What does convergence insufficiency look like?

This is what reading is like for someone with convergence insufficiency.

What is convergence insufficiency?

To understand convergence insufficiency, it is first necessary to understand what convergence is. Convergence is the coordinated movement and focus of our two eyes inward. This is what normal eyes do when a person is performing close work such as reading that requires us to focus both of our eyes inward on close objects (books, papers, computer screens, etc.). Humans learn to converge very early in life.

A person who cannot converge properly has a problem with the coordinated movement of their eyes inward to look at close objects. The most common convergence problem is convergence insufficiency.

When we are not able to converge our eyes easily and accurately, problems may develop, such as:

Eye strain
Headaches
Double vision
Difficulty reading and concentrating
Avoidance of near work
Poor sports performance
Dizziness or motion sickness

Here is a video on convergence insufficiency from the National Eye Institute:

Treatment of Convergence Problems

Eye coordination problems like convergence insufficiency generally cannot be improved with eye glasses or surgery. A program of Vision Therapy may be needed to improve eye coordination abilities and reduce symptoms and discomfort when doing close work.

Studies support vision therapy to treat convergence insufficiency

The National Eye Institute, a division of the National Institutes of Health for the U.S. Department of Health and Human Services, released a statement concerning the effectiveness of office-based vision therapy for treatment of Convergence Insufficiency. Dr. Mitchell Scheiman, FCOVD, who completed the 12-week study, known as the Convergence Insufficiency Treatment Trial (CITT), found that approximately 75 percent of those who received in-office therapy by a trained therapist plus at-home treatment reported fewer and less severe symptoms related to reading and other near work after the office-based vision therapy.

"This NEI-funded study compared the effectiveness of treatment options for convergence insufficiency," said Paul A. Sieving, M.D., Ph.D., director of the NEI. "The CITT will provide eye care professionals with the research they need to assist children with this condition."

"There are no visible signs of this condition; it can only be detected and diagnosed during a comprehensive eye examination," said principal investigator Mitchell Scheiman, O.D., FCOVD, of Pennsylvania College of Optometry at Salus University near Philadelphia, PA. "However, as this study shows, once diagnosed, CI can be successfully treated with office-based vision therapy by a trained therapist along with at-home reinforcement."

Notably, the study also found that the most popular treatment typically offered by ophthalmologists, pencil push-ups, was not effective. The press release issued by the National Eye Institute to announce the findings of the RCT provides a short summary of the study.

There have also been follow-up studies by Scheiman et al. showing that the results obtained from vision therapy are were long-lasting and that the treatment kinetics are favorable – meaning that that rate at which patients get better with vision therapy makes office-based vision therapy an effective and practical treatment

In 2005 Scheiman et al. published a clinical trial in Optometry and Vision Science on the vision therapy treatment of convergence insufficiency in young adults ages 19-30. Once again, the results proved the efficacy of vision therapy treatment over other modalities that were in use at the time. The study authors concluded:

"This first multicenter, randomized clinical trial of the treatment of symptomatic CI in young adults demonstrated that of the three treatment modalities, only vision therapy/orthoptics was effective in achieving normal clinical values for both the near point of convergence and positive fusional vergence. Patients in the pencil pushups group achieved normal values only for positive fusional vergence at near and patients in the placebo vision therapy/orthoptics group did not achieve normal findings for either the near point of convergence or positive fusional vergence at near.Therefore, the effectiveness of vision therapy/orthoptics in improving the near point of convergence and positive fusional convergence values at near in adults cannot be explained on the basis of a placebo effect. Based on the results of this preliminary study, it would appear thatpencil pushups, the most popular treatment for CI, is not effective for achieving clinically significant improvements in symptoms or signs associated with CI in young adults."

A study published in 2010 by Alvarez et al. in Optometry and Vision Science adds to the depth of the scientific evidence by showing that vision therapy produced demonstrated changes in eye movements together with significantly increased functional activity within the frontal areas of the brain, the cerebellum, and brain stem. These regions of the brain are likely to ―participate in a collicular-cortical dorsal visual networks and may reflect increased processing of visual material specific to near space. This study demonstrates the motor and neurological mechanism by which vision therapy operates. The brainscan images published in the Alvarez study are worthy of review.

Pages

Thursday, May 17, 2012