Swing-Door Overlay Tympanoplasty: Surgical Technique and Outcomes.

OBJECTIVES: The classical overlay tympanoplasty is technically difficult with some disadvantages and thus less popular. However, it is particularly useful for large, anterior perforations. In this study, we describe the technique of a modified overlay graft in the tympanoplasty coined as the swing-door overlay tympanoplasty and report its outcomes. METHODS: Retrospective review of patients undergoing the swing-door overlay tympanoplasty at a tertiary referral center between 2003 and 2016 was performed. Patient who had ossicular abnormality, previous tympanoplasty, and profound hearing loss were excluded. The surgical technique is described in detail. The outcomes were evaluated by the graft success rate, complication rate, and hearing results. The hearing level was determined by four pure-tone average at 0.5, 1, 2, and 4 kHz. Air-bone gap closure was mainly assessed. RESULTS: A total of 306 patients (110 males and 196 females) were included. The mean age was 49.1±16.6 years. Follow-up periods ranged from 6 to 108 months with an average of 18.4 months. The overall graft success rate reached 98.4%. Five graft failures occurred with reperforation in three cases and lateralization in two cases. Postoperative complications occurred in 12 cases (3.9%). Air-bone gap changes (closures) were 7.8±12.8, 5.2±12.2, 5.7±10.2, and 6.0± 12.8 dB at 0.5, 1, 2, and 4 kHz, respectively (all P<0.001) with an average improvement of 6.2 dB. Postoperative airbone gap was closed to ≤20 dB in 86.9%. CONCLUSION: The swing-door overlay tympanoplasty is a highly successful surgical technique suitable for all types of tympanic membrane perforations. This approach is technically easier than classical overlay tympanoplasty and affords an excellent graft success rate with satisfying hearing results.

Artificial Rod and Cone Photoreceptors with Human-Like Spectral Sensitivities.

Photosensitive materials contain biologically engineered elements and are constructed using delicate techniques, with special attention devoted to efficiency, stability, and biocompatibility. However, to date, no photosensitive material has been developed to replace damaged visual-systems to detect light and transmit the signal to a neuron in the human body. In the current study, artificial nanovesicle-based photosensitive materials are observed to possess the characteristics of photoreceptors similar to the human eye. The materials exhibit considerably effective spectral characteristics according to each pigment. Four photoreceptors originating from the human eye with color-distinguishability are produced in human embryonic kidney (HEK)-293 cells and partially purified in the form of nanovesicles. Under various wavelengths of visible light, electrochemical measurements are performed to analyze the physiological behavior and kinetics of the photoreceptors, with graphene, performing as an electrode, playing an important role in the lipid bilayer deposition and oxygen reduction processes. Four nanovesicles with different photoreceptors, namely, rhodopsin (Rho), short-, medium-, and longwave sensitive opsin 1 (1SW, 1MW, 1LW), show remarkable color-dependent characteristics, consistent with those of natural human retina. With four different light-emitting diodes for functional verification, the photoreceptors embedded in nanovesicles show remarkably specific color sensitivity. This study demonstrates the potential applications of light-activated platforms in biological optoelectronic industries.

Detection of retinitis pigmentosa by differential interference contrast microscopy.

Differential interference contrast microscopy is designed to image unstained and transparent specimens by enhancing the contrast resulting from the Nomarski prism-effected optical path difference. Retinitis pigmentosa, one of the most common inherited retinal diseases, is characterized by progressive loss of photoreceptors. In this study, Differential interference contrast microscopy was evaluated as a new and simple application for observation of the retinal photoreceptor layer and retinitis pigmentosa diagnostics and monitoring. Retinal tissues of Royal College of Surgeons rats and retinal-degeneration mice, both well-established animal models for the disease, were prepared as flatmounts and histological sections representing different elapsed times since the occurrence of the disease. Under the microscopy, the retinal flatmounts showed that the mosaic pattern of the photoreceptor layer was irregular and partly collapsed at the early stage of retinitis pigmentosa, and, by the advanced stage, amorphous. The histological sections, similarly, showed thinning of the photoreceptor layer at the early stage and loss of the outer nuclear layer by the advanced stage. To count and compare the number of photoreceptors in the normal and early-retinitis pigmentosa-stage tissues, an automated cell-counting program designed with MATLAB, a numerical computing language, using a morphological reconstruction method, was applied to the differential interference contrast microscopic images. The number of cells significantly decreased, on average, from 282 to 143 cells for the Royal College of Surgeons rats and from 255 to 170 for the retinal-degeneration mouse. We successfully demonstrated the potential of the differential interference contrast microscopy technique's application to the diagnosis and monitoring of RP.