Rapid B-scanning of the vitreous.

Abstract

SUMMARY Ultrasonic examination is an essential investigation in most patients awaiting vitrectomy. Rapid B-scanning of the vitreous is described utilising a new system capable of high resolution and good tonal quality. Several patterns of haemorrhagic invasion of the vitreous cavity are illustrated, together with detachment, collapse, and retraction of the vitreous gel.Diagnostic ultrasound has been used for many years for the investigation of ocular and orbital diseases (Oksala, 1963;Baum, 1964;Purnell, 1966;Ossoinig, 1972;Coleman, 1972;Bronson, 1972). Examination methods currently available include A-, B-, C-, and M-scanning and ultrasonic holography. Apparatus capable of ophthalmic A-, B-, and C-scanning and holography was designed by Aldridge et al. (1974) and has been on clinical trial at Moorfields Eye Hospital for the past three years. A report of its use in the investigation of orbital lesions is to be published shortly (Restori and Wright, 1977). This paper presents our experience of real-time Bscanning of the vitreous cavity, particularly in patients being considered for vitrectomy. controls include gain, transmission pulse duration, scanning speed, and a swept gain facility to compensate for sound attenuation in the globe and orbit.The system is capable of good resolution and is remarkably free of artefacts. The scanning mechanism has been built to a high standard of rigidity and precision, and the instantaneous position of the transducer is transferred to the display tube with minimum error. These are design criteria for holographic imaging and undoubtedly contribute to the quality of the B-scan display.Adequate sensitivity and accurate echo registration allow weak echoes to be detected and displayed. The dynamic range of the system is 40 dB, and an amplifier to compress this 40 dB into the 20 dB dynamic range of an oscilloscope would improve the grey scale appearance of the B-scan display.A time-gate has proved useful in selecting echoes for amplitude quantitation from any B-scan section.

Histopathological assessments reveal retinal vascular changes, inflammation, and gliosis in patients with lethal COVID-19

“…In fundus photographs, other studies identified hemorrhages, cotton wool spots, dilated veins, and tortuous vessels [13,37]. These are commonly seen as manifestations of diabetes mellitus and systemic hypertension but are also associated with several other etiologies, including ischemic, embolic, connective tissue, neoplastic, and infectious [38][39][40][41]. In our histological study, we detected amorphous debris in the outer plexiform layer corresponding to hemorrhages.…”

Ultrasonographic Findings of Some Ocular Affections in Dogs

“…The prevalence of retinal detachment most frequently observed in eyes with maturity of cataract and glaucoma. This is in correlation with (McLeod et al, 1977;Gonzalez et al, 2001 andDar, et al, 2014). In conclusion, ultrasonography of the eye is a safe, rapid, noninvasive and reliable method for diagnose almost eye affections.…”

Histopathological assessments reveal retinal vascular changes, inflammation and gliosis in patients with lethal COVID-19

“…These are commonly seen as manifestations of diabetes mellitus and systemic hypertension but are also associated with several other etiologies, including ischemic, embolic, connective tissue, neoplastic, and infectious [31][32][33] . CWSs compromise localized accumulations of axoplasmic debris at the level of retinal ganglion cell axons resulting from axoplasmic flow interruption due to vascular or mechanical causes 34 . In our histological study, we detected amorphous debris in the outer plexiform layer corresponding to hemorrhages.…”