The role of Perifoveal Arteriolar Tortuosity in Optical Coherence Tomography Angiography (OCTA) images as an early indicator of hypertensive retinopathy.

PURPOSE: To assess the value of increased perifoveal retinal vascular tortuosity in optical coherence tomography angiography (OCTA) images as a biomarker of early hypertensive retinopathy and compare its clinical sensitivity and accuracy with traditional morphological changes used for Scheie classification. METHODS: OCTA images of 81 eyes (40 eyes from 20 hypertensive subjects and 41 eyes from 21 control subjects) were obtained retrospectively. Hypertensive retinopathy changes in randomized eyes were graded according to the Scheie classification, and perifoveal vessels were traced in a masked fashion. Tortuosity values of the perifoveal vessels were then calculated along with interobserver agreement in determining the morphometric values. RESULTS: There were no differences in perifoveal venular tortuosity between the hypertensive and control groups (Mean = 1.13 ± 0.04 vs. 1.13 ± 0.03), but significant differences existed for arterioles (Mean = 1.14 ± 0.05 vs. 1.11 ± 0.04). Tortuosity measurements demonstrated a significant interobserver agreement (p < 0.001), while Scheie ratings had a poor interobserver agreement (p = 0.735). There was a significant difference in Scheie classification between the hypertensive and control groups (Mean = 1.06 ± 0.54 vs. 0.50 ± 0.43, p = 0.005). CONCLUSIONS: OCTA-based perifoveal retinal arteriolar tortuosity may be a potential reliable biomarker with certain advantages for detecting early hypertensive retinopathy than morphological changes used for the Scheie classification. This may have broad applications and establish important parameters in utilizing OCTA for screening protocols, considering the importance of early detection of systemic hypertension.

Transsphenoidal retrieval of a needlefish beak remnants from the optic canal.

KEY POINTS: Penetrating orbital trauma from marine creatures, especially needlefish, should be considered after injuries sustained in open water. Advances in endoscopic sinus surgery have enabled surgeons to remove certain orbital foreign bodies through endoscopic endonasal approaches. 3D segmentation is a valuable pre-operative tool in complex endoscopic orbital cases.

Epiretinal Membrane Formation following Rhegmatogenous Retinal Detachment Repair: A Retrospective Cohort Study.

INTRODUCTION: This study aimed to investigate the incidence of and risk factors for epiretinal membrane (ERM) formation following primary rhegmatogenous retinal detachment (RRD) repair. METHODS: This comparative, retrospective, single-center cohort study included eyes with primary RRD treated between 2011 and 2023 at Massachusetts Eye and Ear, Boston, Massachusetts, with pars plana vitrectomy (PPV), scleral buckle (SB), PPV+SB, or pneumatic retinopexy (PnR). Demographic, clinical, and surgical parameters were collected from medical records. The primary outcome was the risk of ERM formation, while the secondary outcome was the risk of ERM requiring surgery. Univariable and multivariable Cox regression were performed, and a hazard ratio (HR) and 95% confidence interval (95% CI) were reported. RESULTS: Overall, 394 eyes were included. The mean age was 58.49 ± 12.8 years, and most patients were male. There was a significantly lower risk of ERM formation following SB compared to PPV in the univariable analysis (HR = 0.2, 95% CI = 0.08-0.60, p = 0.003); however, there was no significant association between treatment modality and ERM formation on multivariable Cox regression controlling for confounding factors (p = 0.24). ERM formation was found more commonly in patients who were older (HR = 1.0 per 1 year increase in age, 95% CI = 1.01-1.04, p = 0.001), those with worse baseline visual acuity (HR = 1.3, 95% CI = 1.09-1.71, p = 0.008), and those with macula-off RRDs (HR = 2.1, 95% CI = 1.41-3.32, p < 0.001). CONCLUSION: Surgical modality does not have a significant impact on the risk of ERM following retinal detachment repair. However, age, baseline visual acuity, and macular status are important predictors of ERM formation after RRD repair.

Association of Patient Age and the Thyroid Eye Disease-Clinical Activity Score.

