Faculty Bibliography

PURPOSE: To develop a grading system to evaluate the scleral spur visibility and to investigate the association between this and the angle width. METHODS: Sixty healthy normal subjects (33 with open angles and 27 with narrow angles on dark room gonioscopy) underwent anterior segment imaging with the Visante OCT (Carl Zeiss Meditec, Dublin, CA). The anterior chamber angles at 12-o' clock hour positions were imaged and analyzed. The scleral spur at each clock hour position was independently graded by 2 observers. A scleral spur visibility score (SSVS) of 2 denotes clear visibility of the scleral spur. SSVS of 0 and 1 represent undetectable and moderately by visibile scleral spur, respectively. The interobserver agreement of the SSVS was evaluated with kappa statistics. The associations between age, sex, axial length, refraction, angle width [mean anterior chamber angle detection with edge measurement and identification algorithm (ACADEMIA) angle], and the mean SSVS were examined with univariate and multivariate analyses. RESULTS: The mean gonioscopy grades were 3.6 and 0.8 for the open and narrow angle groups, respectively. The interobserver agreement in grading the scleral spur visibility was 0.71. The inferior angle (6:00) had the worst visibility of the scleral spur (SSVS=1.05+/-0.49) whereas the scleral spur of the nasal angle (3:00) showed the best visibility (SSVS=1.66+/-0.46). There were significant differences between SSVS at 6:00 and the other clock hours except for 5:00 and 7:00. The mean SSVS correlated positively with gonioscopy grade, anterior chamber depth, and ACADEMIA angle, and negatively with age. The only significant factor associated with scleral spur visibility was the ACADEMIA angle (P=0.013) after adjustment for other covariates. CONCLUSIONS: The visibility of the scleral spur is an important determinant of the dimension of anterior chamber angle

OBJECTIVES/HYPOTHESIS: Anatomic variants of the jugular bulb (JB) are common; however, abnormalities such as large high riding JB and JB diverticulum (JBD) are uncommon. Rarely, the abnormal JB may erode into the inner ear. The goal of our study is to report a large series of patients with symptomatic JB erosion into the inner ear. STUDY DESIGN: Retrospective review in an academic medical center. METHODS: Eleven patients with JB abnormality eroding into the inner ear were identified on computed tomography (CT) scan of the temporal bone. RESULTS: Age at presentation was from 5 years to 82 years with six males and five females. The large JB or JBD eroded into the vestibular aqueduct (n = 9) or the posterior semicircular canal (n = 4). The official radiology report usually identified the JB abnormality; however, erosion into these structures by the JB was not mentioned in all but one case. All patients were symptomatic with five having conductive hearing loss (CHL) and three complaining of pulsatile tinnitus. Those with pulsatile tinnitus and four of five with CHL had erosion into the vestibular aqueduct. Vestibular evoked myogenic potential (VEMP) findings in three of six patients were consistent with dehiscence of the inner ear. CONCLUSIONS: High riding large JB or JBD can erode into the inner ear and may be associated with CHL and/or pulsatile tinnitus. CT scan is diagnostic and should be examined specifically for these lesions. As patients with pulsatile tinnitus may initially undergo a magnetic resonance imaging scan, identification of JB abnormality should prompt CT scan or VEMP testing to evaluate for inner ear erosion

Long-term synaptic plasticity is a putative mechanism for learning in adults. However, there is little understanding of how synaptic plasticity mechanisms develop or whether their maturation depends on experience. Since inhibitory synapses are particularly malleable to sensory stimulation, long-lasting potentiation of inhibitory synapses was characterized in auditory thalamocortical slices. Intracortical high-frequency electrical stimulation led to a 67% increase in inhibitory synaptic currents. In the absence of stimulation, inhibitory potentiation was induced by a brief exposure to exogenous brain-derived neurotrophic factor (BDNF). BDNF exposure occluded any additional potentiation by high-frequency afferent stimulation, suggesting that BDNF signaling is sufficient to account for inhibitory potentiation. Moreover, inhibitory potentiation was reduced significantly by extracellular application of a BDNF scavenger or by intracellular blockade of BDNF receptor [tropomyosin-related kinase B (TrkB)] signaling. In contrast, glutamatergic or GABAergic antagonists did not prevent the induction of inhibitory potentiation. Since BDNF and TrkB expression are influenced strongly by activity, we predicted that inhibitory potentiation would be diminished by manipulations that decrease central auditory activity, such as hearing loss. Two forms of hearing loss were examined: conductive hearing loss in which the cochleae are not damaged or sensorineural hearing loss in which both cochleae are removed. Both forms of hearing loss were found to reduce significantly the magnitude of inhibitory potentiation. These data indicate that early experience is necessary for the normal development of BDNF-mediated long-lasting inhibitory potentiation, which may be associated with perceptual deficits at later ages

