Retinectomy refers to the excision (removal) of the retina. During retinectomy, the complete peripheral retina may be excised, but the central retina is untouched as its function is more important for vision. Excising only the peripheral retina also prevents postoperative proliferation and traction.
The following are the surgical steps to perform a retinectomy:
It has been reported that cases of retinectomy with use of silicone oil in severe PVR were successful with minimal risk of recurrence.
In cases of larger circumferential tears, liquid perfluorocarbon (PFCL), a material with high-specific gravity and low viscosity is used during retinectomy surgery to stabilize the retina. PFCL, essential for the management of large retinal tears, is injected over the optic disc (circular area at the back of the eye where the optic nerve connects to the retina). The aim of PFCL injections is to assess the residual tractional elements (elements pulling the retina) and stabilize the retina for retinectomy and excision of peripheral retina as well as drainage of subretinal fluid. By effectively stabilizing the retina, PFCLs facilitate the repair of complicated retinal detachments due to proliferative vitreoretinopathy (PVR). At the end of retinectomy, PFCL is exchanged for either gas or silicone oil.
Vitrectomy is the surgical procedure that is widely used in the treatment of retinal detachment with large tears.
The surgery may require an overnight stay or sometimes it is done as an outpatient procedure that lasts for 2-3 hours. Vitrectomy is performed under local anaesthesia with an operating microscope. Three small incisions are made in the sclera (white outer wall of the eye) to infuse fluid in order to maintain the shape of the eye, for a fibre optic light and to insert the surgical instruments. The procedure involves the removal and replacement of the vitreous (clear gel that fills the back of the eye) with special saline solution which resembles the natural vitreous in the eye. Once the vitreous is removed, the retina can be accessed to treat the detachment by removing the scar tissue that is pulling the retina away from the underlying layers of tissue.
After the removal of vitreous gel, the fluid that has collected underneath the retina is removed to flatten the retina into normal position. Laser therapy (intense laser beam) or cryotherapy (freezing temperatures) is then used to scar and seal the retinal tear aiding to keep the retina permanently attached. A gas bubble or silicone oil is injected into the vitreous cavity (the cavity located behind the lens of the eye and in front of the retina containing the vitreous) to hold the retina in place while the scars from the laser and/or cryotherapy heal.
With newer surgical techniques and instrumentation, the surgery can be performed through tiny “self-sealing” incisions without the need for sutures. Surgical recovery generally takes about 6 weeks and vision recovery a little longer.
Scleral buckling is a common treatment modality to fix a retinal detachment. The sclera (outer white part of the eye) is buckled (indented) by sewing silicone, rubber or a semi-hard plastic band to the surface of the eye. The band applies pressure onto the sclera in the area where the retina is detached from its underlying layers. The band works by pushing the sclera towards the middle of the eye so that the torn retina lies against the wall of the eye, counterbalancing any force that pulls the retina away from its place. The band is left in place permanently and is not noticeable after the surgery.
Vitrectomy refers to the removal and replacement of the vitreous (clear gel that fills the back of the eye) with saline. In this procedure, the vitreous is removed so that the doctor can access the back of the eye. The retina is then treated by removing the scar tissue that is pulling the retina away from the underlying layers of tissue.
Vitrectomy generally involves three small incisions in the sclera (outer white part of the eye). But with newer surgical techniques and instrumentation, the surgery can be performed through tiny “self-sealing” incisions without the need for sutures; the procedure is therefore called sutureless vitrectomy. This new technique uses special equipment that enables the surgeon to reach the vitreous using cuts that are very small that close automatically without requiring sutures. This procedure does not cause excess trauma, redness, watering and post-operative discomfort, all of which can occur with the conventional procedure. The overall time required for surgery is also less and the patient can resume his/her routine work earlier.
Retinal detachment usually requires surgery (vitrectomy) during which a tamponade agent is used. Tamponade is the material that is injected into the vitreous cavity (the cavity located behind the lens of the eye and in front of the retina) to hold the retina in place. A tamponade is often needed to reduce the rate of recurrent retinal detachment. Tamponades are various gases or silicone oils that not only hold the retina in place but temporarily seal the retinal tears. These tamponade agents help in the reattachment of the retina by reducing the rate at which the fluid flows between the retina and the underlying layers through open retinal tears. When gas is used, the body will reabsorb it, however, if silicone oil is used, this will need to be removed at a later date once healing has occurred.
Silicone oil is one of the tamponade agents used during the surgery for retinal detachment. This tamponade is particularly useful when retinal traction (pulling on the retina) cannot be completely relieved and for patients who are unable to maintain the head positioning required for a gas tamponade of the retina. Advantages of silicone oil are that the patients can fly post-surgery unlike patients with a gas tamponade where flying should be avoided until the gas bubble has dissolved. Also, only minimal follow-up is required and the patient can see through the oil while the retina is being stabilized.
C3F8 (Octafluoropropane) / SF6 (Sulfur hexafluoride) are gases that are commonly used as tamponade agents during surgery to repair a retinal detachment. The high surface tension between gas and fluid facilitates the effective closure of a retinal tear; and enables the retinal pigment epithelium (RPE: the layer below the retina) to absorb any fluid that remains in the sub retinal space (the space between the retina and retinal pigment epithelium). This helps the reattachment of the detached retina.