Abstract
Purpose :
To determine the relationship between the subfoveal choroidal thickness (CT) and intraocular pressure (IOP) following 23-gauge and 25-gauge vitrectomy for idiopathic epiretinal membrane (ERM).
Methods :
Retrospective observational case series of one hundred patients who had undergone 23-gauge or 25-gauge vitrectomy for an ERM. The measurements of CT and IOP were done at the baseline and 1 day, 1 week, and at 1, 3, 6, and 12-months after the surgery.
Results :
Forty-four eyes of 44 patients (69.8 ± 9.5 years, 26 females) in the 23-gauge group and 56 eyes of 56 patients (70.5 ± 9.4 years, 33 females) in the 25-gauge group were enrolled. There was no difference in age, sex and axial length between the two groups. In both groups, the IOPs on 1 day and 1 week after surgery were significantly lower than baseline (paired t test P <0.001 for both) and the rates of changes of IOP were not different between the 2 groups. The CTs on 1 day and 1 week after surgery were significantly thicker (P =0.002 and P <0.001) than baseline in 23-gauge group, whereas there were no differences in 25-gauge. The CT at 12 months after surgery was significantly thinner than baseline in both group (P=0.006, and P <0.001). The rates of changes in the CT at day 1 and week 1 were negatively correlated with the corresponding rates of change of IOP in the 23-gauge group (r =-0.505, P <0.001, and r =-0.321, P =0.045) but no correlation was observed in the 25-gauge. Multiple linear regression analysis showed that baseline CT and IOP on day 1 were predictive for CT on day 1 in 23-gauge (P <0.001 for both), but no predictive factor was found in 25-gauge.
Conclusions :
CT increases soon after 23-gauge vitrectomy for ERM which is probably due to the transient hypotony, but CT does not change in 25-gauge postoperatively. Twenty-five-gauge vitrectomy may have an advantage that minimal choroidal change would happen postoperatively.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.