Myasthenia gravis is an autoimmune disease characterized by muscle weakness and pathological fatigue due to autoaggressive phenomena with the formation of antibodies directed against various structures of the neuromuscular synapse. In most patients, the disease begins with the involvement of extraocular muscles, presenting with symptoms such as intermittent ptosis of the upper eyelid and/or binocular diplopia. In 15% of cases, clinical manifestations are limited to impairment of the levator palpebrae superioris and extraocular muscles, characteristic of the ocular form of myasthenia gravis. Specialists often encounter challenges in diagnosing this form, as serological and electrophysiological studies may be uninformative, necessitating diagnosis based on patient history and clinical picture. This literature review outlines the key aspects of the pathogenesis, clinical manifestations, methods of diagnosis and treatment of ocular myasthenia gravis.
Миастения гравис — это аутоиммунное заболевание, клинические проявления которого в виде слабости и патологической мышечной утомляемости обусловлены явлениями аутоагрессии с образованием антител, направленных к различным структурам нервно-мышечного синапса. У большинства пациентов заболевание начинается с поражения экстраокулярных мышц и появления таких симптомов, как непостоянный птоз верхнего века и/или бинокулярное двоение. В 15% случаев клинические проявления ограничены лишь нарушением со стороны мышцы, поднимающей верхнее веко, и глазодвигательных мышц, что характерно для глазной формы миастении. При обследовании пациентов врачи зачастую сталкиваются с определенными трудностями, так как серологические и электрофизиологические исследования могут быть неинформативными и диагностировать глазную форму миастении приходится на основании данных анамнеза и клинической картины. В обзоре литературы представлены основные аспекты патогенеза, клинических проявлений, методов диагностики и лечения глазной формы миастении.

BACKGROUND: We investigated the proper timing, efficacy and safety of tacrolimus for juvenile myasthenia gravis (JMG).
METHODS: We conducted a retrospective cohort study for JMG patients treated with tacrolimus at Xiangya Hospital, Central South University, Changsha, China from 2010 to 2023. The clinical information of patients with a follow-up of more than 1 year was collected. Comparisons of clinical features between groups of patients who achieved therapeutic goal and those who did not achieve therapeutic goal as well as between groups of patients treated with tacrolimus within or after 1 year from JMG onset was carried out.
RESULTS: Forty-three patients were enrolled, of whom 28 achieved therapeutic goal. Tacrolimus reduced glucocorticoids (GC) dosages for the 28 cases and 15 cases discontinued GC completely. Generalized myasthenia gravis (GMG) subtype had an association with a group of patients who achieved therapeutic goal (p = 0.001). Median duration from JMG onset to tacrolimus use was 10.50 months for those who achieved therapeutic goal and 36.00 months for those who did not achieve therapeutic goal (p = 0.010). The median Myasthenia Gravis Activities of Daily Living (MG-ADL) score improved significantly (p = 0.003). The initiation of tacrolimus within 1 year of JMG onset showed an association with achievement of therapeutic goal (p = 0.026). GMG subtype showed an association with a group of patients who received tacrolimus within 1 year (p = <0.001). Tacrolimus side effects were tolerable.
CONCLUSIONS: The provision of tacrolimus within 1 year of JMG onset is effective and safe.

BACKGROUND: Here, we describe the clinical characteristics and therapeutic effects of myasthenia gravis (MG) coexisting with thyroid eye disease (TED).
METHODS: We collated clinical data from MG patients in our hospital between 2012 and 2022 and analyzed the clinical characteristics of MG patients with hyperthyroidism, MG patients with TED and ocular myasthenia gravis (OMG) patients with TED.
RESULTS: We recruited 62 MG patients with hyperthyroidism, including 13 MG patients with TED and 10 OMG patients with TED. There were 70 MG patients without hyperthyroidism; 29 of these were OMG. Compared with patients without hyperthyroidism, patients with hyperthyroidism had an earlier age at onset and milder clinical symptoms (P < 0.05). The incidence of thymus hyperplasia in patients with hyperthyroidism and TED was significantly lower than that in patients without TED (38.5% vs. 69.4%, P < 0.05); these patients also had a significantly lower antibody titer for the acetylcholine receptor [0.72 (0.27, 14.93) nmol/L vs. 2.38 (0.28, 49.51) nmol/L, P < 0.05]. Diplopia was significantly more frequent in OMG patients with TED than in patients with OMG (84.6% vs. 44.8%, P < 0.05), and the rate of diplopia in OMG patients with TED was significantly higher after treatment with bromostigmine and glucocorticoid (69.2% vs. 3.4%, P < 0.05).
CONCLUSIONS: MG patients with TED had a significantly lower incidence of thymus hyperplasia and a lower antibody titer for the acetylcholine receptor. Patients with OMG and TED are more likely to develop diplopia; it is very difficult to treat diplopia in these patients.

