Purpose: To study electroretinograms in infantile nystagmus syndrome associated with idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism.
Methods: A total of 30 children with idiopathic infantile nystagmus, 18 with optic nerve hypoplasia, and 18 with albinism were studied. Three electroretinogram protocols were applied according to child's age: 58 (mean: 2.0 years) were recorded with skin electrode to Great Ormond Street Hospital protocol, 11 (mean: 5.3 years) with skin electrode to International Society for Clinical Electrophysiology of Vision protocol, and 7 children (mean: 12.2 years) with HK electrode to International Society for Clinical Electrophysiology of Vision protocol. The electroretinograms were compared to those of age-matched controls.
Results: Electroretinogram waveforms in idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism were comparable to controls in all protocols. Electroretinogram amplitudes in idiopathic infantile nystagmus group showed increased white scotopic and photopic electroretinograms in 26 children (skin electrode to Great Ormond Street Hospital protocol), no difference to the controls in 3 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol), and increased rod electroretinogram in 3 children (HK electrode to International Society for Clinical Electrophysiology of Vision protocol). Optic nerve hypoplasia group showed increased white scotopic, photopic, and blue electroretinograms in 15 children (skin electrode to Great Ormond Street Hospital protocol); increased 30-Hz electroretinogram in 3 children (HK electrode to International Society for Clinical Electrophysiology of Vision protocol); and reduced combined rod-cone, cone, and 30-Hz electroretinograms in 3 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol). Albinism group showed increased white scotopic, photopic, and 30-Hz electroretinograms in 17 children (skin electrode to Great Ormond Street Hospital protocol), while it showed reduced cone and 30-Hz electroretinograms in 5 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol). Implicit times were shorter in albinism.
Conclusion: Electroretinogram waveforms in idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism were normal with mostly increased electroretinograms, while reduced electroretinograms did not show a specific pattern as in early-onset retinal dystrophies.
Keywords: Idiopathic infantile nystagmus; albinism; children; electroretinogram; nystagmus; optic nerve hypoplasia.