Rurality Effect on Michigan Newborn Hearing Screening.

OBJECTIVES: Evaluate the effect of rurality on newborn hearing screen outcomes in Michigan. METHODS: Patients in the Michigan Department of Health and Human Services (MDHHS) Newborn Hearing Screening database that failed or did not receive their initial screen from 2015 to 2020 were evaluated. Using the U.S. Department of Agriculture Rural-Urban Continuum Codes (RUCC), patients were assigned a 1-9 code based on the population of their zip code, with 1 being the most urban and 9 being the most rural and outcomes between these patients were compared. RESULTS: There were 34,928 patients initially identified. Patients that had follow-up testing after a failed NBHS had a slightly higher RUCC than those that did not follow-up, 2.3 versus 2.2, respectively (p < 0.001). There was a significant difference between those that refused screening, with a mean RUCC of 4.2, and those that had a failed initial screen having a mean RUCC of 2.1 (p < 0.001). Similarly, those with equipment failure had a higher mean RUCC, 2.8, compared to those that had screening completed (p < 0.001). CONCLUSIONS: More rural areas are more likely to refuse a newborn hearing screen as well as have equipment failure options. There was no difference in rurality scores of those that had a follow-up screen after a failure and those that did not. LEVEL OF EVIDENCE: IV Laryngoscope, 2023.

Exoscope-Assisted Stapedotomy: Evaluation of Safety and Efficacy.

OBJECTIVE: Evaluate the safety and efficacy of exoscope-assisted stapedotomy. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care neurotology clinic. PATIENTS: Adult patients with otosclerosis undergoing stapedotomy. INTERVENTIONS: Primary stapedotomy. MAIN OUTCOME MEASURES: Evaluation of audiologic outcomes, including pure-tone average, bone-conduction thresholds, word recognition score, and air-bone gap. Complications, need for scutum removal, and length of surgery were also evaluated. RESULTS: A total of 47 patients were identified, and 24 patients underwent surgery with the microscope and 22 with the exoscope. There were significant improvements in pure-tone average, mean bone-conduction thresholds, and air-bone gap for both groups. There was no difference in preoperative or postoperative audiologic status for either group. There was no difference in rates of dysgeusia, chorda tympani nerve damage, dizziness, or facial paresis in either group. CONCLUSIONS: This study indicates similar audiologic outcomes, complication profiles, and visualization when comparing exoscopic and microscopic stapedotomy. Demonstrated here, exoscopic stapedotomy can be safely performed in a transcanal manner.

Characterizing the most Popular Tinnitus Inquiries: Is Tinnitus Incidence on the Rise Since COVID-19?

OBJECTIVE: Approximately 50 million US adults experience chronic tinnitus, yet search behaviors and topics of concern to these patients have not been investigated on a national level. STUDY DESIGN: Observational. SETTING: Online database and tertiary otology clinic. PATIENTS: Nationwide and institutional samples. INTERVENTIONS: None. MAIN OUTCOME MEASURE: A search engine optimization tool was utilized to extract metadata on "People Also Ask" (PAA) questions pertaining to tinnitus. Website quality was assessed using JAMA benchmark criteria. Search volume trends were investigated along with institutional-level data on tinnitus incidence. RESULTS: Of the 500 PAA questions assessed, the majority (54.0%) contained value-type content. The most popular question categories pertained to tinnitus treatment (29.3%), alternative treatment approaches (21.5%), technical details (16.9%), and timeline of symptoms (13.4%). Patients were most interested in treatment with wearable masking devices and most commonly searched for tinnitus as being attributable to a neurologic etiology. Online searches pertaining to unilateral tinnitus symptoms have increased >3-fold since the onset of the COVID-19 pandemic. Likewise, review of patient encounters at our tertiary otology clinic revealed a nearly 2-fold increase in tinnitus consultations since 2020. CONCLUSIONS: Topics of interest and concern identified herein may inform the development of patient education materials and help guide clinical practice. Online search data suggest an increase in tinnitus searches since the onset of COVID-19, which did correlate clinically with an increase in tinnitus consultations at our institution.

Endolymphatic sac decompression effect on secondary symptoms of Meniere's disease.

