Influence of endotamponade on anterior chamber depth and refractive outcome after combined phacovitrectomy: case-control study

Abstract

Purpose: To compare the changes in the anterior chamber depth (ACD) and in the refractive outcomes after combined phacovitrectomy with respect to the endotamponade (balanced salt solution, air, sulfur hexafluoride [SF6, gas]). Setting: Department of Ophthalmology, University Hospital Ulm, Ulm, Germany. Design: Retrospective, longitudinal case-control study. Methods: 160 eyes of 160 patients were included in the study. 120 eyes underwent phacoemulsification with in-the-bag implantation combined with vitrectomy and were divided into 3 groups according to tamponade (balanced salt solution, air, gas). 40 control eyes with cataract surgery only were included. Further inclusion criteria were uneventful surgery, no postoperative complications and absence of corneal pathology. Endpoints were ACD as measured by swept-source optical coherence tomography-based biometry (IOLMaster 700) preoperatively, 1 to 2 days and 6 weeks postoperatively and refractive prediction error (PE) using the Barrett and Haigis formulas. Results: Within the first 2 days after surgery the ACD was shallower in the eyes left with gas or air tamponade, when compared with balanced salt solution or cataract surgery alone (P < .001). This effect diminished 6 weeks later, and all eyes reached comparable ACD (P = .396). The refractive PE was slightly, but statistically significantly higher in the gas group when compared with cataract surgery alone (P = .012 for Barrett, P = .006 for Haigis). Conclusions: The resulting ACD after combined phacovitrectomy was independent of the tamponade used, but a gas-tamponade was associated with a higher refractive PE.