Swd2/Cps35 determines H3K4 tri-methylation via interactions with Set1 and Rad6.

BACKGROUND: Histone H3K4 tri-methylation (H3K4me3) catalyzed by Set1/COMPASS, is a prominent epigenetic mark found in promoter-proximal regions of actively transcribed genes. H3K4me3 relies on prior monoubiquitination at the histone H2B (H2Bub) by Rad6 and Bre1. Swd2/Cps35, a Set1/COMPASS component, has been proposed as a key player in facilitating H2Bub-dependent H3K4me3. However, a more comprehensive investigation regarding the relationship among Rad6, Swd2, and Set1 is required to further understand the mechanisms and functions of the H3K4 methylation. RESULTS: We investigated the genome-wide occupancy patterns of Rad6, Swd2, and Set1 under various genetic conditions, aiming to clarify the roles of Set1 and Rad6 for occupancy of Swd2. Swd2 peaks appear on both the 5' region and 3' region of genes, which are overlapped with its tightly bound two complexes, Set1 and cleavage and polyadenylation factor (CPF), respectively. In the absence of Rad6/H2Bub, Set1 predominantly localized to the 5' region of genes, while Swd2 lost all the chromatin binding. However, in the absence of Set1, Swd2 occupancy near the 5' region was impaired and rather increased in the 3' region. CONCLUSIONS: This study highlights that the catalytic activity of Rad6 is essential for all the ways of Swd2's binding to the transcribed genes and Set1 redistributes the Swd2 to the 5' region for accomplishments of H3K4me3 in the genome-wide level.

Two is not necessarily better than one: A double lens in a pre-metamorphic adult axolotl (Ambystoma mexicanum).

An 8-year-old female pre-metamorphic axolotl (Ambystoma mexicanum) was examined for a suspected anterior lens luxation. Slit-lamp biomicroscopy revealed two lens-like structures in the anterior chamber of the right eye (OD), each with cataractous change. Ultrasound biomicroscopy and optical coherence tomography (OCT) were performed without sedation, and revealed small lenticular structures each with distinct nuclei and cortices. Although a distinct connection of the two lenticular structures could not be definitively ruled out, the structures appeared separate. Each of the lenticular structures was closely associated with its respective iris leaflet. This report demonstrates application of advanced imaging for diagnostic use in axolotl ophthalmology, showing that imaging of the lens can be performed without sedation, topical anesthetic, nor contact gel with high diagnostic quality. Although two distinct lenses were diagnosed with no historical evidence of trauma, the small sizes of each lenticular structure, with no detectable connection between them, are suggestive of a possible regenerative abnormality. This report opens discussion for the regenerative capabilities of the pre-metamorphic adult axolotl and possible implementations of their use in regenerative medicine research for the development of future therapies.

Prospective, Multicenter Study on Tinnitus Changes after Cochlear Implantation.

OBJECTIVE: To investigate the time course of tinnitus changes in patients receiving cochlear implantation (CI) in a prospective, multicenter setting and to determine related factors. MATERIALS AND METHODS: A total of 79 adult patients who underwent CI were included in this study. We used the same questionnaires sequentially 5 times. The questionnaires included the Visual Analog Scale (VAS) for tinnitus severity, the Tinnitus Handicap Inventory (THI), Beck's Depression Index (BDI), and the Brief Encounter Psychosocial Instrument (BEPSI) for stress assessment. RESULTS: Tinnitus was present in 59 (74.7%) of the 79 study subjects. After CI, tinnitus was eliminated in 10 patients (25%) and improved in 16 patients (40%) of the 40 patients who completed the final questionnaires, and most of the tinnitus reduction occurred in the early period of CI use. In an analysis of psychological functioning with CI, BDI was reduced significantly after CI. Multiple linear regression analysis revealed that preoperative auditory steady-state response (ASSR), THI, and final BDI score were significantly associated with the changes in tinnitus after CI. CONCLUSIONS: Most of the tinnitus reduction occurred within 1 month after CI use, and the changes were significantly associated with THI, ASSR, and BDI scores 6 months after CI. CI is a valuable therapeutic modality in tinnitus of a deafened ear.

Formulation and in Vitro Evaluation of Self-microemulsifying Drug Delivery System Containing Fixed-Dose Combination of Atorvastatin and Ezetimibe.

