Lacrimal bone thickness at the lacrimal sac fossa

BACKGROUND AND OBJECTIVE: Because laser dacryocystorhinostomy techniques have become more popular during the past few years, interest has grown concerning the anatomic structures that need to be penetrated in these procedures. The authors therefore studied the thickness and the histologic type of the lacrimal bone at the lacrimal sac fossa. PATIENTS AND METHODS: The thickness of 69 lacrimal bones at the lacrimal sac fossa from 48 patients was measured. RESULTS: The mean thickness was 106 mu m. In 67% of the patients the mean thickness of individual lacrimal bone was less than 100 mu m and in 4% it was more than 300 mu m. The thinnest measured cross section of the lacrimal bone sample was 11 mu m and the thickest was 722 mu m. The lacrimal bone was composed of a thin plate of lamellar bone. CONCLUSION: In most cases the lacrimal bone at the lacrimal sac fossa is so thin that it can be easily penetrated with most surgical instruments.