OBJECTIVE: To evaluate if endolymphatic sac decompression (ESD) significantly improves secondary symptoms of Meniere's disease including tinnitus and aural fullness. STUDY DESIGN: Survey study with retrospective chart review. SETTING: Tertiary care center. METHODS: Survey of adult patients with Meniere's disease that underwent primary ESD surgery from 2015 to 2020. Subjective reporting of pre- and postoperative aural fullness and tinnitus based on postoperative survey. Survey results and audiologic data of the patients that reported were compared pre- and postoperatively. RESULTS: Statistical analysis was performed using weighted kappa statistics to examine the level of agreement. There was a value of 0.12 for pre- and postoperative aural fullness, indicating a difference in the two groups with 77 % having improvement and only 4 % having worsening. There was a value of 0.21 for pre- and postoperative tinnitus, demonstrating a lack of agreement with 58 % having improvement and 4 % having worsening. Overall, there was significant improvement in both tinnitus and aural fullness postoperatively. There was no significant difference in word recognition score, speech reception threshold, or pure tone average between the pre- and postoperative group based on paired t-test. CONCLUSIONS: There is a significant improvement in both aural fullness and tinnitus for patients undergoing ESD with no negative effect on audiologic status. ESD is a viable option for treatment of Meniere's disease with vertigo, aural fullness, and tinnitus relief. Future prospective studies are needed to further improve the evidence of ESD's effect on secondary symptoms of Meniere's disease.

Audiologic comparison of classification systems of advanced otosclerosis.

OBJECTIVE: To identify which patients with advanced otosclerosis may have the greatest audiologic improvement with stapedotomy based on different classifications of advanced otosclerosis. STUDY DESIGN: Retrospective chart review. SETTING: Single tertiary neurotology center. METHODS: Patients were divided into different classifications of advanced otosclerosis based on either a bone conduction threshold of greater than 60 dB HL (Bone Conduction (BC) Group), a word recognition score of less than 70% (Word Recognition (WRS) Group), or pure tone average of greater than 85 dB HL (Pure Tone Average (PTA) Group). Audiologic outcomes and complication profiles were compared between these groups. RESULTS: Nineteen patients met criteria for one or more group. There were 18 patients in the PTA group, 11 in the BC group, and 12 in the WRS group. There was no significant difference in the pre- or postoperative audiologic status between the different groups. CONCLUSIONS: Patients with advanced otosclerosis have significant improvements in pure tone averages and air-bone gaps following stapedotomy regardless of the classification criteria used. Stapedotomy remains a reasonable primary intervention for the majority of patients with advanced otosclerosis.

Rate of Development of Venous Thromboembolism in Lateral Skull Base Surgery.

OBJECTIVES: Venous thromboembolism (VTE) is a major cause of morbidity and mortality for surgical patients. This article aims to determine factors that may have contributed to the development of VTE in patients undergoing lateral skull base surgery, to assess the validity of the Caprini Risk Assessment Model (RAM) score in this subset of patients, and to determine the efficacy of mechanical DVT prophylaxis alone in preventing VTE. STUDY DESIGN: Retrospective chart review. METHODS: A retrospective chart review was conducted of patients who underwent skull base surgery for vestibular schwannoma, and the rate of VTE was assessed. Patient demographics, comorbidities, and treatment factors were examined to determine risk factors associated with the development of a postoperative thrombotic event. Caprini RAM scores were compared for patients who developed a VTE. RESULTS: Among 197 patients, the rate of VTE formation was 3.5%. No individual risk factor independently contributed to the development of a thrombotic event. The mean Caprini RAM score was 4.06 in patients who did not develop a VTE and 5.14 in the patients that did develop a VTE (P = .005). The Caprini score was significant for the risk of VTE formation, with an odds ratio of 2.8 (P = .009, 95% CI = 1.3-6.2). CONCLUSION: Venous thromboembolism rates are relatively low following lateral skull base surgery. While there is no individual risk factor associated with increased VTE risk, the Caprini RAM score appears to be a useful predictor of risk. The Caprini score may be useful in identifying high-risk patients who may benefit from chemoprophylaxis for VTE prevention. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:662-667, 2022.

Audiologic Outcomes of Footplate Drillout for Obliterative Otosclerosis.

