CRAO in Moyamoya Syndrome Associated With Southampton Hemoglobinopathy

Increased risk of open angle glaucoma in patients with moyamoya disease from a nationwide population-based cohort in Korea

This nationwide population-based retrospective cohort study aims to investigate the association between Moyamoya disease (MMD) and open-angle glaucoma (OAG). In this study using the Korean National Health Insurance Service database, a total of 36,432 patients having diagnostic code with MMD between 2002 and 2022, and their age-, sex-matched non-MMD controls (n = 346,769) were included. We used a Cox proportional hazard model to determine the association between MMD and subsequent OAG after excluding cases with preexisting diagnosis of MMD for the initial 2-year. Kaplan-Meier survival analyses with log-rank test were performed to compare the incidence probability of OAG based on the MMD diagnosis. Cox regression analysis showed that the diagnosis of MMD was associated with increased risk of subsequent diagnosis of OAG (adjusted HR, 1.26; 95% CI, 1.14-1.38; P < 0.001). The cumulative incidence probability of OAG was 3.7% in MMD group and 2.9% in control group at the end of the study period, and was significantly higher among MMD patients than controls consistently during the study period (P < 0.001).In conclusion, the nationwide longitudinal data of Korean population revealed a significant association between MMD and OAG. Presence of MMD may increase the risk of developing OAG.

Analysis of Optic Disc Morphology and the Peripapillary Retinal and Choroidal Thickness by the Swept Source Optical Coherence Tomography in Patients with Moyamoya Disease

INTRODUCTION

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disorder. Ocular involvement in patients with MMD has increasingly been recognized and reported in recent years. This study aimed to investigate the changes of optic disc morphology and the peripapillary retinal and choroidal thickness in patients with MMD.

METHODS

This cross-sectional study included 56 patients diagnosed with idiopathic MMD and 56 healthy controls matched by age and gender. All participants underwent swept-source optical coherence tomography to capture the optic disc morphology as well as the peripapillary retinal and choroidal thickness. Optic disc parameters, including cup area, rim area, cup volume, rim volume, cup-disc area ratio (CDR), linear CDR, and vertical CDR were measured and compared between the two groups. Additionally, the thickness of the whole peripapillary retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and choroid were evaluated and analyzed across 12 clock-hour segments around the peripapillary region.

RESULTS

The rim area in MMD patients was significantly less than in controls, while the CDR in MMD patients was significantly larger than that in the control group. There was no statistically significant difference between the two groups regarding disc area, cup area, cup volume, rim volume, vertical and horizontal diameter of disc. The retinal thickness at the 7 o'clock position was significantly thinner in the MMD group compared to the control group and the temporal RNFL thickness, particularly at the 7 o'clock and 9 o'clock positions, was significantly reduced in the MMD group (p < 0.05). The GCL layer at the 7 o'clock position was thinner in the MMD group than in the control group (p < 0.05). The MMD group showed a notably reduced average choroidal thickness, particularly in the inferior-temporal region (p < 0.05). There was a correlation between peripapillary choroidal and GCL layer thickness in the MMD group, but no significant correlations were found with rim area, CDR, or RNFL.

CONCLUSIONS

In patients with MMD, there is an increase in the CDR accompanied by a decrease in the rim area. Additionally, there is thinning of the temporal RNFL, GCL, and choroidal thickness, notably in the inferotemporal quadrant of the optic disc.

Moyamoya Disease Increased the Risk of Retinal Vascular Occlusion: A Nationwide Cohort Study in Korea

PURPOSE

To investigate the risk of retinal vascular occlusion in patients with Moyamoya disease (MMD).

DESIGN

Retrospective, longitudinal cohort study using the Korean National Health Insurance Service database.

PARTICIPANTS

Newly diagnosed MMD patients (n = 34 627), who were diagnosed between 2004 and 2022, and their propensity score matched controls (n = 136 945) were included.

METHODS

We identified retinal vascular occlusion events using diagnostic codes for central retinal artery occlusion, other retinal artery occlusion, and retinal vein occlusion. After a washout period from 2002 to 2003, information on the diagnosis of retinal vascular occlusion was extracted in both MMD and control group during the follow-up period. The association between MMD and the risk of subsequent retinal vascular occlusion was investigated using a time-dependent Cox proportional hazard model and Kaplan-Meier survival analysis with log-rank test adjusted for age, sex, and comorbidities.

MAIN OUTCOME MEASURES

Hazard ratios (HRs) and 95% confidence intervals (CIs) for retinal vascular occlusion development according to the MMD.

RESULTS

Moyamoya disease was associated with an increased risk of subsequent retinal vascular occlusion even after adjusting for confounding variables (HR, 1.22; 95% CI, 1.09-1.36). Among the subtypes of retinal vascular occlusion, central retinal artery occlusion showed a highest HR (2.23; 95% CI, 1.35-3.7). Incidence probability of retinal vascular occlusion was significantly higher among MMD patients than controls (P < 0.001, log-rank test).

