Embryogenesis of a congenital nasolacrimal duct (NLD) cyst is attributed to the failure of the Hasner membrane of the NLD system to cannulate. Prenatal diagnosis of congenital NLD cysts supports the argument for a developmental error, with a postnatal prevalence of 6%. The role of a genetic basis for this malformation has never been ascribed. We present a set of monozygotic twins with bilateral congenital NLD cysts as an argument for a genetic basis of this entity. A case report and literature review were performed. We present two cases of bilateral congenital NLD cysts occurring in a set of monozygotic twins. Patients were delivered at 37 weeks via cesarean section. The pregnancy was complicated by preterm labor at 33 weeks requiring administration of terbutaline and betamethasone. At presentation, twin A had bilateral eye discharge, erythema, and swelling medial to the medial canthi as well as nasal obstruction. Computed tomography (CT) showed classic bilateral cystic masses in the inferior meatus. The diagnosis of bilateral infected congenital dacryocystoceles was made. Twin B initially presented with only bilateral eye discharge and CT showed a dilated NLD system. Twin B subsequently developed early signs of bilateral dacryocystoceles the following day. Both patients underwent lacrimal probing and endoscopic marsupialization of the dacryocystoceles. Biopsies were consistent with dacryocystocele. Dacryocystocele is a common presentation of unresolved neonatal NLD obstruction. This case report in a set of identical twins is an argument for a genetic basis for the formation of this lesion.

Purpose

To develop and validate a new parental questionnaire addressing symptoms and health related quality of life (HRQL) in congenital nasolacrimal duct obstruction (NLDO).

Design

Cross-sectional study.

Participants

Children aged 6 to <48 months with and without clinical signs of NLDO.

Methods

A new questionnaire was developed using semi-structured interviews with parents of children with NLDO and through discussions with expert clinicians. Questionnaires were completed by parents of children with NLDO and without NLDO. Cronbach’s alpha was calculated as a measure of internal-consistency reliability. Factor analysis was used to evaluate a priori subscales; symptoms and HRQL. Discriminant construct validity was assessed by comparing questionnaire scores between children with and without NLDO and between affected and unaffected eyes of children with unilateral NLDO. Instrument responsiveness was determined by comparing pre- and post-surgical intervention scores in a subset of NLDO subjects who underwent surgical treatment.

Main outcome measure

NLDO questionnaire score.

Results

87 children were enrolled, 56 with NLDO and 31 without. All but two questions on the questionnaire showed a good distribution of responses, a high correlation with the rest of the questionnaire and excellent discrimination between patients with and without NLDO. Cronbach’s alpha values were good for the overall questionnaire (0.95), and for two predetermined subscales; symptoms (0.95) and HRQL (0.85). On a 0 to 4 scale, NLDO patients had worse scores compared to non-NLDO patients for both symptoms (mean difference = 2.1; 95% confidence interval (CI): 1.8 to 2.4) and HRQL (mean difference 1.2; 95% CI: 0.8 to 1.5) subscales. NLDO patients had worse scores pre-intervention compared to post-intervention for both the symptoms (mean difference = 2.2; 95% CI: 1.6 to 2.9) and HRQL (mean difference = 1.4; 95% CI: 0.8 to 2.1) subscales. Finally, NLDO patients had worse symptom scores for affected eyes compared to unaffected eyes (mean difference = 2.3; 95% CI: 1.9 to 2.6).

Conclusions

This novel NLDO questionnaire is useful in quantifying parental perception of symptoms and HRQL in childhood NLDO. The questionnaire may have a role in future clinical studies of NLDO