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Diaton Tonometer Clinical Trials Guide

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Diaton Tonometer Clinical Trials Guide

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  1. Diaton Tonometer Clinical Trials Guide: A summary of 15 Clinical Comparison Trials Related to Diaton Transpalpebral & Transscleral Tonometer vs Goldmann, Tonopen, Non-contact, Ocular Response Analyzer, Perkins and Pascal Dynamic Contour Tonometers in Normal, Glaucoma, Keratoconus, post LASIK and post KPro Type 1 subjects + Reviews, Testimonials, Manuals & User Guides, Videos: •Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry. J Ophthalmol. 2015;2015:683895. doi: 10.1155/2015/683895. Epub 2015 Jun 8. http://www.ncbi.nlm.nih.gov/pubmed/26167293 •Diaton Tonometer use in Boston KPro Type 1. Clinical Study from University of Illinois at Chicago: Agreement among Transpalpebral,Transcleral and Tactile Intraocular Pressure Measurements in Eyes with Type 1 Boston Keratoprosthesis •Diaton tonometer in Keratoconus study: Tonometric Values of Intraocular Pressure, Using the Goldmann Tonometer, Tonopen and Diaton Transpalpebral Tonometer in Keratoconus •Clinical Comparison of 3 tonometers: Comparative Agreement Among Three Methods of Tonometry: Goldmann Applanation, Transpalpebral and Dynamic Contour •Diaton tonometer use post LASIK: Diaton tonometer for intraocular pressure measurements after laser in situ keratomileusis •Additional trials/articles can be found here: http://www.tonometerdiaton.com/index.php?do=home.Comparison_clinical_trials_Diato n_Tonometer_Goldmann_Tonopen_Applanation_Tonometers •Instructions Videos and step-by-step Easy to follow picture guides + Quick User Guide+ Training videos can be found here: https://tonometry.wordpress.com/2015/05/19/diaton-

  2. tonometer-manual-quick-user-guide-how-to-use-diaton-tonometer-user-videos-helpful-tonometer-manual-quick-user-guide-how-to-use-diaton-tonometer-user-videos-helpful- tips/ •The following video would give you a great overview to see how quick and easy the test really is: https://www.youtube.com/watch?v=Mfu2leF4UYw •Testimonial: Review of Advantages and Benefits of DIATON Tonometer by Dr Mark Latina and Dr Emil Chynn http://www.tonometerdiaton.com/index.php?do=home.viewNews&item=Review_Diaton _Tonometer_by_Dr_Mark_Latina_Dr_Emil_Chynn_Advantages_Benefits Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry,

  3. Noncontact Tonometry, and Transpalpebral Tonometry. http://www.ncbi.nlm.nih.gov/pubmed/26167293 Cacho I1, Sanchez-Naves J1, Batres L2, Pintor J3, Carracedo G4. Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers. Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers. •Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (p < 0.05). However, no significant differences were found (p > 0.05) for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery (p < 0.05) but no statistical differences were found in SCT (p = 0.08). Correlations between pre- and postsurgery were found for all tonometers used, with p = 0.001 and r = 0.434 for the air pulse tonometer, p = 0.008 and r = 0.355 for Perkins, and p < 0.001 and r = 0.637 for Diaton. Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment. PMID: 26167293 [PubMed] PMCID: PMC4475733 Agreement among Transpalpebral,Transcleral and Tactile Intraocular Pressure Measurements in Eyes with Type 1 Boston Keratoprosthesis Jessica L.Liu,Thasarat S.Vajaranant,Maria S.Cortina,Jacob T.Wilensky. Glaucoma, University of Illinois at Chicago, Chicago, IL Purpose: The use of keratoprostheses (KPro) to restore vision in eyes with corneal opacities has become increasingly popular in the last five years. Intraocular pressure (IOP) is a cardinal measurement employed in glaucoma management. This presents a major problem since glaucoma remains a major visual limiting factor in eyes with KPro and most forms of tonometry require an intact cornea. The purpose of this study is to determine if transpalpebral IOP measurement can be an alternative method of measuring IOP and yield valuable data in eyes with KPro. Methods: We retrospectively reviewed IOP measurements in patients who had received Type 1 Boston KPro, and their IOP were estimated by three different methods during routine visits to their cornea! surgeon. The surgeon estimated the IOP range tactilely by palpation of the globe. A pneumatonometer (Model 30 Classic; Mentor, BioRad, Santa Ana, California, USA) was used to measure IOP by placing the tonometer tip on the sclera peripherally to the contact lens in the inferotemporal quadrant. The Diaton tonometer (BiCOM, Inc., Long Beach, NY, USA) was used to obtain values through the upper lid in accordance with the instructions by the manufacturer. An average of two Diaton IOP measurements was used in the analysis. Since the tactile IOP were recorded as a range rather than a definite number, we computed the percent agreement, the percentage of eyes in which pneumatometer or Diaton lOPs were within 2 mmHg of the tactile IOP range. Two-tailed t-test was used to compare the mean of pneumatonometer and Diaton IOP measurements. Results: The analysis included 23 eyes of 20 patients. The percentage agreement was 85% between tactile range and pnematonometer lOPs, and 95% between tactile range and Diaton lOPs. Pneumatonometer consistently yielded higher IOP values, compared to

