Optical Coherence Tomographic Comparison of Cuban Epidemic and Leber's Hereditary Optic Neuropathy.

Following the epidemic of optic and peripheral neuropathy, which occurred in Cuba between 1991 and 1993, a number of patients have been re-evaluated, including testing with optical coherence tomography (OCT) and electrophysiology. At the same time, a number of patients with Leber's hereditary optic neuropathy have also been evaluated. The purpose of this study was to detect residual loss of retinal nerve fibre layer (RNFL) in patients who suffered Cuban epidemic optic neuropathy (CEON), and to compare these findings with those in patients with Leber's hereditary optic neuropathy (LHON). Optical coherence tomography as well as clinical examinations were performed on 11 patients diagnosed with CEON 15 years following the epidemic and 14 patients with LHON. OCT in CEON patients showed thinning of the RNFL in the temporal sector and normal thickness in other quadrants. However, patients with chronic LHON had more diffuse RNFL loss throughout the retina. OCT findings corresponded with clinical findings in CEON and LHON. There was drop out of the papillomacular bundle in both diseases. Two patients in the acute stages of LHON and three LHON carriers showed thinning of the temporal RNFL only. This is the first report of OCT in CEON that shows residual damage in the papillomacular bundle compared with chronic LHON where there is more diffuse and progressive loss of the RNFL. The importance of OCT for the diagnosis and evaluation of similar optic neuropathies is emphasised.