Distribution Of Myopia Research Articles

The underestimated role of myopia in uncorrectable visual impairment in the United States

We estimate the US prevalence of uncorrectable visual impairment in 2050 accounting for the changing distribution of both age and myopia. Age projections of the US population (from an estimated total of 379 million in 2050), were taken from the US census website. The distribution of myopia, by severity, was calculated from literature-derived prevalence estimates of 58.4% (≤ − 0.50 D, 2050 projection) and 33.1% (≤ − 1.00 D, 1999–2004 estimate) to provide predicted and conservative estimates, respectively. Uncorrectable visual impairment as a function of age and refractive error was modelled by multiple linear regression. Finally, the likely number of individuals in the US with visual impairment in 2050 was calculated. For a projected myopia prevalence of 58.4%, 222 million are projected to be myopic and 48 million will have high myopia (− 5 D or worse). The projected total number with uncorrectable visual impairment is 11.4 million of which 4.9 million cases (43%) of visual impairment will be directly attributed to increased risk of eye disease associated with myopia. For a projected myopia prevalence of 33.1%, 8.9 million are projected to have uncorrectable visual impairment of which 2.4 million cases (27%) will be directly attributed to myopia. It is predicted that between 27 and 43% of uncorrectable visual impairment in the US population in 2050 will be directly attributable to myopia. Failure to account for the increasing prevalence of myopia among the aging population leads to a substantial underestimate of the prevalence of visual impairment.

Comparison Of Subjective Refraction Under Cycloplegia Versus Post Mydriatic Refraction In Pediatric Population

Reduced vision throughout early childhood is typically due to errors of refraction. Objective: To compare refractive status in children (age 5 to 15 years) checked with subjective refraction under cycloplegia versus post mydiatric test (PMT). Methods: Comparative cross-sectional study was conducted in pediatric ophthalmic clinic of College of ophthalmology and Allied vision sciences /Mayo hospital Lahore including 120 non-pathological eyes of 60 subjects. Individuals with nystagmus and deviation of eyes were excluded. Power of SE (P1) was taken as proposed number of glasses to be dispensed. After three days PMT was done and prescription of glasses with BCVA (P2) was noted and prescribed. At PMT (P2-P1) was noted and evaluated. All data entered and analyzed by using SPSS-23. P-value equal or less than 0.05 was taken as significant. Results: Among 120 eyes (n=120), the distribution of myopia was 57.5% and hyperopia was 42%. The mean age of 60 individuals (female: 35% and male: 65%) was 9.47 ± 2.50 years. Among 120 eyes (n=120), the distribution of myopia was 57.5% (n = 69 eyes) and hyperopia was 42% (n = 51 eyes). Interclass correlation: Two-way mixed effects model where people effects are random and measures effects are fixed. a. The estimator is the same, whether the interaction effect is present or not. b. Type C intraclass correlation coefficients using a consistency definition. The between-measure variance is excluded from the denominator variance. c. This estimate is computed assuming the interaction effect is absent, because it is not estimable otherwise.

Refractive errors and biometry of primary angle-closure disease in a mixed Malaysian population.

To assess the refractive status, anterior chamber depth (ACD) and axial length (AL) of patients with primary angle-closure disease (PACD). Retrospective cohort. Data was collected from charts of all PACD patients treated from April 2013 to December 2015. Analysis was done on 137 patient charts with complete biometric data. Patient demographics, PACD type, refractive status (spherical equivalent), ACD and AL were studied. The median age of 137 subjects [53 with primary angle-closure suspects (PACS), 27 with primary angle-closure (PAC) and 57 with primary angle-closure glaucoma (PACG)] was 68y (range 21-88y). The majority was Chinese (n=68; 49.6%) and most of them were women (n=75; 54.7%). The distribution of myopia (n=51; 37.2%) and hyperopia (n=49; 35.8%) was similar. The ACD was shallower in myopes compared to hyperopes (P=0.02) and emmetropia (P=0.049) but the AL was not significantly different between groups. There were no patients blind from PACG. Both myopia and hyperopia can occur in PACD. Despite a shallower ACD in angle closure myopes, the AL was not different between groups.

Familial aggregation and prevalence of myopia in the Framingham Offspring Eye Study.

To examine familial relationships for myopia among siblings and the distribution of myopia in an adult population aged 23 to 78 years. Eye examinations were conducted in a cross-sectional study on the offspring of the Framingham Eye Study cohort. Between 1989 and 1991, 1585 persons, the offspring of 1319 parents, underwent refraction and were tested for best corrected visual acuity. A person was considered myopic if at least one eye had a spherical equivalent refractive error of at least -1.00 diopter. For both sexes, prevalence of myopia decreased with increasing age, from about 60% for ages 23 to 34 years to about 20% for ages 65 years and older. Among men, both age and years of education were related to myopia. Among women, age was related to myopia, but years of education were not. Age-, sex-, and education-adjusted analyses, using the second-order generalized estimating equations approach, showed a strong association of myopia between siblings. The association between siblings decreased with increasing between-siblings age difference: the estimated odds ratio was about 5 for an age difference of 2 years and half that for an age difference of 10 years. The relative importance of genetic and environmental factors in explaining familial relationships for myopia remains unclear. Nevertheless, the large increase in myopia prevalence for more recent birth cohorts and the decrease in the strength of the between-siblings association for myopia with increasing between-siblings age difference suggest an important role for environmental factors in the cause of myopia.

Distribution of myopia in aphakic retinal detachments.

Distribution of myopia in aphakic retinal detachments.