Biomedical subjects

Joo-Heon Yoon

Publications and source records attributed to Joo-Heon Yoon.

At least 37 records · Page 2Linked to original sources

PubMed2005

Optic nerve injury secondary to endoscopic sinus surgery: an analysis of three cases.

Major orbital complications after the endoscopic sinus surgeries are rare and of these, optic nerve injury is one of the most serious. This study was to undertaken to analyze 3 cases of optic nerve injury after endoscopic sinus surgery. The three cases included one patient with a loss of visual acuity and visual field defect, and two patients with total blindness. In all cases, no improvement of visual acuity was observed despite treatment. It is important to frequently check the location and direction of the endoscope during surgery to avoid optic nerve injury. In addition, surgeons must have a precise knowledge of the detailed anatomy through cadaver dissections, an ability to interpret the PNS CT scan and experienced procedural surgical skills.

Adult↗

PubMed2005

Evaluation of polycyclic aromatic hydrocarbons in the activation of early growth response-1 and peroxisome proliferator activated receptors.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental and food contaminants with known or suspected carcinogenic properties. In this study, we have evaluated whether PAHs activate the early growth response (EGR-1) gene and bind to peroxisome proliferator-activated receptor alpha (PPAR alpha) and delta (PPAR beta/delta) in cell culture systems. Luciferase reporter systems were employed and several PAHs were evaluated for their ability to activate EGR-1 and PPARs. Some PAHs enhanced EGR-1 expression and activated PPAR alpha and PPAR beta. Among them, benz(a)anthracene was found to act as a relatively potent activator of PPAR alpha and PPAR beta/delta, and to significantly enhance EGR-1 transcription. These in vitro assays were confirmed by Western blot analysis, using cell lysates of tissue samples from mouse trapped at a highly contaminated Superfund site in the Chattanooga Creek floodplain in Chattanooga, Tennessee. We have found that a PPAR target gene, glycogen synthase kinase-3beta (GSK-3beta), was down-regulated and EGR-1 was up-regulated in the mouse samples of Chattanooga Creek. In addition, select PAHs repressed GSK-3beta and induced CYP4A in FaO rat hepatoma cells. In conclusion, PAHs activate PPAR alpha and PPAR beta/delta, and up-regulate EGR-1 expression in vitro as well as in vivo. These data may provide a diversity of PAH activity in several biological pathways.

Animals↗

PubMed2005

Ginkgo biloba extract (EGb 761) induces apoptosis by the activation of caspase-3 in oral cavity cancer cells.

We have investigated whether Ginkgo biloba extract (EGb 761) induces apoptosis of oral cavity cancer cells and attempted to characterize the apoptotic pathway activated by EGb 761. The inhibition of SCC 1483 oral cavity cancer cells proliferation was noted from 250 micro/ml of EGb 761. Apoptosis was observed after 24 h of incubation with 250 microg/ml EGb 761 and occurred in a time- and dose-dependent manner. Apoptosis was confirmed by DNA fragmentation and PARP cleavage. Co-treatment with the caspase inhibitor (z-VAD-fmk) inhibited apoptosis and PARP cleavage induced by EGb 761. Caspase-3 activity was upregulated by EGb 761 but reduced to the control level by co-treating with z-VAD-fmk. In summary, EGb 761 induces apoptosis of oral cavity cancer cells and caspase-3 is activated in this apoptosis. Therefore, EGb 761 may be considered as a possible chemopreventive agent against oral cavity cancer.

Apoptosis↗

PubMed2005

Expression of 15-lipoxygenase-1 in human nasal epithelium: its implication in mucociliary differentiation.

15-lipoxygenase-1 (15-LO-1) is involved in the differentiation of human tracheobronchial epithelial cells. Here, we investigated the relation between 15-LO-1 expression and the differentiation of human nasal epithelium. In retinoic acid (RA)-sufficient culture media, 15-LO-1 expression in normal human nasal epithelial cell time-dependently increased, but its expression was undetectable in RA-deficient culture media. Moreover, in RA-deficient culture media, IL-4 at 1 ng/ml concentration time-dependently induced 15-LO-1 expression. In addition, MUC8 gene expression, a marker of mucociliary differentiation, was up-regulated by 15-LO-1, which was itself induced by IL-4. In murine nasal mucosa, the expression of leukocyte type-12-LO, a functional equivalent of 15-LO-1, reduced after postnatal day 7. Our findings suggest that 15-LO-1 is related to the differentiation of human nasal epithelium, and that it may mediate the mucociliary differentiation of human nasal epithelium.

