To study retinal nerve fiber layer (RNFL) thickness by optical coherence tomog raphy (StratusOCT) in patients with Leber’s hereditary optic neuropathy (LHON). Cross-sectional study. Thirty-eight patients with LHON were analyzed and comp ared with an age-matched control group of 75 patients. Patients with LHON were classified as having early LHON (E-LHON, n=8) when the duration of the disease was shorter than 6 months and atrophic LHON (A-LHON, n=30) when the duration wa s longer than 6 months. The fast RNFL thickness (3.4) scan acquisition protocol was used. Retinal nerve fiber layer thickness as measured by StratusOCT. Compare d with the control group, eyes with E-LHON showed a thicker RNFL in the 360°av erage measurement (P < 0.01) and in the superior (P < 0.01), nasal (P < 0.05), a nd inferior quadrants (P < 0.05); no significant changes were detected in the te mporal quadrant. Eyes with A-LHON revealed a thinner RNFL in all measurements ( P < 0.001); the fibers of the nasal quadrant showed the lowest amount of reducti on (38%vs. 42%-49.8%in the other quadrants). In cases with A-LHON and visual recovery, RNFL was significantly thicker in all measur ements (P < 0.001), except the temporal quadrant, with respect to A-LHON withou t visual recovery. On the basis of OCT data, the RNFL is thickened in E-LHON an d severely thinned in A-LHON. RNFL is likely to be partially preserved in A-LH ON with visual recovery. The temporal fibers (papillomacular bundle) are the fir st and most severely affected; the nasal fibers seem to be partially spared in t he late stage of the disease. To study retinal nerve fiber layer (RNFL) thickness by optical coherence tomog raphy (Stratus OCT) in patients with Leber’s hereditary optic neuropathy (LHON). Cross-sectional study. Thirty-eight patients with LHON were analyzed and comp ared with an age-matched control group of 75 patients. Patients with LHON were classified as having early LHON (E-LHON, n = 8) when the duration of the disease was shorter than 6 months and atrophic LHON (A-LHON, n = 30) when the duration The value of the fast RNFL thickness (3.4) scan acquisition protocol was used. Retinal nerve fiber layer thickness as measured by Stratus OCT. Compare d with the control group, eyes with E-LHON showed a thicker RNFL in the 360 ​​° A significant difference was detected in the te mporal quadrant (P <0.01) and in the superior (P <0.01), nasal (P <0.05), a nd inferior quadrants LHON revealed a thinner RNFL in all measurements (P <0.001); the fibers of the nasal quad In cases with A-LHON and visual recovery, RNFL was significantly thicker in all measur ements (P <0.001), except the On the basis of OCT data, the RNFL is thickened in E-LHON an d severely thinned in A-LHON. RNFL is likely to be partially preserved in A-LH ON with visual recovery. The temporal fibers (papillomacular bundle) are the fir st and most severely affected; the nasal fibers seem to be partially spared in t he late stage of the disease.