  4. Diaton (p=0.04). The overall IOP mean ± SD was 17.2 ± 6 mmHg for pneumatonometer and 13.8± 5 mmHg for Diaton tonometer. Conclusions: The presence of KPro did not appear to interfere with IOP with Diaton tonometer, and Diaton tonometer yielded IOP readings that were similar to those obtained by palpation. Scleral pneumotonometry yielded values that were consistently higher than tactile estimates and Diaton IOP. In addition to routine IOP estimates by palpation, transcleral and transpalpebral IOP measurements can be considered to monitor patients with KPro. Influence of Corneal Thickness on Tonometrical Values of Intraocular Pressure,using the Goldmann tonometer and transpalpebral Diaton tonometer Federal University of São Paulo – Paulista School of Medicine Department of Ophthalmology and Visual Sciences, Felipe Taveira Daher, MD, Augusto Paranhos Junior,MD, PhD Introduction: The corneal thickness is one of the factors having influence on the tonometrical values. Keratoconus usually evolutes with decrease of corneal thickness and, as a consequence, the tonometrical values may underestimate the real intraocular pressure. The transpalpebral tonometer diaton surges as an equipment that may not be influenced by the corneal thickness and obtain tonometrical values closer to the real intraocular pressure. Purpose: Compare intraocular pressure values acquired by three different tonometers (Goldmann,Tonopen and transpalpebral diaton tonometer) in patients in two groups: control group and keratoconus patients. And evaluate the influence of corneal thickness on each tonometer. Material and methods: Patients were divided into two groups: the control group, with patients without keratoconus or corneal thinning, and the keratoconus group, with patient with keratoconus or corneal thinning. Patients were than submitted to an OCT pachymetry and the intraocular pressure were measured by three tonometers under the study (one measure with Goldmann tonometer and Tonopen, three measures with transpalpebral tonometer). After that, ophthalmic glycerol was applied on the corneal surface and the OCT pachymetry were repeated after five minutes. Finally, the intraocular pressure values were measured again, with the Tonopen and transpalpebral tonometer, one and three retrospectively. There were fourteen volunteers on the control group and twelve volunteers on the keratoconus group. The concordance evaluation between the two groups was made using the Blant-Altman graphic and the interclass correlation coefficient evaluation between three different tonometers independently of the group was made. Results:

  5. The interclass correlation coefficient was satisfactory for the three measures with the transpalpebral tonometer (0.88- CI: 0.80 to 0.92), but not satisfactory among the three tonometers (0.60 – CI: 0.35 to 0.76). The regression analysis of the differences shows a trend of the discordance on the extreme values of the Tonopen and the transpalpebral tonometer comparing to the Goldmann tonometer. For the lowest intraocular pressures the transpalpebral tonometer trends to measure the pressure higher and, for the highest pressures, the transpalpebral tonometer trends to measure lower, which is the same for Tonopen, independently of the group, however the lower intraocular pressure were of the keratoconus group. Conclusion: The measures of the transpalpebral tonometer show satisfactory reproducibility and their concordance with the Goldmann, mainly in the patients with keratoconus on which the pressure values were higher than the Goldmann, may trend to measure a value closer to the real intraocular pressure, as the Goldmann tonometer underestimates the intraocular pressure on patients with keratoconus. Tonometric Values of Intraocular Pressure, Using the Goldmann Tonometer, Tonopen and Diaton Transpalpebral Tonometer in Keratoconus Comparison of Accuracy of diaton Transpalpebral Tonometer Versus Goldmann Applanation Tonometer,Dynamic Contour Tonometer and Ocular Response Analyzer Henry D Perry,MD,Valeriy Erichev,MD PhD; E.S. Avetisov MD;Alla Illarionova,MD, Alexey Antonov MD PURPOSE: To compare intraocular pressure measurements obtained with the diaton transpalpebral tonometer with those from ocular response analyzer (ORA), dynamic (should be in same order as title)contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in patients diagnosed with primary open-angle glaucoma (POAG) and glaucoma suspects, and to determine the effects of central corneal thickness (CCT) and corneal hysteresis (CH) on intraocular pressure (IOP) measurements with these devices. METHODS: 40 patients (80 eyes) age 42-83 years with POAG and glaucoma suspects were included in the study. The average of ORA (corneal compensated IOP [IOP- ORAcc] and Goldmann-correlated IOP [IOP-ORAg]), DCT, GAT, and Diaton tonometer levels were compared and the devices were examined with respect to CCT and CH. Spearman's correlation tests were used for statistical analysis. RESULTS: Mean CCT was 561,2±32,4mum and mean CH was 10.6+/-2.0 mmHg. Mean IOP obtained using DCT was 18,9±4,1 mmHg, whereas those provided by ORA were 18,2±3,4 mmHg for IOP-ORAcc and 18,4±3,5 mmHg for IOP-ORAg. The mean IOP obtained using GAT and Diaton were 18,4±4,1 mmHg and 17,0±3,0 mmHg respectively.The performed analysis of correlation between IOP meanings shows high conformity of results of Diaton with IOP-ORAcc and DCT. The differences between the measurements of DCT, ORA and Diaton were statistically significant. Correlated rates relations: between IOP-ORAcc and DCT 0,89; between IOP-ORAcc and Diaton 0,96; IOP-ORAcc and GAT 0,56; between GAT and Diaton 0,61; GAT and DCT 0,73; DCT and Diaton 0,87.

