Session Title: Free Paper Session 26: Vitreoretinal Surgery VI
Session Date/Time: Sunday 10/09/2017 | 10:00-11:30
Paper Time: 10:06
Venue: Room 116
First Author: : Y.Iwama JAPAN
Co Author(s): : H. Nakashima K. Emi M. Nakatsuji H. Bando T. Ikeda
The main purpose of this study was to evaluate the influence of surgical procedures that cause intraocular pressure (IOP) fluctuations (vitreous shaving under scleral depression and fluid-air exchange) and surgical instruments that prevent intraoperative IOP fluctuations (valved trocar cannulas and the IOP control function of the Constellation Vision System[Alcon Laboratories, Inc, Fort Worth, Texas, USA]) on the incidence of suprachoroidal haemhorrage (SCH) during 25-gauge pars plana vitrectomy (25G-PPV). The secondary objective was to evaluate the clinical features and surgical outcomes of SCH during 25G-PPV.
Intraoperative SCH has been reportedly associated with intraoperative IOP fluctuations. Although the recent shift to smaller-gauge surgery has enhanced IOP stability during vitrectomy, there are no reports on the influence of intraoperative IOP fluctuations on the incidence of SCH during 25G-PPV.
We investigated 3159 cases that underwent 25G-PPV at the Osaka Rosai Hospital between July 2011 and June 2014. First, univariate analysis was performed to evaluate the relationships between the incidence of SCH during 25G-PPV and the surgical procedures and instruments that were associated with IOP fluctuations. Second, on the basis of univariate analysis results, we divided the participants into four groups depending on the surgical procedure performed (P < 0.05 in univariate analysis): cases that underwent neither fluid-air exchange nor vitreous shaving under scleral depression (Group 1, n=1177), fluid-air exchange alone (Group 2, n=488), vitreous shaving under scleral depression alone (Group 3, n=659), and both procedures (Group 4, n=835). The incidence of SCH in each group was obtained and compared. We also investigated the clinical features and surgical outcomes of SCH during 25G-PPV, including the time when SCH was first noted, extent of SCH, postoperative diagnosis and the reoperation rates which include secondary surgical management for SCH.
The incidence of SCH was significantly higher in the cases that underwent fluid-air exchange or vitreous shaving under scleral depression (P = 0.0024 and 0.0084, respectively). In contrast, no significant relationship was found between the incidence of SCH and the use of surgical instruments that prevented IOP fluctuations. This study also demonstrated that the incidence of SCH in Group 4 was significantly higher than that in Groups 1, 2, and 3 (1.08% [9/835] vs. 0.08% [1/1177], 0% [1/488], and 0% [0/659], respectively; P < 0.001). The total incidence of SCH during 25G-PPV was 0.32% (10/3159). SCH was most frequently observed during intraocular manipulations of air-filled eyes. In some cases, SCH was observed during fluid-air exchange; however, SCH was not observed in cases with fluid-air exchange alone. All SCH cases were localized (one to two quadrants), except for one that occurred due to an iatrogenic failure of the infusion; no case had SCH involving the posterior pole. The postoperative diagnosis in almost all the SCH cases (eight-tenths) was rhegmatogenous retinal detachment (RRD). Of all the SCH cases, only one (RRD due to giant retinal tear) required reoperation for a retinal redetachment; no case required secondary surgical management for SCH.
In conclusion, this study demonstrated that there remains a slight risk of SCH during 25G-PPV in cases that require both fluid-air exchange and peripheral vitreous shaving under scleral depression. Otherwise, SCH may be less of a concern during 25G-PPV. In addition, this study demonstrated that SCH during 25G-PPV would occur regardless of the use of surgical instruments that prevent intraoperative IOP fluctuations, such as valved trocar cannulas and the IOP control function of the Constellation Vision System. Based on these results and the time when SCH was first noted during the procedure, surgeons should carefully perform intraocular manipulations under air, particularly for cases that require repeated surgical procedures that cause IOP fluctuations. However, even if SCH occurs during 25G-PPV, the surgical outcomes after SCH may not be so dismal, considering our results that almost all SCH cases were localized and no case required secondary surgical management for SCH.