Nonarteritic Anterior Ischemic Neuropathy Research Articles

Optic Neuropathy Induced by Sildenafil: When Blinded by Pleasure: Case Report and Literature Review)

Sildenafil citrate is phosphodiesterase 5 inhibitor (PDE5i) that is widely used to treat male erectile dysfunction. However, this molecule has been associated with many visual side effects which most are transient but some can lead to persistent vision loss. Non arteritic anterior ischemic neuropathy (NAION) has been reported in some cases as a very rare, but possible, Sildenafil citrate’s visual adverse effect. We present the case of young patient under erectile dysfunction medication who developed an induced toxic neuropathy, while reviewing the other reported cases in medical literature.

Optical coherence tomography evaluation of retinal nerve fiber layer thickness in non-arteritic anterior ischemic optic neuropathy and primary open angle glaucoma: a systematic review and Meta-analysis

AIM: To assess the differences in average and sectoral peripapillary retinal nerve fiber layer (pRNFL) thickness using spectral domain optical coherence tomography (SD-OCT) in patients with non-arteritic anterior ischemic neuropathy (NAION) compared with those with primary open angle glaucoma (POAG). METHODS: A comprehensive literature search of the PubMed, Cochrane Library, and Embase databases were performed prior to October, 2021. Studies that compared the pRNFL thickness in NAION eyes with that in POAG eyes with matched mean deviation of the visual fields were included. The weighted mean difference (WMD) with 95% confidence interval (CI) was used to pool continuous outcomes. RESULTS: Ten cross-sectional studies (11 datasets) comprising a total of 625 eyes (278 NAION eyes, 347 POAG eyes) were included in the qualitative and quantitative analyses. The pooled results demonstrated that the superior pRNFL was significantly thinner in NAION eyes than in POAG eyes (WMD=-6.40, 95%CI: -12.22 to -0.58, P=0.031), whereas the inferior pRNFL was significant thinner in POAG eyes than in NAION eyes (WMD=11.10, 95%CI: 7.06 to 15.14, P≤0.001). No difference was noted concerning the average, nasal, and temporal pRNFL thickness (average: WMD=1.45, 95%CI: -0.75 to 3.66, P=0.196; nasal: WMD= -2.12, 95%CI: -4.43 to 0.19, P=0.072; temporal: WMD= -1.24, 95%CI: -3.96 to 1.47, P=0.370). CONCLUSION: SD-OCT based evaluation of inferior and superior pRNFL thickness can be potentially utilized to differentiate NAION from POAG, and help to understand the different pathophysiological mechanisms between these two diseases. Further longitudinal studies and studies using eight-quadrant or clock-hour classification method are required to validate the obtained findings.

The current clinical role of optical coherence tomography angiography in neuro-ophthalmological diseases.

After the revolutionary effect of optical coherence tomography (OCT) on ophthalmology practice, recent OCT-based technology OCT angiography (OCT-A) also has rapidly gained a wide clinical acceptance. OCT-A is a noninvasive, depth-resolved imaging tool for the evaluation of retinal vascular changes. Since its introduction, the understanding of retinal vascular diseases, pacychoroid spectrum diseases, and other diseases have been enriched in many ways. More importantly, OCT-A provides depth-resolved information that has never before been available. The whole spectrum of neuro-ophthalmological diseases shows consistent peripapillary and macular capillary changes with structural and functional correlation. The superficial and deeper retinal and choroidal vasculatures are affected depending on the nature of the disease process. Therefore, OCT-A play an important role in the diagnosis and management of optic nerve-related diseases as well. In this review, we summarized existing literature on the use of OCT-A in neuro-ophthalmological diseases such as arteritic anterior ischemic neuropathy, nonarteritic anterior ischemic neuropathy, papillitis, papilledema, multiple sclerosis. Currently, OCT-A has an important position as a useful, noninvasive tool in the evaluation of neuro-ophthalmologic diseases; however, OCT-A has several limitations regarding its technical capabilities in challenging neuro-ophthalmic cases. With the improvement in the technical capacity of OCT-A, it will have a more important place in the diagnosis and follow-up of neuro-ophthalmological diseases in future.

Unilateral Isolated Paucisymptomatic Optic Disc Edema.

