Five-year outcome of correctable visual impairment: the Blue Mountains Eye Study

Prevalence and Associated Factors of Uncorrected Refractive Error in Older Adults in a Population-Based Study in France

Importance

Uncorrected refractive error (URE) is a common cause of visual impairment, but its prevalence in groups of older adults who could be pragmatic targets for improving optical correction remains unknown.

Objectives

To estimate the prevalence of URE in older adults, particularly in those with age-related eye disease and those who are unable to attend an outpatient clinic, and to identify the factors associated with URE.

Design, Setting, and Participants

This population-based cross-sectional analysis included 707 adults 78 years or older from the Alienor Study in Bordeaux, France. Data were collected from February 12, 2011, through December 21, 2012, and analyzed from November 1, 2017, through July 7, 2018.

Main Outcomes and Measures

Uncorrected refractive error was defined as the presenting distance visual acuity in the better-seeing eye improved by at least 5 letters on the Early Treatment Diabetic Retinopathy Study chart (≥1 line on the logMAR chart) using the best-achieved optical correction. Multivariate logistic regressions were used to determine the factors associated with URE.

Results

The study population of 707 adults 78 years or older (64.8% women; mean [SD] age, 84.3 [4.4] years) had a prevalence of URE of 38.8% (95% CI, 35.2%-42.5%). Prevalence was high for participants with eye disease (range, 35.0% [95% CI, 28.4%-42.0%] to 44.1% [95% CI, 27.2%-62.1%], depending on the disease) and those without eye disease (30.1%; 95% CI, 24.0%-36.7%). Prevalence was higher in participants who were examined at home (because they could not come to the clinic) than in those examined at the clinic (49.4% [95% CI, 42.8%-55.9%] vs 33.5% [95% CI, 29.2%-37.9%]; P < .001). Having an eye examination performed at home (odds ratio [OR], 1.64; 95% CI, 1.13-2.37), living alone (OR, 0.65; 95% CI, 0.47-0.90), and having the perceptions that the ophthalmologist consultation fees are too expensive (OR, 1.94; 95% CI, 1.12-3.36) and that declining visual acuity is normal with aging (OR, 1.47; 95% CI, 1.04-2.08) were all associated with URE.

Conclusions and Relevance

These study results show that the prevalence of URE was high in this population and suggest that preventive strategies aimed at enhancing optical correction could be directed to all older adults and to specific groups by implementing at-home eye examinations for those who have difficulties attending an outpatient clinic and by focusing on those with eye disease who probably already have a regular ophthalmologic follow-up. More studies are needed to evaluate prevalence of URE in different populations and countries with various eye care systems.

Five-year visual outcome among people with correctable visual impairment: the Liwan Eye Study

IMPORTANCE

Longitudinal data on visual outcome of correctable visual impairments (VI) are of paramount importance for decision-maker to estimate burden and demand to treat avoidable VI.

BACKGROUND

To assess the 5-year visual outcome among participants with correctable VI and to identify associated risk factors.

DESIGN

Population-based longitudinal cohort study.

PARTICIPANTS

Participants with correctable VI at baseline attended the 5-year follow-up visit of the Liwan Eye Study.

METHODS

Presenting visual acuity (PVA) with habitual refractive correction was assessed using an Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Then participants with PVA <6/12 in either eye underwent further non-cycloplegic subjective refraction to obtain their best-corrected visual acuity. Correctable VI was defined as having a PVA of <6/12 in the better eye which could be improved to ≥6/12 after refractive correction.

MAIN OUTCOME MEASURES

The 5-year visual outcome among participants with correctable VI.

RESULTS

Among 1405 participants at baseline examination, 188 (13.4%) had correctable VI, of whom 118 (62.8%) were re-examined at the 5-year follow-up, including 39 (33.9%) who progressed to non-correctable VI, 43 (37.4%) who had persistent correctable VI and 33 (28.7%) who were converted to normal vision. In multivariate logistic regression, compared with participants who were no longer visual impaired, significant risk factors for participants with persistent VI were older, had income <1000 RMB/month, and more myopia spherical equivalent.

CONCLUSIONS AND RELEVANCE

Over two of three participants with correctable VI remained to have VI after 5 years, among whom 50% are correctable by spectacles, highlighting the need to improve the refractive care accessibility to treat avoidable VI in China.

