Factors Affecting Generalization of Ocular Myasthenia Gravis in Patients With Positive Acetylcholine Receptor Antibody

PURPOSE

To evaluate the associated factors of conversion of ocular myasthenia gravis (OMG) to generalized myasthenia gravis (GMG) among patients with seropositive acetylcholine receptor antibody (AchR Ab).

DESIGN

Retrospective cohort study.

METHODS

Setting: Retrospective chart review.

PATIENT

Seventy-one OMG patients with seropositive AchR Ab presented during July 2009 and December 2016. The exclusion criteria were patients who (1) first presented with GMG, (2) were unable to identify the time of onset of OMG or GMG, (3) were unable to provide information about previous treatments before the onset of GMG, and (4) had incomplete or lost medical records.

OBSERVATION PROCEDURE

We collected demographic and clinical characteristics, including onset of OMG and GMG, presence of other autoimmune disorders, history of smoking, presence of thymic abnormalities, and medications received.

MAIN OUTCOME MEASURES

Conversion to GMG and time to conversion.

RESULTS

Thirty-six patients experienced conversion to GMG. Overall incidence of GMG was 14 (95% confidence interval [CI] 10.09-19.4) per 100 patient-years. Probability of conversion at 2 years was .37 (95% CI .27-.49). Overall median conversion time was 4.97 years. Cox proportional hazard model showed that risk factors were female sex (HR 2.52, 95% CI 1.04-6.10), history of smoking (HR 3.42, 95% CI 1.40-8.45), and thymic abnormalities (HR 1.82, 95% CI 0.91-3.67). Protective factors against conversion to GMG were receiving immunosuppressive agents (HR 0.42, 95% CI 0.19-0.97) and pyridostigmine (HR 0.37, 95% CI 0.14-0.93).

CONCLUSIONS

OMG patients with seropositive AchR Ab should be informed that taking pyridostigmine and/or immunosuppressive agents as well as smoking cessation might prevent conversion to GMG.

Syphilitic Optic Neuropathy: Re-emerging Cases Over a 2-Year Period

We report 7 cases of syphilitic optic neuropathy during a 2-year period. All patients were newly diagnosed with human immunodeficiency virus (HIV) infection. Six cases (86%) initially presented with swollen optic disc either unilaterally or bilaterally. Blind spot enlargement was the most common type of visual field defect. Final visual acuity of at least 20/25 was achieved together with visual field improvement and resolution of swollen optic disc. Optic nerve involvement can be the first manifestation of syphilis and HIV co-infection. Syphilitic optic neuropathy has an excellent prognosis if the disease diagnosed promptly and treated properly.

Clinical features and etiology of retinal vasculitis in Northern Thailand

PURPOSE

To report on the clinical features and etiology of patients with retinal vasculitis (RV).

MATERIALS AND METHODS

We reviewed medical records of 47 patients (75 affected eyes) diagnosed with RV. Clinical presentations, ocular complications, associated systemic diseases, and treatment regimens were registered.

RESULTS

Etiology of RV included infectious causes in 10/47, (21%) while an association with systemic and/or ocular non-infectious disorders was noted in 22/47 (47%). Eales' disease and Behcet's disease represented the most common clinical entities in non-infectious group while tuberculosis-associated RV was diagnosed in 6/10 (60%) among those with infectious disorders. RV was bilateral in 28/47 (60%) patients. Retinal veins were most commonly affected (72%, 34/47). Involvement of arteries was present in 12/47 (25%) and was associated with viral infections and Behcet's disease. Ocular complications developed in 60/75 (80%) eyes. The most common complications were elevated intraocular pressure and/or glaucoma (33/75, 44%). Retinal detachment, vitreous hemorrhage, and cystoid macular edema developed in similar percentages (15%).

CONCLUSIONS

RV in Thailand manifested mostly in male patients, was typically bilateral and involved mostly veins. Involvement of arteries was observed in patients with viral infections and Behcet's disease. Tuberculosis was the most common infectious cause.

