The Convergence Insufficiency Treatment Trial (CITT)

Studies estimate that approximately 10% of the population has a vision deficit called convergence insufficiency (CI). CI makes it difficult to sustain focus when looking at something close. The Convergence Insufficiency Treatment Trial (CITT) is a groundbreaking clinical study that has revolutionized the way we understand and treat convergence insufficiency, a common vision disorder that affects the ability to focus on near objects. As a local optometry clinic in Hixson, we feel it's crucial to share the groundbreaking findings of this trial with our patients and our community. In this detailed paragraph, we'll explore the trial's background, methodology, and key findings, along with their implications for optometry practices like ours.

The Convergence Insufficiency Treatment Trial (CITT) in Hixson

Take Our Online Vision Assessment

Amplify Eyecare Chattanooga

CITT Methodology and Treatment Groups

  • The CITT is a multi-center, randomized clinical trial conducted by the National Eye Institute (NEI) and the Convergence Insufficiency Treatment Trial Investigator Group. This study aimed to evaluate the effectiveness of various treatment methods for convergence insufficiency in children aged 9 to 17 years.
  • The trial comprised 221 participants who were randomly assigned to one of four treatment groups: office-based vergence/accommodative therapy (OBVAT), home-based pencil push-ups (HBPP), home-based computer vision therapy/orthoptics (HBCVTO), and office-based placebo therapy (OBPT).
  • The primary outcome measure of the CITT was the near point of convergence (NPC), a measure of how close a person can focus on an object without experiencing double vision. Secondary outcome measures included positive fusional vergence (PFV), Convergence Insufficiency Symptom Survey (CISS) score, and clinical success rates.

Key Findings from the Convergence Insufficiency Treatment Trial (CITT)

The Convergence Insufficiency Treatment Trial is a scientific research study that has been going on for a while. It has shown that both home-based and in-office vision therapy are effective in treating this condition. However, in-office therapy was found to be more effective than home therapy in dealing with this condition.

  • The CITT study found that 73% of children with symptomatic convergence insufficiency showed significant improvement after receiving 12 weeks of office-based vision therapy.
  • The CITT study demonstrated that children receiving office-based vision therapy for convergence insufficiency experienced a reduction in symptoms by an average of 10.7 points on the Convergence Insufficiency Symptom Survey (CISS).
  • In the CITT study, children who received office-based vision therapy were 3 times more likely to achieve normal convergence function compared to children receiving home-based pencil push-ups.
  • The CITT study found that children receiving office-based vision therapy had a success rate of 73%, compared to only 33% for those receiving home-based computer therapy.
  • According to the CITT study, office-based vision therapy led to significantly improved near point of convergence (NPC) and positive fusional vergence (PFV) compared to home-based treatments.
  • The CITT study reported that the improvements in symptoms and clinical signs of convergence insufficiency were maintained in 79% of children who received office-based vision therapy one year after treatment.
  • In the CITT study, 88% of children who received office-based vision therapy reported that they were either "much better" or "completely better" in terms of their symptoms after treatment.
  • The CITT study found that the mean CISS score decreased from 30.7 to 15.1 in children receiving office-based vision therapy, indicating a significant reduction in symptoms.
  • The CITT study revealed that children receiving office-based vision therapy showed an average improvement of 13.4 prism diopters in their near positive fusional vergence.
  • According to the CITT study, only 5% of children receiving office-based vision therapy reported adverse effects, which were mild and transient, such as headaches or eyestrain.
Key Findings from the Convergence Insufficiency Treatment Trial (CITT)
Implications for Optometry Practices

Implications for Optometry Practices

The findings from the CITT have had a profound impact on the way we approach the treatment of convergence insufficiency. Based on the trial's results, we now have clear evidence that office-based vergence/accommodative therapy is the most effective treatment option for this condition. By incorporating this evidence-based treatment approach into our practice, we can offer our patients the best possible care and help them overcome the challenges associated with convergence insufficiency.

Implications for Optometry Practices

Amplify EyeCare Chattanooga's Collaboration with Local Schools and Community Organizations

At Amplify EyeCare Chattanooga, we are committed to raising awareness of convergence insufficiency by forming partnerships with local schools and community organizations. Our collaborative efforts include providing educational workshops, seminars, and vision screenings to identify children who may be experiencing this condition and ensuring they receive timely intervention.

Amplify EyeCare Chattanooga's Dedication to Continuing Education and CITT-Related Research Updates

Our team at Amplify EyeCare Chattanooga is dedicated to staying current with the latest research and developments concerning the CITT and convergence insufficiency. By actively participating in continuing education and monitoring new studies, we strive to offer the most effective, evidence-based treatments to our patients, ensuring their well-being and satisfaction.

Key Findings from the Convergence Insufficiency Treatment Trial (CITT)
Implications for Optometry Practices

What is Convergence Insufficiency?

Convergence insufficiency is a common vision disorder characterized by the inability to maintain proper eye alignment and focus on near objects. This condition occurs when the eyes struggle to work together while focusing on a nearby object, resulting in one or both eyes drifting outward instead of converging at the desired point. Learn more about convergence insufficiency here.

