The eye is filled with a fluid called vitreous gel. In order to perform certain surgeries and procedures on the eye, a vitrectomy must be done to remove this vitreous gel. Vitrectomy surgeries are done by ophthalmologists trained to perform retina surgery. These eye doctors are specialized and have extensive training in retina treatment. If you or someone close to you needs a vitrectomy, you probably have many questions about the entire process. Read on to learn more about this procedure and what to expect before, during, and after it’s done.
What is Vitreous Gel?
Vitreous gel, also called the vitreous humor or simply the vitreous, is a clear substance that is jelly-like in consistency. It occupies the space in the eyeball between the lens and the retina.
This fluid-filled space comprises approximately two-thirds of the eye. The vitreous gel is mostly water, with the remaining one percent of its composition consisting of collagen fibers, hyaluronic acid, glucose, and other ions.
In normal circumstances, the vitreous gel adheres to the retina, blood vessels, and the vitreous base.
Function of the Vitreous Gel
Vitreous gel and other eye fluids mainly serve to hold the shape of the eye. The vitreous gel must remain clear so that light can easily pass through it to reach the retina.
The retina is the light-sensitive tissue that is found lining the back of the eye. Its purpose is to receive light rays and convert them into impulses that travel through the optic nerve. These impulses are then interpreted by the brain as images.
When the vitreous gel is intact and clear, light can pass through the eye and to the retina with no problems. Sometimes, however, there are problems within the vitreous gel that can impede the passage of light through the eye.
When is a Vitrectomy Necessary?
While the vitreous is necessary for optimal vision, sometimes issues may arise that call for the removal of the gel.
These issues may involve the vitreous gel itself or other eye structures that cannot be corrected when the vitreous is in the way.
When there is a bleed into the vitreous gel that does not clear on its own, vision can become blurred. This is called a vitreous hemorrhage. This can happen at any age but is most common after forty.
Vitreous hemorrhage can be caused by:
- Severe eye injury
- Proliferative diabetic retinopathy
- Macular degeneration that is age-related
- Retinal vein occlusions
- Various retinal blood vessel diseases
There are instances where such hemorrhages can clear up on their own. However, this isn’t always the case. When a vitreous hemorrhage is severe or does not clear and affects vision, a vitrectomy is recommended.
Retinal Detachment Repair
Retinal detachment is when the retina is pulled away from its normal position. If left untreated, retinal detachment can cause vision loss that is permanent. If there are small breaks or tears where the retina attaches, detachment can occur without treatment.
The Three Types of Retinal Detachment
Rhegmatogenous detachment occurs when a tear or break in the retina lets fluid get underneath the retina. This collection of fluid causes the retina to separate from the retinal pigment epithelium.
The retinal pigment epithelium is the pigmented cell layer that makes up the outer blood-retinal barrier. This layer transports nutrients to the retina, absorbs light, provides photo-oxidation protection, disposes of old photoreceptor membranes, and secretes important factors for retinal structure integrity.
Rhegmatogenous detachments are the most common type of retinal detachments.
With tractional detachment, the contraction of scar tissue on the retina’s surface causes the retinal separation from the retinal pigment epithelium (RPE). Tractional detachment is less common than rhegmatogenous detachments.
Exudative detachment is caused by retinal diseases and sometimes injury. These causes include inflammatory disorders, eye injury and severe eye trauma.
With exudative detachment, fluid leaks into and accumulates inside the region beneath the retina, causing separation. It differs from rhegmatogenous detachment in that there were no breaks or tears in the retina that allowed fluid movement and accumulation.
Exudative detachment can be caused by:
- Blocked retinal veins that cause serum leakage through vessel walls into the retina
- Posterior scleritis
- Blood pressure imbalances
- Kidney dysfunction
- Choroidal Melanomas
- Metastatic choroid cancer
These are among a number of conditions that cause subretinal fluid accumulation and subsequent retinal detachment. In the case of a detachment, the vitreous gel is removed so that repairs can be made to the detached areas.
Diabetic retinopathy is an eye disease that affects those who are afflicted with diabetes.
The high blood sugar levels that are commonplace with the disease damage the blood vessels of the retina, causing blockage, edema, leakage, and scar tissue deposits.
Additionally, new, abnormal blood vessels may grow on the retina. This is called neovascularization. These new vessels are very fragile and may bleed into the vitreous gel. Depending on the severity, the bleed can cause bothersome floaters or blocked vision. All of these changes can cause total or partial vision loss when left unaddressed.
Proliferative vitreoretinopathy occurs when scar tissue forms on or beneath the retina after a retinal detachment. This scar tissue prevents the retina from properly healing after detachment or tearing.
The problematic scar tissue pulls on the retina, causing it to pucker and fold. This leads to distorted or blurry vision.
A vitrectomy allows for removal of vitreous cells that may have otherwise progressed to more advanced stages of proliferative vitreoretinopathy (PVR). It also allows access to proliferating membranes that would also further PVR progression. Scar tissue can be peeled off during the procedure, allowing retinal healing.