Myelin oligodendrocyte glycoprotein antibody-associated optic neuritis with COVID-19 infection: A case report and literature review

Purpose

Observations

Conclusions and importance

Trauma-Associated Leber Hereditary Optic Neuropathy

A 19-year-old man developed visual loss in the left eye 1 day following a martial arts kick to the head. Vision worsened over a week, when visual loss was noted in the right eye without further trauma. The fundus was initially normal, but visual field testing showed temporal depression right eye with diffuse depression left eye, and traumatic chiasmopathy was suspected. Magnetic resonance imaging (MRI) of the brain demonstrated an enlarged chiasm with intrinsic signal abnormality, but no enhancement. Treatment with intravenous corticosteroids and hyperbaric oxygen therapy did not result in visual improvement. Ancillary testing for atypical optic neuritis was negative, but testing for LHON was positive for the 11778 mutation. This case raises the question of trauma as a precipitating factor for LHON and illustrates the rare occurrence of intrinsic signal abnormalities of the chiasm in this disorder.

Clinical and Spectral-Domain Optical Coherence Tomography Appearance of Optic Disc Melanocytoma: A New Classification and Differentiation from Pigmented Choroidal Lesions

AIMS

The aim of this paper was to compare the features of both the classic, darkly pigmented and the atypical, more lightly pigmented optic disc melanocytoma with those of pigmented choroidal lesions.

METHODS

We analyzed the spectral-domain optical coherence tomography (SD-OCT) features of 9 eyes with optic disc melanocytoma and compared them with those of choroidal melanoma and nevus.

RESULTS AND CONCLUSION

We identified 2 categories of SD-OCT findings in optic disc melanocytoma: (a) type 1, the typical, prominent, hyperpigmented lesion with SD-OCT findings of a hyperreflective, disorganized overlying retina and a posterior hyporeflective shadow, and (b) the less common, atypical, minimally pigmented type 2 lesion overlaid by a relatively well-organized retina that lacks a posterior hyporeflective shadow. Choroidal lesions were characterized by tumor confined beneath the clearly visible hyperreflective line of the photoreceptor and retinal pigment epithelium, with minimal disorganization of the overlying retina.

Changes in Ocular Biomarkers from Normal Cognitive Aging to Alzheimer's Disease: A Pilot Study

Purpose

To identify ophthalmic findings in Alzheimer's type dementia (ATD) compared to normal subjects.

Patients and Methods

This comparative descriptive study included participants from the institution's cognitive fitness center. Complete ophthalmic examinations were performed. Optical coherence tomography (OCT) and OCT angiography (OCTA) were used to analyze retinal thickness and vascular density. The Ocular Surface Disease Index (OSDI) score and tear breakup time (TBUT) were used to assess dry eye. The blink rate was counted by a well-trained observer. Cognitive function was evaluated using the Thai Mental State Examination (TMSE) score. Correlation analysis was performed to compare OCT, OCTA parameters, and TMSE.

Results

We included 24 ATD patients and 39 normal participants as a control group by age and sex-matched. The prevalence of dry eye using the Asia Dry Eye Society criteria was 15% and 13% in normal and ATD patients, respectively. The differences in OSDI scores, TBUT, and blink rate between the two groups were not statistically significant. The parafoveal and perifoveal macular thickness of the ATD group were significantly lower than that of the control group (p<0.01). All parameters of the vessel density of the ATD group were significantly lower than in the control group, including the whole macular vessel density (p<0.01), optic disc vessel density at the nerve head level (p<0.01), and optic disc vessel density at the radial peripapillary capillary level (p<0.05). After age adjustment, there were no statistically significant differences in all the OCT and OCTA parameters. There was a positive correlation between retinal thickness and vessel density in the macular and optic disc region and TMSE scores.

Conclusion

Perifoveal and parafoveal retinal thickness might be more sensitive than peripapillary RNFL thickness to detect neurodegenerative changes in patients with ATD. Macular thickness and vessel density reduction were also positively correlated with cognitive decline.

Validity of Forced Eyelid Closure Test: A Novel Clinical Screening Test for Ocular Myasthenia Gravis

BACKGROUND

Forced eyelid closure test (FECT) is a clinical screening test developed from the original Cogan lid twitch (CLT) sign to assist in the diagnosis of ocular myasthenia gravis (OMG), We evaluated the sensitivity and specificity of FECT compared with CLT and benchmarked to standard diagnostic tests.

