As a new non-invasive and simple subjective examination method, critical flicker fusion frequency (CFF) can dynamically reflect the changes of visual function of human eyes. As a sensitive indicator for early identification of demyelinating diseases and assessment of visual function recovery, it has been used by foreign scholars in the last century in the field of retinal and optic nerve diseases, including chloroquine toxic retinopathy, diabetic retinopathy, central serous retinopathy, age-related macular degeneration, ethambutol-induced optic neuropathy, optic neuritis and non-arteritic anterior ischemic optic neuropathy. Though there was a different decrease of CFF in retina and optic nerve diseases, it may be helpful for the differentiation of retinal and optic nerve diseases according to the degree of CFF improvement and the main damaged color light. Moreover, CFF has a good correlation with other visual functions, visual acuity, visual field, and peak time of visual evoked potential. At present, and relevant domestic studies is still in its infancy. This article summarizes the application of CFF in retinal and optic nerve diseases.

Objective: To analyze the spectrum and epidemiological characteristics of neuro-ophthalmic diseases from single center, and to provide basis for guiding the diagnosis and treatment of neuro-ophthalmic diseases. Methods: Patients with neuro-ophthalmic diseases admitted to the neuro-ophthalmology ward of Chinese PLA General Hospital from January 1, 2010 to December 31, 2021 were enrolled. The age, gender, regional distribution and disease subtypes of all included patients were retrieved and recorded from the electronic case system. Results: A total of 7245 patients with neuro-ophthalmic diseases were enrolled, including 3331 males(46.0%)and 3914 females(54.0%), with a male to female ratio of 1:1.2. The average age was 38.2±17.5 years. 83.25%(6031/7245)were afferent nervous system diseases, 9.92% (719/7245)were efferent nervous system diseases and orbital diseases, and 6.83%(495/7245)were not classified. The ratio of demyelinating optic neuritis(DON)was the highest(40.17%,2910/7245), followed by nonarteritic anterior ischemic optic neuropathy(NAION)(11.37%,824/7245)and traumatic optic neuropathy(TON) (5.15%,373/7245). The ratio of optic nerve atrophy with unknown causes was 7.85%(569/7245). Characteristics of age distribution, the DON and TON were more common in 18-40 age group(the proportion were 48.63% and 44.24%,respectively), the NAION was common in 41-60 age group(66.14%), and the hereditary optic neuropathy was common in younger 18 age group (48.58%). In 2226 DON patients, the proportion of neuromyelitis optica(NMO)/neuromyelitis optica spectrum disorder(NMOSD)-optic neuritis(ON)was the highest(60.02%)and myelinoligodendrocyte glycoprotein antibody(MOG-IgG)ON was 11.68%, while multiple sclerosis(MS)-ON and chronic recurrent inflammatory optic neuropathy(CRION)were relatively low(1.8% and 2.25%,respectively). In DON patients, the male to female ratio was 1:3.08. In NMO/NMOSD-ON patients, the ratio of male to female was 1:8, and that of MOG-ON was 4:5. In atypical ON, the ratio of male to female was higher than that of female(1.28:1). In DON patients, 81.79% of patients were young and middle-aged, and the proportion of children with MOG-ON(less than 18 years old)was 41.15%.Conclusions: DON and NAION are the two most common diseases of neuro-ophthalmic afferent system.

The disease of the posterior visual pathway is a kind of lesion in which the visual pathway itselfor its adjacent structure changes after optic chiasma causes pathological changes, resulting in changes in visual function. Neuro-ophthalmologists are familiar with symmetrical ipsilateral hemianopia caused by occipital lobe lesions, but occipital tip (the last part of the striatal cortex) lesions produce central symmetrical homonymous scotomas, which can easily be overlooked or misdiagnosed. This article reported a case of an olderly male patient treated with decreased binocular visual clarity and distortion. Ophthalmology examination: best corrected visual acuity: 0.8 in the right eye, 1.0 in the left eye; FM-100 examination indicated severe dyschromatopsia; cranial magnetic resonance imaging: infarction of bilateral occipital lobe (right portion of the occipital tip and left anterior portion of striate cortex); 24-2 Humphrey field examination showed a tendency of homonymous scotoma in bilateral eyes (atypical); 10-2 Humphrey field examination showed homonymous hemianopia (scotoma) in the central visual field. These results confirm a diagnosis of the disease of the posterior visual pathway. As an important part of neuro-ophthalmology, the posterior visual pathway can cause various characteristic visual field defects, which can be accompanied by advanced visual dysfunction and other neurological symptoms and signs. The diagnosis and treatment process of this case of occipital tip cerebral infarction with symmetrical homonymous blind spot accompanied by color vision changes suggests that attention should be paid to the diversity of visual field changes and other visual functional abnormalities in the posterior visual pathway lesions, so as to improve the early diagnosis rate and prognosis of the patient s.

