Matthew R. Hoffman

High-Resolution Manometry of Pharyngeal Swallow Pressure Events Associated with Head Turn and Chin Tuck:

Objectives We quantified the effect of swallowing maneuvers on pharyngeal pressure events using high-resolution manometry. Methods Seven subjects swallowed multiple 5-mL water boluses in 3 different postural conditions: neutral, head turn, and chin tuck. Pressure and timing events were recorded with a 36-sensor high-resolution manometry catheter. We analyzed the regions of the velopharynx and the base of the tongue for maximum pressure, rate of pressure increase, pressure gradient, and duration of pressure above baseline. In the region of the upper esophageal sphincter (UES), we analyzed the duration of pressure declination, minimum pressure during UES opening, and maximum pressures before and after UES opening. Results The maneuvers did not have a significant effect on maximum pressure, rate of pressure increase, or pressure gradients in the velopharyngeal or tongue base regions. The duration of pressure above baseline was significantly longer in the velopharynx for head turn. The preswallow maximum UES pressure was significantly greater for neutral swallows than for head turn, and the postswallow maximum pressure was significantly lower for chin tuck. Both maneuvers appeared to prolong UES pressure declination duration, but neither prolongation reached significance. Conclusions High-resolution manometry allows for optimal spatial and temporal resolution during recording of pressure events along the length of the pharynx, and revealed previously undetected task-dependent pressure and timing differences during chin tuck and head turn in healthy adults. These maneuvers appear to influence the UES to a greater degree than the velopharynx or the tongue base. Further studies designed to quantify the effect of other maneuvers and bolus consistencies on the generation of pharyngeal pressure events both in normal and in disordered subjects may lead to hypothesis-driven, optimal, individualized swallowing therapies.

Pharyngeal swallow adaptations to bolus volume measured with high resolution manometry

To determine the effect of bolus volume on pharyngeal swallowing using high‐resolution manometry (HRM).

High-resolution manometry of pharyngeal swallow pressure events associated with effortful swallow and the Mendelsohn maneuver.

Effortful swallow and the Mendelsohn maneuver are two common strategies to improve disordered swallowing. We used high-resolution manometry (HRM) to quantify the effects of these maneuvers on pressure and timing characteristics. Fourteen normal subjects swallowed multiple, 5-ml water boluses using three techniques: normal swallow, effortful swallow, and the Mendelsohn maneuver. Maximum pressure, rate, duration, area integral, and line integral were determined for the velopharynx and tongue base. Minimum pressure, duration of pressure-related change, duration of nadir pressure, maximum preopening and postclosure pressure, area integral, and line integral were recorded for the upper esophageal sphincter (UES). Area and line integrals of the velopharyngeal pressure curve significantly increased with the Mendelsohn maneuver; the line integral increased with the effortful swallow. Preopening UES pressure decreased significantly for the Mendelsohn, while postclosure pressure tended to increase insignificantly for both maneuvers. UES area and line integrals as well as nadir UES pressure duration increased with both maneuvers. Maneuver-dependent changes were observed primarily at the velopharynx and UES. These regions are critical to safe swallowing, as the velopharynx provides positive pressure at the bolus tail while the UES allows a bolus to enter the esophagus without risk of regurgitation. Integrals were more responsive than maximum pressure or duration and should be investigated further.

Automated Analysis of Pharyngeal Pressure Data Obtained with High-Resolution Manometry

We present an algorithm developed in MATLAB that can be applied to both normal and disordered swallowing to automatically extract a wide array of measurements from the spatiotemporal plots produced by high-resolution manometry (HRM) of the pharyngeal swallow. The algorithm was developed from data from 12 normal and 3 disordered subjects swallowing 5-ml water boluses. Automated extraction was compared to manual extraction for a subset of seven normal and the three disordered subjects to evaluate algorithm accuracy. Area and line integrals, pressure wave velocity, and pressure gradients during upper esophageal sphincter opening were also measured. Automated extraction showed strong correlations with manual extraction, producing high correlation coefficients in both normal and disordered subjects for maximum velopharyngeal pressure and maximum tongue base pressure. Timing data were also strongly correlated for all variables, including velopharyngeal pressure duration, tongue base pressure duration, and total swallow duration. Preliminary descriptive data on area and line integrals are presented. Our results indicate that the algorithm can effectively extract data automatically from HRM spatiotemporal plots. The efficiency of the algorithm makes it a valuable tool to supplement clinical and research use of HRM.

Use of Lasers in Laryngeal Surgery

Lasers are a relatively recent addition to laryngeal surgery. Since their invention, laser use and applications have expanded rapidly. In this article, we discuss the benefits and disadvantages of lasers for different procedures, as well as ways to overcome commonly faced clinical problems. The use of lasers in surgery has offered a time- and cost-efficient alternative to cold surgical techniques, and has been used in the treatment of numerous laryngeal pathologies, including stenoses, recurrent respiratory papillomatosis, leukoplakia, nodules, malignant laryngeal disease, and polypoid degeneration (Reinkes edema). However, lasers can incur adjacent tissue damage and vocal fold scarring. These problems can be minimized through understanding the mechanisms by which lasers function and correctly manipulating the parameters under a surgeons control. By varying fluence, power density, and pulsation, tissue damage can be decreased and lasers can be used with greater confidence. The various types of lasers and their applications to the treatment of specific pathologies are reviewed with the intention of helping surgeons select the best tool for a given procedure. Recent applications of lasers to treat benign laryngeal lesions and severe laryngomalacia demonstrate that additional research must be conducted to realize the full potential of this surgical tool.

