Table 2 Months of age at resolution of CNLDO by conservative management in patients with bilateral symptoms Patient Right (months of age) Left (months of age) 1 3 2 2 5 3 3 3 3 4 12 11 5 9 9 6 6 6 7 10 10 8 6 9 other studies, the resolution rate of CNLDO by conservative management in Japanese infants still accounted for a high percentage. More than half (16 of 29) of the resolutions of CNLDO patients were observed before 6 months of age. However, a considerable number of patients resolved in the final 6 months (Table 1). This outcome is similar to that reported by MacEwen and Young (1991b) and Paul (1985). They also calculated the possibility of resolution in each month until 12 months of age. In MacEwen and Young’s study (1991b), patients with CNLDO in the 1st month of age were expected to resolve spontaneously in 96% of the cases before 12 months of age, in 75% at 6 months, in 36% at 9 months and in just 5% at 11 months. Paul’s data (1985) with the conservative management showed a similar tendency, ie, 86% of patients with CNLDO at 3 months of age were expected to resolve before 12 months of age, in 70% of those at 6 months and in 52% at 9 months. In each study, a high percentage of the estimated resolutions occurs in the patients’ early life periods, but the rate decreases with age. MacEwen and Young (1991b) showed that most spontaneous resolution occurs within the ﬁrst 6 months, resulting in a low estimated resolution rate in the latter 6. However, according to our results (Table 1), more than 50% of resolution can be expected even in those with CNLDO at 9 months of age, which is similar to the ﬁgures in Paul’s study (1985). Bilateral symptoms of CNLDO were found in our study (Paul 1985; Noda et al 1991; Saito et al 1999). However, laterality with regard to the time of resolution has not been reported. In the present study, all CNLDO patients resolved simultaneously or within 3 months after any contralateral resolution. When one side of bilateral symptoms resolves at 10, 11, or 12 months of age, it is reasonable to observe patients for at least 3 months, because spontaneous reso- lution or resolution by conservative management can be expected after 13 months of age (Young and MacEwen 1997; Schellini et al 2007). Clinical Ophthalmology 2008:2(2) Resolution of CNLDO by conservative management Lacrimal sac massage is usually performed in conservative management for CNLDO (Crigler 1923; Kushner 1982; Noda et al 1991). Putting pressure on the lower part of the nasolacrimal duct by pressing the common canaliculus is a useful procedure (Crigler 1923; Kushner 1982). Although Noda and colleagues (1991) described the efﬁcacy of lacrimal sac massage for the resolution of CNLDO, it was not made clear whether lacrimal content actually moved downward. However, Foster and colleagues (1996) demonstrated this downward movement using lacrimal scintigraphy. Although in that study, lacrimal content did not move toward the naso- lacrimal duct in all patients, the study did suggest the efﬁcacy of lacrimal sac massage. Early probing performed before 12 months of age (Kapadia et al 2006) has been recommended in Japan (Ishikawa et al 1990; Ohki and Yamazaki 1993; Saito et al 1999). This is because ﬁxation of patients is much easier (Ishikawa et al 1990; Zwaan 1997) and prolonged inﬂam- mation is thought to promote ﬁbrosis of obstructed sites with a decrease in the cure rate (Broggi 1959). However, no evidence has been shown that early probing has a higher cure rate than that for spontaneous resolution (Young and MacEwen 1997). None the reports that recommended early probing included controls; thus their results may potentially be ﬂawed (Young and MacEwen 1997). As well, there is no evidence (MacEwen et al 1994) that prolonged inﬂamma- tion promotes ﬁbrosis of obstructed sites (Broggi 1959). In general, prolonged obstruction of the nasolacrimal duct is thought to be caused by a bone malformation of the lacrimal passages (Takagi et al 2005), and not by the membraneous obstruction of the lower aperture of the nasolacrimal duct (Young and MacEwen 1997). Although the resolution rate from early probing is 92 to 100% before 12 months of age (Kapadia et al 2006), this result is similar to that of spontane- ous resolution or resolution by the conservative management before 12 months of age (Kapadia et al 2006). Probing sometimes produces false passages. Injuries to the lacrimal duct epithelium may cause a cicatricial stricture and prevent the spontaneous resolution of CNLDO (Young and MacEwen 1997). The cure rate from a 2nd probing is greatly decreased (Katowitz and Welsh 1987; Hanavar et al 2000). When bleeding is observed during a probing, it usu- ally indicates false passage formation (Young and MacEwen 1997). When there is a probing failure, iatrogenic canalicular obstructions occur in 44% of patients (Lyon et al 1991). To prevent such iatrogenic obstructions, a “wait and see” policy with conservative management appears the best option. Based on the ﬁndings above, early probing before 12 months 293