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Study: Office-based vergence therapy best for convergence insufficiency
A large study found that combining 12 weeks of office-based therapy with home reinforcement is more effective for treating children with convergence insufficiency than two home-based therapies and an office-based placebo therapy with home reinforcement.
 Dr. Kulp presented the CITT study results during an academy-sponsored press conference at Academy 2008 in Anaheim, Calif. Image: Hemphill N, PCON
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According to a press release issued by the National Eye Institute, the Convergence Insufficiency Treatment Trial (CITT) Group randomly assigned 221 children with symptomatic convergence insufficiency participating in the CITT to undergo 12 weeks of treatment via one of four methods. All children were between 9 and 17 years old.
Specifically, 54 patients were instructed to perform home-based pencil push-ups (group one), 53 patients were assigned to home-based computer vergence therapy and pencil push-ups (group two), 60 patients received office-based vergence therapy with home reinforcement (group three) and 54 patients received office-based placebo therapy with home reinforcement (group four).
At 12 weeks, the mean convergence insufficiency symptom survey score was significantly lower among patients in group three than in all other groups (P < .001), the authors reported.
Patients in group three also showed significantly more improvement in near point of convergence and positive fusional vergence at near vision (P = .005).
The investigators reported successful or improved outcomes in 73% of patients in group three, 43% of patients in group one, 33% of patients in group two and 35% of patients in group four, according to the study.
Marjean Taylor Kulp, OD, MS, FAAO, principal investigator at Ohio State University College of Optometry, presented the study results at Academy 2008 in Anaheim, Calif. “Office-based therapy should be considered as first-line treatment,” she said.
To qualify for the study, children had to meet four specifications, according to the National Institutes of Health Clinical Trials Web site. Patients had to have at least 4 prism diopters more of exophoria at near than at distance, a receded near point of convergence greater than 6 cm, a reduced positive fusional vergence finding and a score of 16 or higher on the Convergence Insufficiency Symptom Survey.
The survey, a series of 15 questions on a four-point scale, was used to evaluate the level of discomfort a child experiences when reading or doing close work.
Mitchell Scheiman, OD, principal investigator at Salus University’s Pennsylvania College of Optometry and the CITT study chair, told Primary Care Optometry News in an interview that one of the primary issues that surfaced as a result of this study was whether or not a primary care optometrist can implement office-based therapy into practice easily.
“Every primary care optometrist can certainly make the diagnosis of convergence insufficiency, but the problem is that the treatment we found to be most effective is office-based vision therapy,” he said. “For the primary care optometrist who currently doesn’t do that, they either have to add that service to the practice or refer the patient to an optometric colleague who does.”
After the 12-week study was completed, Dr. Scheiman and his colleagues conducted a follow-up study to determine how successful 71 of their patients were a year after therapy.
“We followed all the children who were successful at 12 weeks and re-examined them after 6 months and then after a year, because the treatment really has to have a long-term effect, not just be effective after 12 weeks,” Dr. Scheiman said.
Results from the follow-up evaluation will be presented at the ARVO conference in Fort Lauderdale, Fla., in May 2009.
For more information:
- Mitchell Scheiman, OD, can be reached at Pennsylvania College of Optometry; (215) 276-6057; e-mail: mscheiman@salus.edu. Marjean Taylor Kulp, OD, MS, FAAO, can be reached at Ohio State University College of Optometry; (614) 688-3336; e-mail: kulp.6@osu.edu.
References:
- Convergence Insufficiency Treatment Trial Study Group. Randomized clinical trial of treatments for symptomatic convergence insufficiency in children. Arch Ophthalmol. 2008;126(10):1336-1349.
- More information on this trial, NCT 0033861, can be found at the National Institutes of Health Clinical Trials Web site: www.clinicaltrials.gov.