Several studies have documented that, in many settings, only a small proportion of children with significant refractive errors are actually wearing corrective spectacles.
1 2 3 4 5 6 7 8 12 15 17 However, few studies
12 have reported medium or long-term compliance with spectacles among school-age children, and even fewer have examined risk factors for noncompliance.
1 Those few studies that have examined compliance with spectacle wear and risk factors for noncompliance have frequently focused on special populations of children, such as those participating in trials of therapy designed to reduce myopia progression
18 or to treat amblyopia.
19 20 21 22 Unlike the present study, which examined a random sample of schoolchildren in Oaxaca, Mexico, the results of these studies are likely to have very limited generalizability.
The relatively small proportion of children identified as compliant with spectacle wear in the present study, 13%, is generally in accord with other reports, such as that of Villareal et al.,
1 also in Mexico, indicating only 28% compliance among children with myopia worse than −0.75 D. Studies of aphakic spectacle compliance in adults after cataract surgery
23 have also often reported limited medium-term compliance. That our own rate of spectacle wear is even lower than those reported elsewhere in the literature may in part be because outcomes in the present study were based on actual inspection of the child in question, whereas other studies have depended on self-report, which may be expected to give higher, but less-reliable, data.
Two risk factors for noncompliance with spectacle wear in the present study, older age and urban residence, are particularly troubling. The prevalence of myopia among school-age children is well known to increase with age
2 3 4 5 6 7 8 9 11 13 14 15 and several studies have demonstrated a higher prevalence of myopia in urban than in rural populations.
1 5 6 7 8 10 11 Thus, precisely those children who stand to benefit most from corrective spectacles for myopia, older, urban children, are the ones at greatest risk for noncompliance. Spectacle wear among children residing in urban and suburban areas was only 9% (compared with 41% in rural children) in this population. From a programmatic standpoint, a possible interpretation of these results with regard to age may be that intervening to provide spectacles when a child is younger and more likely to comply may allow this pattern of better compliance to be maintained at a later age when the risk of more visually significant refractive error is higher. This hypothesis can be tested within the context of program delivery strategy.
The present study provides some insights into the noncompliant behavior of these older and urban children. Both groups were significantly more likely to list concerns about appearance and being teased as reasons for spectacle nonwear than were younger, rural children. This suggests the need for two-pronged strategies targeting these key at-risk groups with educational messages explaining the need for spectacle wear and also improved designs with greater esthetic appeal. A practical problem with the latter strategy is the fact that on-the-spot delivery of glasses is a critical part of HKI’s strategy of school-based screening, to reduce the barriers to receipt of spectacles inherent in programs providing only chits or prescriptions for spectacles or those delivering glasses at a later date. On-the-spot delivery of glasses requires the use of round frames so that the axis of astigmatism can be adjusted at the time of assembly. Our experience in Mexico and elsewhere has suggested that such round frames (“Harry Potter” glasses) are often less appealing to children concerned about appearance. The fact that only 26% of the subjects in the present study had 1 D or more of astigmatism, this suggests that more than 70% of children requiring spectacles might be accommodated with more cosmetically acceptable oval frames. Alternatively, round frames could be used in rural areas where compliance is less problematic and later follow-up visits to dispense oval frames are presumably more expensive, and oval frames could be used in urban areas where the opposite is likely to be true. The relative cost of dispensing per pair of spectacles presumably could be calculated and compared between competing scenarios to model this strategy.
Another finding in the present study with important programmatic implications is the fact that spectacle compliance was especially low among children with more modest degrees of refractive error. HKI has already implemented a new protocol, which will raise the cutoff for provision of spectacles for nonastigmatic myopia from −0.75 to −1.00 D. In the current sample, this would have reduced the number of spectacles provided by 24.3% (data not shown). This change in protocol, resulting directly from the data reported in the current article, will significantly reduce costs to the program for supplies and labor, thus allowing resources to be focused on specific programs to improve compliance among older, urban children at high risk for spectacle nonwear.
Limitations of the present study should be acknowledged. Subjects included only participants in HKI’s school-based refractive error program and thus excluded children who were not attending school. Children attending school are more likely to be engaged in near work and are thus more likely to be myopic as a group, and to benefit from refractive correction, but these results still cannot be generalized to the population as a whole. Due to practical considerations and the need to complete program interventions in a timely fashion, children did not undergo cycloplegia for retinoscopy, and thus latent hyperopia was not measured, perhaps in part accounting for the low prevalence of significant hyperopia in the sample (3.7%). Vision screening for all subjects was performed by schoolteachers with only minimal training in the measurement of acuity, and the sensitivity and specificity in detecting children with refractive error affecting vision is not known and may have been limited. Visual acuity without glasses was a likely determinant of spectacle wear, but was not recorded for many subjects in this study, and thus could not be included in regression models. Only a single rural school was surveyed, and it is possible that characteristics of the school other than its rural location could have contributed to the observed associations with rural residence. Although children were not told about the date of the follow-up visit to their schools, it is possible that the fact that parents were notified in advance of the follow-up plan (though not the date) may have influenced children’s patterns of spectacle wear. Finally, only three fourths of children who had been dispensed spectacles in the target schools could be located. Complete data were not available for those children who could not be examined, which may have been due to nonattendance at school on the day of examination or to the students’ having moved to a new school district in the intervening period since receiving the spectacles. Thus, although the proportion of children who could be examined was fairly high, the possibility that examined children were not representative of the full population of children receiving glasses cannot be excluded. All of these limitations, though they may affect the validity of our figures as epidemiologic data, are less likely to impact the important programmatic implications of the present study for our own, and potentially other, refractive screening programs for school-aged children.