PURPOSE: To investigate the association between age and clinical activity score (CAS) in patients with active, untreated thyroid eye disease. METHODS: A retrospective review was conducted of patients with active, untreated thyroid eye disease at a single institution between 2010 and 2020 whose ophthalmologic symptoms began no more than 9 months prior to the initial visit. Exclusion criteria included surgical or systemic thyroid eye disease treatment before or during the study period. Demographic and clinical data were collected for all patients, including a 7-point CAS at visit 1 (CAS1) and a 10-point score at visit 2 (CAS2). Patients were stratified by age: Group 1 (18-45), Group 2 (46-70), and Group 3 (71-85). RESULTS: A total of 156 patients were included: mean age 51.7 ± 15.8 years, 79.5% female. CAS1 differed significantly across groups: 1.9 ± 1.0 (Group 1), 2.7 ± 1.4 (Group 2), and 2.2 ± 1.6 (Group 3), p = 0.005. Findings were similar for CAS2: 2.2 ± 1.4 (Group 1), 3.0 ± 1.8 (Group 2), and 2.8 ± 1.9 (Group 3), p = 0.030. Post hoc analysis showed a statistically significant difference between Groups 1 and 2 (p = 0.004, visit 1; p = 0.025, visit 2) but not between other pairs. Patients with CAS1 of 0-3 (n = 129) were younger on average than those with CAS1 4-7 (n = 27): 50.4 ± 16.2 versus 58.2 ± 12.8 years (p = 0.009). Conjunctival redness (p = 0.019) and chemosis (p ≤ 0.001) were more common in older patients at both visits. CONCLUSIONS: Patients aged 46-70 years with active, untreated thyroid eye disease had significantly higher CAS1 and CAS2 than younger patients in this study, largely driven by differences in conjunctival redness and chemosis.

Multi-luminance Mobility Testing Endpoint.

An individual's functional vision may be measured via visual assessment and performance on mobility tasks. Since traditional mobility performance tests neglect to examine the effects of illumination on performance, the multi-luminance mobility test (MLMT) was designed to quantitatively assess the effects of illumination levels on an individual's mobility performance. In this chapter, we describe how the MLMT is conducted and scored in order to properly evaluate a participant's mobility under various light conditions.

Evolution of asymmetric proptosis during the active phase of thyroid eye disease.

PURPOSE: To assess the evolution of proptosis asymmetry during the active phase of bilateral thyroid eye disease (TED). METHODS: A retrospective study was conducted on patients with bilateral, active TED. Patients were measured by a single observer, using Hertel exophthalmometry from the time of initial presentation, during the active phase of TED, to the stable phase, 24-months later. Asymmetric proptosis was defined as a >2 mm intra-orbital difference in Hertel measurements. RESULTS: Fifty-one patients were enrolled. Patients presented at a mean time of 1.1 ± 2.9 months following the onset of TED symptoms. Stability of TED was established at 15.7 ± 12.3 months. At initial presentation, 41% of patients demonstrated asymmetric proptosis. Upon reaching the stable phase, asymmetric proptosis persisted in only 22% of patients. A decline in the rate asymmetric proptosis was greatest within the first 3 months of the active phase. CONCLUSIONS: Asymmetric proptosis is common in the setting of early active TED and decreases by 50% when the stable phase is reached. Therefore, diagnostic imaging is not routinely required to exclude alternative pathology in the cases of asymmetric TED. Perhaps more importantly, this finding supports the surgical paradigm of stable phase, graded orbital decompression, performed when the ultimate globe positions are achieved to avoid late postoperative asymmetry, resulting from the unanticipated evolution of proptosis when surgery is performed during the active phase of TED.

A single-institution review of lacrimal gland biopsies between 1962 and 2017.

PURPOSE: To examine the clinical and histopathologic characteristics of lacrimal gland biopsies at a tertiary academic center. METHODS: A retrospective chart review of patients undergoing lacrimal gland biopsy or excision between 1962 and 2017 was performed via the ocular pathology specimen log. All cases were reviewed for demographics, clinical presentation, and histopathologic diagnoses. RESULTS: Four hundred and two eyes in 356 patients were included in the analysis. Median age was 49 (range 5-91) with a female predominance (255, 72%, p < .001). Most had unilateral involvement (308, 86.5%) and visual acuity of 20/50 or better (332 eyes, 83%). Limitation in extraocular motility was present in 71 eyes (18%), relative afferent pupillary defect in 10 eyes (2.5%), and intraocular pressure 20 mmHg or above in 80 eyes (20%). The pre-operative radiology report commented on the enlargement of the lacrimal gland in 236 eyes (58.7%), and lack thereof in 73 eyes (18.2%). The most common histopathologic diagnoses were nonspecific inflammation or orbital pseudotumor (170, 42%), lymphoma (65, 16%), pleomorphic adenoma (22, 5.5%), adenoid cystic carcinoma (19, 4.7%), granulomatous inflammation (19, 4.7%), and normal lacrimal gland (16, 4%). Three hundred and seven cases were benign (76%) and 95 malignant (24%). The biopsy specimen was diagnostic in 343 (85%), and non-diagnostic in 59 (15%). CONCLUSIONS: This is a comprehensive review of one of the largest ocular pathology databases of lacrimal gland lesions. This study confirms the wide range of inflammatory and neoplastic conditions affecting the lacrimal gland and highlights the nuances of histopathologic diagnoses and diagnostic yield of biopsies in clinical practice.

