only.
The results for refractive errors in the children given a full cycloplegic examination are presented in Table 1 . Hyperopia (SE ≥0.50 D) was found in 58% with a mean of +2.50 D (range 0.5–8.6), 21% had SE ≤−0.50 D with a mean of −1.40 D (range −9.6 to −0.50), and 21% had SE between −0.50 D and +0.50 D (“emmetropia”) with cylindrical error ranging from 0 to 4.75 D. Of 99 children who had SE of emmetropia in both eyes, 83 were prescribed glasses owing to astigmatism in 1 or both eyes and 5 were amblyopic. Astigmatism was the most common finding, appearing in 93% of children; 69% had astigmatism ≥1.50 D; and the mean was 1.97 D (range 0–5.75). Spherical anisometropia of 1.50 D and 1.00 D was found in 13% and 26% of children, respectively. Similarly, cylindrical anisometropia of 1.50 D and 1.00 D was found in 11% and 26% of children, respectively. There was no statistically significant difference between age groups for the different levels of refractive errors or anisometropia ( Table 1 ).
| Age | Total N = 874 | |||
|---|---|---|---|---|
| 3 Years (N = 235) | 4 Years (N = 540) | 5 Years (N = 99) | ||
| Hyperopia SE | ||||
| 0.50–1.99 | 60 (26%) | 147 (27%) | 29 (29%) | 236 (27%) |
| 2.00–3.99 | 46 (20%) | 109 (20%) | 21 (21%) | 176 (20%) |
| 4.00–5.99 | 17 (7%) | 45 (8%) | 8 (8%) | 70 (8%) |
| ≥6.00 | 2 (0.9%) | 16 (3%) | 4 (4%) | 22 (3%) |
| Total (≥+0.50) | 125 (53%) | 317 (59%) | 62 (63%) | 504 (58%) |
| Myopia SE | ||||
| 0.50–1.99 | 49 (21%) | 91 (17%) | 17 (17%) | 157 (18%) |
| 2.00–3.99 | 5 (2%) | 15 (3%) | 2 (2%) | 22 (3%) |
| 4.00–5.99 | 1 (0.4%) | 2 (0.4%) | 0 | 3 (0.3%) |
| ≥6.00 | 0 | 1 (0.2%) | 0 | 1 (0.1%) |
| Total (≤−0.50) | 55 (23%) | 109 (20%) | 19 (19%) | 183 (21%) |
| Astigmatism | ||||
| 0.50–1.25 | 58 (25%) | 126 (23%) | 24 (24%) | 208 (24%) |
| 1.50–3.75 | 155 (66%) | 351 (65%) | 57 (58%) | 563 (64%) |
| 4.00–5.75 | 9 (4%) | 26 (5%) | 10 (10%) | 45 (5%) |
| ≥6.00 | 0 | 0 | 0 | 0 |
| Total (≥0.50) | 222 (94%) | 503 (93%) | 91 (92%) | 816 (93%) |
| Anisometropia | ||||
| Spherical (≥1.5) | 27 (11%) | 69 (13%) | 14 (14%) | 110 (13%) |
| Spherical (≥1.0) | 53 (23%) | 145 (27%) | 30 (30%) | 228 (26%) |
| Cylindrical (≥1.5) | 25 (11%) | 60 (11%) | 13 (13%) | 98 (11%) |
| Cylindrical (≥1.0) | 58 (25%) | 143 (26%) | 22 (22%) | 223 (26%) |
Uncorrected VA for the entire group was 0.4 ± 0.2 (logMAR, mean ± SD), and mean BCVA was 0.2 ± 0.1, with statistically significant differences between age groups only for the right eye ( P = .04 for uncorrected VA and P = .03 for BCVA) showing slightly poorer VA for the 3-year-old age group. VA subgroup results are presented in Table 2 . Most children (76%) were corrected to ≥20/30 (logMAR ≤0.2) in the right eye, with similar results for the left eye.
| Age | Total | |||
|---|---|---|---|---|
| 3 Years | 4 Years | 5 Years | ||
| Uncorrected a | N = 238 | N = 578 | N = 103 | N = 919 |
| ≥20/30 | 56 (24%) | 177 (30%) | 33 (32%) | 266 (29%) |
| 20/40–20/60 | 118 (50%) | 289 (50%) | 57 (55%) | 464 (51%) |
| 20/70–20/80 | 42 (18%) | 83 (14%) | 8 (8%) | 133 (15%) |
| ≤20/100 | 22 (9%) | 29 (5%) | 5 (5%) | 56 (6%) |
| Corrected b | N = 184 | N = 466 | N = 82 | N = 732 |
| ≥20/30 | 129 (70%) | 361 (77%) | 65 (79%) | 555 (76%) |
| 20/40–20/60 | 52 (28%) | 100 (21%) | 14 (17%) | 166 (23%) |
| 20/70–20/80 | 3 (2%) | 2 (0.4%) | 2 (2%) | 7 (1%) |
| ≤20/100 | 0 | 3 (0.6%) | 1 (1%) | 4 (0.5%) |
Results for unilateral and bilateral amblyopia are presented in Table 3 . Altogether there were 95 children with amblyopia, 73 unilateral and 22 bilateral, which was 9% of the examined population and 0.8% of the screened population. Two patients met the definition for both unilateral and bilateral amblyopia. Data on refractive error for the children with unilateral amblyopia are presented in Table 4 . Of the unilateral amblyopic subjects, 63% were hyperopic and 72% had astigmatism ≥1.50 D. Of the bilateral amblyopic subjects, 75% were hyperopic. The percentage of amblyopia increased with increasing amounts of refractive error. Of the children with spherical and cylindrical anisometropia ≥1.00 D, 26% and 19% were amblyopic, respectively. Of those with spherical and cylindrical anisometropia ≥1.50 D, 28% and 27% were amblyopic, respectively. Children in the 5-year-old age group had a higher percentage of amblyopia as compared with the 3- and 4-year-old groups, but this was not statistically significant. Of the patients with unilateral amblyopia, 76% had VA in the amblyopic eye of 20/40–20/80 (logMAR 0.3–0.6). The amblyopic eye had mean BCVA ± SD of 0.5 ± 0.4 (logMAR, range 0.2–2.0). Mean SE ± SD for the amblyopic eye was +1.88 ± 3.46 D (range −12 to 8.63). Mean astigmatism for the amblyopic eye was 2.25 ± 1.39 D (range 0–5.5).
| Age (y) | Unilateral Amblyopia | Bilateral Amblyopia | ||
|---|---|---|---|---|
| Mild a | Moderate b | Severe c | ||
| 3 (n = 291) | 2 (0.7%) | 17 (6%) | 2 (0.7%) | 3 (1%) |
| 4 (n = 611) | 6 (1%) | 31 (5%) | 4 (0.7%) | 16 (2.6%) |
| 5 (n = 105) | 1 (1%) | 8 (7.6%) | 2 (2%) | 3 (3%) |
| Total (N = 1007) | 9 (0.9%) | 56 (5.6%) | 8 (0.8%) | 22 (2.2%) |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
