Amblyopia is the most common cause of visual impairment in children. It occurs when there is a misalignment between what the two eyes see. It happens when one eye is clouded by a cataract, when there is a refractive error, or when the eyes are positioned at different angles.
The brain has a slight preference for the more functional eye at first, but as that eye continues to send useful information to the brain, the brain’s preference for that eye grows stronger at the expense of the other. In this blog post, we will have a look at long-proven, traditional treatment approaches and at novel ones, e.g. dichoptic. We will explain what is dichoptic therapy for amblyopia.
Table of contents
- Traditional Approaches to Treatment: Eye Patching
- What About Binocular Vision?
- A Novel Approach to Treatment: Dichoptic Therapy
- Frequently Asked Questions
Traditional Approaches to Treatment: Eye Patching
Patching vs cycloplegics has been the cornerstone of amblyopic treatment for hundreds of years. Because a patch is simple to apply and cost-effective treatment, patching therapy is usually the first-line procedure.
Challenges and Considerations in Patching Therapy
However, there are numerous flaws since the psychological and social consequences of wearing a patch might cause problems with compliance.
Patching therapy has been challenging for parents to stick to due to the inadequacies and discomfort of reducing a child’s viewing field via the patch.
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Even when visual acuity improves in the amblyopic eye, studies reveal that binocular vision is underutilized. Binocular vision occurs when the visual fields of both eyes overlap, allowing for better depth perception.
What About Binocular Vision?
Understanding binocular vision in amblyopia is crucial. When one eye is patched in patching therapy, the other eye gets stronger, but they don’t work together well. Ultimately, while patching therapy has had some success, there is a clear need for more effective alternatives.
”Because the opposing eye is patched, the two eyes do not develop in synchrony.”
Exploring Atropine Eye Drops as an Alternative to Patching Therapy
Atropine eye drops have been used as an alternative to patching. Atropine inhibits muscarinic receptors in the eye, which control the size and shape of the pupil and lens. It has a mydriatic (increased pupil size) and cycloplegic (paralysis of the fibers controlling lens accommodation) effect, which acts as a blurring therapy for the well-seeing eye.
Atropine eye drops were found to be equally effective as patching for moderate amblyopia. However, given the ease of applying an eye patch versus the inconvenience of putting in drops that cause a strange blurring sensation, it’s no surprise that patching therapy is preferred by both parents and practitioners.
A Novel Approach to Treatment: Dichoptic Therapy
Despite the fact that amblyopia is a binocular problem that has been recognized for many years, the traditional approach has always focused on monocular vision. Binocular approaches to amblyopic vision have only recently been explored.
In the recent amblyopic literature, suggestions for novel therapeutic approaches have made significant progress. Pure monocular therapy, pure binocular therapy, and a combination therapy consisting of both are among the approaches discussed. While we’ve already discussed monocular approaches, we’ll now turn our attention to dichoptic therapy approaches.
Binocular Stimulation Was Previously Missing in Amblyopia Treatment
A new treatment regimen, using dichoptic glasses while playing video games, incorporates a binocular stimulation that was previously missing in amblyopic treatment methodologies. This dichoptic manipulation of different contrasts allows both eyes to be stimulated.
Mechanism of Dichoptic Therapy – Stimulating Both Eyes
By presenting a high-contrast image to the amblyopic eye, the method trains the eyes. This method is distinguished by the fact that it does not aim to suppress the fixing eye, but rather to strengthen neural connections in the amblyopic eye, thereby promoting binocular vision.
Efficacy of Dichoptic Therapy
Numerous clinical trials have shown that dichoptic therapy is more effective than patching as a treatment for amblyopia. Game therapy is less time-consuming than patching and results in better best-corrected visual acuity.
When discussing binocular treatment, clinical suppression must be assessed. Under binocular viewing conditions, clinical suppression refers to the absence of an amblyopic and/or strabismic eye’s contribution. Until recently, there was no gold standard for determining the degree of clinical suppression. According to recent research, the strength of suppression and the degree of amblyopia present have a direct relationship.
There has been a noticeable shift in amblyopic literature in recent years, away from the previous trend of monocular suppression therapy. Binocular therapy has an additional benefit of increased stereopsis in addition to improved visual acuity.
”Binocular therapy has an additional benefit of increased stereopsis in addition to improved visual acuity.”
Treating Amblyopia in Adults with Dichoptic Therapy
Although it was previously believed that adults with amblyopia should not be treated, new research has contradicted this belief, indicating that there may be some benefit to treating amblyopic adults. Many previously held beliefs about amblyopia are being challenged, and as research trials continue to demonstrate the efficacy of dichoptic therapy, it may soon become the gold standard of care.
Frequently Asked Questions
Amblyopia, commonly known as “lazy eye,” is the most prevalent cause of visual impairment in children. It occurs when there is a misalignment between the images perceived by the two eyes. This condition arises due to factors such as cataracts, refractive errors, or misaligned eyes, affecting the development of clear vision.
Amblyopia is fundamentally a binocular problem, meaning it involves how both eyes work together. Traditional approaches often focus on monocular vision, neglecting the importance of synchronized development between the two eyes. Binocular vision, where the visual fields of both eyes overlap, enhances depth perception. Recent advancements recognize the need for novel therapeutic approaches that incorporate binocular stimulation.
A novel binocular treatment approach involves using dichoptic glasses during video game sessions. This method stimulates both eyes simultaneously by presenting high-contrast images to the amblyopic eye. Unlike traditional methods, it aims to strengthen neural connections in the amblyopic eye rather than suppress the stronger eye. Clinical trials have demonstrated the effectiveness of this approach over patching in terms of time efficiency and improved visual acuity.
Contrary to previous beliefs that amblyopia couldn’t be treated in adults, recent research suggests potential benefits for treating amblyopic adults. The shift in treatment trends acknowledges the importance of binocular therapy in not only improving visual acuity but also enhancing stereopsis (depth perception). This change challenges traditional assumptions about the limitations of amblyopia treatment.
Source: Mufti, O., & Ramasubramanian, A. (2019). Binocular Treatment for Amblyopia. Advances in Ophthalmology and Optometry, 4, 65–73. https://doi.org/10.1016/j.yaoo.2019.04.003