Ultrasound Verification of Plaque Brachytherapy Placement in Patients Treated for Primary Uveal Melanoma: A Single-Center Experience.

Introduction: Proper plaque positioning is essential for effective episcleral plaque brachytherapy and can be verified using ultrasound. In this study, we show our center's protocol for intraoperative ultrasound verification of plaque placement and present our single-center local recurrence data in patients with primary UM involving the choroid and/or ciliary body. We also indicate our center's distance metastasis rate for patients presenting with primary UM. Methods: All patients who presented to our institution with UM of the choroid and/or ciliary body between May 2017 and March 2022 and treated with plaque brachytherapy were enrolled. Endpoints include the 24-month local recurrence-free rate (primary) and 24-month metastasis rate (secondary), both estimated using the Kaplan-Meier method (KM). Results: Local Recurrence: 176 patients met the study criteria with median follow-up of 23.2 months. The 24-month recurrence-free probability for this cohort was estimated at 99.1% (95% confidence interval: 0.974-1.00). Metastatic Recurrence: 136 of these patients underwent at least one follow-up surveillance scan. The 24-month metastasis-free survival probability in our cohort was estimated at 87% (95% confidence interval: 81-94%). Conclusions: We show improved local control utilizing ultrasound verification compared to historical controls who received TTT and brachytherapy without intraoperative ultrasound confirmation.

Arterial sheathing in Leber hereditary optic neuropathy.

PURPOSE: Presentation of a case of Leber hereditary optic neuropathy (LHON) with arterial sheathing eleven years after initial loss of vision. OBSERVATIONS: A 46-year-old female was referred for re-evaluation of Leber hereditary optic neuropathy. She first noticed rapid painless loss of vision eleven years prior. Fundus imaging performed at that time did not demonstrate arterial sheathing. Genetic testing revealed the presence of the LHON 11778 G-A mitochondrial mutation. Laboratory values were within normal limits save for angiotensin-converting enzyme elevated to 69 U/L. Eleven years later, visual acuity was count fingers at 12 feet with complete loss of color vision. Funduscopic examination of the optic nerve revealed bilateral pallor, sheathing of the retinal arteries, diffuse vessel narrowing, and tortuous retinal vessels. CONCLUSIONS AND IMPORTANCE: We present a case of LHON that demonstrates retinal arterial sheathing and possibly broadens the spectrum of LHON fundus findings.

GNA11 Mutation in an Intracranial Melanocytoma with Orbital Involvement and Nevus of Ota.

The prognostic value of mutations in G-protein genes GNAQ and GNA11 in patients with intracranial and orbital melanocytomas is unknown. The authors present a case of GNA11 mutation (GNA11Q209L) in a 32-year-old male suffering from a meningeal melanocytoma with orbital involvement and ipsilateral Nevus of Ota. The patient underwent gamma knife stereotactic radiosurgery without biopsy and later partial transcranial resection of the melanocytic tumor that was subject to immunohistochemical and molecular analysis. A 50-gene next-generation sequencing panel revealed a 626A>T mutation in the GNA11 gene. One year later, intracranial extension of the melanocytoma necessitated a ventriculoperitoneal shunt and immunotherapy. Future work is needed to determine how GNA11 mutations in melanocytomas influence prognosis and monitoring strategies.

Analysis of SARS-CoV-2 RNA on surfaces in New York City.

