Hypo-accommodation responses in hypermetropic infants and children.

AIMS

Accommodation to overcome hypermetropia is implicated in emmetropisation. This study recorded accommodation responses in a wide range of emmetropising infants and older children with clinically significant hypermetropia to assess common characteristics and differences.

METHODS

A PlusoptiXSO4 photorefractor in a laboratory setting was used to collect binocular accommodation data from participants viewing a detailed picture target moving between 33 cm and 2 m. 38 typically developing infants were studied between 6 and 26 weeks of age and were compared with cross-sectional data from children 5-9 y of age with clinically significant hypermetropia (n = 15), corrected fully accommodative strabismus (n=14) and 27 age-matched controls.

RESULTS

Hypermetropes of all ages under-accommodated compared to controls at all distances, whether corrected or not (p < 0.00001) and lag related to manifest refraction. Emmetropising infants under-accommodated most in the distance, while the hypermetropic patient groups under-accommodated most for near.

CONCLUSIONS

Better accommodation for near than distance is demonstrated in those hypermetropic children who go on to emmetropise. This supports the approach of avoiding refractive correction in such children. In contrast, hypermetropic children referred for treatment for reduced distance visual acuity are not likely to habitually accommodate to overcome residual hypermetropia left by an under-correction.