Seven-year incidence of uncorrected refractive error among an elderly Chinese population in Shihpai, Taiwan: The Shihpai Eye Study

PURPOSE

To report the 7-year incidence of uncorrected refractive error in a metropolitan Chinese elderly population.

METHODS

The Shihpai Eye Study 2006 included 460/824 (55.8%) subjects (age range 72-94 years old) of 1361 participants in the 1999 baseline survey for a follow-up eye examination. Visual acuity was assessed using a Snellen chart, uncorrected refractive error was defined as presenting visual acuity (naked eye if without spectacles and with distance spectacles if worn) in the better eye of <6/12 that improved to no impairment (≥6/12) after refractive correction.

RESULTS

The 7-year incidence of uncorrected refractive error was 10.5% (95% confidence interval (CI): 7.6-13.4%). 92.7% of participants with uncorrection and 77.8% with undercorrection were able to improve at least two lines of visual acuity by refractive correction. In multivariate analysis controlling for covariates, uncorrected refractive error was significantly related to myopia (relative risk (RR): 3.15; 95% CI: 1.31-7.58) and living alone (RR: 2.94; 95% CI 1.14-7.53), whereas distance spectacles worn during examination was protective (RR: 0.35; 95% CI: 0.14-0.88).

CONCLUSION

Our study indicated that the incidence of uncorrected refractive error was high (10.5%) in this elderly Chinese population. Living alone and myopia are predisposing factors, whereas wearing distance spectacles at examination is protective.

Frequency, course, and impact of correctable visual impairment (uncorrected refractive error)

Uncorrected refractive error has been identified by the World Health Organization (WHO) as one of the priorities for Vision 2020 and a frequent cause of visual impairment. In the past, only the terms presenting visual impairment (PVI) and visual impairment after best refractive correction (BCVI) were used, so that PVI also included BCVI cases. In the more recent literature, visual impairment has been subdivided into two mutually exclusive entities: that which is correctable by refraction (which we now term correctable visual impairment, CVI) and that which cannot be corrected by refraction due to ocular or neurological disease (which we now term non-correctable visual impairment, NCVI, and which is identical to BCVI). PVI remains a useful concept as it includes both types of impairment. Although CVI is reported to be the major form of visual impairment worldwide, its impacts are not yet well understood. CVI has a higher prevalence among vulnerable groups such as older people, less well educated people and those living alone or in rural areas. Systematic data on barriers to refractive correction remain scant, but these may be present at the individual level, within the health service context, or at a social level. Our review indicates that research on CVI is at a relatively early stage and that more detailed research, particularly determining whether it has impacts on independent living and quality of life, is needed before CVI can be justifiably prioritized in health policy.

Correctable and non-correctable visual impairment in a population-based sample of 12-year-old Australian children

PURPOSE

To document the prevalence of correctable and non-correctable visual impairment in a representative sample of Australian children, predominantly age 12 years.

DESIGN

Population-based cross-sectional study.

METHODS

Logarithm of the minimum angle of resolution (logMAR) visual acuity was measured in both eyes unaided, with spectacles if worn, and after subjective refraction if required, in 2353 children, examined during 2004 to 2005. Cycloplegic autorefraction (using cyclopentolate) and dilated fundus examination were performed. Using a cut-off of 0.3 logMAR units (<20/40), presenting visual impairment was defined using unaided visual acuity if spectacles were not worn or with usual correction if spectacles were worn. Impairment not eliminated by refraction was considered non-correctable; any difference between this and presenting impairment was defined as correctable impairment. Myopia was defined as spherical equivalent refraction (SER) < or =-0.50 diopters (D), hyperopia as SER > or =+2.0 diopters, anisometropia as SER difference > or =1.00 diopters, and astigmatism as cylinder > or =1.0 diopters. Amblyopia was defined as corrected visual acuity <0.3 logMAR not attributable to an underlying structural eye or visual pathway abnormality.

RESULTS

Visual impairment was found in the worse eye of 117 children (5.0%) and comprised correctable (82%) and non-correctable impairment (18%). Correctable impairment was due to myopia in 67 (69.8%), hyperopia in 11 (11.5%) and astigmatism in 32 subjects (33.3%). Causes of non-correctable impairment were: amblyopia 66.7%, congenital glaucoma 9.5%, optic nerve hypoplasia 9.5%, congenital nystagmus 4.8%, and cortical blindness 4.8%.

CONCLUSIONS

Visual impairment had a relatively low prevalence in this older childhood population, a large proportion of which was correctable by refraction alone.