The Role of Optical Coherence Tomography Angiography in Optic Nerve Head Edema: A Narrative Review.

Optic nerve head (ONH) edema is a clinical manifestation of many ocular and systemic disorders. Ocular and central nervous system imaging has been used to differentiate the underlying cause of ONH edema and monitor the disease course. ONH vessel abnormalities are among the earliest signs of impaired axonal transportation. Optical coherence tomography angiography (OCTA) is a noninvasive method for imaging ONH and peripapillary vessels and has been used extensively for studying vascular changes in ONH disorders, including ONH edema. In this narrative review, we describe OCTA findings of the most common causes of ONH edema and its differential diagnoses including ONH drusen.

Peripapillary Capillary Network in Methanol Induced Optic Neuropathy.

PURPOSE: To present the optical coherence tomography angiography (OCT-A) findings of the radial peripapillary capillary (RPC) network in an individual with severe bilateral methanol-induced toxic optic neuropathy (MTON) in comparison to a normal subject and a patient with retinitis pigmentosa. CASE REPORT: A 35-year-old man with severe bilateral MTON was referred to the neuro-ophthalmology clinic at the Labbafinejad Medical Center. The Angio Vue OCT 3D set of 4.5 × 4.5 mm was used to measure the disc and peripapillary vessel density. Two subjects were examined with the same protocol as controls to determine the effect on the RPC vessel density in multiple scenarios. One of the controls was a healthy individual with the prerequisite matches of age and sex while the second one was a known retinitis pigmentosa (RP) patient. RPC density was measured as 37.7 in the patient with MTON, 46.9 in the RP patient, and 54.7 in the healthy control. CONCLUSION: The reduction in the RPC vessel density in a patient with MTON compared to that of a healthy individual and also a patient with RP may be due to the loss of capillaries secondary to the loss of nerve fibers and ganglion cells. Moreover, MTON can be considered an optic neuropathy with direct mitochondrial damage to the endothelial cells of the capillaries.

Comparison of Vitamin B12, Vitamin D, and Folic Acid Blood Levels in Plumbism Patients and Controls in Eastern Iran.

The aim of this study was to evaluate the blood levels of folic acid, vitamin B12, and 25-hydroxyvitamin D (25-OHD) in patients with lead poisoning compared with control subjects in Eastern Iran. This analytical case-control study was conducted on 40 lead-poisoned patients who were referred to Imam Reza Hospital in Birjand from 2018 to 2019. Blood samples were collected from an additional 40 individuals without lead poisoning as a control group. The results indicated that the mean vitamin B12, vitamin D, and folic acid levels for the case group were 356.5 ± 200.1 pg/ml, 24.38 ± 9.5 ng/ml, and 7.4 ± 3.7 ng/ml, respectively. Mean folic acid level in the case group was significantly lower than control group (7.4 ng/ml vs. 12.70 pg/ml, P = 0.001), whereas the mean of the vitamin D levels at the case group was significantly higher than that of the control group (24.3 ng/ml vs. 20.1 ng/ml, P = 0.03). Moreover, mean vitamin B12 levels were significantly lower in the case group in comparison with the control group (356.5 pg/ml vs. 500.8 pg/ml) (P < 0.001). In the control group, 3 patients had folic acid below normal level (< 6 ng/mL) while 12 cases had folic acid below normal (P < 0.05). Also, none of the control group had low vitamin B12 concentrations (< 180 pg/ml), while 7 cases had vitamin b12 below normal (P < 0.05). Our results suggest that lead may induce folate and vitamin B12 dysregulation. Although we found that vitamin D levels were insufficient in both case and control groups, they were significantly higher in the case group. The interpretation of this result is unclear given inconsistent literature reports on this relationship.