Ophthalmic findings in an infant with phosphomannomutase deficiency

Introduction: We present the ocular features including full-field electroretinography (ff-ERG) and spectral domain optical coherence tomography (SD-OCT) in a 14-month-old infant with congenital disorder of glycosylation type 1a (PMM2-CDG). Methods and results: An infant with failure to thrive, bilateral neurosensory hearing loss, cerebellar hypoplasia, and pericardial effusions was referred to ophthalmic genetics for evaluation. The patient had fix and follow vision, an intermittent esotropia, moderate myopia, a hypo pigmented macula, and mild attenuation of the retinal vasculature. Electroretinography showed severe reduction in both rod and cone-dependent responses with a negative waveform pattern. Handheld SD-OCT revealed severe attenuation of the outer retina throughout the macula, but with preservation of outer retinal structures in the fovea. Conclusion: PMM2-CDG is a rare congenital disorder for which both ff-ERG and SD-OCT were useful in demonstrating early changes in retinal architecture and function.