Tuesday, September 8, 2015
Struggling young readers may have a subtle, treatable, eye muscle coordination disorder.
By: Dr. Kristine Hopkins is an Associate Professor of Optometry at UAB
As another school year begins, we must once again think about children’s vision and their visual needs at school. This means much more than just whether or not a child can discriminate the letters on a distance visual acuity chart. Children spend 75 percent of their school day reading and doing close work. It is important for us to consider how a child’s eyes work together while reading. For comfortable reading, the eyes must both point at the text to prevent double vision and the focusing system of each eye must adjust focus to make the print clear. For most children, this is effortless but not for all of them.
Up to 6% of school aged children have an eye muscle coordination disorder called Convergence Insufficiency (CI). For children (and adults too) with CI, it is difficult to accurately converge the eyes toward the nose. While reading across the page, a child with CI must work to keep both eyes pointed on the text. If one eye drifts outward, the text becomes double and the child must work to make the print single again. As reading continues and the child fatigues, the double vision and often times blur become more frequent and reading becomes a chore. This struggle can cause a child to read more slowly, lose his place frequently, be inattentive, or avoid reading all together. This can lead to homework battles for parents and frustration for our young students who don’t understand why it seems so easy for their peers.
Unfortunately, most vision screenings are designed to detect the need for glasses (which is important) but they do not look for eye muscle coordination or focusing disorders. In the scope of a screening setting, these disorders would be difficult to detect. A comprehensive eye exam when possible is the best way to detect the need for glasses, test eye teaming, and rule out ocular pathology. In a primary care setting, often asking the right questions will go a long way in identifying children who may be struggling with convergence insufficiency. The Convergence Insufficiency Symptom Survey (CISS) is a well validated tool for detecting CI. It’s a 15 question survey about how a child’s eyes feel while reading. It uses a Likert scale that assigns each response a score. If the sum of the symptom score exceeds 16, the patient is suspected to have CI with 96% sensitivity (88% specificity). A copy of the CISS may be found at http://www.sankaranethralaya.org/pdf/patient-care/Convergence-Insufficiency-Symptom-Survey.pdf . In lieu of a formal survey, health care professionals can ask questions regarding common symptoms of CI that may also be very helpful in identifying children at risk. Children with CI are likely to exhibit the following symptoms while reading or doing near work:
• Tired and/or sore eyes
• Double vision and/or blur
• Difficulty maintaining concentration
• Frequent loss of place
• Avoidance of reading
Fortunately there are well studied, effective treatments for convergence insufficiency. In a multi-center, randomized clinical trial supported by National Institutes of Health, office based vision training was shown to eliminate CI related symptoms in 75% of the children assigned to office-based training. The children receiving home based pencil push-up training and those receiving in-office placebo training had success rates of 33% and 35% respectively. While this study showed that treatment was effective at reducing CI related symptoms and improving eye muscle coordination, it’s still unclear how this affects reading and attention (both suspected of being affected by this disorder). While preliminary studies have shown improvement in attention and reading after the successful treatment of CI, large scale studies are underway.
Children and parents of children with CI often don’t consider that difficulties with reading may be a vision problem. Asking the right questions will often uncover an eye teaming problem like convergence insufficiency and help children receive the treatment they need. Assessments for reading difficulty should begin with a comprehensive eye examination.
1. Borsting EJ, Rouse MW, Mitchell GL, et al. Validity and reliability of the revised convergence insufficiency symptom survey in children aged 9-18 years. Optom Vis Sci 2003;80:832-8.
2. Barnhardt C, Cotter SA, Mitchell GL, Scheiman M, Kulp MT, Group CS. Symptoms in children with convergence insufficiency: before and after treatment. Optom Vis Sci 2012;89:1512-20.
3. Convergence Insufficiency Treatment Trial Investigator Group. A randomized clinical trial of treatments for symptomatic convergence insufficiency in children. Arch Ophthalmol 2008;126:1336-49.
4. Scheiman M, Mitchell GL, Cotter S, et al. A randomized trial of the effectiveness of treatments for convergence insufficiency in children. Arch Ophthalmol 2005;123:14-24.
5. Borsting E, Mitchell GL, Scheiman M, et al. Treatment of symptomatic convergence insufficiency improves attention In school-aged children In: ARVO. Ft Lauderdale, FL; 2011. (presentation)
Dr. Kristine Hopkins is an Associate Professor of Optometry at UAB specializing in clinical care and research of pediatric vision, amblyopia, and binocular vision disorders including convergence insufficiency. She is the site Principal Investigator for the NIH/NEI sponsored Convergence Insufficiency Treatment Trial – Attention and Reading Trial (CITT-ART) currently ongoing at UAB.