We live in a surgical era which strives towards minimal trauma. Ophthalmology is no stranger to minimally invasive microsurgical techniques. With the advent of small incision cataract surgery and foldable intraocular implants we achieve faster and better results with reduced postoperative morbidity. Lacrimal surgery too has seen this trend with the introduction of nasal endoscopes which provide an alternative approach to the treatment of obstructive epiphora where the stenosis is distal to the common canaliculus.

The traditional surgical approach to distal obstruction of the nasolacrimal duct system has been by an external skin incision. Addeo Toti first described the technique of external dacryocystorhinostomy (DCR) in 1904 in which he suggested that having gained access to the sac via an external approach, the part of it adjacent to the canaliculi be preserved and absorbed into the nasal cavity from which part of the nasal mucosa has been removed.1 A mucosal anastomosis with suturing of the mucosal flaps was later described by Dupuy-Dutemps and Bourget.2 With the exception of minor alterations external DCR is still performed in much the same way. The success rate has, however, improved over the years as a result of better preoperative assessment including radiological investigation of the nasolacrimal system, absorbable and less irritant suture materials, improved instruments and anaesthetic procedures.

The success rate of external DCR has been reported at between 80% and 99% depending on the surgeon’s experience.3-10Combining the results of a total of 799 cases shows an overall success rate of 91% for primary surgery and 81% for secondary DCR.3-11 Failure rates with external DCR have been attributed to many factors including position and size of the ostium, common canalicular obstruction, scarring within the anastomosis due to infection or non-absorbable suture material, persistent mucocele, and the sump syndrome.7-9 Postoperative …