  6. CONCLUSIONS: Transpalpebral Tonometry is an accurate method of IOP measurement that is also independent from the biomechanical characteristics of cornea. It can be recommended for IOP measurements of patients diagnosed with glaucoma including those cases where cornea pathology or cornea characteristics have been altered. COMPARATIVE AGREEMENT AMONG THREE METHODS OF TONOMETRY: GOLDMANN APPLANATION, TRANSPALPEBRAL AND DYNAMIC CONTOUR LUIS A. ZARATE,Magdalena García-Huerta,Rafael Castañeda Diez,Mauricio Turati,Felix Gil Carrasco,Jesus Jimenez-Roman,Jose A. Paczka.1GLAUCOMA,ASOCIACION PARA EVITAR LA CEGUERA EN MEXICO,Mexico;2.Glaucoma;3.Asistencia e Investigacion en Glaucoma Purpose: To investigate agreement of intraocular pressure (IOP) as measured by the Goldmann applanation tonometer (GAT), the Pascal dynamic contour tonometer (DCT), and Diaton transpalpebral tonometer (DTT). Methods: Device agreement was calculated by Bland-Altman analysis in 77 eyes of 40 individuals (mean age 58.9 ± 13 years) with a mixed diagnosis of glaucoma suspicion and primary open-angle glaucoma. All measurements were performed in a random order by the same clinician according to standard procedures. Results: Mean IOPs ± S.D. were 14.4 ± 2.9 mm Hg (GAT), 18.8 ± 3.2 mm Hg (DCT; P = 0.005, ANOVA), and 15.1 ± 3.1 mm Hg (DTT). Bland-Altman analysis demonstrated that, on average, DCT IOP measurements overestimated in approximately 3 mm Hg, values derived from GAT and DTT, although agreement was fairly good. Conclusions: All methods of tonometry were adequate to measure IOP in our sample. Agreement among devices was considered good;nevertheless, DCT values of IOP were significantly higher as compared to the other two assessed methods. Clinical study of the influence of the anti-hypertensive drugs on the intraocular pressure level with Non-Corneal Through-The-Eyelid Diaton Tonometer Illarionova A, Ivanov S, Savenkov M Aim: To analyze the influence of the anti-hypertensive medicines on the intraocular pressure (IOP) level in patients. Material and methods: 82 patients with arterial hypertension of the 1-st and 2-nd degree with high cardiovascular risk, 10 patients from this group had the Primary open-angle glaucoma. We used diuretics (Hydrochlorothiazide 12,5-25 mg/day), calcium channel-blocking agents (Amlodipine 2,5-5 mg/day), beta-adrenergic blocking agents (Bisoprolol 2,5-5 mg/day), inhibitors of angiotensin converting enzyme (iACE) (Enalaprilum 5-10 mg/day), nitrates (Isosorbide mononitrate 40-50 mg/day and Isosorbide dinitrate (1,25 mg/day). All the patients were measured IOP with transpalpebral Diaton tonometer before taking the medications, 3 and 24 h after taking the drugs and after 7-14 days. The IOP was measured initially during the use of Isosorbide dinitrate as the spray (ISOKET) 30, 60 and 90 min after taking it. Results: The reliable change of IOP wasn’t detected in patients who were taking diuretics, calcium channel inhibitors, iACE and B1-adrenergic blocking agents neither during the acute pharmacological testing, nor during the intake of the anti- hypertensive drugs. The IOP reduction was found during the intake of the B2-adrenergic blocking agents (mean initial IOP 19,2±1,3 mmHg, mean IOP after 7-14 days 16,3±1,4

  7. mmHg). The increase of IOP was observed during the intake of the nitrates (mean initial IOP 18,8±1,2 mmHg, mean IOP after 7-14 days 23,8±1,3 mmHg). According to the results of the acute pharmacological testing the IOP increase was observed 40 min after the intake of one dose (1,25 mg) of Isosorbide dinitrate and remained increased up to 1,5 hours on patients with POAG (mean initial IOP 22,7±1,8 mmHg, IOP after 40 min 26,1±1,9 mmHg, IOP after 90 min 25,8±1,9 mmHg). Conclusions: Portable, ergonomic ophthalmo-tonometer diaton suits perfectly in general medical practice for IOP monitoring to make anti-hypertensive drugs treatment safe. Transpalpebral tonometer application during intraocular pressure evaluation in the patients with refraction anomaly before and after keratophotorefractive surgery by Prof. A.P. Nesterov, MD., T.B. Dzhafarli, MD., A.R.Illarionova, MD. Russian State Medical University, Moscow. Great success of the modern keratorefractive surgery, especially excimerlaser cornea microsurgery (FRК, LASIK, LASEK, Epi-LASIK) and its wide spread require high attention to the eye morphophysiological rates in pre- and postoperational period. The most important rates are still the characteristics of the cornea, such as thickness and its changes, regenerative response of corneal tissue and its regulation, as well as the data of intraocular pressure (IOP) and their correlation with cornea metrical rates. According to the data of numerous investigations, underestimation of IOP level during applanation tonometry in patients, which were subject to keratophotorefractive surgeries, is of great importance in glaucoma diagnostic search. Hence, the advantages of scleral tonometry application in this category of patients for ophthalmotone appropriate evaluation and timely ophthalmohypertension detection are clear. Purpose The purpose of the study is to evaluate the clinical use of transpalpebral scleral tonometry, reliability of its application in the patients with refraction anomaly in pre- and postoperational period, dynamics of eye morphometric rates (pachymetry of the central corneal zone, IOP) and their correlative bond before and after photorefractive surgeries. Methods We have analyzed the results of prospective comparative case series clinical study in 98 patients (194 eyes) with ametropia of various degrees, among which 59 persons (118 eyes) form the group of patients, who have no keratophotorefractive surgeries in past history, and 39 patients (76 eyes), which were the subject to excimerlaser vision correction (Epi-LASIK, LASIK, FRK) with various length of postoperational period from 7 days to 4 years. The patients age distribution was from 18 to 53 years, the women make 61%, the men - 39%. The following factors were exclusion criteria from the study: Cornea pathology, influencing prognosticly the applanation tonometry results; Upper eyelid and sclera pathology, which are the contraindications for transpalpebral diaton- tonometry.