This paper focuses on the development and physicochemical characterization of a self-microemulsifying drug delivery system (SMEDDS) containing a fixed-dose combination of atorvastatin (ATR) and ezetimibe (EZT). The solubility of both drugs was determined in excipient screening studies. Ternary-phase diagrams were drawn for 27 systems composed of different surfactants, cosurfactants, and oils at different surfactant-to-cosurfactant (S/CoS) ratios, and the system exhibiting the largest percentage area of the self-microemulsifying region was selected. The optimum oil ratio in the SMEDDS was selected by evaluating the mean droplet size of the resultant microemulsions. The underlying mechanism of the lower ATR loading capacity compared with EZT was elucidated by measurement of the zeta potential and UV absorption analysis. The results implied that ATR was located exclusively in the surfactant-cosurfactant layer, whereas EZT was located both in the microemulsion core and the surfactant-cosurfactant layer. In vitro dissolution studies showed that the SMEDDS had higher initial dissolution rates for both drugs when compared with marketed products. More importantly, EZT had a significantly increased dissolution profile in distilled water and pH 4.0 acetate buffer, implying enhanced bioavailability.

Predictors for outcome of paper patch myringoplasty in patients with chronic tympanic membrane perforations.

The purpose of the present study is to evaluate the outcome of paper patch myringoplasty for chronic tympanic membrane (TM) perforations and to explore the predictive factors for a successful closure. A retrospective study was performed in a tertiary referral center. Data of the patients who met the inclusion criteria were analyzed: the treatment outcomes and the potential predictive factors including age, sex, the affected ear, hearing level, duration of perforation, causes, location and size of perforations, relationship between the perforation border and the malleus, status of TM surface, and the number of patch applications. Complete closure was achieved in 27 of the total 43 subjects. Among the 11 clinical and TM factors, only the perforation size remained significant as the predictor after multivariable logistic regression (p = 0.029, OR 4.4). The patients with perforation ≤ 5% of the TM showed higher closure rate (78.3%) than those with perforation >5% (45.0%). In conclusion, paper patch myringoplasty showed overall success rate of 62.8%. In patients with perforations smaller than 5% of the TM, the closure rate was 78.3%. The predictor of the treatment outcome was the perforation size. We can try paper patch myringoplasty first in patients who had dry chronic perforations smaller than 5% of the TM without middle ear disease.

Unusual truncation of N-acylated peptoids under acidic conditions.

The terminal amino groups of peptoids have often been protected with acetyl groups to improve cell permeability and therapeutic potential, and to prevent the poisoning of the catalysts in organometallic reactions. Interestingly, the unusual truncation of the terminal peptoid unit has sometimes been encountered when the acetylated linear peptoids were treated with a TFA cleavage cocktail. In this study, we systematically investigated the electronic effects of acyl groups on the truncation of N-acylated peptoids to rationalize the formation of the deleted peptoids and to establish an appropriate strategy for preventing such undesired truncation.

Childhood tinnitus: clinical characteristics and treatment.

PURPOSE: Troublesome tinnitus in children can have an impact on their lives leading to behavioral or psychological problems. The present study was designed to identify the clinical features of childhood tinnitus, to establish the treatment strategy for each tinnitus category and severity, and to assess the treatment outcomes. MATERIALS AND METHODS: Clinical data were retrospectively collected on 108 tinnitus patients in childhood and adolescence. The authors have classified tinnitus according to the acoustic source: otic (idiopathic subjective), myoclonic, and vascular tinnitus based on the tinnitus quality and appropriate diagnostic approaches. Treatment selection depended on the tinnitus category and severity. Treatment modalities included counseling, a simplified tinnitus retraining therapy, counseling with medications, and surgery. RESULTS: Of all 108 subjects, otic tinnitus was the most common form of childhood tinnitus (n=80) followed by myoclonic (n=21) and vascular tinnitus (n=6). The prevalence of otic tinnitus increased with age. The mean age of myoclonic tinnitus patients was younger than that of the others. The majority of otic tinnitus showed normal hearing. The origin of 81% of myoclonic tinnitus was middle ear muscles. Of all subjects, 67.6% had mild tinnitus responsive to counseling alone. Distressing tinnitus was most common in myoclonic tinnitus. Almost all patients (97%) who were followed up at 3 months (64%) showed improvements. CONCLUSIONS: We suggest that understanding the clinical characteristics of childhood tinnitus, establishing a diagnosis based on the acoustic source, and implementing appropriate therapy customized to the individual tinnitus category and severity would help clinicians to relieve tinnitus children of their troublesome tinnitus effectively.

