ObjectiveTo observe the changes in blood flow density of radial retinal peripapillary capillary (RPC) around the optic disc in patients with non-arteritic anterior ischemic optic neuropathy (NAION) at different stages of the continuous course of the disease. MethodsA prospective cohort study. From January to December 2020, 29 cases of 29 eyes of NAION patients diagnosed in the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine were included in the study. Among them, there were 18 males with 18 eyes and 11 females with 11 eyes. The average age was 53.62±6.67 years old. The affected eye underwent routine eye examination and visual field, optic cohenrence tomography angiography (OCTA) examination. Visual field inspection was performed to obtain the average visual mean defect (MD) value. OCTA was used to measure the thickness of the peripapillary retinal nerve flayer (pRNFL) around the optic disc, the whole en face image vessel density (wiVD), intro disc vessel density (diVD), RPC blood flow density around the optic disc, and macular ganglion cell complex (GCC). The course of disease ≤3 weeks was defined as the acute phase; 4-12 weeks was defined as the subacute phase; ＞12 weeks was defined as the chronic phase. The changes of visual field MD, optic disc RPC blood flow density, pRNFL thickness and macular GCC thickness were observed in the acute, subacute and chronic phases (12-24, ＞24 weeks). A completely randomized design of variance analysis was used to compare the differences in visual field MD, RPC blood flow density, GCC, and pRNFL thickness in different courses. Pearson correlation analysis was used to analyze the correlation between pRNFL thickness, macular GCC thickness, visual field MD changes and RPC blood flow density around the optic disc sex. ResultsThe wiVD of the eyes in the acute phase, subacute phase, and chronic phase (12-24 weeks, ＞24 weeks) were (44.96±2.76)%, (41.50±3.49)%, (39.08±5.43)%, (38.56±6.48)%. There was a statistically significant difference in wiVD of eyes with different disease courses (F=8.939, P＜0.001). The average difference of wiVD between 12-24 weeks and ＞24 weeks in the chronic phase was －0.984, and the difference was not statistically significant (P＞0.05). There was no statistically significant difference in diVD of patients with different courses of disease (F=1.079, P=0.365). The blood flow density of RPC around the optic disc of the affected eye, except for the lower part, the blood flow density of the nasal side, the temporal side, and the upper quadrant, decreased significantly with the progression of the disease, and the difference was statistically significant (F=8.816, 6.069, 8.943; P＜0.05). In the chronic phase, the average difference of blood flow density between the nasal, temporal, and upper sides of the eyes between 12-24 weeks and more than 24 weeks in the chronic phase was －0.984, －0.230, －0.198, and the difference was not statistically significant (P＞0.05). There was no statistically significant difference in the visual field MD of patients with different courses of disease (F=0.277, P=0.842); the overall pRNFL thickness and average macular GCC thickness were compared with statistical significance (F=47.122, 14.954; P＜0.001, ＜0.001), all became significantly thinner with the progression of the disease. The results of Pearson correlation analysis showed that the blood flow density of the entire optic disc wiVD, the blood flow density of RPC in the temporal quadrant around the optic disc and the visual field MD (r=－0.225, －0.268; P＜0.05), and the average thickness of GCC (r=0.480, 0.436; P＜0.01) were all related. ConclusionThe blood flow density of RPC in the entire optic disc and around the optic disc (except the lower quadrant) of NAION eyes gradually decrease with the progression of the disease, and stabilize after 12 weeks of the disease.
