Clinical significance of signal shadowing during intraoperative optical coherence tomography-assisted vitreoretinal surgery.

This study aimed to analyze the clinical significance of signal shadowing during intraoperative optical coherence tomography (iOCT)-assisted vitreoretinal surgery caused by vitreoretinal instruments, tissue dyes, and vitreous substitutes, and to objectively quantify its impact on iOCT imaging. This is a retrospective observational study of postoperative image analysis from one hundred seventeen (117) patients who underwent iOCT-assisted vitrectomy. The image data were divided into three groups: vitreoretinal instruments, tissue dyes, and vitreous substitutes. The data was then processed using graphic software to measure the grade of picture quality distortion and compared to paired image controls without clinically perceptive interference, then analyzed statistically. The intraocular portion of all studied vitreoretinal instruments caused a high average gray level interference compared to controls ranging from 32 to 68% reduction, obscuring the area of interest significantly. The tips of the instruments produced low-grade shadowing, allowing the underlying tissue to be distinguished. The analyzed dyes demonstrated a wide interference range: ICG (- 75.12%), and triamcinolone (- 26.13%) showed dose-dependent high shadowing, while VITREODYNE™ (49.3%) and brilliant blue G (14.06%) exhibited no perceived distortions whilst increasing average gray levels. All analyzed vitreous substitutes (air, SF6, C3F8, PFCL, and silicone oil) showed an insignificant shadowing effect on iOCT. Certain dyes and vitreous substitutes produce a negligible shadowing effect compared to controls and other dyes, providing an advantage during real-time iOCT imaging. All analyzed vitreoretinal instruments showed a significant interference that should prompt the development of new imaging techniques or the implementation of materials with low-grade interference to overcome a clinically relevant shadowing effect on iOCT, maximizing the technology's visual accuracy and surgical diagnostic aid proficiency.

[Epidemiological impact of the COVID-19 pandemic on enucleation cases in Germany]. / Epidemiologische Auswirkungen der COVID-19-Pandemie auf Enukleationsfälle in Deutschland.

PURPOSE: To determine the rate of enucleation in Germany and the impact that the COVID-19 pandemic may have had on its characteristics. METHODS: The rates of enucleation in Germany during 2019 and 2020 were extracted from the diagnosis-related groups (DRG) registry using the operation and procedure classification system codes 5­163.0 through 5­163.23 and 5­163.x. The data were statistically analyzed. RESULTS: The number of enucleations showed a 16.6% reduction from 1295 cases in 2019 compared to 1080 cases in 2020 (p = 0.17). In both years men averaged 54.1% of cases. Patients older than 65 years represented 53% and 56% of cases in 2019 and 2020, respectively. The most common indication for enucleation in both years was phthisis bulbi (n = 373 and n = 307, respectively), accounting for 29.7% of the cases, followed by choroidal malignancies (24%). Enucleation with the simultaneous introduction of an alloplastic orbital implant into Tenon's capsule represented the most common procedure (38.7% combined 2­year average), followed by a sheathed variant (26.6%) and a bulbar implant made of nonabsorbable microporous material (16.8%), without a significant change between years. Enucleations without the introduction of an implant increased from 7.8% in 2019 to 11.1% in 2020 (p = 0.006). The proportion of patients undergoing a reoperation slightly increased from 5.6% to 8% (p = 0.018). Most procedures (65.6%) were performed in large (> 1000 beds) public hospitals. CONCLUSION: Despite the decrease in the total number of procedures performed, the rate of enucleation in Germany was not significantly altered by the COVID-19 pandemic. The rate of enucleation without implants and reoperations significantly increased.