LAUSR

BACKGROUND Dacryocystorhinostomy (DCR) is the gold standard surgical treatment for nasolacrimal duct obstruction. External DCR is the traditional approach (EXT-DCR); however, the advent of minimally invasive surgeries and the development of optic fiber and laser technologies have made it possible to perform laser transcanalicular DCR (T-DCR), a minimally invasive procedure. This study measured the fluorescein transit time (FTT) after EXT-DCR or T-DCR to evaluate the lacrimal drainage and lacrimal pump function after these two types of DCR. SUBJECTS AND METHODS A cross-sectional study of 50 patients who underwent EXT-DCR (EXT-DCR Group) or T-DCR (T-DCR Group), who were anatomically patent upon irrigation, with a minimum 6 months of follow up. The patients' FTT was measured; it was defined as the time from the instillation of the dye into conjunctival sac to its free flow from the rhinostomy site. This evaluation was performed through nasal endoscopy performed intranasally with a blue filter that enabled the faster detection of fluorescein from the ostium site. The mean FTTs of the two groups were compared using the two-sided Student's unpaired t-test. Other variables such as sex, age, previous lacrimal sac size, and the site and shape of the rhinostomy were evaluated to determine their possible relationships with FTT. RESULTS The EXT-DCR group had 80% female patients at a mean age of 58 years. The T-DCR group had the same percentage of female patients (80%) and a mean age of 56 years. The mean FTT group was 47.48 sec in the EXT-DCR and 33.04 sec in the T-DCR group. Functional success was 88% in both groups. CONCLUSION FTT in the DCR-T Group was significantly lower than in the EXT-DCR Group. No other variables exhibited a statistically significant correlation with FTT. Lacrimal drainage was found to be better after T-DCR than after EXT-DCR, results which show that this procedure could prevent lacrimal pump damage.