Diagnostic value and clinical significance of stress hormones in patients with tinnitus.

Tinnitus has been found to be modulated by stress and is also closely related to the emotional state and the limbic system. In the present study, we evaluated the diagnostic and clinical values of several stress hormones in a large number of tinnitus patients. This study included 344 patients with sensorineural tinnitus and 87 normal controls. A questionnaire about tinnitus was administered to the participants, and blood levels of norepinephrine (NE), epinephrine (Epi), a metabolite of serotonin (5-hydroxyindoleacetic acid, 5-HIAA) and cortisol were compared between groups. In results, the mean values of Beck's depression inventory (BDI), Brief Encounter Psychosocial Instrument (BEPSI), NE, and 5-HIAA levels were higher in the tinnitus group, although there was no statistical significance. But, the proportion of participants with elevated 5-HIAA was significantly higher in the tinnitus group (21.8 vs. 8.0 %, P < 0.05), and the 5-HIAA level significantly correlated with the duration of tinnitus, NE and cortisol. Elevated stress-related hormones, as well as hearing loss, BDI, and BEPSI were the most related factors with tinnitus in multiple regression test with age adjustment. However, levels of stress-related hormones did not correlate with subjective measures including BDI, BEPSI and severity of tinnitus. In conclusion, blood stress hormones seemed to have some diagnostic and clinical value in patients with tinnitus, and serotonin is supposed to be the most important hormone in tinnitus. Further studies about the values of stress and stress hormones in tinnitus patients may lead to new approaches regarding diagnosis and clinical management of the disease.

Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model.

The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

Clinical significance of orthostatic dizziness in the diagnosis of benign paroxysmal positional vertigo and orthostatic intolerance.

PURPOSE: Orthostatic dizziness (OD) and positional dizziness (PD) are considerably common conditions in dizziness clinic, whereas those two conditions are not clearly separated. We aimed to evaluate the clinical significance of simple OD and OD combined with PD for the diagnosis of benign paroxysmal positional vertigo (BPPV) and orthostatic intolerance (OI). PATIENTS AND METHODS: Patients presenting with OD (n=102) were divided into two groups according to their symptoms: group PO, presenting with PD as well as OD; group O, presenting with OD. A thorough medical history, physical examination, and vestibular function tests were performed to identify the etiology of the dizziness. Orthostatic vital sign measurement (OVSM) was used to diagnose OI. RESULTS: The majority of patients were in group PO (87.3%). BPPV was the most common cause of OD for entire patients (36.3%) and group PO (37.1%), while OI was most common etiology for group O (38.5%). Total of 17 (16.7%) OI patients were identified by OVSM test. Orthostatic hypotension (n=10) was most frequently found, followed by orthostatic hypertension (n=5), and orthostatic tachycardia (n=2). Group O showed significantly higher percentage (38.5%) of OI than group PO (13.5%) (P=0.039). CONCLUSION: It is suggested that orthostatic testing such as OVSM or head-up tilt table test should be performed as an initial work up for the patients with simple OD. Positional tests for BPPV should be considered as an essential diagnostic test for patients with OD, even though their dizziness is not associated with PD.

Tinnitus in patients with profound hearing loss and the effect of cochlear implantation.

The objectives of this study were to characterize the features of tinnitus in patients with profound sensorineural hearing loss and to evaluate the effect of cochlear implantation (CI) on their tinnitus. Medical records were reviewed for 35 patients who underwent CI, and completed tinnitus questionnaire between March 2003 and August 2011. Of them, 22 had tinnitus prior to CI (62.9 %) and the tinnitus group was older than the non-tinnitus group (47.5 ± 15.1 vs. 28.9 ± 15.2). The mean tinnitus handicap inventory (THI) score of the tinnitus group was 50.5 ± 28.7 before surgery, and the mean THI score and visual analogue scale (VAS) scores for loudness, annoyance, effect on life, and awareness decreased significantly after CI, with a mean follow-up period of 10.7 months. Tinnitus was completely eliminated in ten patients (45.5 %) and THI scores decreased in all patients. In a correlation analysis of the decrease in THI scores, preoperative VAS scores for loudness, awareness, effect on life, and annoyance, as well as preoperative THI scores, were highly correlated with the degree of decrease in THI scores postoperatively. The auditory performance of patients older than 40 years did not differ from that of younger patients, but their tinnitus was more improved after CI. In conclusion, tinnitus is a common complaint in patients with cochlear implants, and is more prevalent in elderly implantees. In the present study, CI improved tinnitus in all patients, although the most severe cases had the greatest benefit.

