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Heimann L, Carlein C, Sorg K, Diller R, Langenbucher A, Schick B, Wenzel GI. Wavelength-specific optoacoustic-induced vibrations of the guinea pig tympanic membrane. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200335R. [PMID: 33675190 PMCID: PMC7934890 DOI: 10.1117/1.jbo.26.3.038001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
SIGNIFICANCE Optoacoustic-induced vibrations of the hearing organ can potentially be used for a hearing device. To increase the efficiency of such a hearing device, the conversion of the light energy into vibration energy within each type of irradiated tissue has to be optimized. AIM To analyze the wavelength-dependency of optoacoustic-induced vibrations within the tympanic membrane (TM), and to define the most efficient and best-suited optical stimulation parameters for a novel auditory prosthesis. APPROACH Single nanosecond laser pulses, continuously tunable in a range of visible to near-infrared, were used to excite the guinea pig TM. The induced vibrations of the hearing organ were recorded at the malleus using a laser Doppler vibrometer. RESULTS Our results indicate a strong wavelength-dependency of the vibration's amplitude correlating with the superposition of the absorption spectra of the different specific tissue components. CONCLUSIONS We investigated the spectrum of the vibrations of the hearing organ that were induced optoacoustically within a biological membrane embedded in air, in an animal model. First applications for these results can be envisioned for the optical stimulation of the peripheral hearing organ as well as for research purposes.
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Affiliation(s)
- Larissa Heimann
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
| | - Christopher Carlein
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Katharina Sorg
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
| | - Rolf Diller
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Achim Langenbucher
- Saarland University, Medical Center, Department of Experimental Ophthalmology, Homburg, Germany
| | - Bernhard Schick
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
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Low JCM, Ober TJ, McKinley GH, Stankovic KM. Quantitative polarized light microscopy of human cochlear sections. BIOMEDICAL OPTICS EXPRESS 2015; 6:599-606. [PMID: 25780749 PMCID: PMC4354578 DOI: 10.1364/boe.6.000599] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/13/2015] [Indexed: 05/31/2023]
Abstract
Dysfunction of the inner ear is the most common cause of sensorineural hearing loss, which is the most common sensory deficit worldwide. Conventional imaging modalities are unable to depict the microanatomy of the human inner ear, hence the need to explore novel imaging modalities. We provide the first characterization of the polarization dependent optical properties of human cochlear sections using quantitative polarized light microscopy (qPLM). Eight pediatric cadaveric cochlear sections, aged 0 (term) to 24 months, were selected from the US National Temporal Bone Registry, imaged with qPLM and analyzed using Image J. Retardance of the bony otic capsule and basilar membrane were substantially higher than that of the stria vascularis, spiral ganglion neurons, organ of Corti and spiral ligament across the half turns of the spiraling cochlea. qPLM provides quantitative information about the human inner ear, and awaits future exploration in vivo.
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Affiliation(s)
- Jacob C. M. Low
- The University of Manchester, Oxford Road, Manchester, M13 9PL,
UK
| | - Thomas J. Ober
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139,
USA
| | - Gareth H. McKinley
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139,
USA
| | - Konstantina M. Stankovic
- Massachusetts Eye and Ear Infirmary, Department of Otolaryngology and Eaton Peabody Laboratories, 243 Charles Street, Boston, Massachusetts 02114,
USA
- Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts,
USA
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Ye Q, Geng Y, Zhang XZ, Chen WL, Tian TJ, Xie SS, Huang Z. Mechanism study of laser cochleostomy-induced early hearing loss in a rat model. Lasers Med Sci 2013; 29:739-47. [PMID: 23912777 DOI: 10.1007/s10103-013-1388-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Abstract
Hearing loss following laser-assisted ear surgery has been reported. However, the mechanism responsible for the hearing loss remains largely speculative. The aim of this study was to investigate the correlation between laser-induced hearing loss and changes in the number of hair cell ribbon synapses and ultrastructure in the cochlea. Laser cochleostomy was performed with a superpulsed carbon dioxide (CO2) laser at 2 and 5 W in Sprague-Dawley rats. Auditory brainstem responses (ABRs) were measured preoperatively and 2 days after surgery. The synapse numbers in apical and middle cochlear turns were quantified. Transmission electron microscopy was employed to further examine the subcellular changes in the cochlea. Click and tonal ABR threshold shifts in both 2 and 5-W groups displayed a frequency-dependent loss within the frequency range measured. Laser cochleostomy induced a significant decrease of synapse numbers in the middle turn in both groups (p < 0.05). Electron microscopy data indicated varying degrees of auditory nerve degeneration in both groups. Auditory nerve degeneration might contribute to laser-caused hearing loss even under low-energy laser cochleostomy. The high-energy laser-induced hearing loss was associated with more reduction of synapse number.
