Primary external dacryocystorhinostomy versus primary endonasal dacryocystorhinostomy: a review

This paper aims to compare the efficacy, mean operative time and adverse effects of primary external dacryocystorhinostomy (DCR) versus primary endonasal DCR in treating acquired nasolacrimal duct obstruction. Searches were performed for studies comparing the two procedures. Two reviewers independently extracted data from 14 eligible studies. A random effects model was used to analyse the studies. Outcome measures were defined as patency of the nasolacrimal canal and mean operative time,and adverse effects as cutaneous scarring and bleeding.Both procedures were comparable in efficacy in terms of full success, partial success and anatomic patency. Subgroup analysis showed no significant difference between prospective and retrospective studies as well as between non-laser endonasal DCR versus external DCR and laser endonasal DCR versus external DCR. Endonasal DCR had a significantly shorter mean operative duration, be it laser endonasal DCR (mean difference: 37.65 min, 95% confidence intervals:3.54-71.75 min, P: 0.03) or non-laser endonasal DCR (mean difference: 19.22 min, 95% confidence intervals: 2.15-36.28 min, P: 0.03). The odds of post-operative bleeding was not significantly different between the two procedures, whereas post-operative cutaneous scarring was unique to external DCR and occurred in 50 out of 402 (12.44%) external DCRs recorded. Endonasal DCR has comparable success rates with external DCR and has a shorter operative time and no cutaneous scar. However, drawbacks include the steep learning curve and higher costs.