Abstract
Purpose :
Intraocular gas is widely used in pars plana vitrectomy (PPV) for macular hole and retinal detachment repair. However, the role of gas in PPV for vitreomacular traction (VMT) repair has not been extensively studied. This study analyzes whether the placement of long-acting gas during PPV improves the overall visual acuity and anatomic outcomes in eyes undergoing VMT repair.
Methods :
A retrospective review of patients who underwent a 23G PPV (Constellation, Alcon) was performed. Only eyes with the preoperative diagnosis of VMT were included in the study. Eyes that underwent PPV with silicone oil placement were excluded. 34 eyes met this inclusion criteria and were divided into 2 groups: 15/34 (44%) eyes with PPV/gas (C3F8 or SF6) placement (Group A) and 19/34 (56%) eyes with PPV/no gas placed (Group B). Best corrected visual acuity (BCVA) were compared by using the Snellen acuity chart in logMAR notation. Change in central subfield thickness (CST) (µm) by optical coherence tomography (OCT)(Cirrus, Zeiss) was compared. Statistical analysis was performed using the unpaired 1 tail T-test.
Results :
In Group A, 15/15 (100%) of eyes showed complete resolution of the VMT with no evidence of cystoid macular edema (CME). In Group B, 6/19 (32%) eyes showed CME changes on OCT at 2 months postop. In Group A, the average CST preop was 336.4 µm and improved to 259.53 µm postop (23% reduction, p<0.05). In Group B, the average CST preop was 307.73 µm and improved to 306.58 µm postop (0% reduction, p>0.05). The mean BCVA in Group A was logMAR 0.45 (20/56) preoperatively, 0.68 (20/96) at two months postop and 0.41 (20/51) at 6 months postop. The mean BCVA in Group B was 0.56 (20/73) preop, 0.36 (20/46) at 2 months postop, and 0.27 (20/37) at 6 months postop. Cataract progression was more rapid in Group A and accounted for the lower BCVA.
Conclusions :
Our results suggest that the PPV/gas eyes achieve a more immediate anatomical improvement postop as compared to the PPV/no gas group. Most likely, the gas acts as a tamponade which realigns retinal layers. The use of gas may result in less postop CME and ultimately decreased need for further treatment. While gas decreases the BCVA in the immediate post-op period, these eyes showed considerable improvement in vision at 6 months postoperatively. Cataract surgery may be required sooner in the PPV/gas group. Additional prospective studies are necessary.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.