Monday, November 03, 2008
Training the Eyes to See - Convergence Insufficiency, Vision Therapy, Reading, and Computer Vision Syndrome
In a long-awaited randomized blinded clinical trial, office-based convergency insufficiency training was found to improve symptomatic convergence insufficiency over home-based exercises, computer-based therapy + home exercises, or placebo therapy in the office (mock therapy training - monocular exercises only).
"A successful or improved outcome was found in 73%, 43%, 33%, and 35% of patients in the OBVAT (office-based vergence/accommodative therapy with home reinforcement), HBPP (home-based pencil push-ups), HBCVAT+ (home-based computer vergence/accommodative therapy and pencil push-ups), and OBPT (office-based placebo therapy with home reinforcement ) groups, respectively."
Some of us may have only become familiar with the side effects of convergence insufficiency when we get older (presbyopia - trouble focusing on small print, eye pain, etc.) or perhaps if we're having to work too many hours per day at the computer (e.g. computer vision syndrome). No wonder it is such a puzzle to children who may not necessarily know how good their vision should be normally, and why they are having such a hard time with reading.
It's interesting to see the magnitude of benefit with office-based training over home or even home + computer-based training. Bravo for the developmental optometrists for performing a randomized control trial involving their therapy. Why is office-based training so much better? Not sure. Some possibilities - better motivation and compliance, greater flexibility in administering therapy tasks, optimized task rotations?
A study such as this is just the beginning, but a necessary start.
Every child with difficulty reading should be given the Convergence Insufficiency Symptom Survey pdf to see whether convengence insufficiency is contributing to the problem. The mean score for children wtih convergence insufficiency 30 vs. 8.4 (for more info, see here).
Common screening questions include: Do you lose your place while reading or doing close work? Do you have to re-read the same line of words? Do you notice the words blurring or coming in and out of focus when reading or doing close work...
Randomized Clinical Trial of Treatments for Symptomatic Convergence Insufficiency in Children pdf
Kids Eye Problems Emerge in Homework Battle