Megaloblastic anemia and bilateral disc edema: An enigma… Have we figured it out yet?

Micronutrient Deficiencies Presenting with Optic Disc Swelling Associated with or without Intracranial Hypertension: A Systematic Review

Idiopathic intracranial hypertension (IIH) is a neurological disorder characterised by optic disc swelling secondary to raised intracranial pressure (ICP) of unknown cause. Obesity is the most established and prevalent risk factor in developed countries. As obesogenic diets are high in calories and nutrient-poor, there may be associated nutritional deficiencies that contribute to the clinical presentation of IIH. Yet none, aside from iron deficiency, are currently included in the inclusion or exclusion criteria for the diagnosis of IIH. Our primary aim was to determine which micronutrient deficiencies, aside from iron deficiency, could present with optic disc swelling associated with or without intracranial hypertension that could potentially meet current IIH diagnostic criteria. To this end, we conducted a systematic search of articles published between 1 January 1980 and 18 December 2020 reporting cases of optic disc swelling associated with micronutrient deficiencies. In total, 65 cases met the eligibility criteria from initial searches: all were case reports and case series with a high risk of bias. Our findings suggest that patients with IIH or unexplained optic disc swelling ought to be screened, investigated, and treated for associated micronutrient deficiencies in vitamin A, B1 and B12; and weight loss interventions in IIH patients ought to promote better nutrition in addition to overall calorie restriction.

Deep-Learning-Based Hemoglobin Concentration Prediction and Anemia Screening Using Ultra-Wide Field Fundus Images

Background: Anemia is the most common hematological disorder. The purpose of this study was to establish and validate a deep-learning model to predict Hgb concentrations and screen anemia using ultra-wide-field (UWF) fundus images.

Methods: The study was conducted at Peking Union Medical College Hospital. Optos color images taken between January 2017 and June 2021 were screened for building the dataset. ASModel_UWF using UWF images was developed. Mean absolute error (MAE) and area under the receiver operating characteristics curve (AUC) were used to evaluate its performance. Saliency maps were generated to make the visual explanation of the model.

Results: ASModel_UWF acquired the MAE of the prediction task of 0.83 g/dl (95%CI: 0.81–0.85 g/dl) and the AUC of the screening task of 0.93 (95%CI: 0.92–0.95). Compared with other screening approaches, it achieved the best performance of AUC and sensitivity when the test dataset size was larger than 1000. The model tended to focus on the area around the optic disc, retinal vessels, and some regions located at the peripheral area of the retina, which were undetected by non-UWF imaging.

Conclusion: The deep-learning model ASModel_UWF could both predict Hgb concentration and screen anemia in a non-invasive and accurate way with high efficiency.

Papilledema: A Review of the Pathophysiology, Imaging Findings, and Mimics

Increased intracranial pressure is the most common cause of papilledema. Multiple etiologies such as cerebral edema, hydrocephalus, space occupying lesions, infection, and idiopathic intracranial hypertension among others should be considered. Imaging plays a critical role in the detection of pathologies that can cause papilledema. MRI with contrast and CE-MRV, in particular, are key for the diagnosis of idiopathic intracranial hypertension. This review will focus in common and infrequent causes of papilledema, the role of imaging in patients with papilledema as well as its potential mimickers.

The effects of vitamin B12 deficiency on retina and optic disk vascular density

PURPOSE

In this study, we aimed to determine the alterations in the retina and peripapillary vascular density in patients with vitamin B12 deficiency.

MATERIAL AND METHOD

The patients were divided into two groups regarding their vitamin B12 levels as the low vitamin B12 group (< 200 pg/ml) and the normal vitamin B12 group (≥ 200 pg/ml). The retinal nerve fiber layer thickness (RNFLT) and the central macular thickness (CMT) were measured through an SD-OCT analysis. The foveal avascular zone (FAZ), vessel density (VD) of the superficial capillary plexus (SCP), and deep capillary plexus (DCP) of the macula, and the VD of the radial peripapillary capillary plexus (RPCP) for the optic disk were determined by OCT-A.

RESULTS

Thirty-three patients were in the low vitamin B12 group and 54 were in the normal group. The mean RNFLT measurements were significantly lower in the low vitamin B12 group (p = 0.001). The RPCP values in all quadrants were significantly lower in the patients with vitamin B12 deficiency (p = 0.001); moreover, there was a significant increase in the FAZ value with a decrease in both superficial (p = 0.001) and deep (p = 0.001) VDs. There was a significant positive correlation between the serum vitamin B12 levels and the RPCP values and superficial and deep VDs, while the FAZ value was negatively correlated with the vitamin B12 levels.

CONCLUSION

Vitamin B12 deficiency has diverse effects on ocular structures and retinal vasculature. Decreased VDs and increased FAZ may be associated with severe ocular alterations in the long term, which should be further investigated.