How Can Stargardt Disease Cause Vision Loss in Children?

September 8, 2023

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According to the estimates presented by the Investigative Ophthalmology and Visual Science, approximately 49.1 million people were blind in 2020 worldwide. Globally, 221.4 million people had moderate vision impairment while 33.6 million people had severe vision impairment. An enormous proportion of the world’s population is affected by eye diseases and vision loss.

We seem to overlook how rapidly vision loss is spreading its roots among an enormous chunk of the population. The fact that cases of vision loss are rapidly multiplying among children is even more disturbing.

According to the 2019 American Community Survey (ACS), approximately 547,083 children are dealing with vision problems in the US. Around 270,761 females and 276,322 males under the age of 18 are living with vision difficulties.

Common Vision Problems in Children

Some common vision problems amongst children include

Amblyopia

An abnormal formation of a neural connection between the eye and the brain causes vision loss in early childhood. This condition called amblyopia, also known as lazy eye, is found in around 2 percent of children aging 6 to 72 months according to Prevent Blindness Wisconsin.

Myopia

Myopia, also termed nearsightedness, refers to a defective vision of distant objects. Myopia has affected 9% of children aging 5 to 17 years according to Prevent Blindness Wisconsin.

Hyperopia

Hyperopia, commonly known as farsightedness, is a condition that causes defective vision of nearby objects, while distant objects can still be seen clearly. About 13% of children aging 5 to 17 years are affected by hyperopia.de

Astigmatism

Astigmatism is an imperfection in the curvature of the eye’s cornea. It is a refractive error that causes blurred or distorted vision for both distant and nearby objects. When the light enters an astigmatic eye, it does not properly focus on the retina, causing a blurry image. Nearly 15 to 28% of children are affected by astigmatism globally.

Effects of Vision Loss in Children

Vision loss has a profound impact on every aspect of the lives of those affected by it. Sequential learning and observation are the tools that children with low vision use the most in their learning process. By processing the limited information they manage to gather through observation, they build up an image. Mobility, independence, and quality of life are largely affected by vision loss. A visually impaired child may struggle with the following aspects:

Social engagement: There are more chances of visually impaired children to miss out on social interactions and activities. They might not be able to see and respond to someone smiling or waving at them which means they are often deprived of non-verbal communications or noticing and responding to gestures. Due to their limited interactions and response to what is happening in their surroundings, they also have trouble making friends.

Communication: It is a common behavior of children to ask lots of questions about their surroundings out of curiosity. This adds new words to their vocabulary every day. Children with vision loss might not be able to develop a vast vocabulary as the words they learn lack visual references.

Cognitive development: Mental processes such as conceptual thoughts and logical memory get largely affected. According to a study published in the journal Cerebral Cortex, as soon as a person goes blind, an alteration can be noticed in the density of the neurotransmitter receptors. Neurotransmitter receptors are present in the cortex processing sensory signals. Blindness also profoundly affects the hippocampus, a part of the brain that plays a part in processing information.

Motor development: an exploration of the surroundings plays a key role in cognitive as well as motor development. But a child with visual impairment may not feel encouraged to move around and explore.

Causes of Vision Loss in Children

Vision loss, in simpler terms, can be defined as difficulty in seeing even when wearing contact lenses or eyeglasses. According to Prevent Blindness Wisconsin, around 3% of US citizens under the age of 18 are legally blind or have vision impairment. There are some general as well as medical reasons that cause blindness in children.

Head or Eye Injury

Trauma or injury to the eye or head can also cause visual field loss. The affected area of the brain as well as the extent of the damage determine the degree of vision loss.

Vision Problems in Early Childhood

Common eye conditions like myopia, astigmatism, strabismus, and so forth, can cause partial to complete vision loss if left untreated.

Congenital Eye Problems

Some inborn or congenital eye conditions may also cause complete or partial vision loss in children. These conditions commonly include optic nerve hypoplasia (ONH), congenital cataracts, albinism , retinopathy of prematurity (ROP), and many others.

Vitamin-A Deficiency

Vitamin A plays a significant role in nourishing and protecting the cornea. With a deficiency of vitamin A, the cornea is prone to get damaged or scarred, consequently causing blindness. According to the Danbury Eye Physicians and Surgeons, 250,000 to 500,000 cases of childhood blindness are yearly recorded due to vitamin A deficiency.

