Childhood-Onset Leber Hereditary Optic Neuropathy-Clinical and Prognostic Insights

PURPOSE: To investigate the clinical and molecular ge-netic features of childhood-onset Leber hereditary optic neuropathy (LHON) to gain a better understanding of the factors influencing the visual outcome in this atypical form of the disease.center dot DESIGN: Retrospective cohort study.center dot METHODS: We retrospectively included 2 cohorts of pa-tients with LHON with onset of visual loss before the age of 12 years from Italy and the United Kingdom. Ophthal-mologic evaluation, including best-corrected visual acu-ity, orthoptic evaluation, slit-lamp biomicroscopy, visual field testing, and optical coherence tomography, was con-sidered. Patients were classified based on both the age of onset and the pattern of visual loss.center dot RESULTS: A total of 68 patients were stratified based on the age of onset of visual loss: group 1 ( < 3 years): 14 patients (20.6%); group 2 ( >3 to < 9 years): 27 patients (39.7%); and group 3 ( >9 to <12 years): 27 patients (39.7%). Patients in group 2 achieved a better visual out-come than those in group 3. Patients in groups 1 and 2 had better mean deviation on visual field testing than those in group 3. The mean ganglion cell layer thickness on optical coherence tomography in group 2 was higher than those in groups 1 and 3. Patients were also catego-rized based on the pattern of visual loss as follows: Suba-cute Bilateral: 54 patients (66.7%); Insidious Bilateral: 14 patients (17.3%); Unilateral: 9 patients (11.1%); and Subclinical Bilateral: 4 patients (4.9%).center dot CONCLUSIONS: Children who lose vision from LHON before the age of 9 years have a better visual prognosis than those who become affected in later years, likely rep-resenting a "form frustre" of the disease. (Am J Oph-thalmol 2023;249: 99-107. (c) 2022 Elsevier Inc. All rights reserved.)