The Prevalence of Optical Coherence Tomography Artifacts in High Myopia and its Influence on Glaucoma Diagnosis.

PRCIS: Optical coherence tomography (OCT) artifacts occur much more frequently in highly myopic eyes compared with non-highly myopic eyes. A longer axial length is predictive of having OCT artifacts. PURPOSE: To investigate the types and prevalence of artifacts on OCT scans in patients with and without high myopia. MATERIALS AND METHODS: Patients were divided into 4 groups based on whether they had glaucoma and/or high myopia. All peripapillary retinal nerve fiber layer (RNFL) scan images were individually inspected for the presence of artifacts. RESULTS: Two hundred twenty-six patients were enrolled. The prevalence of OCT artifacts was 18.6% in non-high myopes and 51.9% in high myopes ( P <0.001). Outer RNFL border misidentification was the most common type of artifact for non-high myopes, whereas retinal pathology-related artifact was the most common in high myopes. Univariable regression analysis showed that a longer axial length [odds ratio (OR) 1.815, P <0.001], a higher pattern standard deviation (OR 1.194, P <0.001), and thinner RNFL (OR 0.947, P <0.001) were predictive factors for the presence of OCT artifacts. The diagnostic capability of global RNFL thickness before and after manual correction of segmentation errors did not differ for both non-high myopes [area under the receiver operating curve 0.915-0.913 ( P =0.955)] and high myopes [area under the receiver operating curve 0.906-0.917 ( P =0.806)]. CONCLUSION: The prevalence of OCT artifacts was the highest in patients with both high myopia and glaucoma. The most common type of OCT artifact is different for non-high myopes and high myopes. Physicians need to be aware of a higher likelihood of OCT artifacts, particularly in those with a longer axial length, worse visual field, and thinner RNFL thickness.

Field evaluation of personal sampling methods for multiple bioaerosols.

Ambient bioaerosols are ubiquitous in the daily environment and can affect health in various ways. However, few studies have been conducted to comprehensively evaluate personal bioaerosol exposure in occupational and indoor environments because of the complex composition of bioaerosols and the lack of standardized sampling/analysis methods. We conducted a study to determine the most efficient collection/analysis method for the personal exposure assessment of multiple bioaerosols. The sampling efficiencies of three filters and four samplers were compared. According to our results, polycarbonate (PC) filters had the highest relative efficiency, particularly for bacteria. Side-by-side sampling was conducted to evaluate the three filter samplers (with PC filters) and the NIOSH Personal Bioaerosol Cyclone Sampler. According to the results, the Button Aerosol Sampler and the IOM Inhalable Dust Sampler had the highest relative efficiencies for fungi and bacteria, followed by the NIOSH sampler. Personal sampling was performed in a pig farm to assess occupational bioaerosol exposure and to evaluate the sampling/analysis methods. The Button and IOM samplers yielded a similar performance for personal bioaerosol sampling at the pig farm. However, the Button sampler is more likely to be clogged at high airborne dust concentrations because of its higher flow rate (4 L/min). Therefore, the IOM sampler is a more appropriate choice for performing personal sampling in environments with high dust levels. In summary, the Button and IOM samplers with PC filters are efficient sampling/analysis methods for the personal exposure assessment of multiple bioaerosols.