BACKGROUND: This study sought to determine the presence of SARS-CoV-2 virus on surfaces that trainees and faculty of an academic eye clinic came into contact with during daily life at the time of the COVID-19 pandemic in New York City. METHODS: This cross-sectional analysis involved collection of at least two samples by teams on four different days (November 9, 2020 - December 18, 2020) using sterile swabs (Puritan HydraFlock, Garden Grove, CA). Collection sites were grouped into four zones depending on proximity and amount of time personnel spent there. Samples were transported to the laboratory in transport medium and RNA was extracted using the QIAamp DSP Viral RNA Mini Kit (Qiagen, Germantown, MD). Presence of viral RNA was investigated using the Luna Universal Probe One-step RT-qPCR kit (New England Biolabs, Ipwsich, MA). RESULTS: 834 samples were submitted. Two were positive for SARS-CoV-2 RNA. The first was a sample from a patient bathroom sink handle in the main emergency department. The second was a nasal swab sample from a staff member who had been assigned to collect samples. Prior to this positive result, this asymptomatic staff member had tested positive for COVID-19, had quarantined for two weeks, and had received a negative test. CONCLUSION: Though COVID-19 is currently widespread in the United States, this study shows that health care personnel working in New York City at the Columbia University Irving Medical Center have a low chance of encountering viral RNA on surfaces they are in close contact with during daily life.

Toxicity of pathogenic ataxin-2 in Drosophila shows dependence on a pure CAG repeat sequence.

Spinocerebellar ataxia type 2 is a polyglutamine (polyQ) disease associated with an expanded polyQ domain within the protein product of the ATXN2 gene. Interestingly, polyQ repeat expansions in ATXN2 are also associated with amyotrophic lateral sclerosis (ALS) and parkinsonism depending upon the length of the polyQ repeat expansion. The sequence encoding the polyQ repeat also varies with disease presentation: a pure CAG repeat is associated with SCA2, whereas the CAG repeat in ALS and parkinsonism is typically interrupted with the glutamine encoding CAA codon. Here, we asked if the purity of the CAG sequence encoding the polyQ repeat in ATXN2 could impact the toxicity of the ataxin-2 protein in vivo in Drosophila. We found that ataxin-2 encoded by a pure CAG repeat conferred toxicity in the retina and nervous system, whereas ataxin-2 encoded by a CAA-interrupted repeat or CAA-only repeat failed to confer toxicity, despite expression of the protein at similar levels. Furthermore, the CAG-encoded ataxin-2 protein aggregated in the fly eye, while ataxin-2 encoded by either a CAA/G or CAA repeat remained diffuse. The toxicity of the CAG-encoded ataxin-2 protein was also sensitive to the translation factor eIF4H, a known modifier of the toxic GGGGCC repeat in flies. These data indicate that ataxin-2 encoded by a pure CAG versus interrupted CAA/G polyQ repeat domain is associated with differential toxicity, indicating that mechanisms associated with the purity of the sequence of the polyQ domain contribute to disease.

Atypical Cogan Syndrome Featuring Orbital Myositis and Dacryoadenitis.

A 39-year-old male presented with bilateral hearing loss and progressive left eye vision loss over a 14-month period. The development of systemic symptoms including arthralgias, enlarged lymph nodes, and profound leg weakness, prompted a workup for lymphoproliferative disease, infection, and autoimmune inflammatory conditions which was unrevealing. Subsequently, the right visual acuity declined from 20/25 to 20/70 and the left to hand motions due to corneal interstitial keratitis. There was limitation of left infraduction. Neuroimaging revealed dural thickening of the internal auditory canals, cavernous sinuses, cerebellum, and along the optic nerves. There was fusiform enhancing enlargement of the left inferior and medial rectus muscles and pathologic enlargement of the left lacrimal gland. Biopsy of the left lacrimal gland and left inferior rectus revealed fibrosis and lymphocytic infiltration. The patient was diagnosed with atypical Cogan syndrome and treated with oral prednisone, with improvement in visual acuity of the right eye, motility of the left eye, and systemic weakness.

Characterization and clinical course of 1000 patients with COVID-19 in New York: retrospective case series.

