Studies in Refraction

Objective and Subjective Refractive Error Measurements in Monkeys

“…To the extent that our sample of nontreated, fellow eyes are reflective of normal monkeys, our subjective measures indicate that most adolescent monkeys are clinically emmetropic and that, as in adolescent humans, the end point for emmetropization in macaques is essentially emmetropia rather than a low to moderate degree of hyperopia as suggested by studies of refractive development in young monkeys. 20,22 The overall pattern of results in rhesus monkeys is similar to those reported in humans [1][2][3] and in many, but not all, laboratory animals, particularly animals with small eyes. For example, in tree shrews, 11 pigeons, 8 fish, 23 and frogs, 9 refractive errors measured by retinoscopy are more hyperopic than those obtained using electrophysiological methods that are presumably equivalent to subjective refractions.…”

“…While most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about +0.25 D or less, 1, 2 and decrease with age. 3 …”

“…In humans, many studies have found systematic differences in the refractive errors determined by retinoscopy and subjective refraction. Although most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about ϩ0.25 D or less, 1,2 and decrease with age. 3 However, objectively measured refractive errors in laboratory animals, particularly those obtained via retinoscopy, are often reported to be much more hyperopic than their presumed subjective refractions, especially in animals with small eyes.…”

Objective and Subjective Refractive Error Measurements in Monkeys

“…To the extent that our sample of nontreated, fellow eyes are reflective of normal monkeys, our subjective measures indicate that most adolescent monkeys are clinically emmetropic and that, as in adolescent humans, the end point for emmetropization in macaques is essentially emmetropia rather than a low to moderate degree of hyperopia as suggested by studies of refractive development in young monkeys. 20,22 The overall pattern of results in rhesus monkeys is similar to those reported in humans [1][2][3] and in many, but not all, laboratory animals, particularly animals with small eyes. For example, in tree shrews, 11 pigeons, 8 fish, 23 and frogs, 9 refractive errors measured by retinoscopy are more hyperopic than those obtained using electrophysiological methods that are presumably equivalent to subjective refractions.…”

“…While most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about +0.25 D or less, 1, 2 and decrease with age. 3 …”

“…In humans, many studies have found systematic differences in the refractive errors determined by retinoscopy and subjective refraction. Although most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about ϩ0.25 D or less, 1,2 and decrease with age. 3 However, objectively measured refractive errors in laboratory animals, particularly those obtained via retinoscopy, are often reported to be much more hyperopic than their presumed subjective refractions, especially in animals with small eyes.…”

Accuracy of refractive error measurements in children with strabismus comparing cycloplegic autorefractometry to dry monocular Mohindra retinoscopy

“…Retinoscopy procedure is subject to measurement bias and intra- and inter-observer variability [ 27 ]. Nevertheless, previous studies indicated that experienced eye specialists can obtain accurate measurements [ 28 , 29 ]. In our study, the Mohindra retinoscopy technique was performed by highly experienced optometrists (experience of more than 10 years), which may have contributed to the high correlation between the results of the two techniques.…”

Comparison of Refractive Measures of Three Autorefractors in Children and Adolescents

“…5,6 However, retinoscopy is subject to measurement bias and intraobserver/interobserver variations, although experienced clinicians can provide reliable measurements. [7][8][9] Since the invention of automated refractors, such devices have been increasing in popularity in clinical practice, as well as in epidemiological research, particularly for large-scale vision screening in children. [10][11][12][13] Noncycloplegic autorefraction was shown to have a tendency toward minus overcorrection in school-age children resulting in overdiagnosis of myopia, 14,15 whereas cycloplegic autorefraction is potentially more sensitive than subjective refraction and was recommended to be a necessity for precise measurement of refractive errors, especially in hyperopic eyes and in pediatric cases.…”

Objective and Subjective Refractive Error Measurements in Monkeys

“…To the extent that our sample of nontreated, fellow eyes are reflective of normal monkeys, our subjective measures indicate that most adolescent monkeys are clinically emmetropic and that, as in adolescent humans, the end point for emmetropization in macaques is essentially emmetropia rather than a low to moderate degree of hyperopia as suggested by studies of refractive development in young monkeys. 20,22 The overall pattern of results in rhesus monkeys is similar to those reported in humans [1][2][3] and in many, but not all, laboratory animals, particularly animals with small eyes. For example, in tree shrews, 11 pigeons, 8 fish, 23 and frogs, 9 refractive errors measured by retinoscopy are more hyperopic than those obtained using electrophysiological methods that are presumably equivalent to subjective refractions.…”