Animals↗

PubMed2005

MUC8 as a ciliated cell marker in human nasal epithelium.

CONCLUSIONS: This study indicates that MUC8 protein is expressed in ciliated cells from human nasal epithelial cells and is upregulated by IL-1beta treatment. These results suggest that MUC8 gene and protein expression levels could be used as a ciliated cell marker in human nasal epithelium. OBJECTIVES: To examine MUC8 mRNA expression patterns according to the mucociliary differentiation of normal human nasal epithelial (NHNE) cells, and to investigate the localization of MUC8 proteins in nasal polyps. MATERIAL AND METHODS: Passage-2 NHNE cells were cultured using an air-liquid interface technique. On Days 2, 7, 14 and 28 after confluence, ciliated cells were counted by means of cytospin slide immunostaining using H6C5 and beta-tubulin, and MUC8 mRNA levels were determined using real-time quantitative polymerase chain reaction (PCR). After synthesizing polyclonal anti-MUC8 peptide antibodies, MUC8 immunostaining was performed using nasal polyps. MUC8 mRNA and protein levels were determined in NHNE cells treated with IL-1beta (10 ng/ml for 24 h) using reverse transcriptase-PCR and Western blot analysis. RESULTS: The increases in the number of ciliated cells and the MUC8 gene expression level with increasing culture time in the NHNE cells were quite similar. MUC8 was expressed in the ciliated cells of human nasal polyps. The MUC8 protein level and the mRNA level were upregulated as a result of IL-1beta treatment.

Antibodies↗

PubMed2005

Sulindac sulfide-induced apoptosis in sinonasal cancer cells.

CONCLUSIONS: These results demonstrate that sulindac sulfide can induce cell death in maxillary cancer cells, and that sulindac sulfide-induced apoptosis is related to the extracellular signal-regulated kinase/p38 MAPK-caspase 3 signaling pathway. OBJECTIVE: Head and neck cancer is the sixth commonest cancer in the human body. Squamous cell carcinoma accounts for most sinonasal cancers. However, little is known regarding the biochemical mechanism(s) of cell death in sinonasal cancers. Recently, human epidemiological and clinical intervention studies have indicated that sulindac, a non-steroidal anti-inflammatory drug, exhibits chemopreventive activity in colorectal cancer. In this study, we aimed to investigate whether sulindac sulfide can induce apoptosis in sinonasal cancer cells and what type of molecular mechanisms induces the death of sinonasal cancer cells. MATERIAL AND METHODS: Sinonasal cancer cells (Asan Medical Center Head and Neck Cancer 5) were treated with various concentrations of sulindac sulfide. The degree of cell death was determined by means of a fluorescence-activated cell scan and the signal transduction pathway for cell death was examined. RESULTS: Human nasal cavity cancer cells treated with sulindac sulfide underwent cell death, and the induction of apoptosis occurred in a dose-dependent manner. Moreover, sulindac sulfide-induced apoptosis was abolished by treatment with the caspase inhibitor Z-VAD-fmk and the mitogen-activated protein kinase (MAPK) inhibitors PD98059 and SB203580.

Amino Acid Chloromethyl Ketones↗

PubMed2005

Expression of Na+/H+ exchanger isoforms in normal human nasal epithelial cells and functional activity of Na+/H+ exchanger 1 in intracellular pH regulation.

