Anisometropia
Anisometropia occurs when eyes have unequal focusing because two eyes have different refractive power. The word comes from two Latin words – aniso = different and metropia = measure. This typically occurs because there is asymmetry present in the eyes. The difference between the eyes usually causes blurry vision and viewing of objects unequally. For example, in one eye an object may appear smaller than it appears in the other eye. The general vision in unequal and disproportionate in some structural fashion. Although this condition can be present at birth, it is often not diagnosed until sometime during childhood.
In this article:
- Anisometropia treatment
- Refractive Correction
- iPad games for correction of anisometropia
- Patching
- Atropine
- Neutral Density Filter
- Neuro-pharmacology
- Treatment of anisometropia in children
- Treatment of anisometropia in adults
- Anisometropia prognosis
- References
Anisometropia treatment
Treatment for Anisometropia is to correct the difference between the two eyes. Nowadays there are plenty of options for correction. Often this is done by prescriptive eyeglasses or contact lens. However, in more severe case eyeglasses may not be sufficient.
Refractive Correction
Refractive correction is a method in which surgical intervention corrects or improves your vision. The most commonly known example of refractive correction is LASIK eye surgery. Procedures can adjust your eyes focusing ability, as well as implant a lens inside your eye. The angles of your cornea can also be manipulated in order to correct whichever type of anisometropia you have. These procedures are beneficial for those who wish to decrease your dependence on corrective lenses and do not have any underlying eye disease.
iPad games for correction of anisometropia
Binocular treatment may work by a fundamentally different mechanism, and has been reported successful in adults with amblyopia, including those previously treated with patching. A new binocular game (“Dig Rush”) has become available that may be more engaging than the falling-blocks game and for which a pilot study found better adherence and evidence of effectiveness among amblyopic children aged 4 to 9 years.
A binocular iPad game was effective in treating childhood amblyopia and was more efficacious than patching at the 2-week visit. Binocular games that rebalance contrast to overcome suppression are a promising additional option for treating amblyopia. In children aged 7 to 12 years who have received previous treatment for amblyopia other than spectacles, there was no benefit to VA or stereoacuity from 4 or 8 weeks of treatment with the dichoptic binocular Dig Rush iPad game.
Patching
Patching is a treatment used to in order to strengthen the weaker eye. This method has been successful and is often times used concurrently with corrective lenses. Data shows that patching is most successful in young children, however the largest concern with this issue is noncompliance. There are high rates of noncompliance with this treatment plan, and thus will remain ineffective if not done properly and consistently. It is easier said then done. Try to convince the child not to use one eye. in addition to the inconvenience of something being taped on the face, or glasses with one side patched, this method is associated with headaches, and psychological stigma when at school.
Atropine
Atropine is the most common pharmacological option in the treatment of Anisometropia. Atropine 1% is used in a dropper preparation and placed directly into the eye. Atropine is an anticholinergic drug which is used to paralyze visual accommodation and induce blur in the stronger eye. Although Atropine has better treatment compliance, it has been shown minimally less effective that patching.
Neutral Density Filter
Neutral density filters, often referred to as Bangerter filters, are applied to the spectacle lens of the stronger eye to reduce vison. The affected eye will then be chosen and thus strengthen overtime. The use of these filter tends to be a good option for those who have compliance issues with patching.
Neuro-pharmacology
This treatment option is to use pharmacological neurotransmitters to enhance cortical plasticity. The most common used drug for this mechanism of action is Levodopa. The evidence is not entirely strong on this option given that it is a relatively new treatment option, but some feel as though it does improve visual acuity.
Treatment of anisometropia in children
Refractive correction has been successfully used in children to improve visual acuity. Often corrective lenses alone will not be enough, in which cases patching will need to be used to achieve resolution of anisometropia in children.
Treatment of anisometropia in adults
The adult brain is still capable of learning and recovering from injury, and thus responds to treatment of Anisometropia. Results in adult eyes will depend on the severity of the condition and which methods are attempted, as well as length of treatment. Stimulation of adult brain plasticity will be imperative to treatment response.
Anisometropia prognosis
Due to neuroimaging and better understanding of how Anisometropia and the brain relate, prognosis remains hopeful and is now expanding to children and adults. Although treatment best responds in the younger child, it is known through better understanding of brain function that approaching both eyes in the treatment plan leads to overall better prognosis even into adulthood.
References
https://eyewiki.aao.org/Amblyopia