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 non-glaucomatous 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 mu m (range 94.82-100.89 mu m), whereas the average PRNFLT in 8 of the 9 eyes with NLP was 45.42 mu m (range 37.65-51.46 mu m). Conclusions: Eyes with long-standing NLP vision from nonglaucomatous optic neuropathies retain a residual PRNFLT of about 45 mu m 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.