CONCLUSIONS: Both the mRNA and protein of NHE1, -2 and -3 were expressed in NHNE cells. NHE1 is a major NHE isoform which is expressed in the basolateral membranes of NHNE cells. OBJECTIVE: Na+/H+ exchangers are ubiquitous plasma membrane transport proteins implicated in the maintenance of intracellular pH. The aim of this study was to examine the expression of Na+/H+ exchangers as a function of the differentiation of normal human nasal epithelial (NHNE) cells. In addition, we investigated the functional activity of the Na+/H+ exchanger 1 (NHE1) in basolateral membranes. MATERIAL AND METHODS: Cultured passage-2 NHNE cells were used. RNA and histological samples were collected on the day of confluence and on the 7th, 14th and 28th days after confluence in order to determine the effects of time. Cell lysates were collected on the day of confluence to investigate the presence of the proteins. Reverse transcriptase polymerase chain reaction and Western blotting were performed to investigate the presence of mRNA and protein, respectively. The functional activity of NHE1 was examined using 3-methylsulfonyl-4-piperidinobenzoyl guanidine methanesulfonate (HOE694), an NHE1-specific inhibitor, on the day of confluence. RESULTS: The NHE1 mRNA expression level did not change as a function of differentiation. However, the NHE2 mRNA expression levels increased on the 7th, 14th and 28th days after confluence. The NHE3 mRNA expression levels increased on the 14th and 28th days after confluence. Western blot analysis confirmed the expression of NHE1 (91 kDa), NHE2 (90 kDa) and NHE3 (93 kDa). In addition, HOE694 inhibited basolateral NHE activity by 68% at 1 microM and by 85% at 5 microM in the NHNE cells.

Blotting, Western↗

PubMed2005

IL-1beta promotes the ciliogenesis of human middle ear epithelial cells: possible linkage with the expression of mucin gene 8.

CONCLUSIONS: These findings suggest that IL-1beta, increases ciliogenesis in NHMEE cells and that MUC8 protein may play a role in this process. OBJECTIVES: The morphology of the middle ear epithelium changes under various pathologic conditions. We compared the density of ciliated cells and the level of mucin gene 8 (MUC8) mRNA in the middle ear epithelial cells of mucoid otitis media (MOM) patients with those of normal controls. We also investigated the effect of IL-1beta on the ciliogenesis and expression of MUC8 mRNA in cultured normal human middle ear epithelial (NHMEE) cells. In addition, we localized the MUC8 protein in cultured NHMEE cells. MATERIAL AND METHODS: The surface morphology of NHMEE cells was examined using scanning electron microscopy. Reverse transcriptase polymerase chain reaction was performed to determine the level of MUC8 mRNA expression. After synthesis of MUC8 polyclonal antibody, we performed immunohistochemical staining. RESULTS: The density of ciliated cells was increased in the middle ear epithelium of both MOM patients and IL-1beta-treated cultures. Similarly, the expression of MUC8 was increased in both cases. MUC8 antibody was primarily stained on the ciliated cells of NHMEE cells.

Case-Control Studies↗

PubMed2005

Effect of hypo-, iso- and hypertonic saline irrigation on secretory mucins and morphology of cultured human nasal epithelial cells.

CONCLUSION: We speculate that isotonic saline is the most physiological irrigation solution in terms of mucus secretion and the cellular morphology of nasal epithelial cells. OBJECTIVE: To determine the most physiologic and effective saline concentration for nasal irrigation in terms of mucus secretion and cellular morphology by using normal human nasal epithelial cells treated with hypo-, iso- and hypertonic saline. MATERIAL AND METHODS: Fully differentiated passage-2 normal human nasal epithelial cells were treated with pure water and with 0.3% (hypotonic), 0.9% (isotonic) and 3% (hypertonic) saline solutions. mRNA expression levels of MUC5AC and MUC5B, which are known to be major airway mucins, were analyzed after 30 min using reverse transcriptase polymerase chain reaction. Total mucin and MUC5AC and MUC5B mucin secretions were analyzed using dot-blotting. Cellular morphology was observed with light microscopy after hematoxylin-eosin staining and with scanning electron microscopy. RESULTS: MUC5AC and MUC5B mRNA levels did not change after treatment with pure water and various concentrations of saline. Total mucin and MUC5AC mucin secretions only increased following pure water treatment, while MUC5B mucin secretion increased with pure water, hypo- and hypertonic saline treatment. Morphologic analysis revealed that pure water severely damaged normal human nasal epithelial cells and that only isotonic saline did not affect their morphology.

Cells, Cultured↗

PubMed2004

Cyclooxygenase inhibitors induce apoptosis in oral cavity cancer cells by increased expression of nonsteroidal anti-inflammatory drug-activated gene.

