Primary Acquired Nasolacrimal Duct Obstruction (PANDO) and Secondary Acquired Lacrimal Duct Obstructions (SALDO)

Abstract

Epiphora resulting from nasolacrimal duct obstruction (NLDO) is common and accounts for about one-third of cases [1]. Symptomatic acquired NLDO has an average annual incidence rate of 30.47 per 100,000 [2]. It is commonly encountered in ophthalmic clinics especially ophthalmic plastics and dacryology clinics. NLDO can be classified as either primary acquired nasolacrimal duct obstruction (PANDO) when it is idiopathic or secondary acquired lacrimal duct obstructions (SALDO) when it is secondary to various etiologies [3, 4]. The term PANDO was given by Linberg and McCormick in 1986 [4]. They described a female preponderance, a usual onset of epiphora after the age of 40 years, subsequent development of associated symptoms, and signs of chronic or acute dacryocystitis, which constitute the clinical syndrome of primary acquired nasolacrimal duct obstruction (PANDO) [4].