Abstract
Purpose:
Neovascular glaucoma (NVG) requires aggressive management to prevent secondary angle closure; PAS formation limits the ability to control the intraocular pressure (IOP) without surgery and thus visual prognosis is poor. Aqueous tube shunts are often needed in the management of NVG; however, the timing of shunt placement for optimal therapeutic results is unclear. This retrospective study evaluated the hypothesis that early tube placement may improve visual prognosis and longterm IOP.
Methods:
A retrospective chart review of 90 eyes that received tube shunts at Los Angeles County/University of Southern California Medical Center were reviewed. Patients with prior tube surgeries within the 4 month review period were excluded. Patients were stratified into early and late groups. Patients who received surgery within 2 weeks of diagnosis were placed in the early group and those after 2 weeks in the late group. Primary outcome measures were change in visual acuity from baseline presentation and change in IOP. Categorical visual acuity measures were assessed with Fisher’s exact test and two-tailed Student’s t-test was used to analyze IOP.
Results:
43 eyes (47.8% of eyes reviewed) received tubes with NVG as an indication. Nine (20.9%) received tubes within 2 weeks of diagnosis. 34 (80.1%) received tubes after 2 weeks. Early and late groups received surgery within 6.1±4.4 and 116±184.1 days, respectively. There was no statistical difference between early and late treatment groups in presenting IOP (early 53.3±18.6, late 53.3±18.6; p = 0.25) or IOP after medical therapy but prior to tube placement (early 40.4±22.0, late 39.6±14.5; p = 0.89). There was also no difference in postoperative visual acuity from baseline between groups on postoperative day 1, week 2, week 6, and month 4 (Fisher’s exact test, p = 0.55, p = 0.61, p = 0.99, p = 0.31 respectively). Additionally, there was no significant difference in IOP between groups at the 4 month follow up (4 month early 15.3±5.4, late 15.8±5.7; p = 0.97).
Conclusions:
Our results suggest that early tube placement for NVG does not improve visual prognosis or postoperative IOP. However, these findings must be interpreted with caution due to small sample size. Inability to control pressure with medical management likely dictates surgical timing over a therapeutic window. Further analysis is required to elaborate on the timing and effectiveness of tube surgery in NVG.