METHODS

This study was a retrospective chart review of 48 patients using electronic medical records of those that presented with ptosis and/or diplopia at Doheny Eye Institute, University of California, Los Angeles between February 2015 and April 2016. Patients without FECT testing were excluded. FECT and CLT results, and final diagnosis were recorded. To perform FECT, the patient was asked to squeeze his or her eyelids shut for 5-10 seconds then open quickly and fixate in primary position. The excessive upward overshoot of eyelids movement indicated a positive FECT. The test was performed by a neuro-ophthalmologist before establishing the diagnosis. Patients who had equivocal test results and/or inconclusive final diagnosis were excluded.

RESULTS

Of the 48 patients studied, 18 patients (37.5%) had positive FECT; 15 of whom had a final diagnosis of OMG (83.3%). Of the 30 patients with negative FECT, 1 had OMG (3.3%). Of the 48 patients, 35 patients also had a documented CLT result (72.9%). CLT was positive in 11 of these 35 patients (31.4%), and 9 of these 11 had OMG (81.8%). Of the 24 patients with negative CLT, 2 of them had OMG (8.3%). Sensitivity and specificity of FECT were 94% and 91% (joint 95% confidence region: sensitivity × specificity = [0.70, 1] × [0.75, 1]). The relative true-positive fraction (rTPF) between FECT and CLT was 1.15; the relative false-positive fraction was 1.31.

CONCLUSIONS

FECT is a simple clinical screening test with good sensitivity and specificity for OMG.

The epidemiology and mutation types of Leber's hereditary optic neuropathy in Thailand

PURPOSE

Leber's hereditary optic neuropathy (LHON), the most common mitochondrial optic neuropathy, causes visual loss, especially in young adults. Due to the absence of epidemiological data in Southeast Asia, we aimed to determine Thai LHON patients' characteristics (demographic data, mutation types, and prognoses) as the first study in this region.

METHODS

This retrospective chart review enrolled all Thai LHON patients confirmed by three mitochondrial DNA mutations (G11778A, T14484C, and G3460A) between January 1997 and December 2016. Patients with more than one year of follow-up were included in a visual progression analysis. The Mann-Whitney U-test was applied to compare groups, and prognosis-associated factors were analysed with the generalized estimating equation.

RESULTS

In all, 229 patients were enrolled, with only nineteen females. Most mutations were of the G11778A type (91%), with T14484C accounting for the remainder. The age at onset of G11778A (21.9 years; interquartile range [IQR] 14.9, 33.5) was younger than that of T14484C (33.0 years; IQR 19.4, 37.5). Of 45 patients, the T14484C group demonstrated good vision recovery, whereas the G11778A group did not improve (difference in logMAR -0.7 and IQR -1.5, -0.2 versus logMAR 0.0 and IQR -0.3, 0.2, respectively; P value .001). The G11778A mutation, male, and older age were related to poor prognoses.

CONCLUSIONS

The leading mutation in Thai LHON patients is the G11778A missense, followed by T14484C, while G3460A was not detected. The vast majority of patients were young adult males. The G11778A mutation, older age, and male gender are associated with poor vision outcomes. Key messageThe G11778A missense mutation is the most common among Thai LHON patients, followed by T14484C, while G3460A was not found. The G11778A mutation, older age, and male gender are associated with poor vision outcomes.

Disagreement of Radial Peripapillary Capillary Density Among Four Optical Coherence Tomography Angiography Devices

Purpose

This prospective study evaluated the agreement among four optical coherence tomography angiography (OCTA) devices in the assessment of radial peripapillary capillary (RPC) density.