Symptoms of Convergence Insufficiency

The symptoms of convergence insufficiency can vary between individuals and may affect daily activities, such as reading, computer work, or other tasks that require near vision. Common symptoms include:

  • Difficulty focusing on near objects
  • Eyestrain or eye fatigue when performing close-up tasks
  • Headaches or discomfort around the eyes
  • Blurred or double vision
  • Difficulty concentrating on near tasks, often leading to a short attention span
  • Squinting or closing one eye to focus better
  • Frequent loss of place while reading
  • The need to re-read sentences or passages due to comprehension difficulties

Common Questions

The most effective treatment for convergence insufficiency, as determined by the Convergence Insufficiency Treatment Trial (CITT), is office-based vergence/accommodative therapy (OBVAT). This treatment approach involves personalized vision therapy sessions with a trained eye care professional, focusing on improving the eye muscles' ability to work together while concentrating on near objects. The CITT findings revealed that 73% of participants in the OBVAT group achieved clinical success, demonstrating substantial improvements in near point of convergence and positive fusional vergence. Office-based vergence/accommodative therapy has become the gold standard for treating convergence insufficiency due to its proven effectiveness in addressing the condition's symptoms and improving patients' overall quality of life.
The duration of therapy for convergence insufficiency can vary depending on the individual's needs and the severity of their condition. Typically, office-based vergence/accommodative therapy sessions are conducted once or twice a week, each lasting 45 to 60 minutes. The overall treatment period may range from 12 to 24 weeks or more. During this time, patients often receive supplemental at-home exercises to reinforce the skills and techniques learned during in-office sessions. It is important to note that the exact duration of therapy may differ based on factors such as the patient's progress, compliance with at-home exercises, and response to treatment. Close collaboration with an eye care professional ensures that therapy is tailored to the individual's unique needs, allowing for optimal outcomes and improvements in their quality of life.
The Convergence Insufficiency Treatment Trial (CITT)
Dr. McBryar cartoon

Schedule a Functional Vision Exam for Convergence Insufficiency

If you or your child is experiencing convergence insufficiency, we recommend exploring the benefits of office-based vergence/accommodative therapy, as supported by the CITT findings. As eye care professionals, we are devoted to maintaining the highest standards of evidence-based treatment methods and delivering the most current care to our patients. Don't hesitate to book an appointment with us to discuss available treatment options and embark on the path towards better vision and an enhanced quality of life. Contact us at (423) 710 3965 to schedule a functional vision exam.

Patients with functional vision issues visit our clinic from all over Tennessee, and we are proud to be a leading provider of pediatric and functional vision services for patients from Hixson, Chattanooga, Cleveland, and Middle Valley.


Vision therapy is well worth the response, time and effort. Our Son had a hard time focusing and writing neatly. After vision therapy Seth could complete a task in half the time if previously took. His abilities to focus improved greatly and so did his handwriting.

Also, he was better at listening. As a parent, we wanted learning to be fun for our Son, and vision therapy made this possible.

Amanda T.

Vision Therapy is well worth the expense, time and effort. Our son had a hard time focusing handwriting neatly. After vision therapy Seth could complete a task in half the time it previously took his abilities to focus and improved greatly and so did his handwriting.

Also, he was better at listening. As a parent you wanted learning to be fun for our son and vision therapy made this possible.

Alexa H.

Vision Therapy has given or son the tools he needs to be able to scan and read the written word more effectively and efficiently.

He love working with John and these working sessions give him the motivation to gladly work on his homework assignments.

It amazed us to see the difference in the tracking of his eyes and along a line of it's from the beginning to the end of the treatment.

Dr. McBryar , Kristen and John  are all marvelous and we would recommend them to anyone I only wish that we would have found them sooner!

Charlotte M.

Prior to coming to the institute for vision development my son complained of daily headaches. Therapy has eliminated his headaches completely. I love knowing my son is able to learn pain-free for the rest of his life because of the work that has been done over just a few weeks in this office. He he absolutely loved coming that didn't even feel like going to a doctor or therapy. We are grateful for the relief he was able to find by coming here.

Thank you!

Olivia C.

Seems much less frustrated with life

Reads non-stop and fast

Spelling abilities have been hugely improved

Seems much more confident

Thank You!!!

Kelly O.

When we first came to the practice, my son did not have huge issues, but lots of small ones- trouble with reading, sports (hitting the baseball consistently), coordination, etc- that were not easily detectable,but when put together presented issues. The staff here were all very professional and loving towards him. While I was concerned in the reading, my son was concerned with the athletic side. Seeing improvement night off the bat gave him confidence that i have nor seen in him and made him want to not only Come to therapy, but also made him want to work hard. He has surpassed his grade level and above in reading and hit his first home run this year! Thank you!!!

Alice M.
1 2 3 10



Discover effective treatment options for diabetic retinopathy; consult our eye care professionals to protect your vision and overall well-being

Treating diabetic retinopathy Treating diabetic retinopathy is a critical aspect of preserving vision and maintaining the overall quality of life […]

Read More
Carrots for eyes

Are Carrots Good for Your Eyes?

As an optometrist at Amplify EyeCare Chattanooga in Hixson, one of the most common questions Dr. Heather McBryar often encounters […]

Read More

Understanding Foggy vision

Is foggy vision troubling you? Let our experienced optometrist restore your sight – book an appointment today and see the […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

Amplify EyeCare Chattanooga Logo

Working Hours

Monday - Tuesday
7:30AM - 5:15PM

Wednesday - Thursday
8:00AM - 5:15PM

Friday - Sunday

1043 Executive Drive Suite #101 Hixson, TN 37343
(423) 710 3966
Website Accessibility Policy
Safety protocols page
privacy policy
For Patients
Call Us
eyefile-adduserphone-handsetcalendar-fullarrow-uparrow-right linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram