Analysis of ocular clinical features in 13 children with methylmalonic acidemia / 中华眼底病杂志

ABSTRACT

Objective:To observe the clinical features of eyes in children with methylmalonic acidemia (MMA).Methods:A retrospective clinical case study. From June 2019 to June 2022, 13 children with MMA visited on the Department of Ophthalmology of Henan Children's Hospital were included in the study. The anterior segment and fundus were examined under surface or general anesthesia. Best corrected visual acuity (BCVA) and refraction were performed in 9 cases; fluorescein fundus angiography (FFA) was performed in 3 cases; flash electroretinogram (FERG) was performed in 6 cases; flash visual evoked potential (FVEP) was detected in 6 cases; optical coherence tomography (OCT) was performed in 3 cases.Results:Among the 13 pediatric patients with methylmalonic acidemia, 6 cases were male and 7 cases were female. The average age at first visit was 45 months. All cases suffered from hyperhomocysteinemia; 9 cases were with epilepsy; 2 cases were with infantile spasms; 11 cases were with stunting, 13 cases were with repeated pulmonary infection during growth period; 4 cases were with hydrocephalus; 1 cases was with hypertension and renal insufficiency. Genetic dectection results of 8 cases were recorded, MMACHCc.609G>Ap.W203* mutation site was found in all cases. One case was accompanied by corneal ulcer. There were 10 cases with nystagmus, 4 cases with macular degeneration, 3 cases with hyperopic refractive error and esotropia. Nine cases underwent BCVA examination, BCVA was light perception-0.6. In OCT, 2 cases of 3 cases showed retinal thinning and photoreceptor cell layer atrophy in the macular area. In FFA, 2 cases of 3 cases showed circular transparent fluorescence in the macular area. Five cases of 6 cases who with FVEP had different degrees of P100 peak time delay and decreased amplitude, and 4 cases of 6 cases with FERG had decrease of a and b wave in light and dark adaptation. Conclusions:The clinical phenotypes of eyes in children with MMA are various and the severity was different; most of them are accompanied by nystagmus, and the fundus lesions are common in the characteristic bovine eye like macular region. Those with macular disease have severe visual impairment.