CONCLUSIONS

In this nationwide population-based cohort study, patients with MMD in Korea had an elevated risk of retinal vascular occlusion, suggesting that the MMD is one of the risk factors for retinal vascular occlusion.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Western Moyamoya Phenotype: A Scoping Review

Moyamoya, a rare angiographic finding, is characterized by chronic and progressive stenosis at the terminal end of the internal carotid artery, followed by collateralization of the cerebral vasculature at the base of the skull. Coined by Suzuki and Takaku in 1969, the term "moyamoya" means a "puff of smoke" in Japanese, a reference to the angiographic appearance of moyamoya collateralization. Moyamoya is most commonly found in East Asian countries, where much governmental and civilian effort has been expended to characterize this unique disease process. However, despite its rarity, the occurrence of moyamoya in Western countries is associated with significant divergence regarding incidence, gender, sex, age at diagnosis, clinical presentation, and outcomes. Here, we attempted to review the Western literature on moyamoya presentation using the PubMed database to characterize the Western phenotype of moyamoya. We were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). We reviewed papers generated from a search with keywords "moyamoya case report," those reported from a Western institution, and those reported on a relevant association. Our scoping review demonstrated various clinical associations with moyamoya. Moreover, we summarized the demographic profile and clinical symptomatology, as well as reported disease associations to better elucidate the Western phenotype of moyamoya.

CLINICAL SIGNIFICANCE OF RETINAL VASCULAR OCCLUSION IN MOYAMOYA DISEASE: Case Series and Systematic Review

PURPOSE

Although moyamoya disease primarily affects the carotid artery in the ophthalmic artery bifurcation area, retinal vascular abnormalities in moyamoya disease have rarely been reported. The purpose of this report is to describe clinical findings of patients with retinal vascular occlusion in patients with moyamoya disease and present its clinical significance.

METHODS

We reviewed and analyzed patients with moyamoya disease with retinal vascular occlusions. For this, a retrospective medical chart review was performed in a tertiary medical center and a literature search was performed using PubMed and EMBASE until September 2020.

RESULTS

Patients with retinal artery occlusion (RAO) were significantly younger than patients with retinal vein occlusion (25.0 vs. 40.1 years, P = 0.023). Of 14 patients, retinal vascular occlusion was the presenting sign of moyamoya disease in 8 (57.1%) patients. The occlusion site at the carotid artery was proximal to the ophthalmic artery bifurcation area in 8 (57.1%) patients. Legal blindness occurred in 8 (57.1%) patients at final visits.

CONCLUSION

Retinal vascular occlusion is a rare but sight-threatening ocular complication in patients with moyamoya disease. Overall, younger age may be a risk factor for RAO, whereas older age for retinal vein occlusion. Retinal vascular occlusion can be an important indicator of moyamoya disease screening, especially in relatively younger and healthy patients.

The rare hemoglobin variant Hb Mizuho: report of a Swiss family and literature review

Hb Mizuho is a very rare unstable hemoglobin; here, we describe the clinical history of three Swiss family members with Hb Mizuho together with a systematic review of the previously six published cases. The clinical history of the adult woman we report here is unique since this is the first Hb Mizuho presenting with Moyamoya complications and the first case reported with long-term erythrocyte exchange. The literature review showed that Hb Mizuho was mainly reported as a de novo mutation, with the exception of children descended from known cases. All published patients with this unstable hemoglobin showed severe hemolytic anemia with the exception of one; all were regularly transfused. Patients with higher HbF levels might require fewer transfusions. All patients underwent splenectomy at a median age of 4 years and had variable clinical improvement; some achieved complete resolution of transfusion dependency after splenectomy. Iron overload in Hb Mizuho patients seems to be mainly attributed to transfusions and has less to do with ineffective erythropoiesis. Diagnosis might be challenging; a normal hemoglobin electrophoresis should not rule out the diagnosis of unstable hemoglobin in patients with otherwise unexplained hemolytic anemia. This series shows the enormous utility of using molecular techniques for diagnosis.

Central retinal artery occlusion as initial presentation of Moyamoya disease in a middle-aged woman

Purpose

To present a case of central retinal artery occlusion as the first symptomatic manifestation of Moyamoya disease in a middle-aged patient.

Observations

Case report of a 48-year-old female Chinese-American patient who presented with sudden onset painless unilateral vision loss. Fundus photos, optical coherence tomography, fluorescein angiography, magnetic resonance angiography, computed tomography angiography, and catheter cerebral angiogram were performed. The patient's dilated fundus examination showed classic findings of a central retinal artery occlusion. Diagnostic brain imaging demonstrated extensive stenosis of the cerebrovascular network, with almost complete unilateral occlusion of the internal carotid artery along with compensatory collateral vessels. This led to a new diagnosis of Moyamoya disease. The patient was treated with extracranial-intracranial bypass surgery.

Conclusions and importance

Arterial abnormalities in patients with Moyamoya disease are uncommon and have previously only been reported in younger patients in their teens and 20s. Young and middle-aged patients presenting with central retinal artery occlusions should undergo complete neurologic workup including stroke evaluation; in this case, revealing Moyamoya disease, a rare yet life-threatening condition, as the underlying etiology.