UNASSIGNED: It is important to understand the pathophysiology of ocular myasthenia gravis (OMG) to improve treatment.
UNASSIGNED: To use modern video-oculography to characterise saccadic eye movements in patients with OMG, including anti-AChR, anti-MuSK, anti-LRP4, and seronegative OMG.
UNASSIGNED: In total, 21 patients with OMG and five age-matched healthy control subjects underwent video-oculography. Participants performed a sequence of horizontal saccades (3 minutes each) at ±5°, ± 10°, and ±20°, followed by 3 minutes of saccades directed at randomly presented targets at ±5°, ± 10°, and ±15°. We recorded the direction, amplitude, duration, peak, and average velocity of each saccade for each task for each participant.
UNASSIGNED: Saccadic amplitude, duration, and average velocity were all lower in OMG patients than in control subjects (p < 0.021). Saccadic amplitude and velocity decreased over time, but this decrease was similar in OMG patients and control subjects. Fixation drift and ocular disparity tended to be greater in OMG patients than in control subjects. Saccadic intrusions occurred more frequently in OMG patients than in control subjects (p < 0.001). No significant effects of time or group by time on fixation drift or ocular disparity were found.
UNASSIGNED: Saccadic velocities in OMG patients differed from those in normal control subjects, which suggests that OMG affects fast-twitch fibres, although fast-twitch fibres were still able to generate \"twitch\" or \"quiver\" movements in the presence of even severe ophthalmoplegia. Slow-twitch muscle fibres involved in gaze holding were also affected, accounting for increased fixation drift following saccades. Our objective finding of increased fixation drift and a larger number of saccadic intrusions mirror our anecdotal experience of patients with OMG who report significant diplopia despite minimal ophthalmoplegia on examination. Such microsaccades may be a surrogate for compensation of a gaze-holding deficit in MG.

This paper presents an eye image segmentation-based computer-aided system for automatic diagnosis of ocular myasthenia gravis (OMG), called OMGMed. It provides great potential to effectively liberate the diagnostic efficiency of expert doctors (the scarce resources) and reduces the cost of healthcare treatment for diagnosed patients, making it possible to disseminate high-quality myasthenia gravis healthcare to under-developed areas. The system is composed of data pre-processing, indicator calculation, and automatic OMG scoring. Building upon this framework, an empirical study on the eye segmentation algorithm is conducted. It further optimizes the algorithm from the perspectives of \"network structure\" and \"loss function\", and experimentally verifies the effectiveness of the hybrid loss function. The results show that the combination of \"nnUNet\" network structure and \"Cross-Entropy + Iou + Boundary\" hybrid loss function can achieve the best segmentation performance, and its MIOU on the public and private myasthenia gravis datasets reaches 82.1% and 83.7%, respectively. The research has been used in expert centers. The pilot study demonstrates that our research on eye image segmentation for OMG diagnosis is very helpful in improving the healthcare quality of expert doctors. We believe that this work can serve as an important reference for the development of a similar auxiliary diagnosis system and contribute to the healthy development of proactive healthcare services.

UNASSIGNED: The pattern of extraocular muscle involvement in ocular myasthenia gravis varies across different reports, diverging from our own observations. Thus, we employed two novel tools to discern this pattern.
UNASSIGNED: A retrospective analysis was conducted to collect and organize clinical data from 43 patients diagnosed with ocular myasthenia gravis. Each patient underwent both the computerized diplopia test and the Ocular Motor Nerve Palsy Scale assessment to evaluate the involvement of extraocular muscles.
UNASSIGNED: Among the patients, there were 30 male and 13 female individuals, with a total of 113 affected extraocular muscles identified. Among all the affected extraocular muscles, the involvement of the levator palpebrae superioris muscle accounted for 35.40%, medial rectus muscle 7.7%, lateral rectus muscle 16.81%, superior rectus muscle 13.27%, inferior rectus muscle 12.39%, superior oblique muscle 1.77%, and inferior oblique muscle 2.65% of the total affected extraocular muscles. The positivity rates of the Neostigmine test were 89.19%, AChR antibody detection was 59.38%, and repetitive nerve stimulation was 34.38%. The AChR antibody positive rate among patients with only diplopia was 100%; among those with only ptosis, it was 80%; and among those with both diplopia and ptosis, it was 86.67%.
UNASSIGNED: The involvement of the extraocular muscles is not uniform. The levator palpebrae superioris exhibits the highest incidence rate, followed by the four rectus muscles and two oblique muscles. The inferior oblique involvement typically occurs when four or more EOMs are affected. Moreover, the levator palpebrae superioris and medial rectus show a higher tendency for bilateral involvement compared with other extraocular muscles.

Myasthenia gravis is an autoimmune disease of the neuromuscular junction caused by autoantibodies directed against the acetylcholine receptors. It presents with skeletal muscle weakness, often initially presenting with ocular symptoms such as ptosis and diplopia. When myasthenia gravis is isolated to only ocular symptoms, it is referred to as ocular myasthenia gravis (OMG). Here, we present an atypical initial presentation of OMG in a 68-year-old male patient presenting with isolated abducens nerve palsy at the initial onset. With this case report, we highlight the importance of a thorough history and clinical assessment necessary for a timely diagnosis of OMG in patients who present with isolated abducens nerve palsy.

