Background Anisometropia was recently shown to occur in 10% of infants diagnosed with dacryostenosis at a mean age of 1 year. The purpose of this study was to determine whether earlier (<1 year) spontaneous resolution or probing decreases the risk of anisometropia in infants with dacryostenosis.

Methods The medical records of all patients diagnosed as infants with dacryostenosis at Mayo Clinic, Rochester, Minnesota, USA, from 1 January 1988 to 31 December 1992 were retrospectively reviewed. Of 662 consecutive infants diagnosed with dacryostenosis, 244 (36.9%) were subsequently examined in the ophthalmology department and included in the study. Each of the study patients was followed through to 30 June 2011. The main outcome measure was the rate of anisometropia (≥1 dioptre between the two eyes) among those who spontaneously resolved and those who underwent surgery.

Results Among the 244 cases, 189 (77.5%) spontaneously resolved at a mean age of 4.5 months (range 0.3–35 months), and 55 (22.5%) underwent surgery at a mean age of 16 months (range 0–53 months). Anisometropia was diagnosed in 17 (9.0%) of the 189 who spontaneously resolved and in 2 (3.6%) of the 55 operated children (p=0.19). Although there was no significant trend, earlier resolution was associated with higher rates of anisometropia.

Conclusions Early spontaneous resolution of dacryostenosis was more likely to have a higher, not lower, rate of anisometropia than late spontaneous or surgical resolution. Further studies are warranted to clarify the relationship between infantile dacryostenosis and the development of hyperopic anisometropia.