Unilateral transient high myopization after pediatric strabismus surgery: Observation by anterior segment optical coherence tomography

[Purpose] To describe an unusual case of unilateral transient high myopization after pediatric strabismus surgery. [Observations] A 6-year-old girl with intermittent exotropia had undergone strabismus surgery and experienced a transient decrease in best-corrected visual acuity (BCVA, from 20/20 to 20/33) with high myopization (from +0.25 D to −9.00 D). Slit-lamp microscopy showed anterior chamber inflammation and a narrow angle only in the affected eye. Anterior segment optical coherence tomography (AS-OCT) revealed ciliary body detachment, a narrow angle, a shallow anterior chamber, and an anteroposterior elongation of the crystalline lens in the affected eye. Her symptoms of blurry vision and high myopization improved 8 weeks postoperatively. AS-OCT revealed the resolution of the ciliary body detachment, an open angle, and a deep anterior chamber, with normalization of the anteroposterior length of the crystalline lens. Her BCVA recovered to 20/20 with spherical equivalence of 0 D. [Conclusions and Importance] We reported on an extremely rare case of unilateral transient high myopization following strabismus surgery, which was resolved without additional surgery. This myopization was probably caused due to ciliary body inflammation

Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography

Purpose: To evaluate the clinical feasibility of peripheral chorioretinal imaging through a front prism on swept-source optical coherence tomography angiography (SS-OCTA). Methods: We prospectively obtained en face OCTA images using SS-OCTA in 10 eyes of 10 healthy volunteers. For the peripheral chorioretinal imaging, the scanning laser passed and refracted through a 45 −90 −45 right-angle prism. We evaluated the qualitative and quantitative characteristics of chorioretinal vessels in the periphery. Results: Using peripheral chorioretinal imaging through a prism, the retinal vasculature was delineated to the equator on the OCTA images, and varices of the vortex vein ampullae were observed on choroidal OCT images. The 3×3-mm images revealed three-dimensional morphologies unique to the peripheral vasculature, such as the gap between retinal arterioles and venules in the superficial capillary plexus (SCP) and elliptical and greater lobules in the choriocapillaris layer. Compared with OCTA images obtained without the prism, those obtained through the prism demonstrated an approximately 1.24-fold increase in the lengths in the base apex direction, whereas the lengths in the perpendicular direction showed concordance. The peripheral vessel density (VD) in the inferior quadrant was lower than those in the other quadrants on the SCP and deep capillary plexus, whereas on the SCP images of the macula the lowest VD was observed in the temporal subfield. Conclusions: Peripheral chorioretinal imaging allowed us to generate ultra-widefield panoramic OCTA images and demonstrated morphologic characteristics unique to peripheral chorioretinal vessels. Translational Relevance: OCTA imaging through a front prism can be a technique for acquiring chorioretinal vasculature images in the periphery

Human Foveal Cone and Müller Cells Examined by Adaptive Optics Optical Coherence Tomography

Purpose: The purpose of this study was to image and investigate the foveal microstructure of human cone and Müller cells using adaptive optics-optical coherence tomography. Methods: Six healthy subjects underwent the prototype adaptive optics-optical coherence tomography imaging, which allowed an axial resolution of 3.4 µm and a transverse resolution of approximately 3 µm. The morphological features of the individual retinal cells observed in the foveola were qualitatively and quantitatively evaluated. Results: In the six healthy subjects, the image B-scans showed hyper-reflective dots that were densely packed in the outer nuclear layer. The mean number, diameter, and density of hyper-reflective dots in the foveola were 250.8 ± 59.6, 12.7 ± 59.6 µm, and 6966 ± 1833/mm², respectively. These qualitative and quantitative findings regarding the hyper-reflective dots were markedly consistent with the morphological features of the foveal cone cell nuclei. Additionally, the images showed the funnel-shaped hyporeflective bodies running vertically and obliquely between the inner and external limiting membranes, illustrating the cell morphology of the foveal Müller cells. Conclusions: Using adaptive optics, we succeeded in visualizing cross-sectional images of the individual cone and Müller cells of the human retina in vivo. Translational Relevance: Adaptive optics-optical coherence tomography would help to improve our understanding of the pathogenesis of macular diseases

Prevention of Image Quality Degradation in Wider Field Optical Coherence Tomography Angiography Images Via Image Averaging

Purpose: To evaluate the mutual effect of widening the field of view and multiple en face image averaging on the quality of optical coherence tomography angiography (OCTA) images. Methods: This prospective, observational, cross-sectional case series included 20 eyes of 20 healthy volunteers with no history of ocular or systemic disease. OCTA imaging of a 3 × 3-mm, 6 × 6-mm, and 12 × 12-mm area centered on the fovea was performed nine times using the PLEX Elite 9000. We acquired averaged OCTA images generated from nine en face OCTA images. The corresponding areas in the three scan sizes were evaluated for the original single-scanned OCTA images and averaged OCTA images both qualitatively and quantitatively. Quantitative measurements included vessel density (VD), vessel length density (VLD), fractal dimension (FD), and contrast-to-noise ratio (CNR). Results: Significant differences in VD, VLD, FD, and CNR (P < 0.001) were observed due to the mutual effect of averaging and differences in scan size. Both qualitative and quantitative evaluations indicated that the quality of 6 × 6-mm averaged images was equal to or better than that of 3 × 3-mm single-scanned images. However, the quality of 12 × 12-mm averaged images did not reach that of 3 × 3-mm single-scanned images. Conclusions: To some extent, multiple en face OCTA image averaging can compensate for the deterioration in image quality caused by widening the field of view. Translational Relevance: Multiple en face OCTA image averaging can be a technique for acquiring wider field OCTA images with good quality

A New Electrophysiological Method for the Diagnosis of Extraforaminal Stenosis at L5-S1

Study DesignA retrospective study.PurposeTo examine the effectiveness of using an electrodiagnostic technique as a new approach in the clinical diagnosis of extraforaminal stenosis at L5-S1.Overview of LiteratureWe introduced a new effective approach to the diagnosis of extraforaminal stenosis at the lumbosacral junction using the existing electrophysiological evaluation technique.MethodsA consecutive series of 124 patients with fifth lumbar radiculopathy were enrolled, comprising a group of 74 patients with spinal canal stenosis and a second group of 50 patients with extraforaminal stenosis at L5-S1. The technique involved inserting a pair of needle electrodes into the foraminal exit zone of the fifth lumbar spinal nerves, which were used to provide electrical stimulation. The compound muscle action potentials from each of the tibialis anterior muscles were recorded.ResultsThe distal motor latency (DML) of the potentials ranged from 11.2 to 24.6 milliseconds in patients with extraforaminal stenosis. In contrast, the DML in patients with spinal canal stenosis ranged from 10.0 to 17.2 milliseconds. After comparing the DML of each of the 2 groups and at the same time comparing the differences in DML between the affected and unaffected side of each patient, we concluded there were statistically significant differences (p<0.01) between the 2 groups. Using receiver operating characteristic curve analysis, the cutoff values were calculated to be 15.2 milliseconds and 1.1 milliseconds, respectively.ConclusionsThis approach using a means of DML measurement enables us to identify and localize lesions, which offers an advantage in diagnosing extraforaminal stenosis at L5-S1