OBJECTIVE: To evaluate the audiologic outcomes of microdrill fenestration for obliterative otosclerosis compared to traditional stapedotomy technique. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into groups that underwent either microdrill or laser fenestration based on intraoperative severity of disease. Audiologic outcomes and complications were compared between the two groups. RESULTS: There were 588 ears in 519 patients that were evaluated. There was a significant postoperative improvement in pure tone average, air-bone gap, and mean bone conduction thresholds for both the obliterative and nonobliterative group (p < 0.001). There was no significant difference in the pre- or postoperative hearing status between the two groups. There was no significant difference in complications between the two groups, including no cases of postoperative profound hearing loss in the drill fenestration group. CONCLUSIONS: Audiologic outcomes are similar between microdrill fenestration and laser fenestration for otosclerosis. Pure tone average, air-bone gap, and mean bone conduction thresholds all improved postoperatively and were similar between groups.

Risk Factors for Complications Following Lateral Skull Base Surgery and the Utility of ICU Monitoring.

OBJECTIVE: To examine the role of intensive care unit (ICU) management following lateral skull base surgery for vestibular schwannoma and identify risk factors for complications warranting admission to the ICU. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: Two hundred consecutive patients undergoing lateral skull base surgery for vestibular schwannomas. INTERVENTION: Lateral skull base approach for resection of vestibular schwannoma and postoperative monitoring. MAIN OUTCOME MEASURES: Patients were grouped if they sustained an ICU complication, a non-ICU complication, or no complication. Analysis was performed to determine patient or treatment factors that may be associated with ICU complications. Multivariate and three-way analysis of variance compared groups, and multivariate logistic regression determined adjusted odds ratios (aOR) for analyzed factors. RESULTS: Seventeen of 200 patients sustained ICU complications (8.5%), most commonly hypertensive urgency (n = 15). Forty-six (23%) sustained non-ICU complications, and 137 (68.5%) had no complications. When controlling for age, sex, obesity, and other comorbidities, only hypertension (aOR 5.43, 95% confidence interval (CI) 1.35-21.73, p = 0.017) and tumor volume (aOR 3.29, 95% CI 1.09-9.96, p = 0.035) were independently associated with increased risk of ICU complications. CONCLUSIONS: The necessity of intensive care following lateral skull base surgery is rare, with the primary ICU complication being hypertensive urgency. Preoperative hypertension and large tumor volume (>4500 mm3) were independently associated with increased risk for ICU complications. These findings may allow for risk stratification of patients appropriate for admission to stepdown units following resection of vestibular schwannomas. Further prospective, multi-center, randomized studies are necessary to validate these findings before systematic changes to current postoperative care practices.

Effect of Surgical Start Time on Stapedotomy Outcomes.

OBJECTIVE: To examine if performing stapedotomy as the first case of the day provides improved outcomes compared with those performed later in the day. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing stapedotomy for otosclerosis. MAIN OUTCOME MEASURES: Patients were separated into either a first case group or a later case group based on surgical start time. Audiologic outcomes and complications were compared between the two groups. RESULTS: The first case group had a smaller postoperative air-bone gap (ABG) compared with the later case group of 9.81 dB HL compared with 11.73dB HL and 3.79 dB HL compared with 6.29 dB HL at 1000 and 2000 Hz, respectively (p = 0.03, p < 0.01). The mean postoperative ABG was 10.63 dB HL for the first start group compared with 12.12 dB HL for the later start group, which was statistically significant (p = 0.05). CONCLUSIONS: First start stapedotomy is associated with slightly improved audiologic outcomes compared with those starting later in the day, although both groups had significantly improved postoperative outcomes overall. There was no significant difference in complications when comparing stapedotomy by case start time.

Early Outcomes of Simultaneous Translabyrinthine Resection and Cochlear Implantation.

OBJECTIVES/HYPOTHESIS: Hearing rehabilitation after translabyrinthine resection of a vestibular schwannoma (VS) has largely been based on the transfer of acoustic stimulus to the contralateral ear, typically through a contralateral routing of signal hearing aid or bone-anchored hearing aid (BAHA). Cochlear implant, either as a subsequent surgery or simultaneously, has become a more common treatment option; however, there is still relatively limited data available on its success. The purpose of this study is to evaluate the early outcomes of simultaneous cochlear implantation in patients with sporadic VS undergoing translabyrinthine resection. STUDY DESIGN: Prospective, nonrandomized study. METHODS: A prospective study of nonrandomized patients was completed at a tertiary care neurotology center. Audiologic outcomes, primarily based on AzBIO in quiet and background noise, as well as consonant-nucleus-consonant (CNC) testing of the affected ears were utilized. Tinnitus, dizziness, and spatial hearing questionnaries were also completed. Audiologic outcomes and questionnaires were compared between the pre- and postoperative groups. RESULTS: Ten patients were included in the study with 3 month follow-up data. There was statistically significant improvement in AzBO with +10 and +5 signal to noise ratio and in quiet, as well as in CNC testing (P < .05). There was a significant improvement in Tinnitus Handicap Inventory between the two groups. CONCLUSIONS: Simultaneous cochlear implantation is a viable treatment for hearing loss after translabyrinthine approach to VS. These patients have improved hearing in background noise and tinnitus compared to their preoperative state. Further prognostic data are required to determine which patients are the best candidates. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2312-E2317, 2021.

