Nonarteritic Anterior Ischemic Optic Neuropathy Eyes Research Articles

Nonarteritic Anterior Ischemic Optic Neuropathy: Refractive Error and Its Relationship to Cup/Disc Ratio

To investigate refractive error in eyes with nonarteritic anterior ischemic optic neuropathy (NA-AION) and its relationship to cup/disc (C/D) ratio. Cohort study. A total of 608 consecutive patients with NA-AION. At first visit, all patients had a comprehensive ophthalmic evaluation, including recording best-corrected visual acuity, visual fields, anterior segment examination, ophthalmoscopy, and fluorescein fundus angiography. Morphometric measurement of C/D ratio was performed in 65 fellow normal eyes in patients with unilateral NA-AION. Refraction was converted into spherical equivalent for data analysis. The data were analyzed using Pearson correlation, Mantel-Haenszel chi-square test, Cochran-Mantel-Haenszel test, chi-square goodness-of-fit test, and segmented linear regression. Refractive error in NA-AION eyes and any association between refractive error and C/D ratio. Mean age of patients with NA-AION was 60.9 (standard deviation [SD] = 12.6; range 20.5-95.2) years. Median time from onset to refraction was 2 weeks (interquartile range 1-5 weeks). There was a significant association between spherical equivalent and age (P<0.0001). Comparison of refraction in patients with NA-AION who were aged >or=50 years with that of an age-matched general population in the Framingham study cohort showed no significant difference between the 2 groups (P = 0.289). Comparison with the age-matched US population from the 1999-2000 National Health and Nutrition Examination Survey showed a higher proportion of NA-AION eyes with spherical equivalent from -0.5 to 0.5 diopters and a smaller proportion with -3 to <-0.5 and >0.5 to +3 diopters (P<0.001). For horizontal C/D ratio, a higher degree of myopia and higher degree of hyperopia were significantly associated with a larger C/D ratio (P<0.021). A similar pattern was seen for vertical C/D ratio in hyperopia (P = 0.057) but not in myopia (P = 0.428). There was a significant association between spherical equivalent refraction and age (P<0.0001). C/D ratio in persons with NA-AION is significantly smaller than that seen in the general population. Morphometric study in patients with NA-AION showed that a higher degree of myopia and higher degree of hyperopia are significantly associated with a larger C/D ratio. The authors have no proprietary or commercial interest in any materials discussed in this article.

Non-arteritic anterior ischemic optic neuropathy: role of systemic corticosteroid therapy

To investigate systematically the role of systemic corticosteroid therapy in non-arteritic anterior ischemic optic neuropathy (NA-AION). The study consists of a cohort of 613 consecutive patients (696 eyes), first seen in our clinic from 1973 to 2000. Of this cohort, 312 patients (364 eyes) voluntarily opted for systemic steroid therapy, and 301 (332 eyes) for no treatment. At first visit, all patients in both groups had a detailed ophthalmic and medical history, and comprehensive ophthalmic evaluation. Visual evaluation was done by recording Snellen visual acuity, and visual fields with a Goldmann perimeter. The same ophthalmic evaluation was performed at each follow-up visit. Patients in the steroid-treated group were initially given 80 mg Prednisone daily for 2 weeks, and then tapered down to 70 mg for 5 days, 60 mg for 5 days, and then cutting down by 5 mg every 5 days. Visual outcome in the two groups was compared Median follow-up was 3.8 years. At 6 months from onset of NA-AION, of the eyes with initial visual acuity 20/70 or worse and seen within 2 weeks of onset, there was visual acuity improvement in 69.8% (95% confidence interval (CI): 57.3%, 79.9%) in the treated group, compared to 40.5% (95% CI: 29.2%, 52.9%) in the untreated group (odds ratio of improvement: 3.39; 95% CI:1.62, 7.11; p = 0.001). Comparison of visual field defect at 6 months from onset of NA-AION, among those seen within 2 weeks of NA-AION onset with moderate to severe initial visual field defect, there was improvement in 40.1% (95% CI: 33.1%, 47.5%) of the treated group, and 24.5% (95% CI: 17.7%, 32.9%) of the untreated group (odds ratio: 2.06, 95% CI: 1.24, 3.40; p = 0.005). In both treated and untreated groups, the visual acuity and visual fields kept improving up to about 6 months from onset of NA-AION, and very little thereafter. This study suggested that NA-AION eyes treated during the acute phase with systemic corticosteroids resulted in a significantly higher probability of improvement in visual acuity (p = 0.001) and visual field (p = 0.005) than in the untreated group. Both visual acuity and visual fields improved up to 6 months after onset of NA-AION.