Objective To observe the characteristics of multifocal microperimetry and its relationship with visual acuity and multifocal ganglion cell complex (GCC) in nonarteritic anterior ischemic optic neuropathy (NAION). Methods A retrospective case study. A total of 38 patients (54 eyes) with NAION were enrolled in this study. 25 NAION eyes (25 patients) and 29 contralateral health eyes (29 patients) were randomly selected into case group and control group respectively. All eyes underwent best corrected visual acuity (BCVA), slit lamp microscope, indirect ophthalmoscope, color fundus photography, optical coherence tomography (OCT), visual field and multifocal microperimetry. Logarithm of the minimum angle of resolution (logMAR) was used to calculate BCVA. There were no significantly differences on age (t=−0.647), gender, dominant eyes ( χ2=0.128, 0.099), intraocular pressure (t=0.376) between two groups (P>0.05). Macular GCC thickness, superior and inferior GCC thickness were measured by OCT, focal loss volume (FLV) and global loss volume (GLV) were obtained at the same time. Microperimetry were measured by macular integrity assessment instrument (MAIA microperimetry), and mean retinal sensitivities (MS) in macular area 10° and fixation rate in the macular central 2° and 4° were determined. The relationship between MS, macular GCC and BCVA were analyzed by Spearman correlation analysis. Results The mean logMAR BCVA of case group and control group were 0.68±0.79 and 0.07±0.06, respectively. There was significantly statistical difference in MS between two groups (t=−2.507, P=0.037). There were no significantly statistical difference in mean GCC (t=−1.245, P=0.259), superior and inferior GCC (t=−1.336, −1.024; P=0.230, 0.346), FLV (t=1.058, P=0.331) and GLV (P=0.182) between two groups. The correlation between BCVA and MS (r=−0.809, P=−0.005) was observed. However, there were no correlation between BCVA and GCC, superior and inferior GCC, FLV, GLV (r=−0.98, −0.466, −0.061, 0.442, 0.442; P=0.817, −0.244, 0.885, 0.273, 0.273). And also, there were no correlation between MS and GCC, superior and inferior GCC, FLV, GLV (r=0.238, 0.524, 0.286, 0.643, −0.619; P=0.570, 0.183, 0.493, 0.086, 0.102). Conclusions MS reduced in early stage NAION eyes, which did not correlate with macular GCC.
ObjectiveTo observe the blood perfusion changes of peripapillary and macular vessels in patients with nonarteritic anterior ischaemic optic neuropathy (NAION).MethodsRetrospective cohort study. Thirty-six eyes (19 affected eyes and 17 fellow eyes) of 19 patients with NAION diagnosed in People’s Hospital of Wuhan University from November 2017 to January 2019 were included in this study. There were 10 males and 9 females, with the mean age of 55.05±7.11 years. Forty eyes of 20 normal subjects matched with NAION patients were included as controls. BCVA, fundus color photography, SD-OCT and OCT angiography were performed in normal controls and repeated in NAION affected eyes at 1-2 weeks, 1-2 months, 3-5 months intervals. OCT quantitative measurements: average retinal nerve fiber layer thickness (aRNFL) of the disc and its superior values (sRNFL) and the inferior values (iRNFL), average ganglion cell complex thickness (aGCC) in macular region and its superior values (sGCC) and the inferior values (iGCC). OCTA quantitative measurements: average radial peripapillary capillary density (aRPC) and its superior values (sRPC) and the inferior values (iRPC), average vascular density of superficial retina (aSVD) in macular region and its superior values (sSVD) and the inferior values (iSVD), average vascular density of deep layer retina (aDVD), areas of foveal avascular zone (FAZ). The differences of OCT and OCTA quantitative measurements between NAION eyes and the fellow eyes and normal controls were comparatively analyzed. Independent sample t test, paired sample t test or nonparametric rank sum test were performed for comparison among three groups. Pearson or Spearman correlation analysis were used to analyze the correlation between RNFL and RPC, GCC and SVD, RNFL and GCC, RPC and SVD.ResultsAt baseline, the aRNFL, aRPC and aDVD of NAION patients were significantly higher than those of normal controls. Compared with the fellow eyes, the aRNFL increased significantly and the aRPC decreased significantly in NAION affected eyes. The overall differences of aRNFL, aRPC, aGCC and aSVD at four intervals within NAION affected eyes were statistically significant (P＜0.05). The average sRNFL, sRPC, sGCC and sSVD at 1-2 months interval were significantly lower than the average iRNFL, iRPC, iGCC and iSVD (P＜0.05). Correlation analysis: at 1-2 months interval, aGCC was positively correlated with aSVD (r=0.482, P=0.037); at 3-5 months interval, aRNFL was positively correlated with aRPC (r=0.631, P=0.037).ConclusionThere is a sectorial reduction of vascular density of peripapillary RPC and macular SVD with the disease progression of NAION.
