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monotonically associated with worse self-reported visual functioning. Myopic refractive error was more strongly associated with self-reported visual function than was presenting vision.15 The findings of this study are substantiated by a recent trial demonstrating a significant improvement in VSF with provision of glasses among school-aged children having modest levels of refractive error in rural Mexico.16 The VSF score in that study was calculated using the Refraction Status Vision Profile (RSVP) scale17 designed specifically to measure the impact of refractive error and its correction on visual functioning.

Impact of Myopia in Adults

Compared to younger populations, the impact of myopia and refractive error on QoL in adults has been marginally better evaluated (Table 2). In Japan, 200 pathological myopia patients (refraction exceeding −8.0 D [diopter] in one eye or both eyes, aged 18 years and above) reported poorer scores in eye and life satisfaction after adjusting for their daily life activities compared to control patients who had best corrected visual acuity better than 0.8; refractive error between −3.0 and +3.0 D; and no ocular disease.18 In contrast, the general well-being schedule score, which evaluated the patient’s psychological status over the last month, was not reduced in the pathologic myopia patients. This is the only study assessing QoL of pathological myopia patients and thus comparative analyses are difficult.

Generic HRQoL has been also evaluated in patients with correctable visual impairment in different countries. A population-based study of 3153 Australians aged 49 to 98 years, reported that age and sex adjusted HRQoL scores (as measured using the SF-36 questionnaire5), was not affected in participants with unilateral visual impairment correctable by refraction.19 The medical conditions of the participants, such as comorbidity or disabilities, were however not adjusted in these analyses and may have confounded the study findings.20 When participants with bilateral correctable visual impairment of the same Australian cohort (n = 3154) were examined, significant lower scores were reported for physical functioning, social functioning, and the physical component when compared with those with no visual impairment.21 In a smaller population-based Taiwanese study (n = 1361) that included participants aged 65 and above, it was shown that bilateral correctable visual impairment has an impact only in the physical functioning dimension score of SF-36, but no significant

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difference was found in the other seven dimensions.22 Unfortunately, the mean scores for each dimension between participants with correctable visual impairment and those without visual impairment were not reported. Hence, it is difficult to assess if the insignificant difference in social functioning and the physical component was due to the insufficient sample size in this study (127 with correctable visual impairment). Poorer physical component scores of SF-12 were also reported by adults aged 15 to 81 years with visual impairment due to either refractive or pathological causes, selected from the poorest community in Canada.23 Although the study had a small sample size and non-randomly selected study population, their finding also suggested that visual impairment detrimentally affected the physical score of generic QoL.

The vision-specific functioning of patients with corrected and uncorrected myopia was assessed with the VF-11 (a modified version of VF-14) in a recent population-based study of Singaporean Malays.24 Uncorrected myopia was found to be independently associated with poorer overall functioning score and vision-related activities (e.g. reading street signs, recognizing friends, and watching television), but not corrected myopia. This finding suggests that myopia alone does not have an effect on daily activities, but myopia that remains uncorrected affects visual functioning. This finding, however, differs from that found in an Australian study, which showed that corrected myopia affects vision-related QoL. Participants

with myopia corrected with glasses or contact lenses (best corrected visual acuity >20/20) reported a negative impact on some specific aspects of

vision-related QoL, such as having concerns about injuring themselves, difficulties coping with demands in their lives, difficulties fulfilling their work, family, and community roles, and less confidence joining in everyday activities.25 Cultural, study design, and sample size differences may account for the discrepancies between these two studies. Critically though, corrected myopia in the Australian study was more related to the emotional and psychosocial impact of myopia, which was not assessed in the study in Singapore.

A study in United Kingdom investigated the relationship between the severity of myopia and vision-related QoL, as measured by Vision Core Measure 1 (VCM1).26 Patients with severe myopia reported poorer quality of life scores when compared to those with moderate and low levels of myopia. Unfortunately, the findings of this study were limited by a low response rate (28%), and the analyses were not stratified for the correction

90 E.L. Lamoureux and H.-B. Wong

of refractive error. Similar to myopic patients, poorer functioning scores were also reported by nursing home residents who had uncorrected refractive error in one or both eyes.27

Although data pertaining to the impact of myopia per se is limited, there is some information about the impact of uncorrected refractive error on vision-specific HRQoL. In 4550 Hispanics adults aged 40 to 96 years, visual impairment due to refractive errors was associated with decrements on several subscales of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) scale, including general vision, distance vision, driving, peripheral vision, role difficulties, dependency, social functioning, and mental health when compared to those with no eye disease and without uncorrected refractive error.28 Lower NEI-VFQ-25 scores (eight dimensions, including the composite score) were also reported by Australians participants with bilateral visual impairment due to uncorrected refractive error, but not in those with unilateral visual impairment.29 Both studies using the NEI-VFQ-25 scale, however, did not adjust for general health status or non-ocular comorbidities, which have been shown to impact vision-specific HRQoL.20 This may have confounded their findings. Uncorrected refractive error was also associated with a decrement in the nursing home vision-targeted health-related quality of life (NHVQoL) subscales of general vision, reading, psychological distress, activities and hobbies, and social interaction, reported by nursing home residents.27

Overall Conclusion

In spite of myopia being a growing public health problem and its prevalence and severity increasing in different parts of the world, particularly in Asia,30–32 there is remarkably limited data about its impact on HRQoL. In children and younger adults, the limited findings indicate that myopia has little or no impact on general health. On the other hand, and perhaps as anticipated, the meager available data suggest a systematic and positive relationship between worsening levels of myopia and poorer vision-specific functioning. In addition, the available current information seems to indicate that myopia is associated with visual disabilities other than visual acuity measurements, potentially including micropsia and deficits of peripheral vision among children wearing corrective glasses.15 Considering the