Optimization of the Oertli CataRhex 3® phacoemulsification machine.

PURPOSE: The aim of this study was to determine optimal bottle height, vacuum, aspiration rate, and power settings of the Oertli CataRhex 3® phacoemulsification machine. METHODS: Porcine lens nuclei were hardened with formalin and cut into 2.0 mm cubes. Lens cubes were emulsified using the easyTip® 2.2 mm at 30°. Fragment removal time (efficiency) and fragment bounces off the tip (chatter) were measured. Settings tested included bottle height of 60, 80, 100 and 120 cm; aspiration rate of 40, 45, and 50 mL/min; vacuum of 400, 500, and 600 mmHg; and power of 50, 60, 70, 80, 90, and 100%. RESULTS: Efficiency and chatter increased in a linear fashion with increasing vacuum to 600 mmHg (P=0.017, P=0.046, respectively). The most efficient aspiration rate was 50 mL/min, although this finding lacked statistical significance (P=0.66). Increasing power increased efficiency up to 80% without increasing chatter (P=0.042, P=0.71, respectively). Compared to all other power settings, chatter was increased at 100% (P=0.014). CONCLUSION: The most efficient machine settings were vacuum at 600 mmHg, aspiration rate at 50 mL/min, and power at 80%.

The effect of increasing power when grooving using phacoemulsification.

PURPOSE: To determine optimal power settings on the Centurion Vision System during the grooving step in cataract surgery. METHODS: Intact porcine lenses hardened by formalin and placed in a chamber designed to simulate the anterior chamber of the eye were used to test longitudinal power at 40%, 70%, and 100% and torsional power at 0%. Flow rate was set at 40 mL/min. Vacuum was set at 400 mmHg, intraocular pressure was set at 50 mmHg, and a balanced phacoemulsification tip with a 20 degree tip and a 30 degree bevel was used. Efficiency (time to groove the lens in half) was determined. RESULTS: Increasing longitudinal power from 40% to 70% increased efficiency by 28% (P<0.05), and by 32% (P<0.05) when increasing longitudinal power from 40% to 100%. There was no statistically significant increase in efficiency from 70% to 100%. CONCLUSION: For the tested variables, a longitudinal power of 70% was determined to be most efficient during the grooving step of cataract surgery for equivalent 3-4+ nuclei. Further increases in power demonstrated no statistically significant improvement in efficiency.

The effects of nasal closure on quality of life in patients with hereditary hemorrhagic telangiectasia.

INTRODUCTION: Epistaxis is the most common symptom of hereditary hemorrhagic telangiectasia (HHT). Complete nasal closure is one of the treatment options for patients with severe, intractable epistaxis. In our experience, this surgery can be life changing in a positive sense; but many patients as well as their physicians understandably fear that such a procedure will diminish certain aspects of quality of life (QOL). METHODS: Case-control study of HHT patients treated at the University of Utah HHT Center of Excellence with and without nasal closure from January 2005 to January 2016. Patients were matched according to epistaxis severity. Each included patient was issued three surveys: Epistaxis Severity Score (ESS), the Pittsburg Sleep Quality Index (PSQI), and the Nasal Obstruction Symptom Evaluation (NOSE). RESULTS: After treatment, the mean PSQI and NOSE scores were not significantly different between the two groups. However, the mean ESS score in the nasal closure group was significantly lower at 1.10 compared to the severe epistaxis group with a mean score of 3.99 (P = .027). CONCLUSION: The results of this study demonstrate that nasal closure significantly improves epistaxis severity without having a significant effect on sleep or nasal obstruction as they relate to QOL. These findings suggest that nasal closure should be considered for HHT patients with chronic severe epistaxis. LEVEL OF EVIDENCE: 4.

Effect of increasing flow when grooving during phacoemulsification.

PURPOSE: To determine optimum flow settings on the Centurion Vision System during the grooving step in cataract surgery. SETTING: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Intact porcine lenses hardened by formalin and placed in a chamber designed to simulate the anterior chamber of the eye were used to test flow rate settings at 20 mL/min, 40 mL/min, and 60 mL/min. Vacuum was set at 400 mm Hg, longitudinal power at 80%, torsional power at 80%, and intraocular pressure at 50 mm Hg. A balanced phaco tip with a 20-degree tip and a 30-degree bevel was used. Efficiency (time to groove the lens in half) was determined. RESULTS: Increasing flow from 20 to 40 mL/min during grooving increased efficiency by 17% (P = .05), with no significant improvement shown at 60 mL/min. CONCLUSIONS: A flow rate of 40 mL/min was determined to be most efficient during the grooving step of cataract surgery. Further increases in flow rate showed no statistically significant improvement in efficiency, and with only 17% improvement flow rates less than 40 mL/min might be almost as efficient and might be safer.

Effect of chamber stabilization software on efficiency and chatter in a porcine lens model.

