Comparison of postoperative intraocular pressure changes between 23-gauge transconjunctival sutureless vitrectomy and conventional 20-gauge vitrectomy

Abstract

Purpose: To compare the intraocular pressure (IOP) after 23-gauge transconjunctival sutureless vitrectomy (TSV) and conventional 20-gauge vitrectomy for various vitreoretinal diseases.

Methods: This was a retrospective interventional case series including 338 cases of 23-gauge TSV and 476 cases of 20-gauge vitrectomy with minimum follow-up period of 1 month. Postoperative 1 day, 1 week and 1 month IOPs were compared. Multiple regression analysis to assess the actual effect of gauge of vitrectomy on postoperative IOP was performed including intraoperative and postoperative factors influencing postoperative IOP as covariates.

Results: The mean IOP of 20-gauge vitrectomy was significantly higher than that of 23-gauge TSV (20.6 ± 8.02 mm Hg vs 12.8 ± 4.48 mm Hg, P<0.001) at postoperative day 1, but the differences were not significant at postoperative 1 week and 1 month. The IOP pattern of 23-gauge TSV demonstrated more stable course than that of 20-gauge vitrectomy. At 1 day post vitrectomy, the incidence of hypertony was higher in 20-gauge, whereas that of hypotony was higher in 23-gauge. Among risk factors, the 20-gauge vitrectomy showed the strongest association with postoperative 1 day IOP rise.

Conclusion: Twenty-three-gauge TSV has stable and lower IOP in the early postoperative period than the 20-gauge vitrectomy. In patients whose retina and optic nerves are vulnerable to higher or fluctuating IOP, 23-gauge TSV may be more beneficial.

Figure 1

Postoperative IOP changes after 20-gauge vitrectomy and 23-gauge transconjunctival sutureless vitrectomy. Error bars indicate 95% confidence interval. ^*IOP change, calculated by postoperative IOP minus preoperative IOP, was compared between the two gauges and the change was statistically significant only at postoperative 1 day (P<0.001 by Student's t-test).

Figure 2

Comparison of postoperative IOP in cases of epiretinal membrane between 20-gauge vitrectomy and 23-gauge transconjunctival sutureless vitrectomy. Error bars indicate 95% confidence interval. ^*IOP change was significantly different only at postoperative 1 day (P=0.002 by Student's t-test).

Figure 3

Comparison of the incidence of hypotony (IOP<6 mm Hg, (a) and hypertony (IOP>24 mm Hg, (b)) between 20-gauge vitrectomy and 23-gauge transconjunctival sutureless vitrectomy. Error bar indicates the upper bound of 95% confidence interval. ^*P<0.001 by Fisher's exact test. ^†P<0.001 by χ² test.