Eye Conditions

Age-related eye diseases such as age-related macular degeneration, trachoma, cataracts, and glaucoma are the primary causes of blindness in the United States according to the CDC:

Cataracts:

Cataracts, one of the leading causes of blindness in the United States according to the CDC, refers to the clouding of the lens of the eye. It can be congenital or it may occur at any age as well.

Trachoma:

An eye infected by the bacterium Chlamydia Trachomatis leads to the eye disease ‘trachoma’. Trachoma commonly occurs amongst preschool-aged children according to the WHO and the blindness it causes is irreversible. It is a contagious eye disease.

Infantile Glaucoma:

Infantile glaucoma, commonly known as childhood glaucoma, is a rare condition that can also be hereditary. The incorrect development of the drainage system of the eye elevates intraocular pressure, resulting in optic nerve damage. Photosensitivity and cloudiness of the cornea mark the probability of the presence of infantile glaucoma.

Age-Related Macular Degeneration:

Macular degeneration, also referred to as age-related macular degeneration, is the deterioration of the central vision of the eye and is associated with aging. As the name suggests, AMD damages the macula, which is the middle part of the retina responsible for projecting a crisp and clear image.

Another form of Macular degeneration i.e. Juvenile Macular Degeneration, also known as Stargardt’s disease, is one of the root causes of childhood blindness.

What is Stargardt’s Disease?

Stargardt’s disease, also known as juvenile macular degeneration, is a rare and inherited eye disorder that constitutes degeneration of the retina in infants and children. The retina is the tissue present at the back of the eye sensitive to light.

Stargardt’s disease commonly causes the vision to deteriorate during early childhood years, but the signs of vision loss remain unnoticeable until adulthood. According to the National Eye Institute, approximately 1 in 8-10 thousand people get affected by this rare condition. The progressive degeneration of the macula present in the middle of the retina causes distorted vision and grey-black hazy spots instead of a crystal clear central vision.

How Does Stargardt’s Disease Cause Vision Loss in Children?

The retina present in the human eye consists of two types of photo receptors; rods and cones responsible for the conversion of light into electrical signals which are then detected and seen by the brain. Rods and cones are responsible for projecting clear images to the brain in dark settings and bright light respectively.

Both rods and cones get damaged in Stargardt’s disease but due to some unknown reasons, cones present in the macula go through more damage.

The mutations taking place in a gene termed as ‘ABCA4’ is one of the leading causes of vision loss due to Stargardt’s disease. These mutations result in the formation of a protein that alters the normal flow of food and waste in and out of the rods and cones. This leads to the formation and settling of yellowish fatty substances called Lipofuscin in the photo receptor cells of the retina. Accumulation of lipofuscin in and around the macula eventually results in central vision loss. The photo receptor cells die consequently, posing irreversible damage to the vision.

How to Prevent Stargardt’s Disease?

At this time, there is no available and proven cure for Stargardt’s disease or juvenile macular degeneration. However, gene and drug therapies have been areas of interest now for the researchers who are on the hunt for a possible solution to the problem.

To prevent additional eye damage caused by UV rays from the scorching sun, people with Stargardt’s disease are commonly advised to put on sunglasses or eyeglasses in the sun.

The eye doctors also advise people with Stargardt’s disease to put on tinted eyeglasses in bright daylight to completely block the UV rays from the sun.

Some researchers are working day and night to develop a stem cell treatment that will help regenerate the photoreceptors present in the macula, which were previously damaged by Stargardt’s disease.

Low-Vision Solutions for Stargardt’s Disease

The irremediable damage that Stargardt’s disease causes to the eyes cannot be corrected by wearing eyeglasses, contact lenses, or by getting eye surgery.

The advancements in technology have brought about life-changing low-vision solutions to assist the people with low vision to move around doing everyday tasks without compromising their independence. These devices help you make most of your leftover vision.

Some of the remarkable low vision solutions present today include:

Screen Readers
Smart Canes
Electronic Magnifying Systems or CCTV Aids
3D Sound Maps
Low vision glasses:

Low vision glasses like the IrisVision Live headset have transformed the lives of people affected by low vision and blindness. It leverages the leftover vision of the individual suffering from low vision and amplifies it, consequently improving the visual acuity of the eye. By providing the visually impaired with a plethora of smart features on their VR headset, IrisVision Live has earned them back their independence.