Peripapillary nerve fiber layer thickness measured by optical coherence tomography in patients with no light perception from long-standing nonglaucomatous optic neuropathies

BACKGROUND: The residual peripapillary retinal nerve fiber layer thickness (PRNFLT) corresponding to no light perception vision from long-standing nonglaucomatous optic neuropathies has not been documented. Such a benchmark would be useful information because PRNFLT is being used as an indicator of the visual recovery potential in patients with optic neuropathies. METHODS: By means of optical coherence tomography (OCT) using a fast RNFL thickness protocol, we determined the PRNFLT in 8 patients with no light perception (NLP) for at least 1 year from acquired nonglaucomatous optic neuropathies. All patients underwent an assessment of visual acuity, color vision, visual field, pupillary reactions to light stimulation, and ophthalmoscopy. RESULTS: Four of the 8 patients had a normal fellow eye. The average PRNFLT in the 4 normal eyes was 97.90 μm (range 94.82-100.89 μm), whereas the average PRNFLT in 8 of the 9 eyes with NLP was 45.42 μm (range 37.65-51.46 μm). CONCLUSIONS: Eyes with long-standing NLP vision from nonglaucomatous optic neuropathies retain a residual PRNFLT of about 45 μm as measured by OCT. This should be taken into consideration when using PRNFLT to assess visual prognosis in patients with poor vision from various optic neuropathies.