Endophthalmitis is an inflammatory condition of the vitreous humor and/or the aqueous humor. It’s usually caused by an infection. The infection may be endogenous or caused by the spread of organisms from another infection site. If it is an exogenous infection, this means that the infection was directly introduced into the eye through surgery or by foreign bodies, blunt trauma, or penetrating injury.
Noninfectious endophthalmitis can result from causes such as retained pieces of the original lens after a surgical procedure or from various toxins.
If all or part of the natural lens accidentally falls into the vitreous gel during cataract surgery, it can cause inflammation and pressure. The result is noninfectious endophthalmitis that requires vitrectomy for lens material removal.
The macula is the area at the center of the retina that allows us to sharply see what is at the center of our field of vision. It’s vastly important because it allows us to participate in activities such as reading, writing, driving, and seeing fine detail. It also allows us to interpret and appreciate color.
A macular hole is a break in the macula. The condition is usually age-related, occurring in those over sixty years old. A hole can also occur in other eye disorders, such as extreme nearsightedness, eye injury, and retinal detachment.
The macular hole’s location and size will determine the degree to which a person’s vision will be affected. In addition to the loss of detailed, central vision, untreated macular holes can lead to retinal detachment.
Repair by Vitrectomy
When repaired by vitrectomy, the vitreous gel is removed from the eye. This stops it from pulling on the retina.
The vitreous is then replaced with a bubble that contains an air and gas mixture. This bubble serves as a temporary bandage that will hold the edge of the macular hole in place so the break can heal.
When the vitreous pulls away from the retina, sometimes the retina’s surface is damaged and scar tissue forms as the retina heals. When this scar tissue forms over the macula, central and detailed vision can be affected.
Vitreous opacities, or floaters, appear as dots and strands in the eye. While their underlying causes are different, they may indicate a more serious condition.
As A Diagnostic Tool
Sometimes a vitrectomy is performed in order to diagnose a disease or condition. Removing some of the vitreous gel allows for further examination and a proper diagnosis.
This procedure can help diagnose and treat infections, inflammation, and certain types of cancer.
The Vitrectomy Procedure
The vitrectomy procedure involves the use of tiny tools to remove vitreous gel, make repairs, and fill the eye with gas, saline solution, or oil. A vitrectomy is usually an outpatient procedure. Only on rare occasions does the procedure require an overnight stay in a medical facility.
Ophthalmologists will either use local or general anesthesia when performing a vitrectomy.
An Explanation of Tools and Cuts
During the procedure, the eye receiving the operation will be prepared with an antiseptic solution, while the other eye is covered for protection.
The eye is held open with a small eyelid speculum and three small openings, or cuts, are made. These openings are made in the pars plana, which is the white part of the eye. This white part is also called the sclera.
One opening is for an infusion line that will make sure that eye pressure remains constant.
The next opening is for a cutting device called a vitrector that aspirates the vitreous gel.
The third opening is made to accommodate a tiny light source and microscope so the inside of the eye is illuminated and easily viewed.
Other surgical instruments are usually on hand in case there is a bleed to be cauterized or scar tissue that needs to be removed during the procedure.
Filling the Eye
After repairs are completed and the eye is filled, the openings are usually sutured with small, absorbable stitches. If the openings were “suture-less,” they are small enough to reseal on their own without sutures. Antibiotic injections may be used to prevent infection.
When gas or saline is used, the eye’s natural fluids will replace the filler in time. When a silicone oil is used, it may need to be removed at a later date.
Post-operative recovery and care will vary depending on the patient and the condition treated. There are some general recovery instructions that may be given after the procedure.
You may be instructed to use anti-inflammatory and antibiotic drops prescribed by your ophthalmologist after your eye patch is removed as an extra measure to prevent infection, inflammation, and pain.
You may be instructed to wear a plastic eye shield during sleep for the first week following your surgery. The shield should be worn in the shower for the first three days after the procedure.
You may want to apply ice compresses to your eye for relief of discomfort if your ophthalmologist has advised you to do so.
Avoid Bending, Lifting, and Strenuous Activity
Bending over, lifting heavy objects, and strenuous activity can cause pressure changes in the eye because of blood pressure shifts. These activities may also be somewhat jarring. They should all be avoided for at least a week after your procedure.
For procedures done to correct certain conditions such as a macular hole, head positioning after a vitrectomy is important. This is because the injected bubble needs to be in the right position to able to put pressure in the proper place to allow for healing.
Possible Complications After a Vitrectomy
As with any surgical procedure, there are risks and complications to consider. Though this procedure is fairly low risk, it’s important to know about problems that may arise.
Possible but rare complications after a vitrectomy include:
• Cataract development
• High or low pressure inside the eye, especially for patients with glaucoma
• Retinal detachment
• Infection within the eye
• Additional bleeding into the intraocular cavity
Advances in vitrectomy procedure techniques, surgical instruments, and a better understanding of conditions affecting the vitreous and the retina have made this procedure extremely successful.
Eye Health: When a Vitrectomy is Recommended
Your ophthalmologist will provide you with a thorough examination and any test necessary when determining if a vitrectomy is the right treatment for you.
At Magruder Eye Institute, our team of doctors provides you with quality, specialized eye care. Contact us today for more information and feel free to explore our informative website.