A comparative study between 10-MHz and 15-MHz ultrasound probes for retinal evaluation in silicone-oil-filled globes.

PURPOSE: To compare 10-MHz and 15-MHz B-scan probes regarding the detection and localization of retinal detachment (RD) in silicone-oil-filled eyes. METHODS: This cross-sectional observational study included 100 eyes (98 patients) -having media opacity precluding fundus examination- scheduled for silicone-oil removal. Patients were examined in the sitting-position using both frequencies one week preoperatively. Longitudinal and transverse scans were taken in primary-gaze, inferior, inferonasal, and inferotemporal positions to detect the presence/absence and extent of RD. Patients were sub-grouped according to axial lengths (AXLs), state of silicone emulsification, and globe filling. Agreement between sonographic and intraoperative observations was compared. RESULTS: No statistically significant differences were found between 15-MHz and intra-operative findings regarding RD detection (P = 0.752) and accurate localization of inferior, inferonasal, and inferotemporal RD (P = 0.279, 0.606, and 0.599). There were statistically significant differences between 10-MHz and intra-operative findings regarding RD detection and localization (P < 0.001). The 15-MHz probe was superior to 10-MHz probe regarding the accuracy of RD detection and localization (94% and 47%, respectively). The accuracy of 15-MHz probe was 88%, 83%, and 85% in detecting and localizing inferior, inferonasal, and inferotemporal RD compared to 45%, 60%, and 62% with 10-MHz probe. The 15-MHz probe showed better sensitivity while 10-MHz probe showed better accuracy in eyes with short AXLs. The 10-MHz probe showed better sensitivity in patients with sonographic emulsification while15-MHz probe had better sensitivity in detecting vitreoretinal-interface disorders. CONCLUSION: The 15-MHz B-scan probe is more accurate in detecting and localizing recurrent RD in silicone-oil-filled globes with higher sensitivity in detecting vitreoretinal-interface disorders.

Evaluation of sex differences in corneal hysteresis.

PURPOSE: To study sex differences in corneal biomechanical parameters in Egypt as regards to corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc). METHODS: This is a cross-sectional observational study that includes 350 eyes of 350 normal subjects (175 men and 175 women) who were evaluated using the Reichert ocular response analyzer (ORA) to measure CH, CRF, IOPg, and IOPcc. RESULTS: The mean CH in men was 9.69 ± 2.05 mm Hg (range 5.7-14.6 mm Hg) and in women 10.41 ± 1.65 mm Hg (range 7-14.4 mm Hg) with a p value of 0.00038. The mean CRF in men was 9.54 ± 2.16 mm Hg (range 4.9-14.4 mm Hg) and in women was 10.37 ± 1.71 mm Hg (range 7.3-15.5 mm Hg) with a p value of 0.00008. The mean IOPg in men was 14.78 ± 4.15 mm Hg (range 7.2-26.5 mm Hg) and in women was 15.44 ± 3.3 mm Hg (range 8.6-23.7 mm Hg) with a p value of 0.09. The mean IOPcc in men was 16.2 ± 4.08 mm Hg (range 10.9-28.9 mm Hg) and in women was 15.86 ± 3.41 (range 9.7-24.2 mm Hg) with a p value of 0.4. There was a statistically significant difference between men and women in CH and CRF while IOPg and IOPcc showed no statistically significant difference (p>0.05). CONCLUSIONS: There is a statistically significant difference between men and women in CH and CRF, where women show higher values, while no statistically significant difference exists between the groups in IOPg or IOPcc.