The PATTERN OF PATHOLOGIES IN B-SCAN OCULAR ULTRASOUND

Abstract

Background: The superficial location of the eye, its cystic composition, and the advent of high-frequency ultrasound make sonography ideal for imaging the eye. The use of ultrasound for diagnostic imaging of the eye originates with the work of Mundt and Hughes. (A-scan) and Baum and Greenwood (B-scan) in the 1950s. Ocular B-mode ultrasonography (USG) is an essential adjuvant for the evaluation of ocular diseases. Ultrasound is a valuable tool to evaluate the eye, particularly when direct examination and fundoscopy is not sufficient. MRI and CT have also been utilised to evaluate the eye. However, they are costlier and less available compared to ultrasound. Retinoblastoma and choroidal melanoma are the most frequent intraocular tumours. In the orbit, common pathologies include orbital pseudotumor, Grave’s orbitopathy, and retro-orbital haematoma. B-scan is to rule out possible contraindications to cataract extractions such as retinal detachment or tumours.

Objectives: (i) To determine the pattern of pathologies in patients referred for ocular ultrasound. (ii) To determine the relationship of ocular pathologies by age and sex in patients referred for ocular ultrasound.

Methods: It was a cross-sectional study performed at SKIMS Medical College and the Hospital ultrasound room. Diagnostic ultrasound was performed using a high resolution and high-frequency probe on the affected eye. A data collection sheet was used to record the ultrasound findings. Diagnostic Ultrasound was performed with a high frequency (10MHz) linear transducer. The examination was performed in brightness (B-mode) with the patient in the supine position and the eyes closed, slightly resting the transducer on both eyelids, after application of 4% topical lignocaine and coupling gel. Specific diagnoses was made according to criteria set out in Diagnostic Imaging of the Eye.

Results: Most common age group i.e. 52.84% in our study was 30-49 years followed by 11-29 and >50 i.e. 19 (17.92%). There were 12 (11.32%) patients aged between 1-10 years. Right eye involvement was observed in 49 (46.67%) patients, 42 (40%) patients had left eye involved and 14 (13.33%) had bilateral eye involvement. The most common symptom at presentation was decreased vision in 56.32% of patients followed by leukocoria in 42.57%, trauma in 20.43%, pain and redness in 15.71%, discharge in 3.78% and exophthalmos in 4.32% of patients. On ultrasonography retinal detachment was the most common finding in 28 (26.66%) followed by vitreous haemorrhage in 24 (22.85%), vitreous detachment in 18 (17.14%). 

Conclusion: Ultrasonography is readily available, simple, cost-effective, non-ionizing, non-invasive and a reliable imaging modality for posterior segment ocular pathologies. It readily establishes the diagnosis insignificant number of cases. It has a higher spatial and temporal resolution compared to both CT and MRI for the diagnosis of ocular pathologies. It superseded the accuracy of ophthalmoscopic diagnosis with a significant difference (p-value < 0.0001).