An automatic method to quantify mucosal waves via videokymography.

Objective/Hypothesis: Vocal fold vibration is associated with four distinct vibratory patterns: those of the right‐upper, right‐lower, left‐upper, and left‐lower vocal fold lips. The purpose of this study was to propose a least squares method to quantify the vibratory properties of each of the four vocal fold lips via videokymography (VKG).

Incidence of Myopia in High School Students with and without Red-Green Color Vision Deficiency

PURPOSE To investigate the influence of color vision on myopia development by testing refraction error and axial length of the eye for high school students with and without color vision deficiency (CVD). METHODS A school-based cross-sectional, cluster sample study was conducted to test the color vision and refractive error of 16,539 high school students. Students were screened for CVD using a pseudoisochromatic plate. CVD was confirmed in students failing the test using a Farnsworth-Munsell 100-Hue Test which also served to classify the subtype (protan or deutan). Three classmates of each CVD subject, matched in five myopia risk factors, were chosen to form the normal color vision (CN) control group. Ophthalmic examinations were performed to determine refractive status and axial length. RESULTS Of the students, 309 were found to have red-green CVD and 927 were selected as the CN control group. The prevalence of myopia in the CVD group (45.6%) was significantly lower than that of the CN group (65.8%; P<0.001). The CVD group was also less myopic in refraction (P<0.001) than CN, and protan subjects had shorter axial lengths than those in the control group (P=0.007). CONCLUSIONS Color vision deficiencies appear to influence the development of myopia. The observed lower incidence of myopia in people with CVD may be linked to the reduced functionality of the L/M chromatic mechanism.

Multiparameter comparison of injection laryngoplasty, medialization laryngoplasty, and arytenoid adduction in an excised larynx model.

Evaluate the effect of injection laryngoplasty (IL), medialization laryngoplasty (ML), and ML combined with arytenoid adduction (ML‐AA) on acoustic, aerodynamic, and mucosal wave measurements in an excised larynx setup.

Classification of High-Resolution Manometry Data According to Videofluoroscopic Parameters Using Pattern Recognition

Objective To determine if pattern recognition techniques applied to high-resolution manometry (HRM) spatiotemporal plots of the pharyngeal swallow can identify features of disordered swallowing reported on the Modified Barium Swallow Impairment Profile (MBSImP). Study Design Case series evaluating new method of data analysis. Setting University hospital. Subjects and Methods Simultaneous HRM and videofluoroscopy was performed on 30 subjects (335 swallows) with dysphagia. Videofluoroscopic studies were scored according to the MBSImP guidelines while HRM plots were analyzed using a novel program. Pattern recognition using a multilayer perceptron artificial neural network (ANN) was performed to determine if 7 pharyngeal components of the MBSImP as well as penetration/aspiration status could be identified from the HRM plot alone. Receiver operating characteristic (ROC) analysis was also performed. Results MBSImP parameters were identified correctly as normal or disordered at an average rate of approximately 91% (area under the ROC curve ranged from 0.902 to 0.981). Classifications incorporating two MBSImP parameters resulted in classification accuracies over 93% (area under the ROC curve ranged from 0.963 to 0.989). Conclusion Pattern recognition coupled with multiparameter quantitative analysis of HRM spatiotemporal plots can be used to identify swallowing abnormalities, which are currently assessed using videofluoroscopy. The ability to provide quantitative, functional data at the bedside while avoiding radiation exposure makes HRM an appealing tool to supplement and, at times, replace traditional videofluoroscopic studies.

Influence of Internal Optical Astigmatism on the Correction of Myopic Astigmatism by LASIK

PURPOSE To investigate the influence of the origin of astigmatism on the correction of myopic astigmatism by LASIK. METHODS A retrospective study was conducted of the records of 192 patients (192 eyes) undergoing LASIK for correction of myopia and myopic astigmatism from January to September 2010. Ocular residual astigmatism (ORA) and lenticular astigmatism (LA) were determined by vector analysis using objective refraction and Pentacam (Oculus Optikgeräte GmbH) imaging of both corneal surfaces. Patients were divided into two groups according to ORA (high ORA group: ORA/preoperative refractive astigmatism >1; normal ORA group: ORA/preoperative refractive astigmatism ≤ 1) and LA (high LA group: LA/preoperative refractive astigmatism >1; normal LA group: LA/preoperative refractive astigmatism ≤ 1). Procedural efficacy was compared between those eyes with and without a significant amount of internal optical astigmatism using index of success. RESULTS Mean preoperative vectors for the astigmatism of the anterior cornea, posterior cornea, and lens were -1.33 × 3.0°, -0.33 × 95.3°, and -0.27 × 103.3°, respectively. Mean indices of success in the high and low ORA groups were 1.75 and 0.59, respectively (t=7.81, P<.001). Mean indices of success in the high and low LA groups were 2.07 and 0.70, respectively (t=12.36, P<.001). The higher indices of success in the high ORA and high LA groups suggest a lower efficacy of LASIK in treating astigmatism primarily located intraocularly. CONCLUSIONS Myopic LASIK is less effective in correcting astigmatism when astigmatism is mainly located at the internal optics. Topography and refractive value should be incorporated in the treatment of patients when a significant amount of internal optical astigmatism is detected preoperatively.