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Convergence Insufficiency & Academic Behaviours

As the school year moves into full-swing, it’s interesting to review the latest Convergence Insufficiency (CI) study by the Convergence Insufficiency Treatment Trial (CITT) Study Group1 and pilot studies recently presented at the College of Optometrists in Vision Development (COVD) meeting in the US.2 These studies have provided growing evidence of the association of CI with academic signs, and the improvements in these signs following office based vision therapy.

The role of vision and vision therapy in the academic arena is a source of much heated debate. Much of this debate centres on dyslexia, but has a flow-on effect to assisting those without dyslexia, who may not be progressing as expected academically.

Occasionally some acknowledgement is given to treating conditions such as CI, but only to associated visual discomfort and asthenopia – not to the potential impact on classroom performance.

Signs, Symptoms and Associations

The most commonly recognised symptoms of visual dysfunction associated with near tasks are headaches, eye-strain, visual fatigue and blurred or double vision. A closer look at two robust symptom surveys, the Convergence Insufficiency Symptom Survey (CISS)3 and the Conlon Visual Discomfort Scale (Conlon Scale)4 reveal the inclusion of performance-related symptoms that relate to difficulties with concentration, remembering what is read, loss of place while reading, needing to re-read, using a finger to assist keeping place, and finding reading slow. Clinical experience suggests that these symptoms should be explicitly asked about in the case history, and they often occur in the absence of the more recognised symptoms of asthenopia, double or blurred vision.

Symptomatic individuals reported poor academic grades associated with their symptoms

Studies investigating visual discomfort and visual dysfunction,4-6 report that symptomatic individuals reported poor academic grades associated with their symptoms. The CITT Study Group developed the ABS (Academic Behaviour Survey)7 to examine and quantify the relationship of CI and the frequency of adverse school behaviours and parental concern about school performance.

Parents are asked to rate the frequency of their concerns, specifically relating to the following questions:

1. How often does your child have difficulty completing assignments
at school?

2. How often does your child have difficulty completing homework?

3. How often does your child avoid or say he/she does not want to do tasks that require reading or close work?

4. How often does your child fail to give attention to details or make careless mistakes in schoolwork or homework?

5. How often does your child appear inattentive or easily distracted during reading or close work?

6. How often do you worry about your child’s school performance?

The similarity of some of these questions to other instruments that measure the cognitive or behavioural aspects of attention makes it interesting to note studies that have highlighted a relationship between Attention Deficit Hyperactivity Disorder (ADHD) or ADHD–like behaviours and CI.8 Another study reports a three-fold greater incidence of CI in an ADHD population, and a three-fold incidence of ADHD in a CI population.9 This shift in emphasis to understanding the behavioural characteristics of CI is akin to studies that highlight the social and emotional impact of strabismus.10

It’s certainly not a great leap to predict that some children displaying these behaviours may eventually avoid tasks they find difficult as a means to cope, thus developing an avoidance of reading or learning.

Impact of Successful CI Treatment

The CITT Study Group compared reduction in ABS scores with treatment outcomes.1 Treatment outcomes were scored as “successful”, “improved”, and “non-responder” for participants engaged in a placebo-controlled study comparing various types of vision therapy methods of delivery. Those who were “successful” or “improved” had both statistically significant and clinically meaningful improvements in ABS scores compared to “non-responders”.

Further research data from the CITT Study Group was presented at the 2011 COVD meeting in Las Vegas.11 Preliminary data from the first phase of a new study indicates some compelling findings. The group found that the scores on the Conners 3 ADHD Index showed a highly statistically significant improvement (p < 0.0001) in behaviours following treatment for symptomatic CI. A smaller, associated but non-controlled pilot study indicates potential improvements in reading scores as measured by the WIAT-II (The Wechsler Individual Achievement Test Second Edition) after treatment of symptomatic CI.2


Perhaps the most relevant finding to both patients and practitioners is that improvements in ABS scores were also significantly correlated with reduction in symptoms measured by the Convergence Insufficiency Symptom Survey (CISS), but not changes in “data” such as near point of convergence break, positive fusional vergences (PFV), or the change in the ratio of heterophoria to PFV.

Although the CITT work has produced some compelling evidence about the role of office based therapy in treating CI, much of their work surrounding the impact of these visual conditions on a patient’s life is yet to be fully realised. As practitioners, these latest studies serve as a great reminder that we shouldn’t get lost in the clinical “data” that we measure. Frequently, it is not the magnitude of the deviation from normal in a finding that is most relevant to our patients, but the magnitude of their symptoms and the potential impact this has on their individual quality of life. A patient may not be able to qualify or relate their symptoms to their visual condition.

It is our responsibility as clinicians to ensure we take the time to conduct a thorough and careful case history to explore their symptoms and behaviours in full. This allows prompt treatment of this common, yet commonly overlooked condition.

Paul Graham BAppSc(Optom)Hons FACBO is an optometrist in private practice on the Gold Coast. His practice focuses on vision training, paediatric vision care, orthokeratology and contact lenses. He is an ACBO fellow and is actively involved in organising and delivering continuing education that relates to functional vision care and behavioural optometry.


1. Borsting et al (CITT Study Group). Improvement in Academic Behaviors After Successful Treatment of Convergence Insufficiency. Optom Vis Sci 2012;89 (1): 12-18.

2. www.covd.org/Home/AnnualMeeting/PastMeetings/COVD41stAnnualMeeting/tabid/342/Default.aspx: College of Optometrists in Vision Development; accessed 15 January 2012.

3. Borsting et al (CITT Study Group). Validity and Reliability of the Revised Convergence Insufficiency Symptom Survey in Children Aged 9 to 18 Years. Optom Vis Sci 2003;80:832–838.

4. Conlon et al. Measuring Visual Discomfort. Visual Cognition 1999;6(6):637–663.

5. Conlon et al. Relationships between global motion and global form processing, practice, cognitive and visual processing in adults with dyslexia or visual discomfort Neuropsychologia 2009;47:907–915.

6. Chase et al. Visual Discomfort and Objective Measures of Static Accommodation. Optom Vis Sci 2009;86(7):883-889.

7. Rouse et al (CITT Study Group). Academic Behaviors in Children with Convergence Insufficiency with and without Parent-Reported ADHD Optom Vis Sci 2009;86:1169–1177).

8. Borsting et al. Measuring ADHD behaviors in children with symptomatic accommodative dysfunction or convergence insufficiency: a preliminary study. Optometry 2005;76:588-92.

9. Granet DB, Gomi CF, Ventura R, Miller-Scholte A. The relationship between convergence insufficiency and ADHD. Strabismus 2005;13:163–8.

10. Durnian et al. The psychosocial aspects of strabismus: correlation between the AS-20 and DAS59 quality-of-life questionnaires. J AAPOS. 2009 Oct;13(5):477-80. Abstract cited as an example. Full paper not reviewed.

11. Source: http://visionhelp.wordpress.com/2011/10/30/spotlight-on-visual-attention-at-covd-meeting/. Accessed 15 January 2012.