Abstract
Purpose :
To compare the sutureless 23 gauge (G) pars plana vitrectomy (PPV) with the 20G PPV regarding inflammation, visual outcome and patient comfort.
Methods :
We included 100 patients with symptomatic macular hole or macular pucker, scheduled for vitrectomy in this prospective, randomized, controlled, mono-center clinical trial which followed the tenets of the Declaration of Helsinki.
Patients were randomized 1:1 either to 20G PPV (n=51) or 23G PPV (n=49). All eyes underwent standard 20G or 23G PPV with membrane peeling.
Primary endpoint was change in aqueous humor flare 3 weeks after surgery compared to baseline. Flare was measured with the FM-500 Laser Flare-Cell Meter (Kowa Company, Ltd, Tokyo, Japan) and expressed as photon counts per millisecond (pc/ms).
Secondary outcome measures were postoperative discomfort measured with a visual analog scale, best-corrected visual acuity, postoperative intra ocular pressure (IOP), number of complications and duration of surgery.
Results :
There was no significant difference in change of aqueous humor flare between the groups (20G:3.5 ±9.5 pc/ms, 23G:2.3 ±13.2 pc/ms, p= 0.452). Only in the per protocol set (31 eyes in each group), a lower increase in aqueous flare was observed after 23G PPV (20G:1.9± 6.7 pc/ms, 23G:-0.1±4.8 pc/ms, p=0.039).
Postoperative IOP was lower after 23G PPV (20G:16.9±8.2 mmHg, 23G:12.5±6.2 mmHg, p=0.005), but the rate of postoperative hypo- or hypertension did not differ between the groups (p=0.207).
The gain in ETDRS letters 3 weeks after surgery was higher after 23G PPV (20G:4.2±10.4, 23G:6.8±10.4, p=0.034), but showed no significant difference after 6 month (20G:11.0±13.5, 7.3±15.6, p=0.588).
The mean duration of surgery was shorter in the 23G group (20G:29 ±6 min, 23 G:20±6 min, p<0.0001) and patients after 23G PPV showed higher comfort (Foreign body sensation 20G:22±24, 23G:9 ±14, p=0.002; itching:20G:12±20, 23G:5±10, p=0.021). The rate of complications did not differ between the groups.
Conclusions :
The primary endpoint, a significant lower change in flare values in the 23G group three weeks after surgery, could not be reached, but the level of inflammation decreases faster after 23G PPV. Clear advantages of the 23G PPV are a shorter surgery time, faster visual recovery and a higher comfort in the early postoperative phase. These advantages must be seen in relation to the higher cost of the system.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.