  8. Before and after the surgery all patients were subject to the complete refractive examination, including keratotopography and wavefront-aberrometry (AMO, USA). In a number of patients for cornea state morphologic evaluation we conducted US-biomicroscopy of the corneal optical zone before and in two months after laser correction (Picture 1). Before and after surgery we trice measured pachymetry corneal thickness in central (4 points) zone - central corneal thickness (CCT) in each patient. We realized the study using two devices: US-pachymeter UP 1000 by NIDEK (Japan) and А-scan-pachymeter P55 by Paradigm (USA). IOP was measured with Goldmann applanation tonometer (Rodenstok, Germany), pneumotonometer (NIDEK, Japan) and transpalpebral scleral diaton tonometer (RSIME, Russia, picture 2) using traditional methodology (picture 3), all ophthalmotone measurements were realized the patients being in the sitting position with time interval being 2-3 minutes between two investigators. The surgeries were carried out using excimer laser VISX Star S4 IR (AMO, USA), microkeratome LSK Evolution II (Moria, France) and epikeratome Centurion SES (Norwood, Australia) Statistical treatment of the received results was realized using common methods of medical mathematical statistics. Statistic calculations were carried out using "Analysis Tools Pack". Determination of differences reliability between the groups being compared in the presence of normal distribution in sampling of one-type factors was realized using two-sample t-tests. Correlation analysis by Pearson allowed detecting the character of correlations between showings. Correlation with Р<0,05 was considered to be reliable. Results and discussion In 93,6% cases visual acuity without correction after surgery was 0,6 - 1,0 (Table 1) in the early postoperative period. Results of the study are shown in Tables 2 and 3. While analyzing morphometric parameters in the group of patients which were not the subject to photorefractive surgeries the mean PCT value was 554,5±32,4 m, and the mean value of applanational IOP - 16,1±2,6 mm Hg, the fluctuation being from 10 to 21 mm Hg; mean ophthalmotone level evaluated with diaton tonometer - 14,7±2,5 mmHg, the fluctuation being from 9 to 20 mmHg. At that correlation between values of the applanation tonometer and transpalpebral scleral diaton tonometer was highly reliable (r = 0,73, р±0,005). To define the advantages of scleral tonometry in comparison with the traditional keratoapplanational method we made calculations of real ophthalmotone in the patients of this group taking into account pachymetry (PCT), ophthalmometry and applanation tonometry data. Mean value of the real IOP after applanation value converting was 15,4±2,4 mmHg. Pearson correlation coefficient between real IOP (modified result, received with applanation tonometry) and the value, determined with diaton tonometer was 0,89, р<0,005, which shows high reliability of transpalpebral scleral tonometry. In the groups of patients, underwent photorefractive vision correction, mean PCT was 499,8±50,9 m (fluctuations from 407 to 513 m), mean applanation value of IOP - 12,4±2,91 mmHg (fluctuations from 7 to 20 mm Hg), modified taking into account keratometry IOP rates - 13,9±3,0 mm Hg, mean diaton-tonometry result - 15,1±2,75 mm Hg. At that we notice approximation of diaton-tonometry figures to the modified applanation IOP value taking into consideration keratometric rates - increase of correlation coefficient from 0,51 to 0,81 (table 4).

