Hyperopia
The Effect on Visual Perceptual Skills and Classroom Achievement
Kyle L. Florio, M.S.
Grand Rounds and New Developments
July 18, 2003
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About the Author: Kyle L. Florio received his Bachelor of Arts in Biological Sciences from Southwestern University, Georgetown, Texas in 1997.
He furthered his education in the sciences by receiving his Master of Science in Biological Sciences from Southwest Texas State University, San Marcos, Texas in 2000. He is a fourth year student at the University of Houston College of Optometry, Houston, Texas and will graduate in May of 2004.
Abstract: There is evidence linking uncorrected hyperopia in children with academic learning problems, even when the refractive error is moderate.
A study involving 710 subjects showed that seventy-eight percent (78%) of the 6-12 year old hyperopic children with learning disabilities (all were eye clinic patients) displayed visual perceptual skills dysfunction in contrast to twenty-five percent (25%) of the children who had been shown as not having a learning disability.
1 This is relevant because hyperopia, in addition to being related to school achievement, has been shown to be a significant factor in the rate at which children develop visual perceptual skills.
The term visual perceptual skills in this paper refers to the ability to identify such salient concrete features of absolute and relative quantity, magnitude, and relationships in spatial-temporal presentations.
Visual perceptual skills are developed naturally, normally emerging on a predictable schedule from birth to about age 10-12. Visual perceptual skills are often tested using geometric design copying tests (such as the Spatial Awareness Skills Program [SASP] test and the Rutgers Drawing Test [RDT]).
Although these tests may be considered to assess the same skill, they differ in that the RDT is a screening test while the SASP test provides treatment information.
Treatment options usually include referral, delayed entry into a learning environment that assumes competent visual perceptual skills, a training program to improve the child’s perceptual skills, and/or modification of child’s instruction in a way that takes his developmental deficits into account.
Key Words: Hyperopia, visual perceptual skills, Spatial Awareness Skills Program (SASP), Rutgers Drawing Test (RDT)
Case Report: A five year old male reported to the Development Center, University Eye Institute, Houston, Texas on referral from the child’s school nurse. The child had passed vision screening tests since he was two, but he failed his screening in kindergarten.
Past ocular history was negative for injuries, infections, surgeries, or other pertinent ocular information. The child was born full term by Caesarian delivery with a birth weight of 9lbs, 11oz. His physical status at birth was good, and he thrived during infancy and early childhood.
Motor development was on course: he sat up, stood and walked at the expected ages. His speech/language development was somewhat precocious: first words at 7 months, and three words together slightly later than 12 months. Past medical history revealed good general health, normal hearing, no ear infections, but one febrile seizure of unknown etiology, at age two.
On November 26, 2002 the patient’s visual acuities without correction were 20/50+1 OD and 20/60+2 OS. A manifest refraction revealed moderate/severe hyperopia, +5.25 –0.50 X180 OD and +5.00 DS OS.
Cycloplegic refraction yielded much the same prescription: +5.25 DS OD and +5.75 DS OS. The child’s best corrected visual acuity was 20/25-2 OD & OS. Cover test, without correction, measured orthophoric at near and four prism diopters exophoric at distance. Stereo acuity was measured with the Lang stereo test and revealed 200” (moon).
It should be noted that on two separate occasions the patient would not fixate for any extended period of time during the cover test or stereo acuity assessment. Because of poor fixation it is possible that the quantitative values placed on these measurements are not exact.
The pupils were equal and round with a brisk reaction to direct and consensual light, and no afferent pupillary defect was detected. Color vision testing was unreliable.
Biomicroscopy revealed trace flaking OU and no other remarkable findings. Intraocular pressures were equal and soft to palpitation, and a dilated fundus exam revealed C/D ratios of .2/.2 and .15/.15 respectively.
The macula appeared flat and evenly pigmented, and the vessels had an A/V ratio of 2/3. The peripheral fundus was unremarkable for pathology or abnormalities OU.
The patient also was given tests assessing visual and auditory perceptual skills, his current academic status, and verbal and non-verbal IQ. Only the visual perceptual skills tests will be discussed in detail in this paper. It is sufficient to note that, in regard to the other tests cited above, the patient performed and/or was at his expected age level.
The patient’s visual perceptual skills test scores were; RDT-A =4, estimated drawing age (EDA) = 4.3; SASP=0, age equivalent (AE) = <4.0; Visual perceptual skills training and adaptive instruction were recommended in addition to glasses (+4.75 DS OD, +5.25 DS OS, equal base curve and center thickness).
During a post exam conference the patient’s parents were educated in how to administer the recommended home-based skills training program.
This included the use of certain manipulatives, workbooks, and computer programs. The patient was asked to return for a follow-up visit in six months.
The patient returned June 10, 2003. Aided visual acuities were 20/25 –3 OD & OS. Pupils, binocular alignment, and refractive state were unchanged. Perceptual skills tests were also administered.
