ObjectiveTo investigate the application of critical flicker fusion frequency (CFF) in non-arteritic anterior ischemic optic neuropathy (NAION). MethodsA cross-sectional study. From January 2021 to September 2021, a total of 58 NAION patients (105 eyes) (NAION group) and 33 cases (63 eyes) in the healthy control (HC) group were included from Department of Ophthalmology of First Medical Center, PLA General Hospital. Patients underwent best-corrected visual acuity (BCVA), optical coherence tomography (OCT), visual field, CFF and flash visual evoked potential (F-VEP) examinations. BCVA examination was performed using a Snellen decimal visual acuity chart and was converted to logarithm of the minimum angle of resolution visual acuity. In the affected eyes group, there were 56 cases (72 eyes), 31 cases (43 eyes) male and 25 cases (29 eyes) female, with an average age of 49.28±11.42 years old. And the affected eyes were divided into 4 groups: ＜1, 1-＜3, 3-＜6 and ＞6 months according to the time interval from onset to CFF examination, which were 20 (27.8%), 26 (36.1%), 17 (23.6%) and 9 (12.5%) eyes, respectively. According to the BCVA ≥0.5, 0.1-0.5, ＜0.1 in CFF examination, the affected eyes were divided into a mild, moderate, and severe degree, 33 (45.8%), 32 (44.4%) and 7 (9.8%) eyes, respectively. Sixty-three eyes of 33 cases were in the HC group. There were 17 cases (31 eyes) males and 16 cases (32 eyes) females, with an average age of 35.18±10.96 years. Hand-held CFF detector type 2 (Japan, NEITZ company) was used for the CFF examination. The thickness of peripheral retinal nerve fiber layer (pRNFL), macular inner limiting membrane retinal pigment epithelium (mILM-RPE), F-VEP peak time and peak value and mean visual field defect (MD) values were recorded within 1 week of CFF examination. The CFF value of the above subgroups was analyzed in order using one-way ANOVA. Pearson correlation analysis was used for the correlation between CFF and F-VEP peak time, peak value, BCVA and MD. The correlations between BCVA, visual field, F-VEP, and CFF were analyzed. ResultsThe trichromatic values of red, green and yellow in NAION affected eyes were 22.56±10.30, 24.10±11.51, 24.81±11.41 Hz, respectively, which was significantly reduced compared with the HC group (t=－10.53,－11.11,－11.36; P＜0.05). There was no significant difference in CFF-red, green, and yellow values at different time points after the onset of the disease (F=2.075, 1.893, 2.073; P＞0.05). Compared CFF-red, green, and yellow values in NAION-affected eyes with different degrees, the difference was statistically significant (F=31.579, 27.332, 32.055; P＜0.05). The results of correlation analysis showed that the peak time of F-VEP (r=－0.362, －0.379,－0.357; P＜0.05), BCVA (r=－0.705,－0.695,－0.714; P＜0.05), and which was negatively correlated with CFF three color. MD and CFF were positively correlated (r=0.486, 0.435, 0.450; P＜0.05). ConclusionThe CFF value of the affected eye is decreased significantly in NAION-affected eyes, and CFF is more sensitive than F-VEP in reflecting visual impairment, and has a good correlation with visual function and latency of F-VEP.
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.
ObjectiveTo observe the clinical and imaging characteristics of radiation optic neuropathy (RION). MethodsA retrospective clinical study. A total of 43 patients (69 eyes) who were diagnosed with RION at the Chinese PLA General Hospital from 2010 to 2021 were included in this study. There were 23 males (36 eyes) and 20 females (33 eyes). The age of patients at the time of radiation therapy was 49.54±13.14 years. The main dose of radiotherapy for lesions was 59.83±14.12 Gy. Sixteen patients were treated with combined chemotherapeutic agents. The clinical details of best corrected visual acuity (BCVA) and color photography of the fundus were collected. Forty-six eyes underwent optical coherence tomography (OCT), visual field were examined in 30 eyes, magnetic resonance imaging (MRI) were performed in 40 eyes. The BCVA examination was performed using Snellen visual acuity chart, which was converted to minimum resolution angle logarithm (logMAR) visual acuity during recording. Hyperbaric oxygen therapy (HBOT) was performed in 10 patients (13 eyes), 9 patients (12 eyes) were treated with intravenous methylprednisolone (IVMP), 12 patients (23 eyes) were treated with HBOT combined with IVMP and control group of 12 patients (21 eyes) were only treated with basal treatment. And grouped accordingly. To observe the changes in onset, recovery, and final BCVA of the affected eye as well as thickness changes of the retinal nerve fiber layer (RNFL) of the optic disc and inner limiting membrane-retinal pigment epithelium (ILM-RPE) layer of the macular area, and final outcome of BCVA with different treatment modalities in affected eyes. The RNFL and ILM-RPE layer thicknesses were compared between patients with different disease duration as well as between treatment regimens using independent samples t-test. ResultsOf the 43 cases, vision loss was monocular in 17 patients (39.53%, 17/43) and binocular in 26 patients (60.47%, 26/43). The latency from radiotherapy to onset of visual loss was 36.33±30.48 months. The duration of RION ranged from 1 week to 10 years, in which the disease duration of 37 eyes ≤2 months. Subacute visual acuity loss was present in 41 eyes. logMAR BCVA＜1.0, 1.0-0.3, ＞0.3 were 45, 15, and 9 eyes, respectively. Optic disc pallor and optic disc edema were found in 10 (27.03%, 10/37), 3 (8.11%, 3/37) eyes, respectively, within 2 months. The superior RNFL [95% confidence interval (CI) 2.08-66.56, P=0.038] and the outer circle of the inner limiting membrane to retinal pigment epithelium (ILM-RPE) (95%CI 4.37-45.39, P=0.021) layer thinned significantly during the first month. The center of the ILM-RPE layer thickened (95%CI －32.95-－4.20, P=0.015) significantly during the first two months. The inner circle temporal quadrant of the ILM-RPE layer thickened (95%CI －42.22-－3.83, P=0.022) significantly from the third to sixth month, and the RNFL except for the temporal quadrants and the average RNFL, inner circle superior quadrant and outer circle of the ILM-RPE layer thinned significantly after 6 months (P＜0.05). Among the 40 eyes that underwent MRI examination, 33 eyes (82.50%, 33/40) were affected by T1 enhancement of optic nerve, including 23 eyes (69.70%, 23/33) in intracranial segment; 12 eyes with thickening and long T2 signal (36.36%, 12/33). After treatment, BCVA was restored in 17 eyes (24.6%, 17/69) and final BCVA improved in 9 eyes (13.0%, 9/69). There was no significant difference between HBOT, IVMP and HBOT combined with IVMP therapy in improving BCVA recovery or final BCVA compared with the control group, respectively (t=－1.04, 0.61, 1.31, －1.47, －0.42, 0.46; P＞0.05). ConclusionsThe structural damage of the RNFL and ILM-RPE layer occurred during the first month, the RNFL showed progressive thinning during the follow-up period, while the ILM-RPE layer showed thinning-thickening-thinning. MRI shows T1 enhancement of the optic chiasma and segments of the optic nerve, and the enhanced segments are usually accompanied by thickening and long T2. HBOT and IVMP have no obvious effect on RION.