  9. Correlation analysis of PCT and IOP results in the group of patients, examined both in preoperational period and after photorefractive vision correction showed reliability of this correlation, p<0,005, reduction of IOP for 1 mm Hg is registered PCT being decreased for 29,7 m. At that difference between pre- and postoperational IOP during applanation tonometry was 3,5 mm Hg, and during diaton-tonometry - 1,8 mm Hg, that is statistically dissimilar (t>2, p<0,005), which shows significant advantage of ophthalmotone evaluation if we omit cornea. Conclusion. Thus, cornea thickness is the important factor of IOP evaluation and monitoring and requires the necessity of including corneal pachymetry in the program of examination the patients with suspicion of glaucoma and hypertension, especially after various keratorefractive surgeries while using the traditional corneal methods of ophthalmotonometry. At the same time clinical application of transpalpebral scleral diaton tonometer makes it possible to evaluate IOP using only one device, the procedure being efficient, economical, simple in performance and requiring no additional instrumental examination. Literature Nesterov A.P. Transpalpebral tonometer for intraocular pressure measuring.// Ophthalmology Bulletin - 2003. - Vol. 119. - №1. - P. 3 - 5. Blaker JW, Hersh PS. Theoretical and clinical effect of preoperative corneal curvature on excimer laser photorefractive keratectomy for myopia.//Refract. Corneal Surg. - 1994;-Vol.10:P. 571-574. Buratto L, Ferrari M, Genisi C. Myopic keratomileuesis with the excimer laser: one-year follow- up.//Refract. Corneal Surg. - 1993;-Vol.9:P.12-19. Cennamo G, Rosa N, La Rana A, et al. Non-contact tonometry in patients that underwent photorefractive keratectomy.//Ophthalmologica.- 1997;-Vol. 211:P.341-343 Duch S, Serra A, Castanera J. Tonometriy after laser in Situ keratomileusis treatment. //J Glaucoma. - 2001. - Vol.10. - P. 261 - 265. Emara B.et al. Correlation of intraocular pressure and corneal thickness in normal myopic eyes and after laser in situ keratomileusis.//J. Cataract. Refract. Surg. - 1998;-Vol.24(10):P. 1320- 1325 Mardelli PG, Piebenga LW, Whitacre MM. The effect of excimer laser photorefractive keratectomy on intraocular pressure measurements using the Goldmann applanation tonometer //Ophthalmol. - 1997. - Vol.104. - P. 945-948. Pandav SS, Ashok Sharma, Amit Gupta. Reliability of Proton and Goldmann applanation tonometers in normal and postkeratoplasty eyes. //Ophthalmol. - 2002. - Vol. 109. - P. 979-984. Simon G, Small RH, Ren Q, et al. Effect of corneal hydration on Goldmann applanation tonometry and corneal topography.//Refract. Corneal Surg.- 1993;-Vol. 9:P.110-117 Vakili R, Choudhri SA, Tauber S, Shields MB. Effect of mild to moderate myopic correction by laser-assisted in situ keratomileusis on intraocular pressure measurements with goldmann applanation tonometer, tono-pen, and pneumatonometer. //J Glaucoma. - 2002. - Vol.11. - N6. - P. 493-496. Whitacre MM, Stein R. Sources of error with use of Goldmann-type tonometers. //Surv Ophthalmol. - 1993. - Vol. 38. - P.1 - 30. Wu X, Liu S, Huang P, Wang P. Analysis of intraocular pressure after myopic photorefractive keratectomy. //Chung Hua Yen Ko Tsa Chih. - 2002. - Vol.38. - N10. - P.603-605. Zadok D, Raifkup F, Landao D. Intraocular pressure after LASIK for hyperopia. //Ophthalmol. - 2002. - Vol. 109. - P.1659-1661. Picture 1 Topographic ultrasonic biomicroscopy of the cornea in optical zone of normal myopia eye (А), after PRK (B) and after LASIK (C)

  10. Cornea, as the basic optical lens of the eye, is the main element to be influenced during various, and first of all laser, surgeries with refractive, reconstructive, optical and other purposes. Picture 2 Transpalpebral scleral diaton tonometer Comparison of the Diaton Transpalpebral Tonometer Versus Goldmann Applanation R. S. Davidson 1; N. Faberowski2 ; R. J. Noecker3 ; M. Y. Kahook1 1. Ophthalmology, Rocky Mountain Lions Eye Institute, Aurora, CO, USA. 2. Ophthalmology, Denver Health Medical Center, Denver, CO, USA. 3. Ophthalmology, UPMC, Pittsburgh, PA, USA. Financial Disclosure The authors have no financial interest in the subject matter being presented Background Diaton tonometry is a unique approach to measuring intraocular pressure (IOP) through the Eyelid. It is a non-contact (no contact with cornea), pen like, hand-held, portable tonometer. It requires no anesthesia or sterilization. Purpose To investigate the agreement in the measurement of intraocular pressure (IOP) obtained by transpalpebral tonometry using the Diaton tonometer versus Goldmann applanation in adult patients presenting for routine eye exams.

  11. Methods Retrospective chart review of consecutive IOP measurements performed on 64 eyes of 32 patients age 34-91 years with both the Diaton tonometer and Goldmann applanation. Results between groups were examined using analysis of variance (ANOVA) where appropriate. Results Mean IOP was 15.09 +/-4.31 mm Hg in the Goldmann group and 15.70 +/-4.33 mm Hg in the Diaton group (p=0.43). Mean IOP variation between groups was 1.74 +/-1.42 mm Hg (range 0-8). 83% of all measurements were within 2 mm Hg of each other. Conclusions The transpalpebral method of measuring IOP with the Diaton tonometer correlates well with Goldmann applanation. Diaton applanation may be a clinically useful device for measuring IOP in routine eye exams. http://tonometerdiaton.com/index.php?do=home.Comparison_Study_Diaton_Tonometer_ Goldmann Comparison of the Diaton Transpalpebral Tonometer Versus Tono-Pen Applanation Theodore H. Curtis, M.D.1, Douglas L Mackenzie, M.D.1, Robert J. Noecker M.D.2, and Malik Y. Kahook M.D.1 1The Rocky Mountain Lions Eye Institute, University of Colorado Health Sciences Center, Aurora, CO 2Eye and Ear Institute, University of Pittsburgh Medical Center, Pittsburgh, PA Financial Disclosures · None of the authors have financial interests relevant to the supject discussed. Purpose · To compare intraocular pressure (IOP) measurements obtained with Diaton trans- palpebral tonometry versus Tonopen applanation tonometry in children and adults. Introduction · Goldmann applanation is the gold standard for IOP measurement · It has been supplanted by TonoPen applanation in many settings because of it's ease of use, portability, convenience, and minimal training requirements. · The TonoPen requires contact with the corneal surface, and has the risks of iatrogenic corneal injury, spread of pathogens, and requires topical anesthetics. Introduction · The newly-developed Diaton tonometer is a handheld device that measures pressure through the tarsal plate (Figures 1 & 2). · It avoids contact with the cornea and the need for topical anesthesia. Figure 1: The Diaton Transpalpebral Tonometer Figure 2: Using the Diaton Tonometer Methods