Qualitative and quantitative gains were apparent. His scores were: RDT-A =8, EDA= 4.8, SASP= 2, AE=4.6 to 4.11. The parents were advised to continue the home-training program over the summer and to return to clinic in three months for a full eye exam and a follow-up developmental assessment.
Discussion: There is a high prevalence of hyperopia in young children. Hyperopia, unlike myopia, is not acquired, nor does it worsen significantly over time in the normal eye. On the contrary, it often reduces as the child grows into pre-adolescence. Most neonates are 1.00 D or more hyperopic, with the mean refractive error being about +2.00 D2,3,4 (spherical equivalent +1.4 D).5
There is no significant difference in the average refractive error between girls and boys.6 The process of emmetropization during school age years, somewhat reduces the prevalence of hyperopia, with the resultant being 26% of the adolescent population is hyperopic.4
Although it is uncommon for a refractive state to affect a child’s interest in word games and other activities which heighten awareness of the phonemic attributes of spoken words, it is very likely to affect a child’s interest in near-point visual activities (e.g., puzzles, cutting out and coloring patterns, and block play).7
Such activities require sustained near-point fixation and result in extra burden placed on the accommodation system. These near-point activities are believed essential in a child’s intellectual and academic development.
Perceptual development provides the tools and the processes essential to the utilization of one’s intellect.8 An example is provided in a study by Rosner and Rosner, comparing the visual characteristics of children who were not making satisfactory progress in school. Nineteen percent (19%) of the group who had school learning difficulties were myopic (> -0.25), and fifty-four percent (54%) were hyperopic (> +0.75). The opposite (and remarkably symmetrical) trend was displayed by the group of children who did not have school learning difficulties.
Fifty-four percent (54%) of that group were myopic, and only sixteen percent (16%) were hyperopic.9
Of particular interest is a subset of studies by Hirsch which examined the relationship among classroom achievement, IQ score, and the refractive status of school aged children.
The general conclusion of these studies was that myopes out-perform hyperopes on IQ tests which require reasonably competent reading ability, but the results were not the same on tests that depend instead on rapid visual perception.5,10 Grosvenor’s further testing indicated that myopes do, infact, out-perform hyperopes (but not emmetropes) on IQ tests which require sustained reading ability.1,7,10
Further study has been done to address a second topic: the minimal amount of uncorrected hyperopia that appears to impede elementary school performance.
The results suggest that practitioners should consider the potential benefit to be derived from compensatory lenses for children who exhibit 1.25 D or more of hyperopia; even if they are asymptomatic and capable of excellent unaided visual acuity at near and distance.
The benefits of spectacle correction for infants with hyperopia can be achieved without impairing the normal developmental regulation of refraction.11
Statistical analysis indicated significantly lower achievement test scores among hyperopic children (first through fifth grade) whose refractive errors exceeded 1.25 D.12
Additional basis for the belief that uncorrected hyperopia may impede a child’s success in elementary school performance lies in a study involving 710 elementary school-aged children (6-12 years old).
The study reported that substandard visual analysis skills were observed in eighty-two percent (82%) of the hyperopes (> +0.75 D), thirty-eight percent (38%) of the emmetropes, and only fourteen (14%) of the myopes (> -0.25 D).1 Most myopes manifest their refractive ametropia well past the age of 6 or 7 years.
It is, therefore, difficult to propose that myopia is the generator of skills that are typically well developed by that age.7 In addition, Grosvenor concluded that if left untreated, even a moderate degree of hyperopia may have a significant and detrimental influence on how readily a child develops the capacity to view spatially organized information in an analytical manner and how well/easily a child gets started in school.1
Rosner and Rosner identified the age of four as the threshold age at which hyperopic children should receive correction. The study compared visual perceptual skills among young +2.25 D hyperopes as they related to the age when compensatory lenses were first obtained.
The data suggested that early application of compensatory lenses had beneficial subsequent effects; hyperopic children who start to wear glasses early in life seem more likely to develop appropriate visual perceptual skills than are hyperopic children who obtain their first glasses closer to the time of entering first grade.13,14
When children have delayed visual perceptual skills, treatment/training has been shown to be effective.
The data collected from a visual perceptual skills training study involving inner-city preschool children, are testament to the efficacy of a perceptual skills treatment/training program.
The data showed that inner-city kindergarten children were able to show age norm15 visual-motor skills after participating in a visual perceptual skills training program during their year in a pre-school class.
In contrast, those children who had not received pre-school training demonstrated significantly poorer visual-motor skills.16
Conclusion: A clear relationship has been documented between hyperopia and school learning difficulties, at least in part because hyperopia tends to have a negative effect on the development of visual perceptual skills and visual perceptual skills.
These, in turn, have a strong influence on how well a child learns the basic skills taught in a standard mainstream primary grade classroom.
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