Audiologic Outcomes After Oval and Round Window Reinforcement Surgery.

INTRODUCTION: Oval window (OW) and round window (RW) reinforcement surgery has been used for symptomatic treatment of multiple clinical entities, most commonly perilymphatic fistula and superior semicircular canal dehiscence. Owing to the theoretical acoustically negative effect of stiffening the windows, there has been concern of an unfavorable effect on audiologic outcomes due to the procedure. The purpose of this study is to specifically evaluate audiologic outcomes after OW and RW reinforcement. METHODS: A retrospective review of patients undergoing transcanal OW or RW reinforcement was completed. Patients were evaluated both as a total group and as two groups separated into "third window" and "two-window" groups based on their specific diagnosis. Primary outcomes included changes in individual pure-tone thresholds, pure-tone average (PTA), air-bone gap, speech reception threshold (SRT), and word recognition scores (WRS) between the preoperative and postoperative groups. RESULTS: Seventy-one patients were included in the study. The combined cohort demonstrated a significant postoperative 2.75 dB increase in the air conduction hearing level at 4000 Hz (p < 0.05). This was almost entirely accounted for by a 2.18 dB increase in the air-bone gap at this frequency (p < 0.05). There were no significant changes in PTA, SRT, or WRS between in the combined group or in the subgroup analysis. CONCLUSION: OW and RW tissue reinforcement resulted in a statistically significant but likely clinically insignificant decrease in hearing at the 4000 Hz frequency. There was no worsening of PTA, WRS, or SRT.

Frequency-specific Electrocochleography and Traveling Wave Time as a Clinical Test for Menière's Disease.

INTRODUCTION: Menière's disease is a clinical entity with no definitive objective testing. It has been hypothesized that underlying endolymphatic hydrops stiffens the basilar membrane leading to increased speed of the acoustic stimulus, therefore traveling wave velocity has been proposed as an objective test to aid in the diagnosis. The objective of this study is to compare electrocochleography frequency-specific action potential latency, basilar membrane traveling wave time, and summation to action potential (SP/AP) ratio in Menière's and non-Menière's patients. METHODS: Tympanic electrocochleography was performed with frequency-specific action potential latency time and SP/AP ratio recorded. Patient demographics, symptoms, audiogram data, AAO-HNS classification of Menière's disease, management interventions, and follow-up were recorded. Statistical analysis was performed to compare outcome measures across patient groups, demographics, and clinical data. RESULTS: Ninety-one patients (182 ears) were included. There was a significant difference between a "definite" Menière's diagnosis and an "unlikely" or "probable" diagnosis by an average of 13 dB HL for the pure-tone thresholds at 250 Hz on the affected side (p = 0.006). There was no significant difference in pure-tone thresholds at any other frequency, AP latency at any frequency, or AP/SP ratio between the different Menière's classification groups. CONCLUSIONS: Our study fails to show significance of the traveling wave velocity as an objective test for Menière's disease. A significant correlation was found with low-frequency hearing loss between AAO-HNS Menière's classification groups.

Hydroxyapatite cement cranioplasty in the setting of simultaneous translabyrinthine resection of cerebellopontine angle tumors and cochlear implantation.

Cochlear implantation (CI) has become an option for the treatment of hearing loss after translabyrinthine resection of vestibular schwannomas. The surgical video presents the case of a 67-year-old male who had translabyrinthine resection of vestibular schwannoma with simultaneous CI and closure with a hydroxyapatite (HA) cement cranioplasty. HA cement cranioplasty can be utilized in place of abdominal fat graft for the closure of translabyrinthine approaches with similar efficacy and complication profile. To the authors' knowledge, this is the first reported case of a simultaneous CI and translabyrinthine resection of vestibular schwannoma with HA cement cranioplasty. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID211.

