The Impact of Orbital Volume on Post-traumatic Enophthalmos: A Systematic Review and Meta-analysis.

PURPOSE: Orbital volume increase has been previously linked with post-traumatic enophthalmos. However, this varies and some studies show no correlation. This systematic review and meta-analysis aimed to synthesize the correlation between orbital volume and enophthalmos and to determine if surgical intervention, enophthalmos measurement method, fracture location, or timing affect this correlation. METHODS: Automation tools were used to assist in this review of 6 databases. Searches were performed across all dates. Included studies quantitatively reported orbital volume and enophthalmos following traumatic orbital wall fractures in at least 5 adult subjects. Correlational data were extracted or calculated. Random-effects meta-analysis was used with subgroup analyses for each of the secondary aims. RESULTS: Twenty-five articles describing 648 patients were included. The pooled correlation between orbital volume and enophthalmos was r =0.71 ( R2 =0.50, P <0.001). Operative status, enophthalmos measurement method, and fracture location did not affect pooled correlation. The delay between trauma or surgery and enophthalmos measurement was not shown to modulate correlation for unoperated patients ( R2 =0.05, P =0.22) but showed a negative relationship for postoperative patients ( z =-0.0281, SE=0.0128, R2 =0.63, P =0.03), but this was heavily influenced by a single article. All results had high residual heterogeneity. Studies were rated as moderate, low, or very low quality with few stating explicit hypotheses or limitations. CONCLUSIONS: Bony orbital volume expansion accounts for around 50% of post-traumatic enophthalmos. The other half is probably explained by soft tissue or geometric bony, rather than volumetric, changes.

Thermodynamic analysis of the topologically close packed σ phase in the Co-Cr system.

Density functional theory (DFT) calculations show that it is essential to consider the magnetic contribution to the total energy for the end-members of the σ phase. A more straightforward method to use the DFT results in a CALPHAD (Calculation of phase diagrams) description has been applied in the present work. It was found that only the results from DFT calculations considering spin-polarization are necessary to obtain a reliable description of the σ phase. The benefits of this method are: the DFT calculation work can be reduced and the CALPHAD description of the magnetic contribution is more reliable. A revised thermodynamic description of the Co-Cr system is presented which gives improved agreement with experimental phase boundary data for the σ phase.

360-Degree laser retinopexy in primary vitrectomy for rhegmatogenous retinal detachment: factors associated with its use and impact on surgical outcomes.

BACKGROUND: To determine patient and surgical factors associated with the use of 360-degree laser retinopexy during primary pars plana vitrectomy (PPV) ± scleral buckle (SB) for rhegmatogenous retinal detachment (RRD) and its impact on surgical outcomes. METHODS: Patients who underwent PPV ± SB for repair of non-complex RRD at a single centre were included in this retrospective study. The primary outcome was single surgery anatomical success (SSAS). Secondary outcomes included visual acuity, epiretinal membrane formation, the presence of cystoid macular oedema, tonic pupil and corneal epithelial defects. Multiple logistic regression and multivariate regression was used. RESULTS: The study included 192 cases, of which 130 received 360-degree laser. Worse preoperative logMAR visual acuity (P = 0.009), male sex (P = 0.060), higher PVR grades, supplemental SB (P = 0.0468) and silicone oil/C3F8 tamponade (P < 0.0001) were associated with 360-degree laser use. No significant associations between 360-degree laser and SSAS (P = 0.079), final logMAR visual acuity (P = 0.0623), ERM development (P = 0.8208), postoperative CMO (P = 0.5946), tonic pupil (P > 0.9999) or corneal epithelial defects (P = N/A) were found. CONCLUSIONS: 360-degree laser retinopexy during primary PPV ± SB for RRD was associated with more complex cases and more extensive operations. Even when accounting for this, there was no difference in surgical outcomes or complication rates.