Unilateral isolated optic disc edema (UIODE) represents a challenging clinical presentation that frequently precipitates an extensive diagnostic work-up. Patients without an apparent diagnosis despite appropriate investigations are often categorized as having "papillophlebitis," an entity that is poorly defined in the existing literature. Our aim was to describe the characteristics of a series of patients with paucisymptomatic UIODE, determine the optimal diagnostic approach to such cases, and clarify the clinical features of presumed papillophlebitis. We retrospectively identified 29 patients with UIODE who were seen by neuro-ophthalmologists at a single center between 2005 and 2019. Each patient presented with isolated, unilateral disc edema that was either entirely asymptomatic or associated with minimal visual symptoms. Patients underwent a comprehensive neuro-ophthalmic evaluation and several ophthalmic and systemic investigations. Data from the initial visit and all subsequent clinical visits were collected, including patient demographics, examination findings, and details of the diagnostic work-up. Our 29 patients with UIODE were found to have a variety of underlying diagnoses including unilateral papilledema due to idiopathic intracranial hypertension (10 patients), optic nerve sheath meningioma (5), incipient nonarteritic anterior ischemic neuropathy (4), vitreopapillary traction (3), orbital masses (2), a peripapillary choroidal neovascular membrane (1), and presumed papillophlebitis (4). The duration of disc edema varied considerably based on the etiology, but most patients had favorable visual outcomes. A systematic approach to the evaluation of UIODE, combined with long-term follow-up, led to a definite diagnosis in a majority of patients, with only 4 patients presumed to have papillophlebitis, a diagnosis the actual existence of which remains controversial.

Bilateral Delayed Nonarteritic Anterior Ischemic Neuropathy Following Acute Primary Angle-closure Crisis

Bilateral Delayed Nonarteritic Anterior Ischemic Neuropathy Following Acute Primary Angle-closure Crisis

24 HOUR BLOOD PRESSURE PROFILE IN YOUNG AND MIDDLE-AGED PATIENTS WITH RETINAL VEIN OCCLUSION

Background. Absence of nocturnal decrease (non-dipper) or an extreme decrease of blood pressure (BP) (overdipper) may be a sign of vascular dysregulation. Non-dipper pattern is associated with increased risk of strokes and cardiovascular events. Over-dipper pattern increases the risk of non-arteritic anterior ischemic neuropathy and glaucoma progression. Daily BP profile in young and middle-aged adults with retinal vein occlusion (RVO) has not been previously examined. The target organ damage is determined by BP dynamics, regional microcirculation and associated perfusion pressure decrease, which verifies the relevance of our study. Objective. To evaluate the diurnal BP variation, the prevalence of arterial hypertension (HTN) and its character, ocular blood flow in RVO in young and middle-aged adults. Design and methods. The study included 30 patients with RVO. In all patients, routine ophthalmic examination was performed, as well as an additional ocular blood flow assessment (ophthalmoplethysmography, ophthalmorheography, ophthalmosphygmography, and fluorescein angiography). 24‑hour blood pressure monitoring (BPM) was performed to estimate systemic hemodynamics. Results. Statistically significant differences between eyes were noted in visual acuity (p = 0,001) and retinal thickness in macular area (p < 0,001). Patients with HTN showed lower visual acuity (р = 0,04), ocular blood flow parameters (p < 0,05) and retinal mean sensitivity (RMS) (р = 0,02) according to automated static perimetry. Fluorescein angiography showed zones of peripheral retinal ischemia with a mean area of 103 mm 2 (from 0 to 250 mm 2 ). 8 patients had masked HTN according to ambulatory BPM. Depending on the night decrease of BP 13 patients had an extreme decrease of BP (over-dipper), 12 had non-dipper pattern and 5 had dipper pattern. No relation between evaluated parameters was found. However, non-dippers showed a tendency towards lower hemodynamic and automated static perimetry parameters. Conclusions. The prevalence of HTN was 57%, while 47% demonstrated masked HTN. Lower ocular blood flow parameters and RMS according to automated static perimetry were associated with HTN. Vascular dysregulation is considered as a possible cause of RVO in young and middle-aged adults. Its manifestation is the equal frequency of non-dipper and over-dipper patterns. Ambulatory BPM in patients with RVO can be recommended for the detection of HTN, BP profiles, and indirectly, for the evaluation of ocular perfusion pressure, risk stratification and the selection of adequate and individualized antihypertensive therapy to reduce the risk of developing and progressing cardiovascular diseases and mortality.

