What is Juvenile Glaucoma?
Glaucoma is a disease that gradually damages the optic disc in the eye, leading to loss of vision. The main factor that can be changed or controlled is the internal pressure of the eye. A key fact to remember is that glaucoma is the leading cause of permanent blindness. It impacts over 2 million people in the United States and 67 million people worldwide.
There are two main types of glaucoma: open-angle glaucoma and angle-closure glaucoma. An unusual form of the former is juvenile open-angle glaucoma. This version often begins between the ages of 3 and 40, can display higher internal eye pressure, and can result in more severe vision loss compared to the form of glaucoma typically seen in adults.
This juvenile form of glaucoma is often genetically linked. One gene in particular has been found abundantly in patients with this form of glaucoma, called the myocilin gene.
To help understand how glaucoma affects the eye, think of the eye as two parts, the front and the back. The front part, which is located before the lens, is split into two areas. The backmost area of this front part has a body that creates a fluid called aqueous humor. This fluid moves from the back area to the front area through the pupil, then leaves the eye through two routes. Most of the fluid flows through a meshwork and a canal, while a lesser amount of fluid moves into spaces through a muscle. Both pathways drain the fluid into the blood flow.
What Causes Juvenile Glaucoma?
Juvenile open-angle glaucoma often develops due to issues in the formation of the trabecular meshwork, an area in the eye involved in fluid drainage. If this wasn’t formed properly, it could lead to poor drainage of eye fluid, causing an increase in eye pressure and potential damage to the optic nerve.
There are several risk factors that can increase the chances of developing juvenile-onset open-angle glaucoma:
* Being male: In a study of 125 individuals with this condition, 64% were male.
* Nearsightedness: It was found in a research study of 23 patients that 87% of people with this condition were nearsighted.
* High eye pressure: An eye pressure over 40 mmHg is commonly seen in individuals with juvenile-onset primary open-angle glaucoma.
* African ancestry
* Mutation in the MYOC gene.
Risk Factors and Frequency for Juvenile Glaucoma
Juvenile open-angle glaucoma is a relatively rare eye condition, affecting around 0.38 out of every 100,000 people aged between 4 and 20 years old. In one study that reviewed 239 patients with childhood glaucoma, it was found that 4% of these patients were diagnosed with juvenile open-angle glaucoma.
Signs and Symptoms of Juvenile Glaucoma
Both juvenile open-angle glaucoma and adult-onset primary open-angle glaucoma share similar characteristics. It’s important to note that many people with juvenile open-angle glaucoma don’t experience symptoms. However, those who do have symptoms might experience an enlarged eye, blurred vision, eye pain, reduced sharpness of vision, tearing, frequent blinking, and sensitivity to light. A family history of glaucoma should also be considered as a potential indicator of the condition.
- Enlarged eye
- Blurred vision
- Eye pain
- Decreased visual clarity
- Tearing
- Blinking often
- Glare or light sensitivity
visual field test indicating characteristic changes associated with glaucoma in
the left eye, as observed on perimetry.
Testing for Juvenile Glaucoma
When examining a young person for open-angle glaucoma, several tests and checks are usually performed. These include measuring their eye pressure (IOP), testing their vision, examining the optic disc (a structure at the back of the eye), and assessing the front part of their eye (the anterior chamber angle). The specific processes usually involve:
- Eye pressure (IOP): A commonly used method for accurate pressure measurement is the Goldmann Applanation Tonometry.
- Optic disc: In juvenile open-angle glaucoma, the optic discs are typically larger than those seen in adults with the same condition.
- Pachymetry: This is a measure of cornea thickness done before any surgical intervention. Thinner corneas are seen as a risk factor for juvenile open-angle glaucoma.
- Anterior chamber angle: This part usually appears normal upon examination, but if eye pressure is extremely high, there may be abnormalities.
In other words, if a young person is suspected to have open-angle glaucoma, doctors will typically perform the above steps to get a better idea of what’s going on and decide the best treatment pathway.
Treatment Options for Juvenile Glaucoma
The goal of treatment for juvenile open-angle glaucoma, which is a type of eye disease, is to stop further damage to the optic nerve by reducing the internal pressure in the eye, often referred to as IOP. Optic nerve images are usually taken to measure the disease’s progress. Usually, the eye pressure in juvenile open-angle glaucoma doesn’t respond well to medication, so surgery is often necessary.
