Pars plana vitrectomy (PPV) is a surgical technique introduced by Robert Machemer that provides access to the posterior segment of the eye, enabling the treatment of various vitreoretinal diseases.
PPV requires a great deal of technical skill and knowledge to ensure good outcomes, restoring vision and improving the quality of life in patients suffering from many vitreoretinal diseases.
While PPV can be highly beneficial, it is also associated with potential complications. These complications can cause severe patient morbidity and blindness, making it essential for clinicians to have thorough knowledge and understanding of the procedure and post-operative management.
PPV can be considered for a variety of clinical scenarios, as it enables the operating surgeon to access both the vitreous and retina. Let's explore the common indications for PPV based on the type of pathology affecting the vitreous and/or the retina.
One of the most common indications for PPV is when there is pathology that opacifies the vitreous, leading to reduced vision. For instance, non-clearing vitreous hemorrhage caused by diseases such as proliferative diabetic retinopathy, trauma, retinal detachment (RD), intraocular tumors, and retinal vascular diseases.
Modern day pars plana vitrectomy (PPV) is a common procedure employed by vitreoretinal surgeons to gain access into the posterior segment of the eye. This allows for the treatment of many conditions ranging from vitreous debris (floaters) and epiretinal membranes, to retinal detachments, subretinal hemorrhages, and intraocular tumors.
Since the development of the modern-day three-port vitrectomy system by Conor O’Malley and Ralph Heintz in 1974, there have been multiple advances in instrumentation. These advancements include smaller gauge instruments, vitrectomy machines that provide higher cut rates and more stable intraocular pressures (IOPs), and visualization systems, most recently with "heads up" three-dimensional viewing systems with 3D glasses.
It is necessary to provide education to patients who undergo this procedure and to participate in their care. Obtaining informed consent from the patient — where risks, benefits, and alternatives to surgery are discussed — is often the most important part of the procedure.
During the discussion prior to surgery, patients must be made aware of what to expect before, during, and after the procedure. Important questions about attire, dietary restrictions, medications, anesthesia, procedure duration, recovery period, post-operative positioning, and visual prognosis should be addressed.
Vitreoretinal surgical cases may require very delicate movements in close proximity to the surface of the retina. Therefore, limiting eye movement and patient comfort are addressed, in most scenarios, via a retrobulbar block to obtain akinesia and anesthesia.
Now the patient is ready for surgery. After entering the OR, everyone in the room pauses to agree on the patient, the eye being operated on, and the procedure being performed. The actual surgery part of this procedure is broken down into four steps: gaining access, performing the vitrectomy, performing the indicated procedure, and closing the incisions.
If there is no air or gas bubble placed in the eye, then there are no head positioning requirements. However, if any amount of gas or air is placed in the eye, then positioning is needed. The location of the pathology in the retina will determine what position and for how long the positioning is required.
Modern-day retina surgery is a wonderful tool that physicians can use to improve, maintain, and save vision in patients who previously were destined for blindness. Understanding the basics of vitrectomy surgery can greatly improve the quality of care provided to the patient by all members involved in the patient’s care.