PURPOSE: To study the characteristics of nonarteritic anterior ischemic optic neuropathy (NAION) as measured with optical coherence tomography (OCT) at diagnosis and during the first year after the episode. DESIGN: Cohort study. PARTICIPANTS: Twenty-seven patients diagnosed with NAION in our center between April 1, 2004 and March 31, 2006. METHODS: Patients diagnosed with NAION underwent at the time of diagnosis and 6 weeks and 3, 6, and 12 months after presentation a complete ophthalmologic evaluation, including determination of Snellen visual acuity (VA), visual fields (VFs) (standard automated perimetry, Swedish Interactive Threshold Algorithm strategy 24-2), and optic nerve head (ONH) scanning with StratusOCT. MAIN OUTCOME MEASURES: Characteristics of the ONH and their relationship with VA and VFs. RESULTS: Initial mean retinal nerve fiber layer (RNFL) thickness in the affected eye was 200.9 microm (standard deviation [SD], 52.3 microm); this represented a 96.4% increase relative to the fellow eye. Percentages of RNFL loss 3, 6, and 12 months after onset were 38.9%, 42.3%, and 43.9%, respectively. At the 6-month visit, RNFL percentage decreases for the superior, nasal, inferior, and temporal quadrants were 51.5%, 28.5%, 41.2%, and 38.2%, respectively. Reduction in the superior quadrant RNFL thickness was statistically higher. Using regression analysis, it was found that for every micrometer of mean RNFL thickness lost there was a 2-decibel decrease in VF mean deviation (MD) and that there was a 1-line drop in Snellen VA for every 1.6 microm lost. The mean ONH area was 2.6 mm2 (SD, 0.4) in the unaffected eye; there was no correlation with VA, VF MD, or RNFL thickness of the affected eye at the last follow-up visit. CONCLUSIONS: Optical coherence tomography can diagnose optic disc edema and monitor RNFL loss over time. It is most useful at onset and 6 months after NAION, when RNFL loss has reached a plateau and is correlated with visual function. Future studies that aim to determine if a drug or intervention is useful for treating NAION may include OCT assessment of the RNFL thickness, because it provides an objective outcome measure correlated with visual performance.
PURPOSE: To study the characteristics of nonarteritic anterior ischemic optic neuropathy (NAION) as measured with optical coherence tomography (OCT) at diagnosis and during the first year after the episode. DESIGN: Cohort study. PARTICIPANTS: Twenty-seven patients diagnosed with NAION in our center between April 1, 2004 and March 31, 2006. METHODS:Patients diagnosed with NAION underwent at the time of diagnosis and 6 weeks and 3, 6, and 12 months after presentation a complete ophthalmologic evaluation, including determination of Snellen visual acuity (VA), visual fields (VFs) (standard automated perimetry, Swedish Interactive Threshold Algorithm strategy 24-2), and optic nerve head (ONH) scanning with StratusOCT. MAIN OUTCOME MEASURES: Characteristics of the ONH and their relationship with VA and VFs. RESULTS: Initial mean retinal nerve fiber layer (RNFL) thickness in the affected eye was 200.9 microm (standard deviation [SD], 52.3 microm); this represented a 96.4% increase relative to the fellow eye. Percentages of RNFL loss 3, 6, and 12 months after onset were 38.9%, 42.3%, and 43.9%, respectively. At the 6-month visit, RNFL percentage decreases for the superior, nasal, inferior, and temporal quadrants were 51.5%, 28.5%, 41.2%, and 38.2%, respectively. Reduction in the superior quadrant RNFL thickness was statistically higher. Using regression analysis, it was found that for every micrometer of mean RNFL thickness lost there was a 2-decibel decrease in VF mean deviation (MD) and that there was a 1-line drop in Snellen VA for every 1.6 microm lost. The mean ONH area was 2.6 mm2 (SD, 0.4) in the unaffected eye; there was no correlation with VA, VF MD, or RNFL thickness of the affected eye at the last follow-up visit. CONCLUSIONS: Optical coherence tomography can diagnose optic disc edema and monitor RNFL loss over time. It is most useful at onset and 6 months after NAION, when RNFL loss has reached a plateau and is correlated with visual function. Future studies that aim to determine if a drug or intervention is useful for treating NAION may include OCT assessment of the RNFL thickness, because it provides an objective outcome measure correlated with visual performance.
Authors: Deanna P Lyttle; Lenworth N Johnson; Edward A Margolin; Richard W Madsen Journal: Graefes Arch Clin Exp Ophthalmol Date: 2015-10-20 Impact factor: 3.117
Authors: Evelyn C O'Neill; Helen V Danesh-Meyer; Paul P Connell; Ian A Trounce; Michael A Coote; David A Mackey; Jonathan G Crowston Journal: Nat Rev Neurol Date: 2010-03-09 Impact factor: 42.937
Authors: Gema Rebolleda; Laura Diez-Alvarez; Alfonso Casado; Carmen Sánchez-Sánchez; Elisabet de Dompablo; Julio J González-López; Francisco J Muñoz-Negrete Journal: Saudi J Ophthalmol Date: 2014-10-05