Purpose of the study: To evaluate a group of patients with unilateral isometropic amblyopia according to presence of possible amblyogenic factors.
Material and methods: 37 patients (18 girls and 19 boys) with unilateral amblyopia without strabismus and with anisometropia of less than 1 D in any of the meridians were analysed according to such possible risk factors of amblyopia as age of examination, age of mother on delivery, sex, family history, puerperal complications, birth weight, refraction error, left or right eye. Depth of amblyopia, state of binocular vision and results of optical and pleoptical treatment were also evaluated.
Results and discussion: No significant risks were found regarding the age of patient, sex, left or right eye, birth weight, age of mother on delivery, puerperal complications and family history. Refraction error was not high. Depth of amblyopia did not correlate with amount of refraction error. Central fixation was present only in 50% and stereopsis only in 42% of patients. 10 patients revealed no significant defect of fixation or binocular vision. All patients responded significantly poorly to treatment.
Conclusions: Presence of amblyopia in patients with isometropia cannot be explained by genetic or puerperal risk factors. It might have developed in the period sensitive for amblyopia as a result of anisometropia that was later diminished by the process of emmetropisation or microstrabismus which was spontaneously cured. Some cases can be described as idiopathic because no defect can be detected. Early in life screening is necessary to successfully diagnose and treat amblyopia in childhood.