Retinoschisis (Separated Retina)

What is Retinoschisis (Split Retina)?

Retinoschisis is an eye condition that can affect both the young and old, males and females. Retino- refers to the retina, while -schisis refers to split. 

While retinoschisis is a commonly used name, eye doctors may also refer to it as:

• Congenital Retinal Cyst
• Congenital Vascular Veils in the Retina
• Giant Cyst of the Retina
• Vitreoretinal Dystrophy

If you have retinoschisis, it means the eye’s retina (at the back of the eye) has split into two layers. When this happens, the disorder can cause slow vision loss: 

• Center of vision (fovea). In this case, a person with impaired central vision can have visual acuity (sharpness) between 20/30 and 20/200. The decreased vision happens because tiny cysts (saclike blisters) form between the separated layers of the retina and damage nerve tissue. When this occurs, glasses or contact lenses are not a possible solution in improving visual acuity. 
• Peripheral vision. A person with retinoschisis can lose some peripheral vision if the inner layer of nerve cells breaks off from the outer layer of cells. 

Additionally, there are different types of retinoschisis. The two primary categories include senile retinoschisis and juvenile retinoschisis. The former can affect both males and females in middle age (although possibly earlier), while the latter impacts boys and young males primarily. 

For a proper diagnosis, care, and follow-up of the condition, it is crucial to visit an eye care specialist. Different diagnostic tools are available, and some people with retinoschisis may be eligible for specific treatments. 

Retinoschisis may be confused with other eye diseases like amblyopia (lazy eye). If a family member has retinoschisis and you have been diagnosed with amblyopia, you should speak with an ophthalmologist experienced in retinoschisis diagnosis to rule it out. 

Types of Retinoschisis

To reiterate, two primary forms of retinoschisis are possible: senile and juvenile retinoschisis. However, specific clinical characteristics and health conditions can lead eye doctors to diagnose more specified forms of retinoschisis. 

1. Degenerative Retinoschisis

Health professionals may use degenerative retinoschisis or acquired retinoschisis to describe senile retinoschisis. 

This eye disorder affects both males and females in middle age. However, it can also appear in some people at an earlier age. A person with degenerative retinoschisis may be asymptomatic.

Often, the diagnosis is incidental and can occur after a referral to a retinal specialist under the presumptive diagnosis of retinal detachment (loosening of a thin layer in the retina).  

In typical cases of degenerative retinoschisis, there is a shallow rise of inner retinal layers, and disease progression is not typical. Many times, it involves the peripheral retina. Many people with this eye disorder do well and require only follow-up. 

According to the American Academy of Ophthalmology (AAO), the prevalence rate of degenerative retinoschisis is 4% of people aged 40 years and up. 

2. X-linked Juvenile Retinoschisis (XLRS)

Juvenile retinoschisis (or congenital X-linked retinoschisis) is a hereditary eye disorder that affects males. It is a genetic disease of the retina that almost always affects both eyes (bilateral). 

The eye disorder impacts males more often than females. The former group only has one X chromosome, which means the mutation or abnormal gene on that chromosome can trigger the onset of juvenile retinoschisis. Even if females have the mutation on an X chromosome, the presence of a second X chromosome lets them typically retain normal eyes. 

When a person develops juvenile retinoschisis, vision worsens early in life. Visual acuity may be between 20/60 and 20/120. However, there comes the point when vision usually stabilizes until another decline in vision occurs in late adulthood. In severe cases, decreased visual acuity due to this eye disorder may be considered legal blindness. 

Juvenile retinoschisis is estimated to impact one in 5,000 to 25,000 people and is one of the leading causes of juvenile macular degeneration.  

3. Tractional Retinoschisis

Tractional retinoschisis is an eye disorder that may be confused with tractional retinal detachment. However, some unique characteristics define tractional retinoschisis. 

For example, people with this condition will have a tractional (pulled or drawn up) elevation of the retina. This layer will be transparent, and pigment lines will not develop. While holes can be present in the raised retina, no change in its contour will occur. 

People with diabetes or sickle cell disease may have an increased risk of tractional retinoschisis.

