Isoametropic amblyopia in highly hyperopic children.

Purpose: The purpose of this study was to evaluate the visual outcome and associated findings in isoametropic amblyopia due to high hyperopia.

Methods: Children with > or = 5 D spherical equivalent hyperopia and < or = 1.5 D anisometropia and < or = 1.5 D cylinder in both eyes were selected. Data were collected on the magnitude of spherical equivalent hyperopia, corrected visual acuity (VA) with the Snellen or Tumbling E charts, age at correction, duration of correction, ocular motility and strabismus. Children who had VA of < or = 0.4 in both eyes were defined as having isoametropic amblyopia. Associations between isoametropic amblyopia and factors affecting VA were analysed.

Results: A total of 160 children met the criteria. The mean follow-up was 55.8 months. In all, 31 of the children had isoametropic amblyopia. The mean age at presentation was significantly higher (5.5 years versus 4.1 years; p < 0.05) and strabismus was significantly less prevalent (p = 0.001) in the isoametropic amblyopes than in the high hyperopia group as a whole. A total of 83.9% of the isoametropic amblyopes had best corrected VA > 0.5 at the last visit. The duration of optical correction was positively correlated with the last recorded VA measurement.

Conclusion: Isoametropic amblyopia is not rare among highly hyperopic children. Visual acuity improves satisfactorily with spectacle correction. The duration of optical correction seems to be an important factor in visual prognosis.