Remarkable visual improvement in Leber hereditary optic neuropathy.

Objective: Leber hereditary optic neuropathy (LHON) typically has a poor visual outcome. In this study, we examined 8 cases of LHON that demonstrated remarkable visual improvement.

Methods: Retrospective observational study, clinical case series METHODS: We analyzed the clinical histories and outcomes of 8 patients (16 eyes) whose best corrected visual acuity (BCVA) improved to 0.7 or higher in at least 1 eye.

Results: The median age of onset of the 7 male patients and 1 female patient was 17 years (range 8-58). Genetic testing revealed m.11778G>A mutations in 6 and m.14484T>C mutations in 2 of the patients. Of the 16 eyes, 15 improved to a BCVA of 0.7 or higher, whilst 1 eye achieved a final BCVA of 0.5. The lowest BCVA was below 0.1 in 12/16 eyes. BCVA improved to 0.1 or better within 1 year in 6/12 eyes and to 0.7 or better within 2 years in 12/15 eyes. In 10 eyes monitored by use of Humphrey Field Analysis (HFA; Fastpac, 30-2 program), the mean deviation improved from - 13.2 dB (- 23.6 to - 4.54) at its lowest to - 5.0 dB (- 15.6 to - 0.9) at the final measurement. Final HFA showed residual defects in the temporal region in 7/16 eyes. In the chronic phase, 10/12 eyes displayed either normal optic disc findings or partial temporal pallor.

Conclusions: In LHON cases with remarkable visual improvement, the recovery began earlier, and the visual field defects were relatively mild and tended to persist in the temporal region after improvement. Understanding these cases of notable improvement may inform future treatment strategies.