We have investigated whether NAG-1 is induced in oral cavity cancer cells by various NSAIDs and if apoptosis induced by NSAIDs can be linked directly with the induction of NAG-1. NAG-1 expression was increased by diclofenac, aceclofenac, indomethacin, ibuprofen, and sulindac sulfide, in the order of NAG-1 induction, but not by acetaminophen, piroxicam or NS-398. Diclofenac was the most effective NAG-1 inducer. Incubation with diclofenac inhibited cell proliferation and induced apoptosis. The expression of NAG-1 was observed in advance of the induction of apoptosis. Conditioned medium from NAG-1-overexpressing Drosophila cells inhibited SCC 1483 cells proliferation and induced apoptosis. In summary, some NSAIDs induce NAG-1 expression in oral cavity cancer cells and the induced NAG-1 protein appears to mediate apoptosis. Therefore, NSAIDs may be considered as a possible chemopreventive agent against oral cavity cancer.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2004

Prostaglandin E2 induces MUC8 gene expression via a mechanism involving ERK MAPK/RSK1/cAMP response element binding protein activation in human airway epithelial cells.

MUC8 gene expression is overexpressed in nasal polyp epithelium and is also increased by treatment with inflammatory mediators in nasal epithelial cells. These data suggest that MUC8 may be one of important mucin genes expressed in human airway. However, the mechanisms of various inflammatory mediator-induced MUC8 gene expression in normal nasal epithelial cells remain unclear. We examined the mechanism by which prostaglandin E(2) (PGE2), an arachidonic acid metabolite, increases MUC8 gene expression levels. Here, we show that ERK mitogen-activated protein kinase is essential for PGE2-induced MUC8 gene expression in normal human nasal epithelial cells and that p90 ribosomal S 6 protein kinase 1 (RSK1) mediates the PGE2-induced phosphorylation of cAMP-response element binding protein. Our results also indicate that cAMP-response element at the -803 region of the MUC8 promoter is an important site of PGE2-induced MUC8 gene expression. In conclusion, this study gives insights into the molecular mechanism of PGE2-induced MUC8 gene expression in human airway epithelial cells.

Cell Line, Tumor↗

PubMed2004

Surgical outcome of radical maxillectomy in advanced maxillary sinus cancers.

We investigated the surgical outcome of radical maxillectomy in advanced maxillary sinus cancers invading through the posterior wall and into the infratemporal fossa. Twenty-eight patients with maxillary sinus squamous cell carcinoma, who visited the Otorhinolaryngology Department at Severance Hospital from March, 1993 to February, 2001 and underwent the surgery, were analyzed retrospectively by reviewing clinical medical records and radiologic test results. The mean follow- up period was 78.8 months.(26-162 months) Local recurrence, sites of local recurrence, and the 2-year disease-free survival rate were analyzed. Of the total 28 cases, 9 cases were T3, and 19 cases were T4. Total maxillectomy was performed in 12 cases (42.9%) and radical maxillectomy in 16 cases (57.1%). Regardless of staging, radical maxillectomy was performed only when cancers invaded through the posterior wall and into the infratemporal fossa. When cancers only maginally or did not invade the posterior wall, total maxillectomy was performed. The 2-year disease-free survival rate was 75% for both total and radical maxillectomy, and the local recurrence rates were 8.3% and 18.7% respectively. All recurrence occurred at the posterior resection margin of the maxillectomy. We strongly recommend the use of radical maxillectomy in the cases of advanced maxillary sinus cancers invading the infratemporal fossa. Radical maxillectomy can provide sufficient safety margins and lower the local recurrence rate.

Adult↗

PubMed2004

Angiocentric T-cell and NK/T-cell lymphomas: radiotherapeutic viewpoints.

