Effectiveness of indocyanine green gel in the identification and complete removal of the medial wall of the lacrimal sac during endoscopic endonasal dacryocystorhinostomy

Objective We investigated the effect of using indocyanine green (ICG) gel, a mixture of ICG and Viscoat, on complete removal of the medial wall of the lacrimal sac as well as the success rate of endoscopic endonasal dacryocystorhinostomy (DCR) for primary acquired nasolacrimal duct obstruction. Methods Consecutive cases of endoscopic endonasal DCR between January and December 2010 were included in a retrospective, comparative manner. A total of 91 patients with primary acquired nasolacrimal duct obstruction were enrolled. Surgical method was selected according to time period. In the ICG gel group, we used ICG gel, which is a fluorescent-colored viscoelastic substance made of ICG dye (25 mg) and Viscoat. ICG gel was injected into the lacrimal sac via the inferior canaliculus prior to lacrimal sac dissection. The anatomic and functional surgical success rates of endoscopic endonasal DCR in each group were compared. Results Our study included 49 cases in the ICG gel group and 42 cases in the control group. The functional success rate of endoscopic endonasal DCR reached 93.9% (46 of 49) in the ICG gel group compared with 71.4% (30 of 42) in the control group (Pearson's χ² test, p value = 0.004). In contrast, there was no statistically significant correlation between use of ICG gel and anatomic success rate of endoscopic endonasal DCR. Conclusions Using ICG gel during lacrimal sac dissection may enhance the functional success rate of endoscopic endonasal DCR for primary acquired nasolacrimal duct obstruction by facilitating easier identification and subsequent complete removal of the medial wall of the lacrimal sac.