Outcomes of 8 × 8 mm osteotomy in powered external dacryocystorhinostomy

PURPOSE: To study the endoscopic ostium characteristics and outcome of 8 × 8 mm osteotomy in external dacryocystorhinostomy (DCR) using the microdrill system. METHODS: This prospective interventional pilot study was performed on 40 eyes of 40 patients with primary acquired nasolacrimal duct obstruction (NLDO) from June 2021 to September 2021 in patients undergoing external DCR. An 8 × 8 mm osteotomy was performed using round, cutting burr attached to a microdrill system. Success was defined as patent ostium on lacrimal syringing (anatomical) and a Munk score <3 (functional) at 12 months. Postoperative endoscopic ostium evaluation was done using a modified DCR ostium (DOS) scoring system at 12 months. RESULTS: The mean age of the study participants was 42.41 ± 11.77 years and the male-to-female ratio was 1:4. The mean duration of surgery was 34.15 ± 1.66 minutes and that for osteotomy creation was 2.5 ± 0.69 minutes. The mean intraoperative blood loss was 83.37 ± 11.89 ml. Anatomical and functional success rates were 95% and 85%, respectively. The mean modified DOS score was “excellent” in 34 patients (85%), “good” in 1 patient (2.5%), “fair” in 4 patients (10%), and “poor” in 1 patient (2.5%). Complications included nasal mucosal injury in 10% (4/40) of patients, complete cicatricial closure of ostium in 2.5% (1/40), incomplete cicatricial closure in 10% (4/40), nasal synechiae in 5% (2/40), and canalicular stenosis in 2.5% (1/40). CONCLUSION: An 8 × 8 mm–sized osteotomy created by powered drill and covered by lacrimal sac–nasal mucosal flap anastomosis in external DCR is an effective technique that has minimal complications and shorter surgical time.