Possibilities and limits of minimal invasive lacrimal surgery.

Endoscopy of the lacrimal drainage system with miniaturized endoscopes has been possible since 1990 and permits the direct evaluation of the lacrimal drainage system. Additionally, attached instruments permit recanalization in cases of stenosis of the lacrimal drainage system. Both an Erbium-Yag Laser and a miniaturized drill are available, with which a stenosis of the lacrimal drainage system can be opened under endoscopic control. Favorable findings for endoscopic recanalization are stenoses in the area of the canaliculi or the lacrimal sac, for which the success rate of recanalization is approximately 75%. Unfavorable prognostic factors are submucous scar formations due to a dacryocystitis in the patient's history. Endoscopic findings have also improved the understanding of diseases of the lacrimal drainage system. Punctal stenoses causing epiphora often show intact mucous membranes before and behind the stenosis and it is possible to cure these patients without extensive surgical procedures. Micro-surgical procedures and dacryocystorhinostomy complete the spectrum of the endoscopic surgical possibilities in the lacrimal drainage system.