ObjectiveTo observe the morphological characteristics of internal carotid artery (ICA) siphon and ophthalmic artery (OA) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) based on CT angiography (CTA) three-dimensional reconstruction of ICA siphon and OA models. MethodsA retrospective cohort study. From January 2017 to January 2019, 26 patients with 31 eyes (NAION group) who were diagnosed with NAION by ophthalmic examination at Beijing Friendship Hospital, Capital Medical Universitywere included in the study. Among them, there were 11 males with 13 eyes, and 15 females with 18 eyes; the age was 67.52±6.30 years old. Nineteen eyes of 19 non-affected contralateral eyes were selected as the contralateral eye group. Among them, there were 9 males with 9 eyes and 10 females with 10 eyes; the age was 65.95±5.66 years old. Twenty-six eyes of 26 age- and sex-matched subjects with normal fundus examination during the same period were selected as the normal control group. All subjects underwent best corrected visual acuity (BCVA), intraocular pressure, fundus photography and CTA examination. The data obtained from CT scans were reconstructed by 3D model, and the anatomical morphology of ICA siphon was divided into U-shape, V-shape, C-shape and S-shape; the diameter of ICA siphon portion and the diameter at the beginning of OA were measured. One-way analysis of variance was used to compare the diameter of the OA at the beginning of the OA and the diameter of the ICA siphon between the three groups of eyes. ResultsThe diameters at the beginning of OA in the NAION group, the contralateral eye group, and the normal control group were 1.17±0.20, 1.34±0.17, and 1.39±0.15 mm, respectively, and the differences among the three groups were statistically significant (F=12.325, P<0.05); there was no significant difference between the contralateral eye group and the normal control group (P=0.310). In the NAION group, the anatomical morphology of the ICA siphon was U-shaped and V-shaped in 20 (64.52%) and 8 (25.81%) eyes respectively, and S and C-shaped in 3 eyes (9.67%); in the contralateral eye group, in the control group, the ICA siphon shape of the eyes examined was U-shaped and V-shaped, and S-shaped and C-shaped were rare. The diameters of the ICA siphons in the NAION group, the contralateral eye group, and the normal control group were 3.50±0.69, 3.22±0.59, and 3.55±0.54 mm, respectively. There was no significant difference between the three groups (F=1.860, P=0.163). ConclusionU-shaped and V-shaped ICA siphons are more common in NAION-affected eyes; the diameter of the starting point of OA is significantly reduced.
ObjectiveTo evaluate the occurrence of nocturnal hypotension (NHP) in nonarteritic anterior ischemic optic neuropathy (NAION). MethodsA evidence-based medicine study. Chinese and English as search terms for NAION and NHP was used to search literature in PubMed of National Library of Medicine, Embase, Web of science, Cochrane Library, Clinical Trials, Wanfang, and China National Knowledge Infrastructure and China Biology Medicine disc. Incomplete or irrelevant literature and review literature were excluded. The literature was meta-analyzed using Review Manager 5.4 and STATA 15.0. The 95% confidence interval (CI) were selected as the estimated value of effect size, the occurrence of NHP in NAION was calculated, and sensitivity analysis and publication bias analysis were also performed to assess the robustness of pooled outcomes. ResultsAccording to the search strategy, 159 articles were initially retrieved, and 8 articles were finally included for meta-analysis, three prospective studies and five retrospective studies. The occurrence of NHP in NAION was 43% (95%CI, 0.36-0.50). Sensitivity analyses confirmed that the evidence was robust. Subgroup analyses showed that the occurrence of NHP in NAION nearly the same in White patients (47%, 95%CI 0.39-0.55) and Chinese patients (41%, 95%CI 0.32-0.51). The occurrence of NHP in NAION was higher in using night mean artery pressure (45%, 95%CI 0.31-0.60) as the diagnostic criteria than using night systolic blood pressure & night diastolic blood pressure (40%, 95%CI 0.32-0.50). ConclusionsThe occurrence of NHP in NAION was 43%; the occurrence was similar in patients of different ethnicities. The diagnosis rate could be improved by using nMAP ＜ 70 mm Hg (1 mm Hg=0.133 kPa) as a diagnostic criterion for NHP. Careful intervention should be taken for the blood pressure of patients with NAION and NHP.
Non-arteritic ischemic optic neuropathy (NAION) is a neurological disease due to poor perfusion in optic disk. It causes severe visual function impairment, characterized by loss of vision and visual field defect. Optical coherence tomography (OCT) is vital for detecting anterior laminar depth, peripapillary nerve fiber layer thickness, ganglion cell complex thickness and peripapillary choroid thickness change in eyes with NAION at different course of the disease. In addition, OCT features are in accordance with visual function impairment. OCT angiography (OCTA) reveals retinal and choroidal vasculature networks in optic and macular area. OCTA revealed vasculature perfusion decline in eyes with NAION, even if their visual sensitivity and visual evoked potential were normal. Studying OCT and OCTA features is vital for exploring the pathogenesis and prognosis of NAION.