  12. · We looked at 74 eyes of 38 consecutive patients who received both Tonopen and Diaton tonometry · TonoPen measurements were taken in the sitting position following topical anesthesia with proparicaine. · Diaton measurements were performed in the sitting position with the patient gazing at a 45o angle, placing the eyelid margin at the superior limbus. If necessary, gentle traction was placed on the brow to align the lid with the limbus. The device was activated when the signaling mechanism indicated the device was vertical. Results · Age range 3-91 years of age (mean 47.5 years). · The average IOP with the Diaton was 16.24 (+/-5.11 mm Hg; range = 7-32 mmHg). · The average IOP with the TonoPen was 16.37 (+/-4.90 mm Hg; range = 8-33 mmHg). · The mean variation between the two modalities was 1.59 mmHg (+/-1.31 mm Hg; range = 0-6 mmHg). · Eighty-one percent of all measurements were within 2 mmHg of each other (Table 1). · There was no statistically significant difference in mean IOP values obtained with the two devices (p=0.87). Table Conclusions · The Diaton tonometer pressure measurements correlated well with TonoPen measurements in this retrospective review. · We did not find problems performing the exam in children, and many were reassured by the fact that no drops were needed. · There may be a notable benefit in patients after refractive surgery or with corneal pathology since the Diaton does not applanate the cornea. · The Diaton tonometer appears to be a clinically useful device in the IOP measurement of both children and adults. References · Li J, Herndon LW, Asrani SG, Stinnett S, Allingham RR. Clinical comparison of the Proview eye pressure monitor with the goldmann applanation tonometer and the TonoPen. Arch Opthalmol 2004;122:1117-21. · Eisenberg DL, Sherman BG, McKeown CA, Schuman JS. Tonometry in adults and children: a manometric evaluation of pneumotonometry, applanation, and TonoPen in vitro and in vivo. Ophthalmology 1998;105:1173-81. · Diaton: digital portable tonometer of intraocular pressure through the eyelid. Operation Manual. Ryazan State Instrument Making Enterprise. Ryazan, Russia. · Garcia Resua C, Giraldez Fernandez MJ, Cervino Exposito A, Gonzalez Perez J, Yebra- Pimentel E. Clinical evaluation of the new TGDc-01 "PRA" palpebral tonometer: comparison with contact and non-contact tonometry. Optom Vis Sci 2005;82:143-50. · Troost A, Yun SH, Specht K, Krummenauer F, Schwenn. Transpalpebral tonometry: reliability and comparison with Goldmann applanation tonometry and palpation in healthy volunteers. Br J Ophthalmol 2005;89:280-3. · Losch A, Scheuerle A, Rupp V, Auffarth G, Becker M. Transpalpebral measurement of intraocular pressure using the TGDc-01 tonometer versus standard Goldmann applanation tonometry. Graefes Arch Clin Exp Opthhalmol. 2005;243:313-6. Test report and a comparison of the pressure measurements of the digital portable tonometer DIATON for the measurement of the intraocular pressure through the eyelid

  13. Ina Conrad-Hegegerer MD., Mr. Fritz Hengerer MD. Eichenstrasse 3, 65468 Trebur, Germany The measurements have been conducted in Germany, in our private doctor's office by Mrs. Ina Conrad-Hegegerer MD. and Mr. Fritz Hengerer MD. The results have been obtained with the following methods: 1.Applanation tonometry by Goldmann(Splitlamp Haag Streit 900) 2.Digital portable Tonometer Diaton 3.Non-Contact tonometry with Niedek Tonometer 1000 The purpose of the measurements is to evaluate the reliability of Diaton in the direct comparison with the already established processes. There were 2 groups of test persons: Healthy subjects and glaucoma patients. Exclusion criteria were: Previous glaucoma patients, eyelid operations or inflammatory states of the front eye section. Furthermore, patients were excluded where a Goldmann tonometry could not be performed (Keratokonus, Epitheledema). The static analysis contains: a) Mean b) Standard deviation c) Median error d) Correlation coefficient (Pearson) Table 1. shows the measurements on healthy patients, Table 2. on those with glaucoma. The results of the statistical analysis are summarized in Table 3. and 4. Summary: The analysis of the measurements confirms the validity of the measurements of the digital portable Tonometer Diaton. TRANSPALPEBRAL TONOMETER FOR INTRAOCULAR PRESSURE MEASURING Eye diseases department of the Russian State Medical University medical faculty, Moscow, Eye tonometry is one of the leading methods used in the patient with ophthalmopathology checkup. The first tonometer acceptable for clinical practice was designed and described in 1884 by A.N.Maklakov [2]. The tonometers introduced earlier had serious drawbacks and were not used in clinical practice. Before this the intraocular pressure (IOP) was evaluated only approximately with the help of eye palpation through the upper eyelid. At present palpation method is still widely used in clinical practice. Using it a skilled ophthalmologist can evaluate approximately whether ophthalmotone is normal (Tn), increased (T+1, T+2) or decreased (T-1, T- 2), distinguish normotension from hyper- or hypotension. The palpation method suffers from subjectivism, uncertainty of results at ophthalmotone moderate change but at the same time it shows the principle possibility of transpalpebral tonometry. Intraocular pressure

