Abstract
Purpose :
To determine the course of postoperative vision decrease and recovery after tube shunt implantation for glaucoma, and to determine the risk factors associated with worse vision after tube shunt procedure.
Methods :
A retrospective review of consecutive adult patients who underwent tube shunt implantation between January 2008 and December 2017 was conducted. Visual acuity was converted to LogMAR for data analysis. Postoperative best-corrected visual acuity (BCVA) compared to preoperative BCVA was analyzed for postoperative 1 week (POW1), 1 month (POM1), 3 months (POM3) and 6 months (POM6) using repeated measures ANOVA. The proportions of patients with significant vision loss by 3-5 lines and by more than 5 lines were calculated. Logistic regression was conducted to identify individual risk factors associated with worse postoperative vision.
Results :
A total of 479 patients with an average age of 64.6±17.2 years were included in the study; 50.9% were males. The mean preoperative visual acuity was 0.75±0.81(95%CI: 0.67-0.83). At POW1 and POM1, mean visual acuity significantly decreased to 0.96±0.83 (95%CI: 0.88-1.04,P <0.001) and 0.82±0.79 (95%CI: 0.74-0.90, P=0.007), respectively. Patients’ mean visual acuity subsequently recovered back to preoperative level at POM3 (mean BCVA 0.77±0.81, 95%CI: 0.69-0.85, P=0.44), and maintained at preoperative level at POM6 (mean BCVA 0.79±0.81, 95%CI: 0.70-0.87, P=0.20). By POM6, 11 patients (2.7%) had mild to moderate vision loss by 3-5 lines, and 5 (1.2%) patients had severe vision loss by more than 5 lines. Univariate analysis showed that phakic status (OR=1.61, P=0.03), without use of 5-Fluorouracil (5-FU, OR=1.92, P=0.016), and the type of tube shunt (OR=1.80, P=0.041) were associated with worse postoperative vision at 6 months. Multivariate analysis also showed phakic status (OR=1.69, P=0.017) and without use of 5-FU (OR=2.0,P=0.011) were associated with worse vision at POM6.
Conclusions :
Immediate postoperative vision loss is common after tube shunt procedure. Postoperative vision recovery back to preoperative level on average took place within 3 months. The risk of significant vision loss by more than 3 lines is relatively uncommon, about 4% in our study population. Risk factors included not using anti-fibrotic agents and phakic status prior to tube shunt surgery.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.