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At least 55 records · Page 3Linked to original sources
PubMed1999

Epidemiologic study of ocular refraction among schoolchildren in Taiwan in 1995.

PURPOSE: In order to understand and update the prevalence of myopia in Taiwan, a nationwide survey was performed in 1995. METHODS: We stratified the cluster sampling by developmental grading of the city, using a size proportional to the population. Two cities were randomly selected from each city grading. The total number of students enrolled was 11,178, including 5,676 boys and 5,502 girls. The refractive status and corneal radius of each student were measured with an autorefractometer under cycloplegia and checked with retinoscopy. Axial length was measured with biometric ultrasound. RESULTS: The myopic rate was from 12% at the age of 6, it increased to 56% at the age of 12, and then to 76% at the age of 15. A myopic rate of 84% was found for the age range of 16 to 18. The prevalence of high myopia (over -6.0 D) at the age of 18 was 20% in girls and 12% in boys. The mean refractive status became myopic at the age of 9, then increased to -3.92 D in girls and -2.71 D in boys at the age of 18. The increase of axial length is correspondent with the progression of myopia. The anterior chamber depth (ACD) was deeper with age and the severity of myopia, whereas the corneal curvature remained unchanged. The lens thickness became thinner from age 7 to 13, then it became thicker with age and the severity of myopia after age 15. The prevalence and degree of myopia in girls was more severe than in boys. CONCLUSIONS: The prevalence of myopia in Taiwan increased year by year. The increase in severity and prevalence of high myopia may be due to earlier onset.

Adolescent↗
PubMed2000

[Ocular refraction and branch of retinal vein occlusion].

PURPOSE: To evaluate the significance of refractive errors in cases of branch retinal vein occlusion (BRVO). METHODS: We included in this study 179 patients with BRVO who attended our department between 1996-2000. We compared this group with an equal number of age, sex and associated diseases matched controls. The spherical equivalents of the refractive errors of patients in both groups were compared using the chi-square test and Student's t test. RESULTS: Hypermetropia was present in 114 patients wit BRVO (63.68%) and in 82 controls (45.8%, p = 0.00048). Myopia was present in 16 patient with BRVO (8.9%) and in 39 controls (21.8%, p = 0.0037). Emetropia was found in 49 patients (27.37%) and in 58 controls (32.4%, p = 0.299). CONCLUSIONS: Hypermetropia is significantly more common in patients with BRVO than in general population, but myopia is significantly less common in these patients than in controls.

Female↗
PubMed2004

[Comparison of ultrasound and optic biometry with respect to ocular refraction after cataract surgery].

In the prospective study of 56 patients with cataract (67 eyes) the authors compared axial length biometry) regarding to postoperative refraction of the eyes. Dioptric power of the intraocular lens (IOL) was determined by SRK II. formula. The difference between predicted and actual postoperative refraction in the spherical equivalent were compared 3 months postoperatively. Axial length measured by ultrasound differed significantly from the axial length measured by optical biometry (p = 0.016). Dioptric power of IOL calculated according to the axial length measured by ultrasound was significantly different from the dioptric power of IOL calculated according to the axial length measured by optical biometry (p = 0.003). The difference between predicted and actual postoperative refraction was not statistically significant (p = 0.384) even if we considered both type of measurement. In conclusion, we found partial coherence interferometry was an accurate and reproducible method for measurement of axial length of the eye before cataract surgery. In the cases of advanced dense cataracts backup of ultrasonic biometry is still necessary.

Cataract↗
PubMed1991

Ocular refraction and its components among younger children in Kaohsiung: a 4-year longitudinal study.

A four-year longitudinal study was made on refraction and its components among 50 children of Kaohsiung, Taiwan, R.O.C. aged from 7 to 10.6 years. The methods of examination of the eyes were the same as that of four years ago, including Mydriacyl refraction, keratometry for corneal curvature radius, and ultrasonic measurement of the refractive components. One eye with amblyopia was excluded. The results of our study showed that all of our cases over 6 years of age had a corrected visual acuity of 0.8 or better, and that the refractive state shifted to myopia in our 4-year follow up. The rate of myopia increased from 2% to 27.3%. Comparisons of refractive components between the years 1983 and 1987 showed significant increases in refractive power, length of vitreous cavity and total axial length of the eyes. Corneal refractive power and lens thickness, however decreased significantly. As for differences in gender, several results were the same for both 1983 and 1987: corneal curvature radius, the length from anterior corneal surface to anterior lens surface, length of vitreous cavity and total axial length were larger in males than females. Finally, total axial length and corneal curvature radius were the factors most affecting the refractive state in younger children.

Child↗
PubMed1986

A longitudinal study of the age dependence of human ocular refraction--II. Prediction of future trends in medium and high myopia by means of cluster analysis.

A sample population of myopes with an initial correction of 2 DS or more is extracted from the longitudinal sample of ametropes reported by Saunders (1986). The myopes are partitioned by means of cluster analysis and, as a result, three distinct groups of myopes are identified. The time/regression equations which best describe the groups are stated. It is concluded that meaningful long-term prognosis of medium and high myopes is unlikely and that reasonable prediction of short-term trends requires at least two consecutive refraction data to determine the group allocation of a myope.

Age Factors↗