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Affiliation(s)
- Qing Ye
- Department of Otolaryngology, Provincial Clinical Medical College, Fujian Medical University, Fuzhou, 350004, China,
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Wrzeszcz A, Dittrich B, Haamann D, Aliuos P, Klee D, Nolte I, Lenarz T, Reuter G. Dexamethasone released from cochlear implant coatings combined with a protein repellent hydrogel layer inhibits fibroblast proliferation. J Biomed Mater Res A 2013; 102:442-54. [PMID: 23533184 DOI: 10.1002/jbm.a.34719] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/15/2013] [Accepted: 02/11/2013] [Indexed: 12/20/2022]
Abstract
The insertion of cochlear implants into the inner ear often causes inflammation and fibrosis inside the scala tympani and thus growth of fibrous tissue on the implant surface. This deposition leads to the loss of function in both electrical and laser-based implants. The design of this study was to realize fibroblast growth inhibition by dexamethasone (Dex) released from the base material of the implant [polydimethylsiloxane (PDMS)]. To prevent cell and protein adhesion, the PDMS was coated with a hydrogel layer [star-shaped polyethylene glycol prepolymer (sPEG)]. Drug release rates were studied over 3 months, and surface characterization was performed. It was observed that the hydrogel slightly smoothened the surface roughened by the Dex crystals. The hydrogel coating reduced and prolonged the release of the drug over several months. Unmodified, sPEG-coated, Dex-loaded, and Dex/sPEG-equipped PDMS filaments were cocultivated in vitro with fluorescent fibroblasts, analyzed by fluorescent microscopy, and quantified by cell counting. Compared to the unmodified PDMS, cell growth on all modified filaments was averagely 95% ±standard deviation (SD) less, while cell growth on the bottom of the culture dishes containing Dex-loaded filaments was reduced by 70% ±SD. Both, Dex and sPEG prevented direct cell growth on the filament surfaces, while drug delivery was maintained for the duration of several months.
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Affiliation(s)
- Antonina Wrzeszcz
- Department of Otolaryngology, Hannover Medical School, 30625, Hannover, Germany
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Goodman SS, Bentler RA, Dittberner A, Mertes IB. The effect of low-level laser therapy on hearing. ISRN OTOLARYNGOLOGY 2013; 2013:916370. [PMID: 24024040 PMCID: PMC3658388 DOI: 10.1155/2013/916370] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 03/27/2013] [Indexed: 11/18/2022]
Abstract
One purported use of low-level laser therapy (LLLT) is to promote healing in damaged cells. The effects of LLLT on hearing loss and tinnitus have received some study, but results have been equivocal. The purpose of this study was to determine if LLLT improved hearing, speech understanding, and/or cochlear function in adults with hearing loss. Using a randomized, double-blind, placebo-controlled design, subjects were assigned to a treatment, placebo, or control group. The treatment group was given LLLT, which consisted of shining low-level lasers onto the outer ear, head, and neck. Each laser treatment lasted approximately five minutes. Three treatments were applied within the course of one week. A battery of auditory tests was administered immediately before the first treatment and immediately after the third treatment. The battery consisted of pure-tone audiometry, the Connected Speech Test, and transient-evoked otoacoustic emissions. Data were analyzed by comparing pre- and posttest results. No statistically significant differences were found between groups for any of the auditory tests. Additionally, no clinically significant differences were found in any individual subjects. This trial is registered with ClinicalTrials.gov (NCT01820416).