Visual Field Abnormalities in Nonarteritic Anterior Ischemic Optic Neuropathy

To evaluate the pattern of various types of visual field defects and their prevalence at initial examination of nonarteritic anterior ischemic optic neuropathy (NA-AION). The data were compiled from 312 consecutive eyes (in 265 patients) that fulfilled our inclusion and exclusion criteria. A comprehensive ophthalmic evaluation was performed, including recording of visual acuity, visual fields with a Goldmann perimeter (using I-2e, I-4e, and V-4e targets regularly), and intraocular pressure; slitlamp examination of the anterior segment; ophthalmoscopy; color fundus photography; and in acute cases, fluorescein fundus angiography. The visual field defects were divided into 2 groups: (1) general field defects and (2) various types of scotoma in the central 30 degrees . The prevalence of various types of visual field defects was estimated for I-2e, I-4e, and V-4e isopters by dividing the total number of eyes with the defect by the total number of eyes that could see that particular target. Exact 95% confidence limits for the prevalence were computed. Of the 265 patients, 169 (63.7%) were male and the mean +/- SD patient age was 55.0 +/- 9.1 years. The median interval between the first visual field test and the onset of NA-AION was 2 weeks. Of the 312 eyes, the I-2e target was seen by 75.3%, the I-4e target by 90.7%, and the V-4e target by 100%. Overall prevalence of general visual field defects was 83.4% with I-2e, 78.8% with I-4e, and 68.9% with V-4e, whereas the prevalence of scotoma(s) within the central 30 degrees was 55.3%, 49.5%, and 36.2%, respectively. Central scotoma was seen in 48.5% with I-2e, 43.8% with I-4e, and 29.2% with V-4e. A detailed prevalence of various types of visual field defects is given. Relative inferior altitudinal defect was most common (34.9% with I-2e and 22.3% with I-4e), but the absolute inferior altitudinal defect was seen in only 8.0%. By contrast, absolute inferior nasal sector visual loss was the most common defect detected in NA-AION (22.4%), but it occurred in only 3.4% with I-2e and 11.0% with I-4e. Overall, loss of the nasal part of the visual field was the most common occurrence. Our study demonstrated that NA-AION eyes may initially show a variety of optic nerve-related visual field defects. Our study also showed that an absolute inferior nasal visual field defect is much more common (22.4%) than an absolute inferior altitudinal visual field defect (8.0%) in NA-AION and could be considered the most characteristic single field defect in NA-AION. We found that a combination of relative inferior altitudinal defect with absolute inferior nasal defect is usually the most common pattern in NA-AION.

Confocal Scanning Laser Ophthalmoscopy of Eyes with Nonarteritic Anterior Ischemic Optic Neuropathy

Purpose: To evaluate optic nerve head topography in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using confocal scanning laser ophthalmoscopy. Methods: Both eyes of patients with NAION were imaged using a Heidelberg retina tomograph (HRT II; version 1.5) several months after initial presentation, when the optic disc edema had settled. Data from the stereometric analysis of optic nerve heads of eyes with NAION were compared to those of fellow eyes without NAION and eyes of an age- and sex-matched control group. Stereometric parameter values of the fellow eyes were compared with those of the control group. Results: Average age of the 23 Caucasian patients was 57.96 ± 10.41 years (range: 28–71 years). Seven patients (30%) were female and 16 (70%) were male. Four patients (17%) had bilateral NAION. Cup area, cup volume, cup/disc area, linear cup/disc area, mean cup depth, maximum cup depth, mean retinal nerve fiber layer (RNFL) thickness, and RNFL cross-sectional area values were smaller in the NAION eyes than in the control eyes (p < 0.05). A comparison of the NAION eyes with their fellow eyes revealed lower mean cup depth, maximum cup depth, mean RNFL thickness, and RNFL cross-sectional area in the diseased eyes (p < 0.05). Moreover, cup area, cup volume, cup/disc area, linear cup/disc area, mean cup depth, maximum cup depth values were smaller in the fellow eyes than the control eyes (p < 0.05). Conclusion: Using an objective imaging method, confocal scanning laser ophthalmoscopy, eyes with NAION were shown to have a smaller cup volume and cup/disc area, but not a smaller optic disc area than control eyes.