Methods

The study included 48 eyes of 48 subjects (14 healthy, 19 glaucomatous, and 15 non-glaucomatous optic neuropathy). Each participant was scanned using four OCTA devices in a random sequence: RTVue XR Avanti (RTVue), DRI OCT Triton (Triton), Revo NX 130 (Revo), and PLEX Elite 9000 (PlexE). All 6 × 6-mm grayscale OCTA images from each device were analyzed for RPC density using a customized algorithm. Agreement between each pair of devices was assessed using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

Results

There was a poor correlation between devices in all comparisons (RTVue-Triton, ICC = 0.34; RTVue-Revo, ICC = 0.31; RTVue-PlexE, ICC = 0.28; Triton-Revo, ICC = 0.31; Triton-PlexE, ICC = 0.17; Revo-PlexE, ICC = 0.34). Significant proportional biases (P < 0.05) and wide limits of agreement with apparent constant biases were identified in all comparisons. The mean difference was greatest for the RTVue-Revo pair (-49.3%; 95% confidence interval [CI], -52.9 to -45.8) and smallest for the Triton-PlexE pair (-7.7%; 95% CI, -10.1 to -5.3).

Conclusions

The RPC densities obtained from each device had poor inter-device agreement and significant biases and cannot be used interchangeably.

Translational Relevance

RPC density obtained from different OCTA devices is not interchangeable; thus, the progression of optic neuropathy should be monitored using the same OCTA device.

Incidence, risk factors and ophthalmic clinical characteristic of ethambutol-induced optic neuropathy: 7-year experience

Background

The purpose of this research was to investigate the characteristics, clinical manifestations, incidence, and risk factors in ethambutol-induced optic neuropathy (EON) in the Thai population.

Methods

Patients treated with ethambutol for tuberculosis (TB) were retrospectively identified in the medical record of a tertiary hospital in Thailand from January 2012 to August 2019. Development of EON was determined through review of ophthalmology records. Comparison was made between patients with EON and those without EON to identify possible risk factors. Ophthalmic outcomes were characterized.

Results

Among 4,141 patients who received ethambutol for TB treatment, 1,062 had an ophthalmology encounter, and 20 (0.5% overall, 1.88% with ophthalmology encounters) developed EON. In unadjusted analysis, compared to patients without EON, those with EON had a similar daily dose, but longer duration of ethambutol treatment (P=0.02). They were older (mean 43.74 vs. 58.60 years, P=0.001), more likely to have hypertension (P=0.02) and smoke (p=0.01). There were no differences in gender, body mass index, diabetes, dyslipidemia, HIV infection or glomerular filtration rate. The peripapillary retinal nerve fiber layer, ganglion cell analysis, and vascular density as measured using retinal optical coherence tomography were impacted by EON. In adjusted logistic regression analysis, age greater than 60 (OR = 8.71, p = 0.01) and smoking (OR = 7.06, p = 0.01) were independent risk factors for EON.

Conclusion

In patients treated with ethambutol, the incidence proportion of EON was 0.5% among those with ethambutol administered and 1.88% among those with ethambutol and an eye visit. Potential EON risk factors were age, hypertension, smoking, and duration of ethambutol medication. Smoking has not been associated with EON in prior studies.

Complications of Preseptal Versus Pretarsal Botulinum Toxin Injection in Benign Essential Blepharospasm: A Randomized Controlled Trial

PURPOSE

The purpose of this study was to compare ocular complications and efficacy of preseptal (PST) versus those of pretarsal (PTS) botulinum toxin type A (BoNT-A) therapy in cases of benign essential blepharospasm (BEB).

DESIGN

Randomized clinical trial.

METHODS

Setting: university hospital.

PATIENTS

24 participants with BEB were enrolled from August 2019 to June 2020. All patients and the outcome evaluator were masked to the injection allocation.

INTERVENTIONS

for each participant, 1 eye was randomized to receive PST BoNT-A injection, and the fellow eye received PTS BoNT-A injection of the same amount from a single investigator. At baseline, 1, and 3 months after the injection, we collected the symptoms of tearing, lagophthalmos, ptosis, and diplopia and measured margin-to-reflex distance (MRD) 1 and 2 (mm), degree of lagophthalmos (mm), presence of ectropion, entropion, limitation of ocular motility, tear film breakup time (second), Schirmer's test (mm) , ocular surface staining scores (Oxford's scheme), and Jankovic rating scale of both eyes separately. Main outcome measurements were complications of the injection.

RESULTS

There were statistically significant higher rates of self-reported lagophthalmos in PTS (n = 12; 52.17%) than in PST (n = 7; 30.43%) BoNT-A injections (P = .024) and significantly higher estimated measurements of lagophthalmos in PTS (0.59 mm; 95% confidence interval [CI]: 0.44-0.72) than in PST (0.26 mm; 95% CI: 0.12-0.40) injection at 1 month using an interaction model (Bonferroni-corrected P = .001). No significant differences in the efficacy and other complication outcomes between the injection locations were observed.

