Preferred retinal locus preserves vision in cytomegalovirus retinitis

To report a rare case of preserved vision via preferred retinal locus (PRL) in a child with cytomegalovirus (CMV) retinitis.

A 7-year-old with congenital CMV infection presented with blurred vision in the left eye. Comprehensive ophthalmic imaging included fundus photography, fluorescein angiography, adaptive optics scanning laser ophthalmoscopy (AO-SLO), microperimetry, and optical coherence tomography (OCT).

Fundus imaging showed an atrophic foveal lesion without leakage. AO-SLO revealed relatively preserved parafoveal cone density. Microperimetry demonstrated near-normal retinal sensitivity in areas adjacent to the fovea. OCT indicated ellipsoid zone disruption and mild intraretinal cysts. Despite structural foveal damage, the patient maintained 20/30 vision in the left eye by adopting a stable extrafoveal PRL.

This case demonstrates the role of PRL in preserving visual function in CMV retinitis, highlighting that foveal integrity is not the sole determinant of acuity. The findings provide insight into adaptive mechanisms and visual rehabilitation strategies in pediatric viral retinopathies.