Endoscopy of the lacrimal system

Until recently, diagnosis of disorders of the lacrimal system has depended on digital dacryocystography and on clinical examinations such as the fluorescein dye test, lacrimal probing, and irrigation. The lacrimal system and its mucous membranes can now be viewed directly with a lacrimal endoscope. While the first endoscopes were rigid and limited by poor picture quality in axial illuminations, the new generation of endoscopes are a great leap forward for new diagnostic and therapeutic approaches.

132 patients ranging in age from 8 months to 73 years with nasolacrimal obstruction were referred to the lacrimal department. Diagnostic lacrimal imaging utilising various small calibre endoscopes less than 0.5 mm in external diameter was performed. The endoscopes are coupled to specially designed lacrimal probes as well as a CCD camera and a video recorder. The imaging was performed during standard lacrimal probing and irrigation in an outpatient clinic setting in 120 of 132 patients

All patients reported the pain of endoscopy as being similar to that of standard lacrimal probing and irrigation. No adverse effects such as bleeding or lacrimal perforation were noted. Endoscopic manipulation was not too difficult and the picture quality, depth of focus, and illumination were satisfactory in all cases. The most common site of stenosis was the nasolacrimal duct (59 patients), followed by the lacrimal sac (39 patients) and the canaliculi (34 patients). In 25 patients, partial obstruction, rather than complete stenosis, was visualised as a narrow lumen, which widened during irrigation. In 14 of 28 patients, obstruction was due to canalicular submucosal folds and was removed with laser. In addition, the colour and consistency of the lining mucosa correlated with type of obstruction. Normal mucosa is smooth and light pink in colour. Inflammatory changes manifest as thickened and reddish grey mucosa. More complete stenosis is shown as fibrotic plaques with grey white inelastic membranes.

Lacrimal endoscopy is a new, non-invasive method used to view directly and localise obstructions precisely. It allows differentiation between inflammatory, partial, and complete stenosis. Endoscopy enables one to choose the appropriate surgical therapy for patients. Patients tolerated the procedure well without any adverse reactions or effects. While it may not replace standard probing and irrigation, this technique is an extremely useful adjunct in determining the proper surgical modality, ease, and tolerance of the endoscopic manipulation by patients, and obtaining sharp and clear images of the nasolacrimal outflow system anatomy and pathology. Differentiation of various types of obstruction by precise location and severity can be achieved.