Journal List > J Korean Ophthalmol Soc > v.50(3) > 1008491

Park, Lee, and Oum: Comparisons of Corneal Topographic Change Between 20-Gauge and 23-Gauge Pars Plana Vitrectomy

Abstract

Purpose

To compare the changes in corneal topography between 23 gauge (G) pars plana vitrectomy (PPV) and 20 G PPV.

Methods

Forty-three eyes of 42 patients who underwent PPV were divided into 2 groups: 20G PPV (Group I, n=18) and 23 G PPV (Group II, n=25). Both groups were followed up over 3 months postoperatively. ORBSCAN II was performed to compare the corneal topographic change of 20 G PPV and 23 G PPV.

Results

In a 5 mm zone, significant postoperative change in the mean corneal surface cylinder was found between the 1st day and the 1st month in Group I, while no significant change was found in Group II. Postoperatively, the increase in the mean corneal surface cylinder in Group I was significantly higher than in Group II between the 1st day and the 1st month. Clinically significant astigmatism, induced by surgery, was found only in Group I one week after the operation. In a 3 mm zone, there was no significant change in the mean corneal surface cylinder in both groups postoperatively. The difference in the mean corneal surface cylinder between the 2 groups at the postoperative periods showed no significant change. Surgically induced astigmatism was significantly higher in Group I than in Group II between the 1st day and the 1st month postoperatively.

Conclusions

PPV with the 23 G system is a sutureless transconjunctival surgery, which appears to be more effective due to insignificant corneal surface and astigmatic changes in the early postoperative period.

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Figure 1.
Changes in mean astigmatism (in 5-mm zone) after 20-gauge and 23-gauge pars plana vitrectomy.* Statistically significant change between preoperative and each postoperative periods; Statistically significant change between Group I and Group II at each time interval.
jkos-50-353f1.tif
Figure 2.
Changes in mean astigmatism (in 3-mm zone) after 20-gauge and 23-gauge pars plana vitrectomy. Significant changes of mean astigmatism were not found in both groups postoperatively.
jkos-50-353f2.tif
Table 1.
Methods of surgery
  No. of eyes
Group I Group II
PPV* 0 14
PPV+Silicone oil injection 2 2
PPV+Gas (C3 F8 or SF6) injection 5 9
Silicone oil removal 11 0
Total 18 25

*PPV=pars plana vitrectomy.

Table 2.
Changes of mean corneal power
  Preoperative (D*) Postoperative (D)
1 day 1 week 1 month 3 months 6 months
Group I 43.10±3.25 43.57±2.60 43.55±3.03 43.17±2.09 43.53±1.91 43.33±2.60
Group II 42.92±1.56 42.95±1.27 42.95±1.19 42.79±1.40 42.62±1.80 42.54±1.43
p value > 0.05 > 0.05 > 0.05 > 0.05 > 0.05 > 0.05

*D=diopters.

Table 3.
Changes of anterior chamber depth
  Preoperative (mm) Postoperative (mm)
1 day 1 week 1 month 3months 6 months
Group I 3.72±0.40 3.59±0.70 3.84±1.00 3.62±0.37 3.80±0.50 3.79±0.61
Group II 3.26±1.16 3.13±0.84 3.25±0.60 3.48±0.66 3.45±0.65 3.49±1.22
p value > 0.05 > 0.05 > 0.05 > 0.05 > 0.05 > 0.05
Table 4.
Surgically induced astigmatism after 20-gauge and 23-gauge pars plana vitrectomy in 5-mm zone
  Surgically induced astigmatism (D*)
1 day 1 week 1 month 3 months 6 months
Group I 1.56±1.58 1.48±1.73 1.30±1.07 0.33±1.07 0.45±2.41
Group II 1.25±1.16 0.02±1.38 0.29±1.45 0.00±0.79 0.21±0.89
p value < 0.05 < 0.05 < 0.05 > 0.05 > 0.05

*D=diopters.

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