أبحاث طبية / Medical Research

**Title:** Accuracy of B-Scan Ultrasonography in the Diagnosis of Posterior Segment Pathologies in Patients Undergoing Pars Plana Vitrectomy (PPV) **Background:** Visualization of the posterior segment of the eye can be limited by conditions like dense cataract, vitreous hemorrhage, corneal opacity, or hyphema. B-scan ultrasonography offers real-time imaging of intraocular structures and helps detect retinal detachment (RD), vitreous hemorrhage (VH), posterior vitreous detachment (PVD), intraocular tumors, and choroidal detachment. PPV provides direct intraoperative visualization and is the gold standard for diagnosis. Evaluating B-scan accuracy is crucial for improving diagnostic confidence, guiding surgery, and avoiding unnecessary interventions. **Problem:** B-scan ultrasonography is widely used, especially in resource-limited settings, but local data comparing its accuracy with intraoperative findings is limited. **Objectives:** * **General:** Assess the accuracy of B-scan ultrasonography for posterior segment pathologies in patients undergoing PPV. * **Specific:** Determine sensitivity, specificity, PPV, NPV; compare preoperative B-scan with intraoperative findings; evaluate accuracy for specific conditions like RD, VH, and choroidal detachment. **Research Questions:** 1. How accurate is B-scan ultrasonography for posterior segment pathologies? 2. What are its sensitivity and specificity compared to intraoperative findings? 3. Does accuracy vary by pathology type? **Methodology:** * **Design:** Prospective observational study * **Location:** Al Jawareh Eye Hospital, Dongola, Sudan * **Population:** Patients undergoing PPV with preoperative B-scan * **Inclusion:** Scheduled for PPV, media opacity preventing fundus visualization * **Exclusion:** Incomplete records, poor-quality ultrasound images * **Sample:** All eligible patients during study period (convenience sampling) * **Data:** Demographics, clinical data, B-scan findings, intraoperative findings * **Outcome Measures:** Sensitivity, specificity, PPV, NPV of B-scan ultrasonography * **Analysis:** SPSS software; cross-tabulation; Kappa statistic; significance at p<0.05 **Ethics:** Approved by the institutional review board; informed consent obtained; patient confidentiality maintained. **Expected Results:** * High sensitivity of B-scan for RD and VH * Moderate specificity for some conditions * Strong agreement between ultrasound and intraoperative findings * Accuracy may vary depending on pathology type **Limitations:** Operator dependency, small sample size, selection bias, limited generalizability. **Timeline:** 6–9 months, including proposal approval, data collection, analysis, and report writing.

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