BACKGROUND:The most prevalent long-term complications in patients undergoing laparoscopic adjustable gastric band (LAGB) surgery are symmetric pouch dilation and gastric prolapse (slippage). However, no published data or a reliable model are available to evaluate the actual mechanism of band slippage or how to prevent it. The objective of the present study was to construct an animal model of anterior gastric band prolapse and to use this model to evaluate the effectiveness of various arrangements of gastrogastric sutures and gastric wraps in preventing prolapse. METHODS:The esophagus of male mongrel dogs was accessed through the left chest, and a pressure transducer and an insufflation catheter were introduced. An AP-S Lap-Band (Allergan, Irvine, CA) filled to 10 cm(3) was placed using the pars flaccida technique. A standardized cut of meat was placed into the esophagus to simulate food impaction at a tight LAGB. After the placement of multiple different gastrogastric suture configurations, air was insufflated into the gastric pouch by way of the esophagus. RESULTS:Prolapse, identical to that seen in clinical practice, was reliably reproduced in this model by increased esophageal pressure acting on a LAGB outlet obstruction. In addition, prolapse was reproduced with all gastrogastric configurations that did not secure the anterior gastric wall to within 1.5 cm of the lesser curve. CONCLUSION/CONCLUSIONS:The results of the present study support the theory that prolapse is caused by esophageal peristalsis against an occlusion at the level of the LAGB. In this canine model, gastrogastric sutures encompassing the anterior gastric wall were integral to preventing prolapse.

Tensor Fascia Lata muscle and musculocutaneous flap has been used in the past for reconstruction of trunk defects and also as a free flap for soft tissue reconstruction elsewhere in the body. Transferring the iliac crest along with the muscle as a free flap has been described earlier, reported for bridging calcaneal defect and small mandibular defects. The use of this flap as a source of free vascularised bone has not been widely practised since these initial few reports. Anatomical studies were carried out to assess the feasibility of using this flap for reconstructing maxillary and other head and neck defects, following which it was successfully used for these indications. The preliminary report describes the flap anatomy, method of harvest and its potential uses in head and neck reconstruction.

OBJECTIVE: To evaluate changes in lower eyelid position using digital image analysis in patients who have undergone an orbicularis suspension flap combined with blepharoplasty. METHODS: A total of 68 patients (136 eyes) underwent a lower eyelid orbicularis oculi suspension flap combined with blepharoplasty. Digital image analysis was used to standardize each patient's preoperative and postoperative photographs for accurate objective comparison. The photographs were analyzed for lower eyelid position. RESULTS: The mean (SD) preoperative standardized distance from the center of the pupil to the lower eyelid margin (MRD2) in all procedures was 5.53 (0.74) mm. The mean (SD) postoperative standardized MRD2 was 5.22 (1.0) mm. There was a statistically significant difference in MRD2 position such that the postoperative MRD2 position decreased or the lower eyelid position was elevated by an average of 0.31 mm in comparison to the preoperative position (P < .001). CONCLUSIONS: A well-performed suspension flap can elevate the lower eyelid position to a more natural and anatomically appropriate position. By resuspending the ptotic orbicularis muscle, the suspension flap also reinforces the underlying attenuated orbital septum. Such cases may not achieve the optimum level of rejuvenation if isolated lower eyelid blepharoplasty is performed