Nasolacrimal duct obstruction

Congenital NLD occlusion is common. In a large prospective study of neonates and infants during the first year of life, 20 per cent of eyes showed evidence of symptomatic occlusion.22 The NLD becomes canalised late in foetal development. At birth, the duct lumen is markedly irregular with numerous folds and often fails to completely canalise. Most commonly, occlusion occurs at the extreme distal end of the duct just before it empties into the nasal cavity valves of Hasner (Figure 3).
Symptoms of congenital NLD occlusion include watering and mucopurulent discharge. A fluorescein disappearance test is useful in the differential diagnosis of an infant presenting with persistent epiphora and discharge. A drop of 1 per cent fluorescein is instilled into the lower fornix and the eye is examined in blue light 5-10 minutes later. Complete clearance of the dye indicates infants with a normal nasolacrimal drainage system. Retention of the dye within the tear film is indicative of obstruction. Management of congenital NLD obstruction should be conservative in the first instance since there is a high rate of spontaneous resolution: 70 per cent of affected children are symptom-free by three months of age, and over 90 per cent by their first birthday. Conservative management consists of simple lid hygiene, coupled with gentle massage of the lacrimal sac.22 Topical antibiotics should only be given when there is clinical evidence of infection.
In the UK, nasolacrimal duct probing under general anaesthesia is the intervention of choice in cases that have not resolved by one year. The treatment has a 90-95 per cent success rate when performed in the first two years of life, but is less effective in older children. Probing and syringing in adult NLD obstruction are generally ineffective, although recent advances in minimally evasive surgical techniques have provided alternatives that carry a high probability of symptomatic relief.21