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Affiliation(s)
- Shawn S. Goodman
- Department of Communication Sciences & Disorders, The University of Iowa, Iowa City, IA 52242, USA
| | - Ruth A. Bentler
- Department of Communication Sciences & Disorders, The University of Iowa, Iowa City, IA 52242, USA
| | | | - Ian B. Mertes
- Department of Communication Sciences & Disorders, The University of Iowa, Iowa City, IA 52242, USA
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Peng Z, Chen XQ, Gong SS, Chen CF. Low-level laser therapy for tinnitus. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2012. [DOI: 10.1002/14651858.cd009811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zazzio M. Pain threshold improvement for chronic hyperacusis patients in a prospective clinical study. Photomed Laser Surg 2010; 28:371-7. [PMID: 19821704 DOI: 10.1089/pho.2008.2347] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate if laser therapy in combination with pulsed electromagnetic field therapy/repetitive transcranial magnetic stimulation (rTMS) and the control of reactive oxygen species (ROS) would lead to positive treatment results for hyperacusis patients. BACKGROUND DATA Eight of the first ten patients treated for tinnitus, who were also suffering from chronic hyperacusis, claimed their hyperacusis improved. Based upon that, a prospective, unblinded, uncontrolled clinical trial was planned and conducted. ROS and hyperacusis pain thresholds were measured. MATERIALS AND METHODS Forty-eight patients were treated twice a week with a combination of therapeutic laser, rTMS, and the control and adjustment of ROS. A magnetic field of no more than 100 microT was oriented behind the outer ear, in the area of the mastoid bone. ROS were measured and controlled by administering different antioxidants. At every treatment session, 177-504 J of laser light of two different wavelengths was administered toward the inner ear via meatus acusticus. RESULTS The improvements were significantly better in the verum group than in a placebo group, where 40% of the patients were expected to have a positive treatment effect. The patients in the long-term follow-up group received significantly greater improvements than the patients in the short-term follow-up group. CONCLUSION The treatment is effective in treating chronic hyperacusis.
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Zhang KY, Wenzel GI, Balster S, Lim HH, Lubatschowski H, Lenarz T, Ertmer W, Reuter G. Optoacoustic induced vibrations within the inner ear. OPTICS EXPRESS 2009; 17:23037-43. [PMID: 20052230 DOI: 10.1364/oe.17.023037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An acoustic transient can be generated inside an absorbing tissue as a result of laser-tissue interaction after pulsed laser irradiation. Herein we report a novel application of this physical process, the optoacoustic wave generation in the inner ear and subsequently the induction of basilar membrane vibrations. These laser induced vibrations show a direct correlation to the laser energy and an indirect correlation to the distance from the irradiation focus. Through these characteristics they may be used, in a new generation of cochlear implants, to improve the frequency specific cochlear activation and consequently improve speech perception in hearing impaired patients with residual hearing.
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Affiliation(s)
- K Y Zhang
- Laser Center Hannover, Hollerithallee 8, 30419 Hannover, Germany.
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Wenzel GI, Balster S, Zhang K, Lim HH, Reich U, Massow O, Lubatschowski H, Ertmer W, Lenarz T, Reuter G. Green laser light activates the inner ear. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:044007. [PMID: 19725719 DOI: 10.1117/1.3174389] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The hearing performance with conventional hearing aids and cochlear implants is dramatically reduced in noisy environments and for sounds more complex than speech (e. g. music), partially due to the lack of localized sensorineural activation across different frequency regions with these devices. Laser light can be focused in a controlled manner and may provide more localized activation of the inner ear, the cochlea. We sought to assess whether visible light with parameters that could induce an optoacoustic effect (532 nm, 10-ns pulses) would activate the cochlea. Auditory brainstem responses (ABRs) were recorded preoperatively in anesthetized guinea pigs to confirm normal hearing. After opening the bulla, a 50-microm core-diameter optical fiber was positioned in the round window niche and directed toward the basilar membrane. Optically induced ABRs (OABRs), similar in shape to those of acoustic stimulation, were elicited with single pulses. The OABR peaks increased with energy level (0.6 to 23 microJ/pulse) and remained consistent even after 30 minutes of continuous stimulation at 13 microJ, indicating minimal or no stimulation-induced damage within the cochlea. Our findings demonstrate that visible light can effectively and reliably activate the cochlea without any apparent damage. Further studies are in progress to investigate the frequency-specific nature and mechanism of green light cochlear activation.