PURPOSE: To investigate the patterns of local failure and the risk factors predictive of local failure and to establish the dose-response relationships influencing the probability of local control in patients with Stage I and II angiocentric T-cell or natural killer (NK)/T-cell lymphoma who were treated with radiotherapy (RT) alone. METHODS AND MATERIALS: We retrospectively reviewed the data from 102 patients with Ann Arbor Stage I and II angiocentric T-cell or NK/T-cell lymphoma who underwent RT alone to a median dose of 45 Gy (range, 20-70 Gy) between 1976 and 1998. The patterns of local failure, risk factors predictive of local failure, dose-response relationships, and survival data were analyzed. Because of the protean feature of local recurrences, the sites of local failure were allocated to one of three categories: true recurrence (TR), marginal recurrence (MR), and elsewhere recurrence (ER). RESULTS: Despite a higher complete remission rate (72%) after RT, 60 patients experienced treatment failure, including local failure in 48 (47%), regional failure in 3 (3%), and systemic failure in 28 (27%). The patterns of local failure were TR in 42, MR in 3, and ER in 5 patients. The median time to recurrence for TR/MR was shorter than that for ER (1 month for TR/MR vs. 12 months for ER). Patients with TR/MR had a more unfavorable prognosis than those experiencing ER (2-year survival rate after salvage treatment: 6% for TR/MR vs. 80% for ER; p <0.01). The dose-response curve was sigmoid in shape within the range of 20-54 Gy, which followed the plateau at doses in excess of about 54 Gy. A positive correlation was observed in the dose-response curve for the probability of local control (p = 0.017, logistic regression analysis). The overall 5-year actuarial survival and local recurrence-free survival rate for all patients was 42% and 53%, respectively. Achievement of complete remission was the most statistically significant risk factor predictive of TR/MR and the most important prognostic factor. CONCLUSION: Our data confirm that local failure remains the major obstacle for patients who receive RT alone and that achievement of complete remission is a particularly important determinant of treatment success. Although dose escalation up to >54 Gy cannot entirely reduce the incidence of TR/MR, we believe it is important to identify an appropriate subset of patients for whom an additional boost dose may be beneficial. Given the high rate of local failure, an investigational approach should be conducted to supplement RT using radiosensitizers or more effective chemotherapeutic agents in future trials.

Adolescent↗

PubMed2004

Membrane-specific expression of functional purinergic receptors in normal human nasal epithelial cells.

Extracellular purines and pyrimidines regulate various physiological responses via the cell surface receptors known as purinoreceptors and may exert autocrine or paracrine effects on ion transport, fluid transport, ciliary beat frequency, and mucin secretion. Therefore, this study aims to investigate the expression patterns of the purinoreceptors in normal human nasal epithelial (NHNE) cells. In RT-PCR, the mRNAs for several P2X (P2X3, P2X4, P2X7) and P2Y (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12) receptors were identified in NHNE cells. Functional localizations of P2 receptors were investigated by measuring intracellular calcium concentration ([Ca2+]i) increases in membrane-specific manner using a double-perfusion chamber. Absence of the responses of alphabeta-methylene ATP and 2-methylthio-ATP excluded functionally active P2X3, P2X4, and P2Y1 receptors as far as [Ca2+]i increase is concerned. Applications with ATP and UTP revealed that luminal membranes of NHNE cells express P2Y2 and P2Y6 receptors and basolateral membranes express P2Y2 receptor. Expressions of P2Y2 and P2Y6 receptors in NHNE cells were further verified by immunoblotting using specific antibodies. In addition, the results with 2,3-O-(4-benzoyl)-benzoyl-ATP indicate that the P2Y11 receptor may be present on the luminal side. In conclusion, the NHNE cells express functionally active P2Y2, P2Y6, and P2Y11 receptors in a membrane-specific pattern, which may play an important role in the control of mucin and fluid secretion in NHNE cells.

Base Sequence↗

PubMed2004

Purinergic stimulation induces Ca2+-dependent activation of Na+-K+-2Cl- cotransporter in human nasal epithelia.

Increasing evidence suggests that P2 receptors (P2Rs) in airway epithelial cells perform critical functions in auto- or paracrine regulation of fluid and mucus secretion. In the present study, we characterized the effects of P2R stimulation on Na(+)-K(+)-2Cl(-) cotransporter (NKCC) activity in normal human nasal epithelial (NHNE) cells. [Ca(2+)](i) and pH(i) were measured in primary cultures of NHNE cells using a double perfusion chamber, which enabled us to analyze membrane-specific transporter activities. NKCC activities were estimated by the pH(i) reduction due to Na(+)-dependent and bumetanide-sensitive intracellular uptake of NH(4)(+). NKCC activities were observed in the basolateral membrane, but not in the luminal membrane, of NHNE cells. Interestingly, P2Rs were expressed in both membranes, and the stimulation of either luminal or basolateral P2R increased NKCC activity. Blockades of luminal Cl(-) channels, basolateral K(+) channels, or protein kinase C did not affect the activation of NKCC by basolateral P2R stimulation. The effects of luminal P2R stimulation were partially reduced by Cl(-) channel blockers. However, chelation of intracellular Ca(2+) by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) treatment completely blocked the stimulatory effects of luminal and basolateral P2Rs on NKCC. In addition, increasing [Ca(2+)](i) by treatment with ionomycin-stimulated NKCC activity. These results provide evidence that stimulation of P2Rs directly activates basolateral NKCC by Ca(2+)-dependent pathways in NHNE cells, which is an important aspect of the purinergic regulation of ion and fluid secretions in human airway epithelia under physiologic and pathologic conditions.