Role of the Paf1 complex in the maintenance of stem cell pluripotency and development.

Cell identity is determined by the transcriptional regulation of a cell-type-specific gene group. The Paf1 complex (Paf1C), an RNA polymerase II-associating factor, is an important transcriptional regulator that not only participates in transcription elongation and termination but also affects transcription-coupled histone modifications and chromatin organisation. Recent studies have shown that Paf1C is involved in the expression of genes required for self-renewal and pluripotency in stem cells and tumorigenesis. In this review, we focused on the role of Paf1C as a critical transcriptional regulator in cell fate decisions. Paf1C affects the pluripotency of stem cells by regulating the expression of core transcription factors such as Oct4 and Nanog. In addition, Paf1C directly binds to the promoters or distant elements of target genes, thereby maintaining the pluripotency in embryonic stem cells derived from an early stage of the mammalian embryo. Paf1C is upregulated in cancer stem cells, as compared with that in cancer cells, suggesting that Paf1C may be a target for cancer therapy. Interestingly, Paf1C is involved in multiple developmental stages in Drosophila, zebrafish, mice and even humans, thereby displaying a trend for the correlation between Paf1C and cell fate. Thus, we propose that Paf1C is a critical contributor to cell differentiation, cell specification and its characteristics and could be employed as a therapeutic target in developmental diseases.

Validity of Rapid Antibody Testing for COVID-19 Vaccine in Homeless People.

(1) Background: There is a paucity of data regarding the validity of rapid antibody testing for SARS-CoV-2 vaccine response in homeless people worldwide. The objective of this study was to evaluate a rapid SARS-CoV-2 IgM/IgG antibody detection kit as a qualitative screen for vaccination in homeless people. (2) Methods: This study included 430 homeless people and 120 facility workers who had received one of BNT162b2, mRNA-1273, AZD1222/ChAdOx1, or JNJ-78436735/AD26.COV2.5 vaccines. They were tested for IgM/IgG antibodies to the SARS-CoV-2 spike protein with the STANDARD™ Q COVID-19 IgM/IgG Plus Test (QNCOV-02C). ELISA/competitive inhibition ELISA (CI-ELISA) was subsequently run to assess the validity of the serological antibody test. (3) Results: The sensitivity of homeless people was 43.5%. The status of homelessness was related to a lower agreement between serological antibody testing and CI-ELISA (adjusted OR (aOR), 0.35; 95% CI, 0.18-0.70). However, the Heterologous boost vaccine presented higher agreement between serological antibody testing and CI-ELISA (adjusted OR (aOR), 6.50; 95% CI, 3.19-13.27). (4) Conclusions: This study found weak agreement between the rapid IgG results and confirmatory CI-ELISA testing in homeless people. However, it can be used as a screening test for the acceptance of homeless people with heterologous boost vaccination in facilities.

Korean clinical practice guidelines: otitis media in children.

Acute otitis media (AOM) and otitis media with effusion (OME) are common infections in children, and their diagnosis and treatment have significant impacts on the health of children and the costs of providing national medical care. In 2009, the Korean Otologic Society organized a committee composed of experts in the field of otolaryngology, pediatrics, and family medicine to develop Korean clinical practice guidelines (CPG) for otitis media in children with the goal of meeting regional medical and social needs in Korea. For this purpose, the committee adapted existing guidelines. A comprehensive literature review was carried out primarily from 2004 to 2009 using medical search engines including data from Korea. A draft was written after a national questionnaire survey and several public audits, and it was editorially supervised by senior advisors before publication of the final report. These evidence-based guidelines for the management of otitis media in children provide recommendations to primary practitioners for the diagnosis and treatment of children younger than 15 yr old with uncomplicated AOM and OME. The guidelines include recommendations regarding diagnosis, treatment options, prevention and parent education, medical records, referral, and complementary/alternative medicine for treating pediatric otitis media.

Preauricular sinus: advantage of the drainless minimal supra-auricular approach.