Usually, doctors first try to treat juvenile open-angle glaucoma with medication, and surgery is considered as a last resort if medication doesn’t help. In many cases, medication is used temporarily until surgery can be performed. A study found that 83% of young patients with this type of glaucoma end up needing a specific type of eye surgery called trabeculectomy.
The medication regimen for juvenile open-angle glaucoma often includes β blockers, topical carbonic anhydrase inhibitors, prostaglandin analogs, and α-adrenergic agonists. If a patient doesn’t have conditions like asthma, β-blockers are often the first choice for treatment. Topical carbonic anhydrase inhibitors aren’t as potent as β-blockers, but they can be valuable if used in conjunction with other treatments or as alternatives if β-blockers can’t be used. Prostaglandins have been found to be more useful in treating adult glaucoma than childhood glaucoma. α-adrenergic agonists can also be effective, but they can cause various body-wide side effects that require careful monitoring when prescribed to young patients.
In terms of surgical options, there are different types, including trabeculectomy, drainage implants, angle procedures, and procedures to destroy part of the eye’s fluid-producing tissue. For juvenile open-angle glaucoma, trabeculectomy is the standard surgical treatment and usually results in a good outcome. Medication to reduce eye pressure is not normally needed for three years after this operation. Mitomycin C or other antifibrosis drugs are used during surgery to prevent fibrosis, a type of scar tissue formation. Although using Mitomycin C during trabeculectomy results in a lower eye pressure, it also increases the risk of certain complications like retinal damage and infection.
Glaucoma drainage implants are another surgical option and are typically used in cases where scarring prevents a trabeculectomy. There are different types of implants, and according to one study, the Ahmed glaucoma valve implant has a high success rate. It successfully brought the eye pressure into a healthy range and no patient went blind. The Molteno implant, another type of glaucoma drainage implant, also resulted in healthy eye pressure in a test in which 52 eyes with juvenile glaucoma were assessed.
Trabeculoplasty with lasers can also be used to treat glaucoma by reducing the eye’s internal pressure. Selective laser trabeculoplasty is a type of this procedure that uses a specific laser to increase fluid drainage, thus reducing pressure. This method causes less damage and structural change than older laser techniques, but it doesn’t typically reduce eye pressure as much as surgery does. Therefore, it’s often not as effective as other treatment options for primary open-angle glaucoma, especially in younger patients with a structural abnormality in the drainage angle of the eye.
What else can Juvenile Glaucoma be?
There are also other conditions that might be mistaken for juvenile open-angle glaucoma because they have similar symptoms. These include:
- Glaucoma present at birth (Congenital Glaucoma)
- Glaucoma caused by steroids (Steroid-induced Glaucoma)
- Glaucoma caused by an injury (Traumatic Glaucoma)
- Glaucoma related to inflammation (Inflammatory Glaucoma)
- Other forms of the most common type of glaucoma (Primary Open-angle Glaucoma)
What to expect with Juvenile Glaucoma
The outlook for young patients with open-angle glaucoma is usually positive if the condition is identified and treated early. In a study done in Japan, out of 47 cases of juvenile glaucoma, 21 (45%) had normal vision, while 13 (28%) were in an advanced stage, mainly due to a delay in diagnosis.
Even if the patient requires a type of eye surgery known as a trabeculectomy, it’s possible to reduce the pressure in the patient’s eye and stop any further loss of their visual field.
Possible Complications When Diagnosed with Juvenile Glaucoma
If glaucoma is not treated in time, it can lead to serious issues like impaired vision and even blindness. Unfortunately, glaucoma can often go undiagnosed because it doesn’t always show symptoms until it has progressed significantly.
There can also be other complications based on the type of surgery carried out to treat glaucoma. These can include:
- Redness or pain in the eye
- Cornea irritation
- Continued high eye pressure
- Low eye pressure, or hypotony
- Fluid accumulation under the retina, known as choroidal effusions
- Bleeding over the retina, known as suprachoroidal hemorrhages
- Infections
- Cataracts, which can either begin to form or progress if they’re already present
Preventing Juvenile Glaucoma
Even though juvenile open-angle glaucoma is not widely seen, it’s paramount that both patients and their parents are well-informed about this condition. Given that individuals with this condition have a higher probability of experiencing issues with vision, including blindness, gaining a clear understanding of the disease and its symptoms is essential. Catching this condition early on and starting treatment as soon as possible greatly improves the chances of maintaining good eyesight and avoiding permanent loss of visual field.