Ophthalmological characteristics in children with Leigh syndrome - A long-term follow-up

To describe ophthalmological characteristics in children with Leigh syndrome (LS), an inherited, progressive, mitochondrial encephalomyopathy, at diagnosis and over time, and relate the results to causative genetic mutations.

Forty-four children with LS (19 females), with a median age of 2.4 years (range: 0.6-14.2 years) at diagnosis, were studied at the Queen Silvia Children's Hospital, Gothenburg, Sweden. Twenty-eight children had known genetic defects. The children underwent an ophthalmological examination, including visual acuity (VA), eye motility, refraction, slit lamp examination, ophthalmoscopy and a full-field electroretinogram (ff-ERG). Seventeen children were available for follow-up over a mean time of 5.4 years (range: 0.3-14.8 years). The results of these children were compared with an age- and sex-matched reference group of healthy children (n = 119).

Altogether 36/44 of the children (82%) had ophthalmological abnormalities. The most common findings were refractive errors (n = 16/25), low VA (n = 9/36), strabismus (n = 8/42), reduced eye motility (n = 8/40), optic atrophy (n = 7/41), retinal pigmentation (n = 6/40) and nystagmus (n = 6/42). Several ophthalmological manifestations appeared over time. In 5/22 children, ff-ERG showed retinal dystrophy. No significant correlation between phenotype and genotype was found. The children with LS had significantly lower VA (p < 0.0001, Mantel-Haenszel chi-square exact test), more astigmatism (p = 0.012, Fisher's exact test) and higher incidence of strabismus (p = 0.0002) compared to controls at follow-up.

In this unique cohort of children with LS, the vast majority showed ophthalmological findings at diagnosis, which increased over time. Therefore, we recommend that all children diagnosed with LS should be followed up with regular ophthalmological examinations.