  14. The eyeball is a reservoir of the spherical form, filled with fluid, incompressible contents. IOP is caused by the influence of the elastic forces, arising in eye coverings while they are being stretching. IOP level is determined by watery moisture (WM) circulation in an eye and by pressure in episclera veins [3]: PO=F/C+Pv, where PO – IOP; F – WM minute volume; C – coefficient of easiness of WM flow-out from an eye, Pv – pressure in episclera veins. IOP increases while moving from vertical to horizontal position and especially in Trendelenburg position and while squeezing the neck’s veins because of the pressure increasing in episclera veins (Pv) [4]. IOP is a dynamic, continuously changing value. They distinguish its system, rhythmic fluctuations around relatively constant level and momentary changes of casual character. IOP fluctuations around the level depend on changes in bloodfilling of intraocular vessels and on outer pressure on the eyeball. There are 3 types of rhythmic IOP fluctuations around the level [3]: 1.eye pulse (from 0,5 to 2,5 mm Hg), 2.respiratory waves ( from 0 to 1 mm Hg), 3.Hering-Traube waves (from 0 to 2,5 mm Hg). The successive measurings of IOP in the same eye with a tonometer vary from each other mainly due to the ophthalmotone rhythmic fluctuations. Winking, pressing of the eye with orbicular muscle or external muscles of the eyeball momentary increase IOP, provide eye massage and decrease venous congestion. At the same time changes of orbicular and transpalpebral muscles tone during tonometry are often the cause of error while measuring IOP level. Statistically normal IOP varies from 9 to 21 mm Hg (on average 15-16 mm Hg). It has daily and seasonal fluctuations. The IOP distribution in the normal population is asymmetrical (splayed to the right). In middle age the distribution asymmetry increased. More than 3% of healthy persons have IOP above 21 mm Hg [4]. The ophthalmotone measuring accuracy in the area of the normal and reasonably increased (up to 30 mm Hg) IOP is especially important for a practical doctor. Intraocular pressure regulation Each eye is adjusted to a certain IOP level (balance pressure) which is supported by passive and active mechanisms. IOP being increased pressure of moisture flow-out and filtration from an eye increased, WM production being decreased its flow-out decreased and the balance pressure restores. Active mechanisms of IOP regulation have been not enough studied. Collaboration of hypothalamus, adrenal glands, vegetative nervous system and local autoregulatory mechanisms is possible. Opthalmotonometry The IOP measuring is based on the eyeball deformation under the influence of an outer effect. At that the values of deformation (S), the force (W) influencing the eye and IOP (Pt) as a first approximation are connected with each other with the following dependence [5]: Pt = f(W/ S). All tonometers fall into devices: 1) with constant and variable pressure force on the eye, 2) with constant and variable value of eye deformation, 3) corneal, scleral and transpalpebral, (4) applanation, impression and ballistic. Ophthalmotonometers used in the Russian Federation 1.Maklakov tonometer and Filatov-Kalve elastotonometer. 2.Goldmann applanation tonometer (reference)

  15. 3.Perkins and Dregger applanation tonometers 4.Grolman non-contact applanation tonometer, 1972 5.Schiotz impression tonometer 6.diaton transpalpebral tonometer All the tonometers mentioned above (besides diaton) measure IOP through cornea. Advantages and disadvantages of corneal tonometry It is possible to note the following advantages of corneal tonometry: 1) it is more accessible for tonometry on an open eye then sclera; 2) between tonometer and eye cavity there’s no other structures interposition (conjunctiva, eyelid, ciliar body), but cornea; 3) cornea’s individual size, thickness and crookedness are less different in comparison to other parts of eye fibrous membrane. At the same time corneal tonometry has serious drawbacks: 1.Cornea has high pain sensitivity and the tonometry is impossible without prior anesthesia, which in some patients causes conjunctiva irritation, hypostasis of cornea epithelium, short- term IOP increasing, and allergic conjunctivitis. 2.Cornea has regular spherical shape only in the central zone and flattens towards periphery; its thickness increases from 0,5-0,6 mm in the center to 0,8 in the periphery. Besides, the existent individual peculiarities both in cornea’s crookedness and thickness influence significantly on the tonometry results [6, 12]. 3.During the corneal tonometry it is very difficult to prevent the increasing of orbicular and palpebral muscles tone, that leads to IOP increasing. The ophthalmotone increasing may be also connected with the blood pressure increasing during the tonometer’s bringing near the open eye [3]. 4.It is known that a tear may contain bacteria and dangerous viruses (hepatitis B virus, herpes, adenoviruses, AIDS). But the problem of tonometers sterilization is far from perfection [11]. 5.The corneal tonometry is contraindicative in eyelids and cornea edema, nystagmus, conjunctivitis, corneal erosions, keratitis, hypostasis and sores. Diaton tonometer – basic principles Transpalpebral ophthalmic tonometer (diaton) was designed by a group of ophthalmologists and engineers. There was the task to design portable and simple in use device, which could provide IOP measuring through the eyelid not only in ophthalmology studies but at home as well. It should possess enough accuracy, quick operation and provide the possibility to carry out ophthalmotone monitoring that is very important both for glaucoma diagnostics and for controlling the effectiveness of treatment. “Digital Portable Tonometer of Ocular Pressure” (diaton) designed by us fulfills all these tasks (fig.1). Fig.1 The peculiarities of the new tonometer are that IOP measuring is realized through the eyelid that excludes contact with conjuctiva and cornea and does not require anesthetics application. At that the mechanical influence on the eye is realized through the eyelid on sclera. The tonometere’s position while measuring IOP is shown on fig.2.