OBJECTIVES: We performed this study to introduce our minimal supra-auricular approach for the surgical management of a preauricular sinus (PAS) and to evaluate the advantages of this drainless technique. STUDY DESIGN: This was a retrospective study. SETTING: The study was done in a tertiary referral center. METHODS: We enrolled 94 patients (101 ears) with a PAS who underwent surgical treatment via a minimal supra-auricular approach performed by one surgeon between April 1999 and May 2010. After removing the specimen, meticulous subcutaneous suturing and no drain were used in 83 patients (89 ears) and a postoperative drain was inserted in 11 patients (12 ears). Surgical outcomes of this technique were compared between the groups with and without postoperative drain insertion. RESULTS: With a good surgical view and meticulous subcutaneous mattress sutures in our minimal supra-auricular approach for PAS excision, there was no postoperative recurrence or other serious complication. In the drain group, previous operation history was more frequent (P = .010), and the rate of preoperative infection was higher than in the drainless group (P = .018). Postoperatively, a compression dressing was required more frequently (P = .002) and for longer in the drain group (P = .001). The rate of immediate postoperative wound infection was higher in the drain group (P = .003). CONCLUSION: Our drainless minimal supra-auricular approach for the surgical removal of a PAS has advantage in terms of good surgical results of no recurrence and is more comfortable for patients because of the reduced need for a compression dressing. We suggest that this technique is effective and safe for PAS excision.

Pat- and Pta-mediated protein acetylation is required for horizontally-acquired virulence gene expression in Salmonella Typhimurium.

Salmonella Typhimurium is a Gram-negative facultative pathogen that causes a range of diseases, from mild gastroenteritis to severe systemic infection in a variety of animal hosts. S. Typhimurium regulates virulence gene expression by a silencing mechanism using nucleoid-associated proteins such as Histone-like Nucleoid Structuring protein (H-NS) silencing. We hypothesize that the posttranslational modification, specifically protein acetylation, of proteins in gene silencing systems could affect the pathogenic gene expression of S. Typhimurium. Therefore, we created acetylation-deficient mutant by deleting two genes, pat and pta, which are involved in the protein acetylation pathway. We observed that the pat and pta deletion attenuates mouse virulence and also decreases Salmonella's replication within macrophages. In addition, the Δpat Δpta strain showed a decreased expression of the horizontally-acquired virulence genes, mgtC, pagC, and ugtL, which are highly expressed in low Mg2+. The decreased virulence gene expression is possibly due to higher H-NS occupancy to those promoters because the pat and pta deletion increases H-NS occupancy whereas the same mutation decreases occupancy of RNA polymerase. Our results suggest that Pat- and Pta-mediated protein acetylation system promotes the expression of virulence genes by regulating the binding affinity of H-NS in S. Typhimurium.

Effects of a tumor necrosis factor-α antagonist on experimentally induced rhinosinusitis.

This prospective, randomized, and controlled study examined the effects of tumor necrosis factor soluble receptor type I (sTNFRI, a TNF-α antagonist) on experimentally induced rhinosinusitis in rats. The experimental groups received an instillation of lipopolysaccharide (LPS) plus an intramuscular injection of amoxicillin/clavulanate (antibiotic group), an instillation of sTNFRI (sTNFRI group), an instillation of sTNFRI and an injection of amoxicillin/clavulanate (sTNFRI/antibiotic group), or no additional treatment (LPS group). Histopathological changes were determined using hematoxylin-eosin and periodic acid-Schiff (PAS) staining. Leakage of exudate was determined using fluorescence microscopy. Vascular permeability was measured using the Evans blue dye technique. Expression of MUC5AC was measured using reverse transcriptase PCR. The sTNFRI, antibiotic, and sTNFRI/antibiotic groups had significantly less capillary permeability, mucosal edema, PAS staining, and expression of MUC5AC than the LPS group. There were no differences in capillary permeability, mucosal edema, PAS staining, and MUC5AC expression between the sTNFRI and sTNFRI/antibiotic groups. The antibiotic group had PAS staining similar to that of the sTNFRI and sTNFRI/antibiotic groups but had a greater increase in capillary permeability, mucosal edema, and MUC5AC expression. This study shows that sTNFRI reduces inflammatory activity and mucus hypersecretion in LPS-induced rhinosinusitis in rats.

Prevalence and significance of high-frequency hearing loss in subjectively normal-hearing patients with tinnitus.