Calcium↗

PubMed2004

All-trans retinoic acid induces mucociliary differentiation in a human cholesteatoma epithelial cell culture.

OBJECTIVES: Retinoic acid (RA) can prevent keratin formation and induce mucous differentiation in epithelia. In this study, we attempted to induce keratinizing squamous epithelium from human cholesteatoma epithelial (HCE) cells using an air-liquid interface (ALI) technique. We also examined the effect of RA on the phenotype of keratinizing HCE cells. MATERIAL AND METHODS: HCE cells were cultured in RA-free defined media at an ALI or in a submerged state. We examined the morphological differences between ALI and submerged cultures, and histologically investigated the changes of phenotype after RA treatment. We also determined the effect of RA on the mRNA expressions of the cornifin-alpha and mucin genes as indicators of squamous and mucous differentiation, respectively. RESULTS: Using an ALI technique, we were able to differentiate HCE cells into a keratinizing squamous epithelium. When we treated the keratinizing HCE cells with RA, the morphological phenotype progressively changed into mucociliary epithelium. In addition, the expression of cornifin-alpha mRNA was suppressed, and the expressions of mucin gene 5AC (MUC5AC) and MUC5B mRNA increased progressively with RA treatment. CONCLUSION: We successfully developed a culturing system for keratinizing differentiation of HCE cells using the ALI technique in a defined medium. Our study also clearly showed that RA treatment led to mucociliary differentiation of HCE cells.

Cell Differentiation↗

PubMed2004

Extracellular signal-regulated kinase is involved in tumor necrosis factor-alpha-induced MUC5AC gene expression in cultured human nasal polyp epithelial cells.

OBJECTIVES: Mucus secretion and inflammatory cytokines are increased in cases of chronic sinusitis with polyp. In this study we initially investigated the localization of MUC5AC protein in human nasal polyps. We then examined whether tumor necrosis factor-alpha (TNF-alpha) induces MUC5AC gene expression and whether extracellular signal-regulated kinase (ERK) plays a role in TNF-alpha-induced MUC5AC gene expression in cultured human nasal polyp epithelial cells. Finally, we investigated whether MUC5AC and activated ERK are co-expressed in goblet cells. MATERIAL AND METHODS: Human nasal polyp epithelial cells were isolated and subcultured. Passage-2 polyp epithelial cells were treated with 10 ng/ml TNF-alpha. ERK involvement was determined by Western blotting and MUC5AC gene expression by reverse transcriptase polymerase chain reaction. An ERK kinase assay and an inhibitor study using PD98059 were also performed. Immunohistochemical staining using polyclonal MUC5AC antibody and a phospho-specific ERK antibody was done in nasal polyps. RESULTS: MUC5AC was found to be expressed in the majority of goblet cells in human nasal polyp epithelium. TNF-alpha induced MUC5AC gene expression, and ERK activation was found to be essential for TNF-alpha-induced MUC5AC gene expression in cultured human nasal polyp epithelial cells. In addition, both MUC5AC and activated ERK were co-expressed in goblet cells of human nasal polyp epithelium. CONCLUSIONS: TNF-alpha induces MUC5AC gene expression via ERK in cultured human nasal polyp epithelial cells.

Blotting, Western↗

PubMed2004

Diplopia secondary to endoscopic sinus surgery.

OBJECTIVE: Diplopia after endoscopic sinus surgery (ESS) is rare but very serious. In this study, we investigated the characteristics, prognosis and treatment of diplopia occurring after ESS. MATERIAL AND METHODS: A retrospective analysis was carried out to investigate three patients with diplopia after ESS referred to us from other hospitals. RESULTS: In one case, an improvement in ocular motility was seen after surgical treatment. In the other cases, no improvement was observed, despite surgical treatment. CONCLUSION: In order to prevent diplopia after ESS, the surgeon must possess a complete anatomical knowledge obtained by means of cadaveric dissection, the ability to carefully read preoperative CT scans and the necessary surgical experience.

Adult↗