ObjectiveTo determine the correlation between obstructive sleep apnea syndrome (OSAS) and nonarteritic ischemic optic neuropathy (NAION).MethodsIt was a perspective study. A total of 41 consecutive patients with NAION (NAION group) and 41 age- and sex-matched physical examination subjects (control group) in Xi’an No.3 Hospital from December 2016 to December 2018 were enrolled in this study. The apnea hypopnea index (AHI, the number of sleep apneas per hour) was monitored using a polysomnography for patients in NAION group and control group. At the same time, the blood oxygen saturation was continuously recorded. The OSAS can be diagnosed if the AHI value was ≥5. OSAS severity was graded as mild: 5≤AHI＜15; moderate: 15≤AHI＜30; severe: AHI ≥30. The grading of OSAS severity between two groups was compared by Fisher's exact test. The AHI and minimum blood oxygen saturation were compared between NAION group and control group using the Mann-Whitney U test. Spearman correlation analysis was performed on the correlation between OSAS and NAION.ResultsAmong the patients in the NAION group, 31 patients (75.61%) were diagnosed with OSAS. Among them, 6 patients (14.63%) were mild, 9 patients (21.95%) were moderate, and 16 patients (39.03%) were severe. In the control group, 19 patients (46.34%) were diagnosed with OSAS. Among them, 10 patients (24.39%) were mild, 5 patients (12.20%) were moderate, and 4 patients (9.75%) were severe. The difference of OSAS patients of mild, moderate and severe between two groups were statistically significant (Z=0.235, 0.245, 0.312; P=0.012, 0.014, 0.032). The average AHI of patients in the NAION group was 20.25±7.74, and the mean minimum oxygen saturation at night was (87.38±5.53)%. The average AHI of the control group was 18.67±11.67, and the mean minimum oxygen saturation at night was (85.06+4.25)%. The differences of the mean AHI and mean minimum oxygen saturation between two groups were statistically significant (Z=1.124, 2.317, P=0.003, 0.020). There was a positive correlation between OSAS and NAION (Spearman correlation coefficient=0.229, P=0.030).ConclusionThere is a positive correlation between OSAS and NAION.
ObjectiveTo observe the blood perfusion of optic nerve and macular areas and investigate its relationship with visual field defect in nonarteritic anterior ischemic optic neuropathy (NAION).MethodsTwelve consecutive unilateral NAION patients (course of disease ＜3 months) and 12 healthy Chinese adults were enrolled in the study. The affected eyes and fellow eyes from 12 NAION patients were defined as group A and group B; 12 eyes from 12 healthy adults were defined as group C. Best corrected visual acuity (BCVA), intraocular pressure (IOP), indirect ophthalmoscope and computer optometry were performed on all of the three groups of patients. Visual field (VF) and optical coherence tomography (OCT) were performed on NAION patients. Logarithm of the minimum angle of resolution (logMAR) was used to calculate visual acuity. Compared to group B, logMAR BCVA, mean deviation (MD) and pattern standard deviation (PSD) in group A were significant decreased (t=3.278, −4.909, 4.130, P＜0.05). There was no significant difference in spherical equivalent, IOP, peripapillary retinal nerve fibre layer (pRNFL) between group A and group B (t=0.000, 0.890, 1.215; P＞0.05). OCT angiography (OCTA) was used to measure the flow area (FA) at optic disc, flow area at radial peripapillary capillaries (RCFA) and FA, non-perfusion area (NFA), parafoveal vessel density (PVD) and parafoveal vascular index (PVI) in macular area. Pearson correlations between the deficiency of optic blood flow and visual field were analyzed.ResultsThe differences of FA at optic disc and peripapillary RCFA among 3 groups were significant (F=4.162, 3.357; P＜0.050). Compared to group B (t=−5.822, −7.467; P＜0.001) and C (t=9.435, 4.615, P＜0.05), FA at optic disc and peripapillary RCFA in group A was significantly reduced. There is several NAION showed quadrantal FA decreased in optic nerve. However, there was no significant difference in optic disc FA and peripapillar RCFA between group B and C (F=0.004, 0.030; P＞0.050). There was no differences of FA, NFA, PVD and PVI among 3 groups (F=0.488, 1.107, 0.493, 1.086, 1.098, 0.093, 1.093, 1.221; P＞0.05). Positive correlation between optic disc FA, peripapillary RCFA and MD (r=0.542, 0.585; P＜0.05) were observed. However, there was no significant correlation between optic disc FA, peripapillary RCFA and PSD (r=−0.404, −0.430; P＞0.05), and negatively correlated to BCVA (r=−0.617, −0.596; P＜0.05). PRNFL was negatively correlated to optic disc FA (r=−0.643, P＜0.05), but not correlated to peripapillary RCFA (r=−0.377, P＞0.05).ConclusionsThe optic disc blood flow reduced in affected eyes of unilateral NAION whose disease course was less than 3 months, while the macular perfusion was normal. There was a positive correlation between optic disc flow and visual field.