Objective: To characterize patients with coronavirus disease 2019 (COVID-19) in a large New York City (NYC) medical center and describe their clinical course across the emergency department (ED), inpatient wards, and intensive care units (ICUs). Design: Retrospective manual medical record review. Setting: NewYork-Presbyterian/Columbia University Irving Medical Center (NYP/CUIMC), a quaternary care academic medical center in NYC. Participants: The first 1000 consecutive patients with laboratory-confirmed COVID-19. Methods: We identified the first 1000 consecutive patients with a positive RT-SARS-CoV-2 PCR test who first presented to the ED or were hospitalized at NYP/CUIMC between March 1 and April 5, 2020. Patient data was manually abstracted from the electronic medical record. Main outcome measures: We describe patient characteristics including demographics, presenting symptoms, comorbidities on presentation, hospital course, time to intubation, complications, mortality, and disposition. Results: Among the first 1000 patients, 150 were ED patients, 614 were admitted without requiring ICU-level care, and 236 were admitted or transferred to the ICU. The most common presenting symptoms were cough (73.2%), fever (72.8%), and dyspnea (63.1%). Hospitalized patients, and ICU patients in particular, most commonly had baseline comorbidities including of hypertension, diabetes, and obesity. ICU patients were older, predominantly male (66.9%), and long lengths of stay (median 23 days; IQR 12 to 32 days); 78.0% developed AKI and 35.2% required dialysis. Notably, for patients who required mechanical ventilation, only 4.4% were first intubated more than 14 days after symptom onset. Time to intubation from symptom onset had a bimodal distribution, with modes at 3-4 and 9 days. As of April 30, 90 patients remained hospitalized and 211 had died in the hospital. Conclusions: Hospitalized patients with COVID-19 illness at this medical center faced significant morbidity and mortality, with high rates of AKI, dialysis, and a bimodal distribution in time to intubation from symptom onset.

Characterization and clinical course of 1000 patients with coronavirus disease 2019 in New York: retrospective case series.

OBJECTIVE: To characterize patients with coronavirus disease 2019 (covid-19) in a large New York City medical center and describe their clinical course across the emergency department, hospital wards, and intensive care units. DESIGN: Retrospective manual medical record review. SETTING: NewYork-Presbyterian/Columbia University Irving Medical Center, a quaternary care academic medical center in New York City. PARTICIPANTS: The first 1000 consecutive patients with a positive result on the reverse transcriptase polymerase chain reaction assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who presented to the emergency department or were admitted to hospital between 1 March and 5 April 2020. Patient data were manually abstracted from electronic medical records. MAIN OUTCOME MEASURES: Characterization of patients, including demographics, presenting symptoms, comorbidities on presentation, hospital course, time to intubation, complications, mortality, and disposition. RESULTS: Of the first 1000 patients, 150 presented to the emergency department, 614 were admitted to hospital (not intensive care units), and 236 were admitted or transferred to intensive care units. The most common presenting symptoms were cough (732/1000), fever (728/1000), and dyspnea (631/1000). Patients in hospital, particularly those treated in intensive care units, often had baseline comorbidities including hypertension, diabetes, and obesity. Patients admitted to intensive care units were older, predominantly male (158/236, 66.9%), and had long lengths of stay (median 23 days, interquartile range 12-32 days); 78.0% (184/236) developed acute kidney injury and 35.2% (83/236) needed dialysis. Only 4.4% (6/136) of patients who required mechanical ventilation were first intubated more than 14 days after symptom onset. Time to intubation from symptom onset had a bimodal distribution, with modes at three to four days, and at nine days. As of 30 April, 90 patients remained in hospital and 211 had died in hospital. CONCLUSIONS: Patients admitted to hospital with covid-19 at this medical center faced major morbidity and mortality, with high rates of acute kidney injury and inpatient dialysis, prolonged intubations, and a bimodal distribution of time to intubation from symptom onset.

The Intracerebral Hemorrhage Score: Changing Perspectives on Mortality and Disability.

BACKGROUND: Intracerebral hemorrhage (ICH) remains a devastating diagnosis. While the ICH Score continues to be used in the clinical setting to prognosticate outcomes, contemporary improvements in management have reduced mortality rates for each scoring tier. The aims of this study were to examine mortality rates within ICH Score strata and examine if these findings are stable when major disability is included in categorizing poor outcomes. METHODS: From a single-institution cohort built between 2009 and 2016, 582 patients were extracted based on the criteria for complete ICH Score, discharge mortality, and functional status for survivors. Mortality rates were stratified by ICH Score and compared with both historical and similar contemporary cohorts. Poor outcome was defined as severe disability (modified Rankin Scale score 5) in addition to death, stratified by ICH Score, and compared. A secondary analysis of patients with ICH Score of 2 was performed in light of the primary results. RESULTS: Mortality rates stratified by ICH Score were notably lower than expected for low- and moderate-grade ICH compared with the original cohort. However, when defining a poor outcome as including severe disability (modified Rankin Scale score 5) in addition to death, the rates for poor outcomes were higher for patients with ICH Score of 2 (51.16% vs. 26%, P = 0.017) and no different for any other score group compared with the original cohort. CONCLUSIONS: Though the original ICH Score overestimates mortality for low-grade and moderate-grade hemorrhages, it may underpredict severe disability.

