The vitreous is a clear fluid with a gelatinous consistency that fills the central cavity of the eye. It constitutes about 2/3 of the total volume of the eye. Some problems affecting the back of the eye may require surgical removal of the vitreous: vitrectomy.
During this type of surgery, the surgeon removes part or all of the vitreous body from the center of the eye and replaces it with a solution of saline water or with a bubble of gas or oil.
Removal of the vitreous is necessary to allow the surgeon to perform treatments that cannot be performed with the fluid in place. Thanks to vitrectomy, the surgeon can in fact correct serious retinal detachments, cure large lacerations at the level of the retina, remove hemorrhages of the vitreous body, remove scar tissue that, formed in excess, wrinkles and tears the retina causing vision problems.
Vitrectomy is also essential for removing a foreign object stuck in the eye from an injury.
Who Should Undergo Vitrectomy
The factors for which such an intervention may be necessary are manifold. The ophthalmologist can recommend a vitrectomy in the presence of these diseases or conditions:
- diabetic retinopathy, with bleeding or scar tissue that affects the retina or the vitreous gel;
- some forms of retinal detachment (i.e. when the retina lifts from the back of the eye);
- macular hole (a hole or a tear in the macula);
- macular pucker (the presence of abnormal wrinkles or folds in the macula);
- an eye infection called endophthalmitis;
- severe eye injury;
- some problems that arose during cataract surgery.
How a Vitrectomy is Performed
Vitrectomy is usually performed in an outpatient surgery center and requires, depending on the type of intervention, a local or general anesthesia. The operation can last from one to a few hours.
During surgery, the ophthalmologist makes a small cut in the white part of the eye, the sclera. Based on the diagnosis, the surgeon performs one or more of these steps: removes all the clouded vitreous scar tissue from the retina, any cataracts or foreign body.
The mass that has been removed from the eye is replaced with a saline solution needed to help the retina stay in its correct position; this fluid, constituted for 99% by natural vitreous fluid and by a very small part of gelling substance, is then naturally replaced by the body in the course of a few hours.
In some cases, depending on exactly what the starting problem is, a special synthetic gas or silicone oil can be applied inside the eye. The synthetic gas is absorbed over time and replaced with the natural fluid of the eye called aqueous fluid. If silicone oil is used instead of gas, an operation may be necessary to remove it later, but in most cases it can remain positioned in the long term.
After surgery, the patient is monitored while resting and recovering from anesthesia.
Precautions After Vitrectomy
After the operation, the ophthalmologist prescribes a pain reliever and eye drops to be used for up to 4 weeks. It will be necessary to wear a protective patch on the operated eye for a few days.
Special precautions are necessary if the vitreous body has been replaced with a gas bubble. In this case, the patient must remain in a prone position (or in a lateral position) for a certain period of time. It is very important to follow these instructions to heal properly.
Since a rapid change in altitude can affect the size of the gas bubble, flying by plane is not recommended until it has disappeared.
The quality of vision regained after surgery depends on previous eye conditions and can vary between a full 10/10 vision and a vision sufficient to move safely.
Advanced Vitrectomy Techniques: Greater Safety and Less Invasiveness
The surgical instruments used for the vitrectomy operation evolve and improve over the years and are today more versatile and smaller than ever.
The vitrectomy is performed by introducing instruments of very small caliber through the scleral wall of the eye to access the vitreous cavity. Normally, three scleral incisions (sclerotomies) are made: one to introduce an infusion cannula that maintains constant eye pressure, a second to illuminate the operating field by allowing the intraocular light from an optical fiber to penetrate, and the last to introduce the vitrectome, the tool used to cut and suck the glass gel.
The ideal size of these instruments is a fundamental aspect: most surgeons have passed over the last twenty years from the use of conventional 20-gauge vitrectomy systems (i.e. suction needles and cannulas of 0.9 mm in diameter) to systems with 23 or 25 Gauge (0.5 mm), which are the main indication in macular surgery such as pucker, macular hole, and diabetic macular edema.
Minimally Invasive 27 Gauge Vitrectomy
The 27 Gauge system (0.3 mm in diameter) is the latest addition. In addition to cases of pediatric surgery where the use of reduced instrumental gauges is essential, it is particularly suitable for patients diagnosed with epiretinal membranes, retinal detachment or proliferative diabetic retinopathy with vitreous hemorrhage.
The 27 Gauge minimally invasive vitrectomy offers satisfactory results in a wide variety of cases and has significant advantages both during surgery and in the postoperative course:
- the decrease in the diameter of the scleral incisions in the eye in fact allows to minimize the manipulation of the eyes during surgery;
- the decrease in corneal lesions makes anatomical and functional recovery faster;
- the inflammatory reaction in the anterior chamber after surgery is minor;
- in many cases sutures are not necessary to close the accesses made (the smaller corneal incisions, called “sutureless” or “self-sealing”, are more comfortable and safe for the patient).
Combined Phaco-Vitrectomy System
A further vitrectomy technique involves the use of phacoemulsification (FACO), which consists the fragmentation of the vitreous body by ultrasound and the aspiration of the same through a small probe.
The benefits of combining phacoemulsification and vitrectomy in one surgical procedure, known as phaco-vitrectomy, are truly remarkable and include minimizing surgery-related tissue trauma, an acceleration of functional recovery, and a general increase in comfort of the patient.
In particular, phaco-vitrectomy should be the preferred approach to reduce the high rate of cataract development after vitreoretinal surgery and to improve the patient’s previous visual acuity.
Although today the sophisticated instruments available to surgeons make the surgery extremely safe and effective, a careful preliminary visit is always necessary to evaluate costs and benefits and choose the best type of operation for the health of your eyes.