UNASSIGNED: To report the prevalences of other non-thyroid autoimmune diseases and identify factors associated with their presence in ocular myasthenia gravis (OMG) subjects.
UNASSIGNED: A total of 208 subjects with OMG diagnosis were included. Demographic data, clinical characteristics, the ice-pack test, the acetylcholine receptor (AChR) antibody test, electrophysiology tests (single-fiber electromyography and repetitive nerve stimulation), the presence of thymoma, generalized myasthenia gravis conversion, and the presence of other non-thyroid autoimmune diseases (defined as the presence of at least one other non-thyroid autoimmune disease) were retrospectively reviewed. Factors associated with the presence of other non-thyroid autoimmune diseases were analyzed by univariate and multivariate logistic regression.
UNASSIGNED: Of the total 208 subjects, 21 (10.10%) exhibited the presence of other non-thyroid autoimmune diseases (19 subjects (9.14%) and 2 subjects (0.96%) had one and two other non-thyroid autoimmune diseases, respectively), and systemic lupus erythematosus (SLE) was diagnosed in 9 subjects, followed by Sjogren\'s syndrome (7 subjects), rheumatoid arthritis (6 subjects), and ankylosing spondylitis (1 subject). Therefore, the prevalences of SLE, Sjogren\'s syndrome, rheumatoid arthritis, and ankylosing spondylitis in OMG subjects were estimated to be 4.33% (95% confidence interval (CI): 2.29-8.02%), 3.37% (95% CI: 1.64-6.79%), 2.88% (95% CI: 1.33-6.14%), and 0.48% (95% CI: 0.08-2.67%), respectively. Positivity of the AChR antibody was the only significant factor associated with the presence of other non-thyroid autoimmune diseases (odds ratio 4.10, 95% CI: 1.11-15.21, p = 0.035).
UNASSIGNED: The presence of other non-thyroid autoimmune diseases was found in approximately 10% of OMG patients, with SLE displaying the highest prevalence. We recommend screening and monitoring for other non-thyroid autoimmune diseases in OMG patients, particularly those with positivity of the AChR antibody.

OBJECTIVE: To clarify the clinical features of patients with Double seronegative (DS) ocular myasthenia gravis (OMG).
METHODS: Sixty-one patients diagnosed with DS OMG at the Department of Ophthalmology, Hyogo Medical University Hospital over a 5-year period from 2017 were included. Patients were classified into three groups based on the initial examination findings: group P (ptosis alone), group M (ocular motility disorder alone), and group PM (combination of both). We retrospectively reviewed the patients and clarified their clinical features.
RESULTS: There were 32 males and 29 females, with a mean age of 49.8 ± 20.9:1-82 years. Twenty-one patients (34.4%) were in group P, 23 (37.7%) in group M, and 17 (27.8%) in group PM. The proportion of males (73.9%) was significantly higher in group M compared with the other two groups. The diagnosis was proven by detection of neuromuscular junction (NMJ) disorder in 73.8%, oral pyridostigmine trial test in 13.1%, and eight patients (13.1%) in group M were diagnosed after surgical treatment. The clinical symptoms were resolved by oral pyridostigmine treatment in 54.1% of cases.
CONCLUSIONS: About 30% of patients with DS OMG had no obvious NMJ disorder, and an oral pyridostigmine trial test was necessary to diagnose these patients. Although DS OMG is often considered as the mildest form of MG, its prognosis is not optimistic and it requires aggressive therapeutic intervention.
BACKGROUND: Trial registration number: 202104-750, \"2016/4/18,\" retrospectively registered.

BACKGROUND: Currently, there is no universally accepted standard treatment for ocular myasthenia gravis (OMG) in children. We aimed to investigate the possible proper regimens and timing of treatment for pediatric OMG cases based on the clinical manifestations: OMG with ptosis only and OMG with other features.
METHODS: One hundred and forty two OMG cases attended at the Department of Pediatrics, Xiangya Hospital, Central South University, from 2010 to 2019 were included, and information from medical records was reviewed and recorded. Comparisons of clinical characteristics between patients with OMG with ptosis only and patients with OMG with other features as well as between patients treated with glucocorticoid (GC) within or after six months from disease onset were performed.
RESULTS: OMG with other features constituted about 54.9% of the cases, and 66.2% of the patients achieved optimal outcome. Patients with OMG with ptosis only responded to pyridostigmine alone more than patients with OMG with other features who required several therapies (P < 0.001). Patients with OMG with ptosis only had a larger proportion of optimal outcome than the patients with OMG with other features (P = 0.002), and the difference remained significant even when the individual outcome groups were compared (P < 0.001). Patients who received GC within six months had a greater proportion of optimal outcome than those who received it after six months (P < 0.001).
CONCLUSIONS: Although OMG with other features is a more common subtype of OMG, it is also more severe than OMG with ptosis only. An earlier addition of GC leads to optimal outcome.