Isoametropic amblyopia in highly hyperopic children

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

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.

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.

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.