OBJECTIVES: We investigated the incidences of high-frequency hearing loss (HFHL; above 2 kHz) and extended high-frequency hearing loss (EHFHL; above 8 kHz) in patients with tinnitus and subjectively normal hearing, and evaluated their effects on the clinical and audiological features of the patients. METHODS: The sample included 85 patients with sensorineural tinnitus who had normal hearing sensitivity in the frequencies from 250 Hz to 2 kHz, and who had undergone extended high-frequency audiometry between July 2009 and February 2010. We investigated the incidences of HFHL and EHFHL in these patients and analyzed the significance of the hearing losses. RESULTS: The incidence of HFHL or EHFHL was 88%. The proportion of patients with EHFHL, among the patients who had normal hearing sensitivity up to 8 kHz, was about 74%. The patients with normal hearing sensitivity at all test frequencies were significantly younger, had larger otoacoustic emissions, and had tinnitus that was less loud as measured by tinnitus matching than did the subjects with HFHL and/or EHFHL. However, other comparisons of clinical factors in the three groups did not show any differences. CONCLUSIONS: Even if patients with tinnitus do not have any subjective hearing impairment, most of them have HFHL and/or EHFHL. The effects on the clinical features of the patients are still vague.

Tinnitus in patients with chronic otitis media before and after middle ear surgery.

The objective of this study was to investigate the clinical features of tinnitus in patients with chronic otitis media (COM) and to evaluate changes in tinnitus following middle ear surgery in relation to audiologic outcome. Medical records were reviewed for 117 patients with COM who underwent middle ear surgery between March 2009 and March 2010. Of them, 44 patients who pre-operatively reported tinnitus on a tinnitus questionnaire and 28 patients who completed a tinnitus questionnaire 8 weeks after surgery were evaluated to determine the clinical characteristics of tinnitus in patients with COM and any change in tinnitus following middle ear surgery, respectively. New tinnitus symptoms that developed after surgery were also evaluated in previously asymptomatic patients. The pre-operative incidence of tinnitus in patients with COM was 43% (50/117), with 87% of these patients displaying sensorineural tinnitus. After middle ear surgery, tinnitus handicap inventory scores were reduced in 82% of patients (23/28). Mean values of loudness, annoyance, effect on life, and awareness of tinnitus were also significantly reduced. One patient displayed newly developed tinnitus after surgery. Analysis of the relationship between improvement in tinnitus and audiologic outcome demonstrated that the group of patients whose tinnitus handicap inventory was reduced by more than 10 showed significantly greater improvements in mean air-conduction thresholds than did patients in the other group. In conclusion, following middle ear surgery, most patients experienced a reduction in tinnitus and restored hearing, with surgery perceived as an important contributory factor.

Effect of central corneal thickness on intraocular pressure with the rebound tonometer and the applanation tonometer in normal dogs.

OBJECTIVE: To evaluate the effect of central corneal thickness (CCT) on the measurement of intraocular pressure (IOP) with the rebound (TonoVet(®)) and applanation (TonoPen XL(®)) tonometers in beagle dogs. ANIMAL STUDIED: Both eyes of 60 clinically normal dogs were used. PROCEDURES: The IOP was measured by the TonoVet(®), followed by the TonoPen XL(®) in half of the dogs, while the other half was measured in the reverse order. All CCT measurements were performed 10 min after the use of the second tonometer. RESULTS: The mean IOP value measured by the TonoVet(®) (16.9 ± 3.7 mmHg) was significantly higher than the TonoPen XL(®) (11.6 ± 2.7 mmHg; P < 0.001). The IOP values obtained by both tonometers were correlated in the regression analysis (γ(2) = 0.4393, P < 0.001). Bland-Altman analysis showed that the lower and upper limits of agreement between the two devices were -0.1 and +10.8 mmHg, respectively. The mean CCT was 549.7 ± 51.0 µm. There was a correlation between the IOP values obtained by the two tonometers and CCT readings in the regression analysis (TonoVet(®) : P = 0.002, TonoPen XL(®) : P = 0.035). The regression equation demonstrated that for every 100 µm increase in CCT, there was an elevation of 1 and 2 mmHg in IOP measured by the TonoPen XL(®) and TonoVet(®), respectively. CONCLUSIONS: The IOP obtained by the TonoVet(®) and TonoPen XL(®) would be affected by variations in the CCT. Therefore, the CCT should be considered when interpreting IOP values measured by tonometers in dogs.