In vivo roles of the basic domain of dynactin p150 in microtubule plus-end tracking and dynein function.

Microtubule (MT) plus-end-tracking proteins accumulate at MT plus ends for various cellular functions, but their targeting mechanisms are not fully understood (Akhmanova A and Steinmetz MO. Tracking the ends: a dynamic protein network controls the fate of microtubule tips. Nat Rev Mol Cell Biol 2008;9:309-322.). Here, we tested in the filamentous fungus Aspergillus nidulans the requirement for plus-end localization of dynactin p150, a protein essential for dynein function. Deletion of the N-terminal MT-binding region of p150 significantly diminishes the MT plus-end accumulation of both dynein heavy chain and p150, and causes a partial defect in nuclear distribution. Surprisingly, within the MT-binding region, the basic domain is more critical than the CAP-Gly (cytoskeleton-associated protein glycine-rich) domain for maintaining plus-end tracking of p150, as well as for the functions of dynein in nuclear distribution and early endosome movement. Our results show that the basic domain of A. nidulans p150 is important for p150-MT interaction both in vivo and in vitro, and the basic amino acids within this domain are crucial for the plus-end accumulation of p150 in the wild-type background and for the p150-MT interaction in the ΔkinA (kinesin-1) background. We suggest that the basic amino acids are required for the electrostatic interaction between p150 and MTs, which is important for kinesin-1-mediated plus-end targeting of dynactin and dynein in A. nidulans.

Polymyxin B, in combination with fluconazole, exerts a potent fungicidal effect.

OBJECTIVES: The objective of this study was to identify existing clinical compounds that either possess a fungicidal activity alone or can act synergistically with fungistatic antifungals. METHODS: We screened a clinical compound library for drugs that exhibited anti-Aspergillus activity. Among selected compounds, the cationic peptide antibiotic polymyxin B was chosen for further characterization because it can be used parenterally and topically. The fungicidal effect of polymyxin B and its synergistic interactions with azole antifungals were tested against a variety of fungal species. The toxicity of the drug combination of polymyxin B and fluconazole was compared with that of each drug alone in mammalian cell cultures. RESULTS: We found that polymyxin B possesses a broad-spectrum antifungal activity at relatively high concentrations. However, because of its synergistic interactions with azole antifungals, polymyxin B at much lower concentrations exerts a potent fungicidal effect against Cryptococcus neoformans, Candida albicans and non-albicans Candida species and moulds when combined with azoles. The combination of polymyxin B and fluconazole at concentrations within susceptible breakpoints is particularly potent against C. neoformans isolates, including fluconazole-resistant strains. The drug combination displayed no additional toxicity compared with polymyxin B alone when tested in cell culture. CONCLUSIONS: The combination of polymyxin B and fluconazole has the potential to be used in the clinic to treat systemic cryptococcosis. Our findings suggest that combining cationic peptide antibiotics with azole antifungals could provide a new direction for developing novel antifungal therapies.

Dynein light intermediate chain in Aspergillus nidulans is essential for the interaction between heavy and intermediate chains.

Cytoplasmic dynein is a complex containing heavy chains (HCs), intermediate chains (ICs), light intermediate chains (LICs), and light chains (LCs). The HCs are responsible for motor activity. The ICs at the tail region of the motor interact with dynactin, which is essential for dynein function. However, functions of other subunits and how they contribute to the assembly of the core complex are not clearly defined. Here, we analyzed in the filamentous fungus Aspergillus nidulans functions of the only LIC and two LCs, RobA (Roadblock/LC7) and TctexA (Tctex1) in dynein-mediated nuclear distribution (nud). Whereas the deletion mutant of tctexA did not exhibit an apparent nud mutant phenotype, the deletion mutant of robA exhibited a nud phenotype at an elevated temperature, which is similar to the previously characterized nudG (LC8) deletion mutant. Remarkably, in contrast to the single mutants, the robA and nudG double deletion mutant exhibits a severe nud phenotype at various temperatures. Thus, functions of these two LC classes overlap to some extent, but the presence of both becomes important under specific conditions. The single LIC, however, is essential for dynein function in nuclear distribution. This is evidenced by the identification of the nudN gene as the LIC coding gene, and by the nud phenotype exhibited by the LIC down-regulating mutant, alcA-LIC. Without a functional LIC, the HC-IC association is significantly weakened, and the HCs could no longer accumulate at the microtubule plus end. Thus, the LIC is essential for the assembly of the core complex of dynein in Aspergillus.