Incidence, Pathophysiology, Complications, and Management of Positive Vitreous Pressure During Penetrating Keratoplasty: A Literature Review.

Positive vitreous pressure (PVP) is common during open anterior segment surgery and penetrating keratoplasty (PKP) has a reported incidence rate of 40-50%. Despite adequate perioperative preventive precautions, positive pressure occurs during surgery and optimum management of PVP is required to avoid serious complications. Many pharmacological and mechanical approaches can be employed either preoperatively or intraoperatively to decrease vitreous pressure. Surgical techniques such as graft-over-host technique, the modified graft-over-host technique, techniques employed mattress sutures and needle, or Vitreous aspiration or vitrectomy can be effectively used to manage intraoperative PVP during PPK. This article reviews the incidence, risk factors, prevention, and different approaches to the management of positive vitreous pressure during PKP to analyze the available evidence in order to improve the safety profile of PKP and prevent sight-threatening complications.