The burden of laryngomalacia and its effects on caregivers: A support group survey evaluation.

OBJECTIVE: To evaluate which factors may affect anxiety and child's health perception of parents with children that have laryngomalacia. STUDY DESIGN: Survey Study. SETTING: "Coping with Laryngomalacia" - largest online laryngomalacia support group for parents with children who have laryngomalacia. SUBJECTS: and Methods: A survey was sent to support group member that gathered information regarding the patient's diagnosis and associated course of treatment and evaluated for parental anxiety and perceived health of their child. Analysis was performed to evaluate which variables are associated with increased parental anxiety and worsened perceived child's health. RESULTS: Data was gathered on 434 patients. All caregivers reported some level of anxiety due to the diagnosis and 64% felt completely anxious. Parents who saw an increased number of physicians prior to a pediatric ENT rated their child with poorer health (p < .05). Those that felt their concerns were brushed off initially reported increased anxiety (p < .05). If the child was admitted to the hospital, ICU, required intubation, had feeding troubles, required a feeding tube, or underwent pH monitoring, the patient was rated to have poorer health per the parents (p < .05). CONCLUSION: Laryngomalacia causes a significant burden on patients and their families due to the eating problems, feeding problems, hospital stay, and other various conditions associated with the disease. Caregivers should take a more modern and compassionate approach to management and diagnosis.

Perioperative cost evaluation of canal wall down mastoidectomy.

INTRODUCTION: To evaluate perioperative costs of canal wall-down (CWD) mastoidectomy as an initial surgery compared to revision surgery following initial canal wall-up (CWU) mastoidectomy. METHODS: This study is a retrospective chart review of adult patients who underwent CWD mastoidectomy for chronic otitis media with or without cholesteatoma at a tertiary referral center. Patients were divided into groups that had previous CWU surgery and were undergoing revision CWD and those that were having an initial CWD mastoidectomy. Cost variables including previous surgeries, imaging costs, audiometric testing, and post-operative visits were compared between the two groups using t-test analysis. RESULTS: There was no significant difference with regards to the cost of post-operative visits, peri-operative imaging, or revision surgeries between the two groups. Hearing outcomes based on mean speech reception threshold (SRT) were not statistically different between the two groups (p = 0.087). There was a significant difference in total cost with the revision group having a higher mean cost by $6967.84, most of which was accounted for by the difference in the cost of the previous surgeries of $6488.53. CONCLUSIONS: The revision CWD surgery group had increased total cost that could be attributed to the cost of previous surgery. Increased peri-operative cost was not noted with the initial CWD surgery group for any individual variables examined. Initial CWD mastoidectomy should be considered in the proper patient population to help decrease healthcare costs.

Diving and mental health: the potential benefits and risks from a survey of recreational scuba divers.

INTRODUCTION: Scuba diving is physically and cognitively demanding. Medical guidance regarding physical and mental health (MH) issues and related prescribed medication is often based on limited evidence. There is a paucity of data concerning diving with MH issues. This survey aimed to investigate the prevalence of MH issues and use of prescription medications among United Kingdom (UK) sport divers, and the rate of non-compliance with current guidance among divers suffering depression and anxiety. The positive effects of scuba diving on MH were also considered. METHODS: An anonymous online survey was publicised through diving exhibitions and social media. Measures included diver and diving demographics; GAD-7 Anxiety and PHQ-9 depression questionnaires; diagnosed current and/or past MH conditions; medication usage; comorbid medical conditions/treatments; disclosure of past/current MH issues; and perceived MH benefits of diving. RESULTS: Data from 729 respondents revealed MH issues at rates comparable with the general population. Current and/or past MH issues were reported by 111/729, with 60 having active diagnoses, and 45/60 taking prescribed psychotropic medications; 21/45 did not declare their medication on diver self-certification medical forms. The activity of diving was thought to be beneficial to MH by 119/729 respondents. CONCLUSIONS: Divers experienced expected levels of MH issues, but did not comply with current medical guidelines on modifying or abstaining from diving activity or reporting their MH condition. Changes may be needed to diver training to encourage more accurate reporting and aid development of evidence-based protocols. Guidelines could be reconsidered in light of current diver behaviour, risks and potential MH benefits.