CONCLUSIONS

PTS BoNT-A injection had a higher rate of lagophthalmos than PST BoNT-A injection for BEB.

Health-related quality of life of daily-life-affected benign essential blepharospasm: Multi-center observational study

PURPOSE

To compare Thais' health-related quality of life (HRQOL) and severity grading, efficacy and safety in daily-life-affected benign essential blepharospasm (BEB) patients at baseline and after Botulinum toxin type A (BTX-A) treatment.

DESIGN

Prospective-observational study.

PARTICIPANTS

BEB patients with Jankovic rating scale (JRS) at least 3 in both severity and frequency graded from 14 institutes nationwide were included from August 2020 to June 2021.

METHODS

Demographic data, HRQOL evaluated by the Thai version of EQ-5D-5L and NEI-VFQ-25 questionnaires, and severity grading score evaluated by Jankovic rating scale (JRS) at baseline, 1, and 3 months after the treatment were collected. The impact of the BTX-A injections and their complications were recorded.

RESULTS

184 daily-life-affected BEB patients were enrolled; 159 patients (86.4%) had complete data with a mean age of 61.40±10.09 years. About 88.05% were female, and 10.1% were newly diagnosed. Most of the patients had bilateral involvement (96.9%) and 12.6% had history of BEB-related accident. After BTX-A treatment, HRQOL improved significantly in 4 dimensions of EQ-5D-5L, except self-care. The EQ_VAS (mean±SD) was 64.54±19.27, 75.13±15.37, 73.8±15.85 (p<0.001) and EQ-5D-5L utility score was 0.748±0.23, 0.824±0.19 and 0.807±0.19 at baseline, 1, 3 months after treatment, respectively. From NEI-VFQ-25, HRQOL also improved in all dimensions, except eye pain. The JRS improved in all patients. Self-reported minor adverse events were 22.6%, which mostly resolved within the first month.

CONCLUSION

Daily-life-affected BEB impacted HRQOL in most dimensions from both generic and visual-specific questionnaires. BTX-A treatment not only decreased disease severity, but also improved quality of life.

Microanatomy of the central myelin portion and transitional zone of the oculomotor and abducens nerves

BACKGROUND

The microanatomy of the central myelin portion and transitional zone of several cranial nerves including trigeminal, facial, vestibulocochlear, glossopharyngeal, and vagus nerves have been clearly demonstrated to provide information for neurovascular compression syndrome such as trigeminal neuralgia and hemifacial spasm. However, the study of oculomotor and abducens nerve is limited.

MATERIALS AND METHODS

Oculomotor and abducens nerves were harvested with a portion of brainstem and embedded in paraffin. Longitudinal and serial sections from ten of each cranial nerve were stained and a photomicrograph was taken to make the following observations and measurements: 1) patterns of central myelin portion, 2) length of central myelin portion, and 3) depth of central myelin- peripheral myelin transitional zone.

RESULTS

For oculomotor nerve, the longest central myelin bundle was always seen on the first nerve bundle and that the length of central myelin decreased gradually. For abducens nerve, morphological patterns were classified into four types based on number of nerve rootlets emerging from the brainstem and number of nerve bundles in each rootlet. Length of central myelin portion was between 0.36-6.10 mm (2.75 ± 0.83 mm) and 0.13-5.01 mm (1.66 ± 1.39 mm) for oculomotor and abducens nerves, respectively. The oculomotor nerve transitional zone depth was 0.07-058 mm (0.23 ± 0.07 mm), while for abducens nerve, depth was 0.05-0.40 mm (0.16 ± 0.07 mm). Positive weak correlations between central myelin and depth of TZ were found in oculomotor nerve (r +0.310, p < 0.05) and abducens nerves (r +0.413, p < 0.05).

CONCLUSIONS

Detailed microanatomy of the central myelin and transitional zone might be beneficial for locating the site of compression in neurovascular conflicts at oculomotor and abducens nerves.