PURPOSE: To evaluate the effects of the use of programmable chamber stabilization software (Chamber Stabilization Environment) settings on efficiency and chatter in a porcine lens model. SETTING: John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Porcine eyes were dissected and the lenses extracted. The lenses were then hardened and processed for the experiment. Phacoemulsification of the lens fragments was performed with the Whitestar Signature Pro with the Whitestar handpiece and a 0.9 mm straight Dewey tip with a 30-degree bevel. All arms of the study were run in peristaltic mode with 50 mL/minute aspiration, 100 cm bottle height, and on 100% power. The chamber stabilization software setting was used for each of the 4 study arms with a maximum vacuum of 500 mm Hg. Arm 1 included 20 runs with the up time set to 2000 milliseconds. Arm 2 was performed with similar settings but with an up time of 0 millisecond. Arms 3 and 4 were run with up times of 1000 milliseconds and 500 milliseconds, respectively. RESULTS: The mean efficiency time of each run was as follows: 0 millisecond = 1.4 seconds, 500 milliseconds = 0.95 seconds, 1000 milliseconds = 0.88 seconds, 2000 milliseconds = 0.93 seconds. When compared with 0 millisecond, each of the other arms were significantly faster. Chatter events were comparable between the study arms. CONCLUSION: The chamber stabilization software does not decrease efficiency when compared with full vacuum on if at least 500 milliseconds of up time is maintained.

Hearing loss as a risk factor for dementia: A systematic review.

OBJECTIVES: To review evidence of hearing loss as a risk factor for dementia. Data Sources: PubMed Review methods: A systematic review was conducted using the PubMed database using the search terms (hearing loss OR presbycusis) AND (dementia OR cognitive decline). Initially, 488 articles were obtained. Only those studies evaluating an association between hearing loss and incident dementia or cognitive decline were included in the analysis. This resulted in 17 articles which were thoroughly evaluated with consideration for study design, method for determining hearing loss and cognitive status, relevant covariates and confounding factors, and key findings. RESULTS: All of the 17 articles meeting inclusion criteria indicate that hearing loss is associated with dementia or cognitive decline. The methods used among the studies for ascertaining hearing loss and dementia were notably varied. For hearing loss, peripheral auditory function was tested far more than central auditory function. For peripheral audition, pure tone audiometry was the most commonly reported method for defining hearing loss. Only a few studies measured central auditory function by using the Synthetic Sentence Identification with Ipsilateral Competing Message test (SSI-ICM) and the Staggered Spondaic Word Test (SSW). Dementia was most often defined using the Mini Mental State Exam (MMSE). However, many studies used extensive batteries of tests to define cognitive status, often including a neuropsychologist. Confounding variables such as cardiovascular risk factors were measured in 17 studies and family history of dementia was only evaluated in 1 study. Overall, the methods used by studies to ascertain hearing loss, cognitive status and other variables are valid, making their evaluation appear reliable. CONCLUSION: While each of the studies included in this study utilized slightly different methods for evaluating participants, each of them demonstrated that hearing loss is associated with higher incidence of dementia in older adults. LEVEL OF EVIDENCE: Level V, systematic review.

Long-term Outcomes After Middle Fossa Approach for Traumatic Facial Nerve Paralysis.

OBJECTIVES: Controversy exists regarding the role of surgery for patients with skull base trauma and facial paralysis. Our goal is to report the long-term outcomes of early facial nerve decompression and repair via the middle fossa (MF) approach for patients with traumatic paralysis. STUDY DESIGN: Retrospective case series. SETTING: Academic medical center. PATIENTS: There were 18 patients who met surgical criteria: immediate complete paralysis, greater than 90% degeneration on electroneurography (ENoG), and no voluntary electromyography (EMG) potentials within 14 days after trauma and 1 year minimum follow-up. INTERVENTION: MF approach for traumatic facial paralysis and for irreversible injuries nerve grafting was performed. MAIN OUTCOME MEASURE: Long-term facial function, hearing results, and surgical complications. RESULTS: At MF decompression, 11 patients had an anatomically intact facial nerve. Of these patients with intact nerves, 72.7% obtained normal to near normal facial function (HB I or II) at 1 year: 27.3% to HB I, 45.5% to HB II, and 27.3% to HB III. At surgery, seven patients were found to have injuries that required nerve grafting and 100% improved to HB III. For all patients, facial nerve function significantly improved after surgery (p < 0.01). The average difference in pure tone average and word recognition after surgery was +2.9 dB and +3.3%, respectively (p = 0.44; p = 0.74). Minor, transient complications occurred in three patients and an abscess required drainage in one patient, but no other major complications. CONCLUSION: In our series, all patients with traumatic complete paralysis and poor facial prognosis achieved a long-term outcome of HB III or better after MF approach for decompression and repair of the facial nerve.