Monday, September 12, 2016

Assessing the need for children’s eye exams

By: Tamara Oechslin, OD, PhD
UAB Eye Care Pediatric Optometry Services

Children have returned to school again, and, as we make sure that they have all their supplies for the year, we also need to make sure that they are prepared to meet their necessary visual demands in order to perform their best academically. Approximately 80% of learning is visual, and children spend the majority of their day reading and doing near/desk work that should involve clear, comfortable vision. Unfortunately, more than 25% of students have a vision disorder that interferes with their ability to learn, and this number increases to 70% in students with individual education plans.[1] Schools provide vision screenings to their students, yet these screenings do not replace comprehensive eye exams that can provide a formal diagnosis and treatment for vision problems that can be subtle and not obvious to the child or parents.[2]

Vision screenings requiring a child to read letters on a chart are designed to detect myopia and identify children who may need glasses to see far away. Identifying these students is certainly important to insure he/she can see across the classroom. We know that myopia typically develops in the early to middle school-age years (average age = 10.4 (±1.8) years)[3] and progresses throughout the teens.[4] Because its progression can reduce vision by as much as three or four lines on the visual acuity chart each year,[3] some children grow quickly enough that they can have significant changes in their glasses prescriptions within a school year. This myopic progression is also accompanied by an increase in axial length of the eye[5] which should be monitored with a dilated eye exam to assess the integrity and health of the retina during this active growth phase. As healthcare providers, it is important that we educate and remind parents that their children need to be followed regularly by an eye care professional to monitor not only for changes in their glasses prescription but also the health of their eye.

Farsighted children, or those with hyperopia, usually see well for distance vision screenings[6] and, therefore, may not be referred for additional testing. To see clearly, hyperopic children must recruit extra focusing effort (accommodation) to see clearly at all distances but especially for near work like reading. The added effort is likely the reason that farsightedness has been associated with poor reading ability[7, 8] and reduced academic performance in school-aged children.[9] Current research indicates a relationship between moderate amounts of hyperopia in young children who do not have glasses and poor early literacy outcomes, especially in the presence of poorer near acuity or reduced depth perception.[10] Most screenings do not test near acuity and, even if a child can pass a brief near test, he or she may not have the stamina to maintain the appropriate focusing ability throughout a full school day. [11] These children may experience headaches, eyestrain, or general inattentiveness by the end of the day.[7, 12] A comprehensive eye exam includes measures of a child’s near focusing ability and an accurate measure of his or her refractive prescription after pupil dilation. This is important because the dilation drops used by the eye care professional relax the child’s accommodation, and this measure is considered the gold standard for precise quantification of hyperopia.

Because vision problems can elicit discomfort with extended near work, we should think of good vision as more than simply reading 20/20 on a chart across the room. While most people become presbyopic and need bifocals around the age of forty, this process begins during the middle school years.[13] Children who previously “grew out” of the need for glasses, may need to revisit reading glasses as this is also an age when reading and homework demands increase at school. Subtle problems with convergence, or the two eyes not working well together for near work, occur in up to 13% of school-age children [14] without presenting as a cosmetic eye turn. These children commonly report eyes that hurt/feel sore, frequent headaches, intermittent blur, and losing their place when reading or doing close work.[15] Comprehensive eye exams include measures of focusing and eye teaming ability to investigate how well a child’s two eyes function together to maintain comfortable binocular vision for extended near work.

In the primary care setting, well-designed vision screenings play an important role in determining which children may need referrals for potential glasses. Additionally, children presenting with problems with reading or academic performance, complaints of headaches or eyestrain when doing schoolwork, or other suspicion of a vision problem by parents or teachers warrant a referral for a comprehensive eye exam by an eye care professional. While there are many sources for academic difficulty, ruling out a vision problem should be a top priority. Under the ACA, major medical health plans must provide for vision coverage for children[16]. As health care providers, we must educate our young patients and their parents on the importance of comprehensive vision care and encourage them to use these valuable benefits.

1. Walline, J., Vision Problems of Children with Individualized Education Programs. J Behav Optom, 2012. 23(4): p. 87-93.
2. Childhood Vision Screening, American Academy of Optometry, Editor. 2016: Orlando, FL.
3. Jones-Jordan, L.A., et al., Time outdoors, visual activity, and myopia progression in juvenile-onset myopes. Invest Ophthalmol Vis Sci, 2012. 53(11): p. 7169-75.
4. Goss, D.A., Cessation age of childhood myopia progression. Ophthalmic Physiol Opt, 1987. 7(2): p. 195-7.
5. Mutti, D.O., et al., Refractive error, axial length, and relative peripheral refractive error before and after the onset of myopia. Invest Ophthalmol Vis Sci, 2007. 48(6): p. 2510-9.
6. Moore, B., Optometric Clinical Practice Guide: Care of the Patient with Hyperopia, American Optometric Association, Editor. 2008: St. Louis, MO.
7. Simons, K., Hyperopia, accommodative dysfunction and reading. Binocul Vis Strabismus Q, 2004. 19(2): p. 69-70.
8. Grisham, D., M. Powers, and P. Riles, Visual skills of poor readers in high school. Optometry, 2007. 78(10): p. 542-9.
9. Williams, W.R., et al., Hyperopia and educational attainment in a primary school cohort. Arch Dis Child, 2005. 90(2): p. 150-3.
10. Vision In Preschoolers -- Hyperopia In Preschoolers Study Group, Uncorrected Hyperopia and Preschool Early Literacy: Results of the Vision in Preschoolers-Hyperopia in Preschoolers (VIP-HIP) Study. Ophthalmology, 2016.
11. McBrien, N.A. and M. Millodot, The effect of refractive error on the accommodative response gradient. Ophthalmic Physiol Opt, 1986. 6(2): p. 145-9.
12. Chase, C., et al., Visual discomfort and objective measures of static accommodation. Optom Vis Sci, 2009. 86(7): p. 883-9.
13. Anderson, H.A., et al., Age-related changes in accommodative dynamics from preschool to adulthood. Invest Ophthalmol Vis Sci, 2010. 51(1): p. 614-22.
14. Rouse, M.W., et al., Frequency of convergence insufficiency among fifth and sixth graders. The Convergence Insufficiency and Reading Study (CIRS) group. Optom Vis Sci, 1999. 76(9): p. 643-9. 15. Rouse, M., et al., Validity of the convergence insufficiency symptom survey: a confirmatory study. Optom Vis Sci, 2009. 86(4): p. 357-63.

Dr. Tamara Oechslin is an Assistant Professor at UAB School of Optometry specializing in clinical care and research of pediatric, binocular, and developmental vision disorders.

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