Choroidal Thickening in Patients with Sleep Apnea Syndrome

Sleep apnoea syndrome (SAS) is characterised by repetitive episodes of cessation of breathing during sleep, resulting in hypoxaemia and hypercapnia. Ophthalmological consequences such as glaucoma, non-arteritic anterior ischaemic neuropathy and papilloedema are relevant to hypoxaemia. The choroid is a vascular structure that performs several regulatory functions for the retina. Defects in this structure contribute to degenerative, inflammatory, and neovascular changes in the retina. The authors examined the choroidal thickness (CT) in sleep apnoea patients using optical coherence tomograpy (OCT). The sleep apnoea patients were divided into subgroups according to their apnoea-hypopnoea index (AHI) scores, and statistical analysis was performed using the AHI and minimal arterial oxygen saturation (min. Spo2) values. There was a medium-high negative correlation between CT and AHI (Spearman rho: r = −0.744, p = 0.000), and a positive correlation between CT and min. Spo2 values (Pearson correlation: r = 0.308, p = 0.000).

Comparison of optic nerve morphology in eyes with glaucoma and eyes with non-arteritic anterior ischemic optic neuropathy by Fourier domain optical coherence tomography

The aim of this study was to compare the optic nerve head (ONH) and peripapillary retinal nerve fiber layer (RNFL) thickness in eyes with glaucoma and non-arteritic anterior ischemic neuropathy (NAION) by Fourier domain optical coherence tomography (FDOCT), and to evaluate the diagnostic capability of FDOCT in glaucoma and NAION. This study included 26 eyes with glaucoma (36.6%), 15 eyes with NAION (21.1%) and 30 eyes of normal subjects (42.3%). Those with the following conditions were excluded; a visual field defect greater than one hemifield, spherical equivalent (SE) more than ±6 D, or the onset of NAION within 6 months. FDOCT was used to analyze the characteristics of ONH and RNFL thickness. Among the three groups of subjects, glaucomatous eyes had the largest cup area and cup volume, and the smallest rim area, rim volume and disc volume (P<0.05). NAION eyes had the smallest cup area and cup volume (P<0.05), but their rim area, rim volume and disc volume were comparable to those of control eyes (P>0.05). The cup-to-disc (C/D) ratio was increased in glaucomatous eyes but reduced in NAION eyes compared with control eyes. Glaucomatous eyes had the greatest loss of RNFL thickness in the temporal upper (TU), superior temporal (ST) and temporal lower (TL) regions (P<0.05), whereas NAION eyes had the smallest RNFL thickness in the superior nasal (SN) and nasal upper (NU) regions (P<0.05). The areas under the receiver operator characteristic curve (AROCs) of the temporal, superior and inferior RNFL in glaucomatous eyes were greater compared with that of the disc area (P<0.05). In addition, the AROCs of the temporal, superior and inferior RNFL were higher compared with that of nasal RNFL (P<0.05). The AROCs of all parameters for NAION were not significantly different, with the exception of superior, nasal superior and inferior temporal RNFL (P<0.05). In conclusion, FDOCT is able to detect quantitative differences in the optic disc morphology and RNFL thickness between glaucomatous and NAION eyes. These differences may provide new insights into the clinical characteristics and diagnosis of the two diseases.

Absence of bilateral vision loss from amiodarone: A randomized trial

Amiodarone's role as a cause of toxic optic neuropathy is based on case reports. Annual frequency estimates of 0.36% to 2.0%, which have been made without reference to the dose or duration of treatment, are 12 to 200 times higher than those for idiopathic nonarteritic anterior ischemic neuropathy. The object of this study was to determine the incidence, dose, and time until onset of bilateral vision loss from amiodarone as a secondary end point in an investigation of amiodarone's role in preventing sudden death. Randomized subjects received body weight-determined doses of closed-label amiodarone (n = 837) or placebo (n = 832) in a prospective double-masked manner. Closed-label amiodarone subjects were followed, unless death occurred, for a minimum of 27 months. Median follow-up in survivors was 45.5 months. The end point was removal from the study because of bilateral vision loss. No subject was removed from the study because of bilateral vision loss. Subjects receiving continuous amiodarone for 4 to >60 months at daily doses of >2.0 mg/kg (n = 696), >3.0 mg/kg (n = 559), or >4.0 mg/kg (n = 219) had maximum possible (95% confidence) annual incidences of bilateral toxic vision loss of 0.23%, 0.29%, or 0.74%, respectively. The maximum possible annual incidence rate of bilateral vision loss from amiodarone in all 837 subjects (median age 60 years) receiving a mean daily dose of 3.7 mg/kg (300 mg) was 0.13%. At the doses commonly used clinically, bilateral vision loss from amiodarone toxic optic neuropathy occurs infrequently, if at all.

Do vardenafil and tadalafil have advantages over sildenafil in the treatment of erectile dysfunction?

Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70 years of age. Sildenafil, vardenafil and tadalafil have all been shown to be similarly effective in the treatment of men with ED of vary etiologies, to have similar adverse effects profiles, and to improve quality-of-life by similar amounts. As these phosphodiesterase 5 (PDE5) inhibitors all increase the hypotensive effects of nitrates, they are not suitable for use in patients taking nitrates for the treatment of ischaemic heart disease. All three inhibitors must be used with caution in patients taking alpha(1)-adrenoceptors antagonists for benign prostatic hyperplasia. Although nonarteritic anterior ischaemic neuropathy has been reported in some users of the PDE5 inhibitors, there is no conclusive evidence that PDE5 inhibitors cause this rare effect. Tadalafil has a longer half-life than sildenafil or vardenafil, and a longer duration of action than sildenafil and vardenafil. Most preference studies have shown tadalafil to be preferred, but there are serious limitations to some of these studies. One approach to treatment is to give each patient a short- and long-acting agent, and for individuals to decide their preference.

Efficacy of levodopa and carbidopa on visual function in patients with non-arteritic anterior ischaemic optic neuropathy

The benefit of levodopa and carbidopa therapy in improving visual function in patients with non-arteritic anterior ischaemic neuropathy (NAION) was evaluated. Twenty-four subjects with NAION were randomly selected to receive either levodopa-carbidopa or a placebo. Visual functions of neither the study nor the placebo groups showed improvement. Side effects of levodopa such as dizziness, orthostatic hypotension, vomiting and cardiac arrhythmia were seen. Levodopa and carbidopa had no therapeutic effect on visual recovery in our patients with NAION.

This Issue of Acta

This Issue of Acta

Participation in the Ischemic Optic Neuropathy Decompression Trial: sex, race, and age

Background The Ischemic Optic Neuropathy Decompression Trial (IONDT) is a randomized, single masked, multicenter trial designed to assess the safety and efficacy of optic nerve decompression surgery compared with careful follow-up in patients 50 years or older with non-arteritic anterior ischemic neuropathy (Naion).Objectives To examine and evaluate the sex, race, and age distributions of the screened, and subsequently enrolled, IONDT population, especially the proportions of female, minority, and elderly patients, and demographic characteristics of clinical center investigators, the geographical location of IONDT Clinical Centers, and the referral patterns of local physicians.Setting Twenty-five U.S. clinical centers.Participants There were 1,681 referrals to the Clinical Centers; an Eligibility Screening Form providing demographic information was completed for 1,152.Findings Forty-three percent (495/1,152) of screened cases were women. Seven percent (85/1152) were minorities: 33 African-Americans, 34 Hispa-nics, 17 Asians, and 1 Native-American. The average age was 66 ± 10 years with a range of 22-92 years of age. Of the 1,152 referred patients, 305 were eligible for randomization; 258 (85%) of these agreed to participate in the trial. The demographic makeup of the randomized IONDT patients was similar to that of the screened population.Conclusions Women and the elderly are well represented in the IONDT. Because the number of participating minorities was low, we cannot reliably assess their level of participation. Both a low incidence of NAION in minori-

Effect of Levodopa and Carbidopa on Recovery of Visual Function in Patients With Nonarteritic Anterior Ischemic Optic Neuropathy of Longer Than Six Months' Duration

We conducted a pilot clinical trial to determine the efficacy of levodopa in promoting visual recovery in eyes with nonarteritic anterior ischemic optic neuropathy of greater than six months' duration. This prospective, randomized, double-masked, placebo-controlled clinical trial involved 20 subjects with nonarteritic anterior ischemic optic neuropathy of 30 months' mean duration. Subjects were randomly assigned to receive either low-dose levodopa and carbidopa or a placebo for three weeks. At 12 weeks after the baseline visit, the levodopa group then was provided a higher, conventional dose of levodopa and carbidopa for three more weeks. Change in visual function was monitored at four, 12, 16, and 24 weeks after the baseline visit. At 12 weeks after the baseline visit, the levodopa group experienced a significant (P = .016) mean difference in improvement of visual acuity of 5.9 letters from the placebo group. At 24 weeks after the baseline visit, a significant treatment effect (P = .036) for visual acuity was still evident; the levodopa group had a mean gain in improvement of 7.5 letters difference from baseline from the placebo group. Three subjects in the levodopa group experienced a doubling of the visual angle as denoted by a gain of at least 15 letters. Significant improvement was not observed for color vision (P = .82) or mean deviation of visual field loss (P = .82). The study found significant improvement of visual acuity among subjects receiving levodopa and carbidopa despite long-standing visual loss from nonarteritic anterior ischemic neuropathy. Confirmation of our results is awaited from larger population studies and with a longer follow-up time interval regarding the efficacy of levodopa in reversing visual loss in this disease.