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Affiliation(s)
- Gentiana I Wenzel
- Medical University Hannover, Department of Otolaryngology, Carl-Neuberg-Strasse 1, Hannover, 30625, Germany.
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Wenzel GI, Anvari B, Mazhar A, Pikkula B, Oghalai JS. Laser-induced collagen remodeling and deposition within the basilar membrane of the mouse cochlea. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:021007. [PMID: 17477714 PMCID: PMC3651902 DOI: 10.1117/1.2714286] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The cochlea is the mammalian organ of hearing. Its predominant vibratory element, the basilar membrane, is tonotopically tuned, based on the spatial variation of its mass and stiffness. The constituent collagen fibers of the basilar membrane affect its stiffness. Laser irradiation can induce collagen remodeling and deposition in various tissues. We tested whether similar effects could be induced within the basilar membrane. Trypan blue was perfused into the scala tympani of anesthetized mice to stain the basilar membrane. We then irradiated the cochleas with a 694-nm pulsed ruby laser at 15 or 180 Jcm(2). The mice were sacrificed 14 to 16 days later and collagen organization was studied. Polarization microscopy revealed that laser irradiation increased the birefringence within the basilar membrane in a dose-dependent manner. Electron microscopy demonstrated an increase in the density of collagen fibers and the deposition of new fibrils between collagen fibers after laser irradiation. As an assessment of hearing, auditory brainstem response (ABR) thresholds were found to increase moderately after 15 Jcm(2) and substantially after 180 Jcm(2). Our results demonstrate that collagen remodeling and new collagen deposition occurs within the basilar membrane after laser irradiation in a similar fashion to that found in other tissues.
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Affiliation(s)
- Gentiana I. Wenzel
- Baylor College of Medicine, Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, One Baylor Plaza, NA102, Houston, Texas 77030
| | - Bahman Anvari
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - Amaan Mazhar
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - Brian Pikkula
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - John S. Oghalai
- Baylor College of Medicine, Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, One Baylor Plaza, NA102, Houston, Texas 77030, and Rice University, Department of Bioengineering, Houston, Texas 77005-1892,
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Choi CH, Oghalai JS. Predicting the effect of post-implant cochlear fibrosis on residual hearing. Hear Res 2006; 205:193-200. [PMID: 15953528 PMCID: PMC3623675 DOI: 10.1016/j.heares.2005.03.018] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Accepted: 03/17/2005] [Indexed: 11/18/2022]
Abstract
Intracochlear scarring is a well-described sequela of cochlear implantation. We developed a mathematical model of passive cochlear mechanics to predict the impact that this might have upon residual acoustical hearing after implantation. The cochlea was modeled using lumped impedance terms for scala vestibuli (SV), scala tympani (ST), and the cochlear partition (CP). The damping of ST and CP was increased in the basal one half of the cochlea to simulate the effect of scar tissue. We found that increasing the damping of the ST predominantly reduced basilar membrane vibrations in the apex of the cochlea while increasing the damping of the CP predominantly reduced basilar membrane vibrations in the base of the cochlea. As long as intracochlear scarring continues to occur with cochlear implantation, there will be limitations on hearing preservation. Newer surgical techniques and electrode technologies that do not result in as much scar tissue formation will permit improved hearing preservation.
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Affiliation(s)
- Chul-Hee Choi
- Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA.
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