Diagnostic accuracy of B scan ultrasonography for posterior segment eye disorders in a tertiary care setting in Eastern India

Introduction: Ophthalmic ultrasound (USG) produces real time high resolution images of the eye and orbit. It can categorize and predict the location of pathology in the posterior chamber of eye very well. It is useful even in pre-operative evaluation and diagnosing posterior segment eye disorders. However, the diagnostic accuracy has usually not being studied thoroughly, with special emphasis to its probability of predicting posterior-segment eye disorders using B-scan USG. Objectives: To find out the prevalence and pattern of posterior segment disorders using B-scan ultrasonography, and to find its diagnostic accuracy. Materials and Methods: The study was prospective in nature and conducted in the department of radiodiagnosis and ophthalmology of a tertiary care center of Eastern India. Patients referred to the radiology department for ruling out intra-ocular pathology using B-scan ophthalmic ultrasound were included in the study, irrespective of any age and gender. Data were captured on an excel sheet and analyzed using Stata 12.1 SE. Results: The mean age of 84 study participants was 37.4 {+/-} 19.5 years, with maximum in between 40-50 years. Males were more (72.6%). 50% presented with low vision, and most commonly associated with cataract (45%). Prevalance of posterior segment eye disorders was 13.1%. Sensitivity and negative predictive values were 100%. Post-test probability was 95.5%. Accuracy was however very less (39.3%). Conclusion: Using B-scan ultrasonography for pre-operative assessment and confirmation of diagnosis increases the probability of detecting presence or absence of posterior segment pathology. Absence of posterior segment disorder using this is also very helpful in ruling out disease entirely. It also a very high sensitivity and hence can be used even in rural health centers.