The effect of ultraviolet radiation on choroidal melanocytes and melanoma cell lines: cell survival and matrix metalloproteinase production.

BACKGROUND: Ultraviolet radiation (UVR) can induce DNA damage and regulate the expression of factors important for tumour growth and metastasis, including matrix metalloproteinases (MMPs). Epidemiological studies suggest that chronic UVR exposure, especially during early adulthood, may be a risk factor in patients with choroidal melanoma. However, the effects of UV(R)-B on human choroidal melanocyte survival and growth are unknown. In this study, we investigated if UV(R)-B affected the in vitro survival, growth and MMP production of choroidal melanocytes and melanoma cells. METHODS: Cultures of primary choroidal melanocytes and melanoma cell lines (OCM-1 and OCM-8) were exposed to UV(R)-B (0-30 mJ/cm(2)). The cell morphology and growth were examined, and cell viability was assessed using an MTT assay. Gelatin zymography was used to assess the enzymatic activity for MMP-2 and -9 in conditioned media following UV(R)-B treatment. RESULTS: UV(R)-B > or =20 mJ/cm(2) was cytotoxic for choroidal melanocytes. Cytotoxic doses of 5 to 10 mJ/cm(2) were found for OCM-8 and OCM-1 melanoma cell lines. Low levels of UV(R)-B (2.5 and 3.5 mJ/cm(2)) significantly reduced melanoma cell viability after 48 h, although melanocyte viability was not affected by doses of UV(R)-B <10 mJ/cm(2). Conditioned media from melanoma cells and melanocytes displayed pro-MMP-2 activity independent of UV(R)-B. Control and UV(R)-B-treated OCM-1 cells secreted active MMP-2 up to 72 h. Pro-MMP-9 activity was seen from 36 h for control and UV(R)-B-treated OCM-1 and OCM-8 cells. CONCLUSIONS: Melanocytes appeared more resistant to physiological doses of UV(R)-B than melanoma cells; the potential of melanocytes to initially survive DNA damage following UV(R)-B exposure may be relevant to the subsequent transformation of melanocytes to melanomas. Although UV(R)-B did not induce the production and/or activation of MMP-2 and -9 in melanocytes or melanoma cells, we are currently investigating whether DNA damage-response genes such as p53 and p21 can be regulated following UVR exposure, and whether they are important for choroidal melanoma development.

In vitro targeting of NG2 antigen by 213Bi-9.2.27 alpha-immunoconjugate induces cytotoxicity in human uveal melanoma cells.

PURPOSE: To examine uveal melanoma cell lines for the expression of human melanoma proteoglycan (NG2) using monoclonal antibody (mAb) 9.2.27 and subsequently to assess the in vitro specificity and cytotoxicity of mAb 9.2.27 conjugated to the alpha-particle-emitting radioisotope 213bismuth (213Bi-9.2.27) for uveal melanoma cells. METHODS: Immunocytochemistry and flow cytometry were used to examine OCM-1, OCM-3, OCM-8, OMM-1, Mel202 and 92-1 melanoma cell lines for NG2 expression. Melanoma cells were treated with test (213Bi-9.2.27) or control (213Bi-A2) alpha-immunoconjugates (AICs). The specific cytotoxicity of 213Bi-9.2.27 AIC was evaluated using an MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfenyl)-2H-tetrazolium, inner salt) assay. Cell death was also assessed using TUNEL. RESULTS: OCM-1, OCM-8, OMM-1, and Mel202 cells strongly expressed NG2. OCM-3 cells showed moderate expression and 92-1 cells were NG2-negative. 213Bi-9.2.27 specifically killed NG2-positive OCM-1, OCM-8, and OMM-1 cells in a concentration-dependent manner. D0 values for 37% cell survival of NG2-positive OCM-1, OCM-8, and OMM-1 cells were 5.8, 5.0, and 5.6 microCi, respectively, and the value was 43.4 muCi for NG2-negative 92-1 cells. CONCLUSIONS: The specific cytotoxicity of 213Bi-9.2.27 AIC for NG2-positive, but not NG2-negative, cells suggests NG2 is a suitable target for alpha-immunotherapy in uveal melanoma. 213Bi-9.2.27 AIC used directly or as adjunct therapy may be a promising new agent for treating NG2-positive uveal melanomas or metastases.