Amblyopia (lazy eye) is the main cause of decreased vision in a single eye in children. This problem has mainly been viewed as an eye-related condition that can be managed by patching the opposite eye in order to force the affected amblyopic eye to be used. This form of therapy though doesn't seem to teach the eyes to work better together or restore full 6/6 vision.
Since amblyopia is as a result of binocular discordance, then binocular treatment is more likely to result in better visual outcomes. The issue with this train of thought is that it isn't clear whether binocular treatment can be compared to patching the unaffected eye when wanting to treat amblyopia. A study was therefore performed to deduce whether other forms of treatment were more effective than patching.
The study
Researchers at the Retina Foundation of the Southwest in Dallas, Texas, U.S.A. randomly chose 28 children (at 7 years of age) diagnosed with amblyopia. The children were randomly divided into 14 of them taking part in the binocular treatment game and the other 14 having the patching treatment performed on them.
The binocular game is an action-adventure game that uses an iPad format. The game requires children to wear specialised eye-wear that separates elements of the game seen by each eye. The amblyopic eye sees high-contrast elements, the opposite eye sees reduced-contrast elements and both eyes visualise high-contrast background elements. In order for the game-play to be successful, both eyes have to visualise their respective game components. The children were asked to play the game at home for 1 hour a day, 5 days a week for 2 weeks (to complete 10 hours of total game-play).
The findings
The primary discovery of the study was that there was a change in the best-corrected visual acuity (BCVA) of the amblyotic eye, in children who were exposed to the binocular treatment game, at the 2-week follow-up visit.
The comparison was staggering since it was found that the children's BCVA in the amblyotic eye, that was managed with the iPad game, had improved more than double than that of the children whose unaffected eyes were patched, and in half of the treatment time too (10 hours of game-play versus 28 hours of patching).
Another discovery was that 5 of the 13 children, nearly 40%, who had received binocular treatment reached 6/8 or better visual acuity compared with 1 of 14 children (only 7%) who were patched.
READ Eye Exercises for Healthy Eyes
The study went on further to allow the children who were patched to start playing the binocular treatment game at the 2-week follow-up stage. All 28 children then continued with the iPad game for another 2 weeks and at the 4-week visit, no difference was found in the BCVA change of the amblyopic eye of both groups of children. It seemed that the children who changed over to the binocular game caught up with the children who were initially treated with the iPad game.
The researchers did admit that further investigations need to be performed to determine whether long-term binocular treatment is as effective in completely managing amblyopia as performing patching.
Visual Convergence Insufficiency
A convergence insufficiency relates to the eyes not being able to work together and move inwards (converge) to allow them to focus properly when visualising nearby objects. Failure for the eyes to converge doesn't allow binocular vision to occur and therefore two images are seen.
Causes
The causes of convergence issues seem to be from misalignment of the eyes due to a problem associated with the muscles of the eyes.
The problematic muscle will cause the affected eye to move outwards when one is trying to focus which causes the symptoms associated with convergence issues.
Symptoms
Not everyone experiences problems with convergence issues, but if they do occur it usually happens when the affected individual is reading or performing work that requires close eye contact. Convergence issues of the eyes can cause the following complaints.
- Closing one eye or squinting in order to focus better.
- Eyestrain.
- Double vision.
- Difficulty reading as words seem to be blurry.
- Headaches.
- Difficulty concentrating.
Complications
Convergence issues can result in difficulties with reading and concentrating which may result in the child struggling to learn properly and can cause him or her to fall behind in class.
Routine eye exams and school-based visual screenings usually don't pick up convergence problems of the eyes. These children are then assumed to have a learning disability due to their poor reading when the problem actually lies with their eyes.
READ Beware Of Sun Damage To Your Eyes
Making the diagnosis
A general practitioner and an optometrist will assess a child that is having issues with reading and who is having eye-related complaints. Simple visual assessments can be done and the child's ability to focus will also be tested.
If a convergence issue is picked up, then further management will be incorporated.
Management
The following treatment options are suggested when managing convergence issues.
- Home or office-based vision therapy - eye-focusing exercises are done on a computer at home or at work to improve visual convergence.
- Pencil push-ups - the patient focuses on a small letter on the side of a pencil and they move the pencil closer to the bridge of their nose, stopping the movement when they experience double vision. A patient's physician will usually suggest performing this exercise for 15 minutes a day, 5 or 6 times a week.
- Combined therapy - many specialists suggest performing vision therapy together with pencil push-ups as the combination may be more effective in managing convergence issues.
- Utilising reading glasses - if visual therapy or pencil push-up exercises aren't effective enough, it may be suggested to use reading glasses to help with this visual problem. Using these glasses is usually more effective for children.
- Observe - some patients may be diagnosed with convergence insufficiency but not show any signs or symptoms of the condition. In these cases, patients are asked to look out for symptoms when reading or doing close work and they may then be re-tested at a later stage.
- Surgery - if non of the above-mentioned treatment options are effective in managing convergence insufficiency, then surgery may be recommended for these patients.
Your thoughts on this