Objective: To evaluate the efficacy and safety of long-term treatment with low-dose rituximab for neuromyelitis optica spectrum disorders (NMOSD). Methods: A prospective self-control study. A total of 38 patients who were diagnosed with NMOSD from July 2020 to April 2021 were recruited for rituximab treatment. All patients collected medical history, ophthalmic examination and serological test. Recorded the annual recurrence rate (ARR), best corrected visual acuity (BCVA), combined autoantibodies and therapy times after the first treatment. The BCVA was examined using Snellen chart, and converted to logMAR. The patients were followed up at least 12(17.29±2.2) months, and the last follow-up was taken as the time point of efficacy evaluation. ARR and BCVA before and after treatment were compared. To analyze the relationship between relapse and age of onset, combination of autoimmune antibodies and autoimmune diseases. The incidence of side effects and duration of additional therapy were recorded. Results: A total of 38 NMOSD patients (4 male/34 female, 61 involved eyes) were included in this study. The ages of onset age were 12-60 years, the median onset age was 23 (18~29.3) years. Duration of disease was 10.0~265 months, the median duration was 65 (48.3~101.0) months. Before treatment, the mean BCVA was 1.15 ± 0.13 , the mean BCVA at last follow-up was 1.54 ± 0.39, which was no significant difference (t=1.120, P=0.267). The mean ARR before and after treatment were 1.50±0.86 and 0.12 ± 0.07, respectively, with significant difference (t=8.304, P<0.001). The mean reinfusion period was 6. 4±2.3 months. Five relapses in 3 patients were observed. There were no significant difference between relapsed patients and non-relapsed patients on onset age, with/without auto-immune antibody ratio, with/without auto-immune diseases ratio (all P>0.05). Of 38 patients, 7 patients had side effects, all patients who had side effects, slowing down the infusion speed of RTX or infusing 5 mg of dexamethasone could relieve the discomfort. Conclusions: Low-dose RTX can effectively clear B lymphocytes, prevent NMOSD recurrence and with good safety.

Optic neuritis(ON)is an inflammatory demyelinating disease of the optic nerve, which is the main cause of vision loss in young and middle-aged people. In recent years, myelin oligodendrocyte glycoprotein antibody-positive ON(MOG-ON)has become a research hotspot in the field of neuro-ophthalmology, and reports at home and abroad are increasing.In March 2021, the Neuro-ophthalmology Group of Ophthalmology Branch of Chinese Medical Association formulated the Evidence-Based Guidelines for the Diagnosis and Treatment of Demyelinating Optic Neuritis in China(2021) , and included MOG-ON as a new optic neuritis subtype in the diagnosis and treatment system of myelinating optic neuritis providing a new reference for the majority of ophthalmologists. Therefore, clinicians need to fully understand the clinical features and treatment progress of MOG antibody-related diseases and MOG-ON, and strive to improve the level of diagnosis and treatment, so that such patients can get more benefits and benefit more patients with optic nerve diseases.

Abstract: The rare disease of chronic infantile neurological cutaneous and articular (CINCA) syndrome, is caused by the over-secretion of interleukin (IL)-1β due to a gain-of-function NLRP3 gene mutation in the autosomal chromosome which often involves in eyes. In this report, we studied a 9-year-old girl with CINCA. The eyes were also involved and presented bilateral papilledema. Genetic testing revealed that the symptoms were caused by a novel gene mutation site (c.913G>A, p. D305N) in conservative domain exon-3 of NLRP3 which is gain-function gene of CINCA. The patient had the characteristic facial features, frontal fossa and saddle nose, manifested the generalized urticaria-like skin rash at two weeks after birth, periodic fever 6 months after birth, sensorineural deafness at 7 years old, and bilateral papilledema, aseptic meningitis and knee arthropathy at 9 years old. White cell counts, C-reactive protein increased and intracranial pressure raised to 300 mmH2O. The meningeal thickening enhanced by gadolinium in magnetic resonance imaging (MRI). Based on clinical features and genetic test, the girl was diagnosed bilateral papilledema secondary to CINCA and administered prednisone and lowered intracranial pressure medicine to resolve symptoms. With 3-year follow-up, patient had no inflammatory flare-up with visual acuity improvement. The finding of novel genetic mutation site (p. D305N) in NLRP3 gene expanded genotype spectrum associated with CINCA. This case also expanded the cause spectrum of papilledema and it highlighted systemic disease history for patients with bilateral papilledema.