What is PPV Surgery for the Eye?
Pars plana vitrectomy (PPV) is a surgical procedure that removes the vitreous gel from the eye through small incisions in the pars plana (the flat part of the eye between the iris and retina) to treat various vitreoretinal disorders affecting the vitreous, retina, or choroid 1, 2.
Surgical Technique
PPV is performed using small-gauge instruments—typically 23-gauge, 25-gauge, or 27-gauge systems—combined with local monitored anesthesia 1. The procedure involves:
- Core vitreous removal through cannulated sclerotomies (small incisions)
- Separation of the posterior hyaloid (the back layer of vitreous) from the optic nerve and macula using aspiration, an illuminated pick, or forceps
- Peripheral vitreous shaving near the cannulas to minimize risk of retinal breaks
- Additional maneuvers as needed: membrane peeling, use of liquid perfluorocarbon, removal of traction and opacities, laser photocoagulation, and in severe cases, retinotomies or retinectomies 1, 2
Surgeons may use off-label dyes (indocyanine green, trypan blue) or triamcinolone during surgery to better visualize the internal limiting membrane and remaining vitreous 1.
Common Indications
PPV treats a wide range of conditions including:
- Epiretinal membrane (ERM) and vitreomacular traction (VMT) causing visual distortion and decreased vision 1
- Rhegmatogenous retinal detachment (retinal tears with detachment) 3, 4, 5
- Tractional retinal detachment 6
- Vitreous hemorrhage 7, 8
- Complications of proliferative diabetic retinopathy 8
- Diagnostic purposes in uveitis or suspected intraocular lymphoma 6
Expected Outcomes
Visual outcomes are generally favorable when appropriately indicated. For epiretinal membrane surgery, studies show that 73-82% of patients experience improved vision, with mean visual acuity improving from approximately 20/120 preoperatively to 20/40 postoperatively 1. However, complete resolution of symptoms is not guaranteed—some patients may have persistent distortion, and in rare cases, vision may worsen 1.
Major Complications
The majority of phakic (non-cataract) patients develop progressive nuclear cataract following vitrectomy, which is the most common complication 1. This occurs at variable rates and may be age-dependent 1.
Other complications include:
- Retinal breaks and detachment: Approximately 1% with modern 23-gauge systems, compared to 3.5% with older 20-gauge systems 1
- Endophthalmitis: Less than 0.05% of cases 1
- Macular hole formation: Potential complication specific to ERM/VMT surgery 1
- Transient hypotony (low eye pressure) and choroidal detachment: More common with smaller gauge systems 9
- Intraocular pressure changes: Particularly concerning in glaucoma patients 1
Postoperative Management
Patients require examination on postoperative day 1 and again at 1-2 weeks, with earlier or more frequent visits if concerning findings develop 1. Critical monitoring includes:
- Intraocular pressure measurement
- Wound site inspection for leaks
- Assessment for retinal complications
- Patient education on retinal detachment warning signs
- Precautions regarding intraocular gas if used as tamponade 1
Important Caveats
PPV is elective rather than urgent surgery for conditions like ERM/VMT 1. The decision to proceed should be based primarily on how much the visual dysfunction impacts the patient's activities of daily living—specifically reading and driving ability—rather than imaging findings alone 1.
Small-gauge PPV does not automatically mean "minimally invasive"—ophthalmologists must not pursue smaller incisions while ignoring surgical principles, underestimating risks, or choosing inappropriate indications 10. The procedure requires specialized vitreoretinal surgical expertise and equipment 1.