The aim of this study is to compare results of endoscopy assisted nasolacrimal probing with the standard simple probing in cases with congenital nasolacrimal duct obstruction . Furthermore, investigators will identify associated anatomical anomalies. Investigators believe results of this study can be valuable in better understanding of this disease and provide a high evidence level necessary to propose a classification and management algorithm.

Children with symptoms of unilateral or bilateral congenital nasolacrimal duct obstruction, no past surgical management, with one or more of the below criteria will be included:

1. Non-resolving symptoms of epiphora and/or discharge.
2. Congenital dacryocele not resolved after 1 week of lacrimal sac massage, and topical antibiotics.
3. As soon as subsidence of acute dacryocystitis. Parents will be asked about symptoms and patients will undergo lacrimal tests before and after operation in one week, one month and 3months based on a special record form. Patients will be randomly assigned to "simple probing" group or "endoscopy assisted probing" group.

All operations will be performed in operative theater and under general anesthesia. Pre- and post-operative examinations will be performed in plastic clinic in Farabi hospital.

Congenital nasolacrimal duct obstruction is the most common cause of epiphora in infancy that can occur in 5% of newborn infants. It may resolve spontaneously in 95% of patients during the first year of life.(1) After that time surgical intervention is justified. Epiphora after birth is most commonly secondary to a developmental anomaly of imperforated membrane (Hasner valve) in distal part of nasolacrimal duct. Patients with congenital nasolacrimal duct obstruction (CNLDO) may show epiphora, eye discharge, acute dacryocystitis and cellulitis and dacryocele. Currently the management of primary CNLDO includes conservative treatment including lacrimal sac massage and topical antibiotics until 12 months of age.

The standard intervention for non-complicated, unresolved cases is simple blind probing of nasolacrimal duct. The overall success rate of one time simple probing is 75%-95 %. Simple probing is performed through a blind passage of a malleable metallic probe through punctum to nasolacrimal duct and inferior meatal space in nasal cavity.Although effective, probing may be associated with traumatic nasal bleeding, nasal mucosal damage,punctal and canalicular injury and false passage. The trauma is further concerned during stent insertion.In the past decade improvement in endoscopic instruments and techniques enabled us to visualize and smoothly manipulate anomalies in the nasal cavity and especially in the inferior meatus. Endoscopic assisted probing has been proposed as a measure to increase accuracy, efficacy and safety of nasolacrimal probing. Furthermore, by this method intranasal pathologies associated with failure of probing could be accurately diagnosed and specifically treated. To the best of our knowledge literature addressing this issue is limited to few limited case series.

The aim of this study is to compare results of endoscopy assisted nasolacrimal probing with the standard simple probing in cases with congenital nasolacrimal duct obstruction . Furthermore, investigators will identify associated anatomical anomalies. Investigators believe results of this study can be valuable in better understanding of this disease and provide a high evidence level necessary to propose a classification and management algorithm.

Children with symptoms of unilateral or bilateral congenital nasolacrimal duct obstruction, no past surgical management, with one or more of the below criteria will be included:

1. Non-resolving symptoms of epiphora and/or discharge.
2. Congenital dacryocele not resolved after 1 week of lacrimal sac massage, and topical antibiotics.
3. As soon as subsidence of acute dacryocystitis. Parents will be asked about symptoms and patients will undergo lacrimal tests before and after operation in one week, one month and 3months based on a special record form. Patients will be randomly assigned to "simple probing" group or "endoscopy assisted probing" group.

All operations will be performed in operative theater and under general anesthesia. Pre- and post-operative examinations will be performed in plastic clinic in Farabi hospital.

Inclusion Criteria:

1. age: 3 weeks\