4. Exudative Retinoschisis 

Retinoschisis can be subclassified into exudative retinoschisis or non-exudative retinoschisis. If a person has exudative retinoschisis, there is a lipid (fat) in color fundus photography and clinical examination. Color fundus (retinal) photography uses a type of camera to collect color images of the condition of the eye’s interior surface. 

Exudation (the presence of lipids) could be more likely in those who are older. 

What Causes Retinoschisis? 

Retinoschisis can have two primary causes:

• Genetics. Retinoschisis can occur in males who have a mutation or abnormal gene on the X chromosome. While females can be carriers of the mutation, it is not common for them to develop the eye disorder. One of the two X chromosomes in females is inactivated (usually that with the mutation), so there is no consequential clinical manifestation. Males with X-linked disorders like retinoschisis will pass the abnormal gene to all of their daughters. 
• Degeneration. It is uncommon to find this eye disorder among people younger than 40. Degenerative retinoschisis often occurs in people in their 50s, 60s, or 80s. Also, males and females develop the eye disorder in equal numbers. 

Is Retinoschisis Hereditary?

Yes. Retinoschisis can be hereditary. 

Juvenile retinoschisis is the genetic form of the retinal disease. In this case, males are those most affected by the condition. However, females can be carriers of the recessive trait.  

All males with this congenital retinoschisis will pass along the X chromosome with the abnormal gene to their daughters. 

Signs & Symptoms of Retinoschisis

A central database called the Human Phenotype Ontology (HPO) provides a detailed and up-to-date list of symptoms related to retinoschisis. 

According to the HPO, approximately 80 to 90% of people with juvenile retinoschisis will have:

• Abnormal eye movement 
• Abnormal vision (a decline in foveal or peripheral vision)
• Cataracts (clouding of the lens of the eye)
• Glaucoma (an ocular disease in which the optic nerve is damaged)

According to the HPO, approximately 30 to 79% of people with juvenile retinoschisis will have:

• Macular atrophy (deterioration of the macula, which is the central part of the retina call)
• Retinal pigment epithelial atrophy (weakening of the pigment tissue that lines the retina)

How Serious is a Split Retina?

A split retina is another term used to describe retinoschisis. 

It is not common for retinoschisis to progress or result in retinal detachment. However, if there is disease progression, symptoms may appear before the loss of central vision, including:

• Flashing lights 
• Loss of peripheral vision 
• Floaters 

Affected individuals with retinoschisis should visit their local eye clinic at least once a year to make sure the eye disorder remains stable. 

Potential Complications of Retinoschisis 

Can Retinoschisis Cause Blindness?

Yes. In severe cases, retinoschisis can cause blindness. 

Severe complications, such as retinal detachment or vitreous hemorrhage (blood vessel leakage in the retina), can result in permanent vision loss.

Finally, the risk of legal blindness is higher in those with juvenile retinoschisis. 

Is Retinoschisis Progressive?

In cases of senile retinoschisis, the eye disorder rarely progresses. 

In cases of juvenile retinoschisis, vision often decreases at a young age before becoming stable during early or mid-adulthood. However, it is common for people with juvenile retinoschisis to experience another decline in vision when they’re in their fifties or sixties. 

Diagnosis & Treatment for Retinoschisis

An eye care specialist will use different diagnostic approaches for retinoschisis, including:

• Optical coherence tomography (OCT). This test uses light waves to create images of the retina. 
• An electroretinogram (ERG). It measures light-stimulated electrical impulses to determine if there’s an impairment of retinal functioning. 
• Ultrasonography or ultrasound. This diagnostic tool can help view abnormalities if the eye has suffered a hemorrhage. 

Concerning treatment, it can vary according to the form of the eye disorder. 

For example, people with senile retinoschisis do not usually need medical treatments. It is recommendable, however, to undergo annual eye examinations to make sure the condition remains stable. 

For those with juvenile retinoschisis, health professionals may use carbonic anhydrase inhibitors (a type of medication) to help reduce cystic spaces. If there is bleeding within the eyeball, laser or cryotherapy (cold) may be an option to cut off the damaged retinal area. Nonetheless, most people with juvenile retinoschisis keep functional vision. 

Finally, genetic counseling may be worth considering for families of children with juvenile retinoschisis. 

Vitamin A has not been conclusively proven to help in retinoschisis.