To evaluate the diagnostic value of the L33-8s linear array ultrasound probe in detecting ciliary body detachment (CBD).

A total of 30 patients (30 eyes) diagnosed with CBD by ultrasound biomicroscopy (UBM) at the Department of Ophthalmology, Beijing Tongren Hospital from June 2024 to August 2025 were included in the case group, while the 30 contralateral healthy eyes were used as controls. All enrolled eyes were examined with both the L33-8s and L20-5s linear array probes. Taking UBM findings as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of both probes were calculated. The McNemar's test was used to compare the differences in sensitivity and accuracy, and a 2×2 chi-square test was used to compare the difference in negative predictive value. Receiver operating characteristic (ROC) curves were plotted, and the area under the curve (AUC) was calculated to evaluate diagnostic capability. The case group was classified into grades 1–4 based on the extent of CBD detected by UBM, and the detection rates of the two probes across different grades were compared.

The L33-8s probe demonstrated a sensitivity of 86.7% (26/30), negative predictive value of 88.2%, and accuracy of 93.3%, while the L20-5s probe yielded corresponding values of 63.3% (19/30), 73.2%, and 81.7%. Statistically significant differences were observed between the two probes in both sensitivity (χ²=5.143, P=0.023) and accuracy (χ²=5.143, P=0.023). The negative predictive value of the L33-8s probe was higher than that of the L20-5s probe, but the difference was not statistically significant (P＞0.05). Both probes demonstrated a specificity and positive predictive value of 100%. ROC curve analysis showed that the AUC of the L33-8s probe was 0.933, which was higher than that of the L20-5s probe (AUC=0.817). The L33-8s probe had significantly higher detection rates for grade 1 and grade 2 CBD than the L20-5s probe (75.0% vs 33.3%; 90.0% vs 70.0%).

The L33-8s probe demonstrates superior diagnostic performance for CBD compared with the L20-5s probe, especially for cases with a small extent of detachment.