“…While most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about +0.25 D or less, 1, 2 and decrease with age. 3 …”

“…In humans, many studies have found systematic differences in the refractive errors determined by retinoscopy and subjective refraction. Although most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about ϩ0.25 D or less, 1,2 and decrease with age. 3 However, objectively measured refractive errors in laboratory animals, particularly those obtained via retinoscopy, are often reported to be much more hyperopic than their presumed subjective refractions, especially in animals with small eyes.…”

Accuracy of refractive error measurements in children with strabismus comparing cycloplegic autorefractometry to dry monocular Mohindra retinoscopy

“…Retinoscopy procedure is subject to measurement bias and intra- and inter-observer variability [ 27 ]. Nevertheless, previous studies indicated that experienced eye specialists can obtain accurate measurements [ 28 , 29 ]. In our study, the Mohindra retinoscopy technique was performed by highly experienced optometrists (experience of more than 10 years), which may have contributed to the high correlation between the results of the two techniques.…”

Comparison of Refractive Measures of Three Autorefractors in Children and Adolescents

“…5,6 However, retinoscopy is subject to measurement bias and intraobserver/interobserver variations, although experienced clinicians can provide reliable measurements. [7][8][9] Since the invention of automated refractors, such devices have been increasing in popularity in clinical practice, as well as in epidemiological research, particularly for large-scale vision screening in children. [10][11][12][13] Noncycloplegic autorefraction was shown to have a tendency toward minus overcorrection in school-age children resulting in overdiagnosis of myopia, 14,15 whereas cycloplegic autorefraction is potentially more sensitive than subjective refraction and was recommended to be a necessity for precise measurement of refractive errors, especially in hyperopic eyes and in pediatric cases.…”

Objective and Subjective Refractive Error Measurements in Monkeys

“…To the extent that our sample of nontreated, fellow eyes are reflective of normal monkeys, our subjective measures indicate that most adolescent monkeys are clinically emmetropic and that, as in adolescent humans, the end point for emmetropization in macaques is essentially emmetropia rather than a low to moderate degree of hyperopia as suggested by studies of refractive development in young monkeys. 20,22 The overall pattern of results in rhesus monkeys is similar to those reported in humans [1][2][3] and in many, but not all, laboratory animals, particularly animals with small eyes. For example, in tree shrews, 11 pigeons, 8 fish, 23 and frogs, 9 refractive errors measured by retinoscopy are more hyperopic than those obtained using electrophysiological methods that are presumably equivalent to subjective refractions.…”

“…While most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about +0.25 D or less, 1, 2 and decrease with age. 3 …”

“…In humans, many studies have found systematic differences in the refractive errors determined by retinoscopy and subjective refraction. Although most of these studies have reported that refractive errors measured by retinoscopy are slightly more hyperopic than subjectively determined refractive errors, the differences between the two measurement methods are generally small, on the order of about ϩ0.25 D or less, 1,2 and decrease with age. 3 However, objectively measured refractive errors in laboratory animals, particularly those obtained via retinoscopy, are often reported to be much more hyperopic than their presumed subjective refractions, especially in animals with small eyes.…”

Accuracy of refractive error measurements in children with strabismus comparing cycloplegic autorefractometry to dry monocular Mohindra retinoscopy

“…Retinoscopy procedure is subject to measurement bias and intra- and inter-observer variability [ 27 ]. Nevertheless, previous studies indicated that experienced eye specialists can obtain accurate measurements [ 28 , 29 ]. In our study, the Mohindra retinoscopy technique was performed by highly experienced optometrists (experience of more than 10 years), which may have contributed to the high correlation between the results of the two techniques.…”

Comparison of Refractive Measures of Three Autorefractors in Children and Adolescents

“…5,6 However, retinoscopy is subject to measurement bias and intraobserver/interobserver variations, although experienced clinicians can provide reliable measurements. [7][8][9] Since the invention of automated refractors, such devices have been increasing in popularity in clinical practice, as well as in epidemiological research, particularly for large-scale vision screening in children. [10][11][12][13] Noncycloplegic autorefraction was shown to have a tendency toward minus overcorrection in school-age children resulting in overdiagnosis of myopia, 14,15 whereas cycloplegic autorefraction is potentially more sensitive than subjective refraction and was recommended to be a necessity for precise measurement of refractive errors, especially in hyperopic eyes and in pediatric cases.…”