  16. Fig.2 The measuring principal of the new tonometer is based on processing the rod movement resulting from its free fall and interaction with the elastic surface of the eye to be measured. The main problem was how to exclude the influence of an eyelid individual peculiarities on the tonometry results. This was solved by pressing the eyelid on the area with the diameter of 1,5 mm to such extent that the pressed area of the lead acts like a rigid transfer link while the rod interacts with the eye at the same time excluding the painful sensation. This method of compensating the eyelid influence led to the choose of dynamic (ballistic) way of dosated mechanical influence on the eye for evaluating its elastic peculiarities. To determine the position in the process of its free fall from the constant height and the interaction with eye through the eyelid the device has position sensor. Value of the points of the rod movement function in time is remembered by the built-in processor. In diagram form the function of the rod movement in time is shown in fig.3. Fig.3 Function of the rod movement in time: H – change in the rod position during the free fall, t – time after the fall starting, B – minimum point of the rod movement function. For point B the following equation is true: P=F/S, where P – IOP, F – eye elasticity force, influencing the rod, S – the area of eye and rod interaction (area of its square). According to Newton’s second law: F=m*a, where m – the rod’s weight, a – the rod’s acceleration while interacting with the eye elastic surface. Then P=m*a/S. The rod’s weight and the interacting

  17. area - S are constants So to evaluate P it is enough to measure the rod movement acceleration (a) in point B. Errors of IOP measuring In clinical practice it is customary to evaluate errors of IOP measuring with the new tonometers in comparison with the results received in the same eyes with Goldman tonometer (Reference tonometer) and taking into consideration scatter of data received during repeated measurings with the same tonometer [8]. Numerous studies carried out in hundreds of patients during several years show high reliability of IOP measurings with diaton tonometer. Scatter of results received using the new tonometer and Goldman tonometer had no systematic character and did not exceed 4 mm Hg. In repeated IOP measurings in healthy eyes the displays fluctuations were in the range 2-4 mm Hg [1]. According to the literature data the scatter of results while carrying out the repeated measurings using Goldman tonometer is 2-3 mm Hg in healthy eyes [10]. While checking various samples of Goldman tonometers produced in lots it is found the systematic difference of the displays of 2-3 mm Hg depending on the variant of each device’s double prism and spring calibration. Eye refraction, astigmatism, cornea’s crookedness and thickness, width of the moisture ring around the flattening area, hyper- or hypofluorescence of the ring [6, 7, 9]. As it was mentioned above, the error of IOP level measuring depends on the character and value of ophthalmotone rhythmic and casual fluctuations as well as on the tonometrist’s skill. The experience of operating diaton and Goldman tonometers shows that their displays have good correlation. Diaton tonometer has accuracy enough for clinical purposes, requires no anesthetics and sterilization. Besides, they are safe (can not damage the cornea), comfortable for the patients and easy in use. They can be used not only in ophthalmology studies but at home as well. LITERATURE 1.Илларионова А.Р., Пилецкий Н.Г.//Клин.офтальмол.-2001-№2.-С.55-56 2.МаклаковА.Н.//Мед.обозр.-1884.-Т.22-С.1092-1095 3.Нестеров А.П., Бунин А.Я., Кацельсон Л.А. Внутриглазное давление: физиология и паталогия.-М.,1974 4.Нестеров А.П. Глаукома.-М.,1995 5.Goldmann H., Schmidt T.//Opthalmologica.-1957-Bd 136.-S.221-231. 6.Mark H.H.//Am.J.Ophthalmol.-1973.-Vol.76-P.223-227 7..//Ibid.-1960.-Vol.49.-P.1149 8.Moses R.A., Liu C.H.// Ibid.-1968.-Vol.66.-P.89-94 9.Motolko M.A.//Can/J/Ophthalmol.-1982.-Vol.17.-P.93-97. 10.Phelps C.D.,Phelps G.K.//Graefes.Arch.Clin.Exp.Ophthalmol.-1976.-Vol.198.-P.39-44 11.Schottenstein M.H.//The Glaucomes/Eds R.Ritch et al.-St.Louis, 1996.-Vol.1.-P.407-428. 12.Whitacre M.M., Stein R.A., Hassanein K.//Am.J.Ophthalmol.-1993.-Vol.115.-P.592-597. Donated DIATON Tonometer was used at Mother Theresa’s orphanage to screen for Glaucoma in Tanzania – a Thank You Letter +Photos are Very Touching A Very Touching “Thank You Letter & Photos from a orphanage in Tanzania which received Diaton tonometer as donation to screen people at Risk for Glaucoma to prevent Blindness:

  18. photo: Donated Diaton tonometer Saves Sight at Mother Theresa’s orphanage Subject: Donation Of Diaton Tonometer Dear Sir/Madam, Attached please find pictures of recent activity at Mother Theresa’s orphanage and old age home were 200 needy people underwent eye exam and glaucoma screening. Fifteen people were glaucoma suspects and 3 with advanced glaucoma. This screening would have not been possible without your generous donation of Diaton tonometer, a wonderful marvel of technology, that made this massive screening for glaucoma an easy one and with perfect accuracy. Old age people normally have dry eyes,poor tear film quality, where there is a risk of corneal damage with schiotz tonometry and applanation tonometry needs use of lots of fluoroscein dye because it dries up fast. With Diaton tonometer this was not a problem ! Diaton tonometer is the best and only device suitable for use with aged patients and those with dry eyes. Thank you Diaton for wonderful device thats going to help save sights of thousands of people. God bless. Please go through attached pictures. Kind regards,Dr. Shabbir Kapasi Ph.D(MA) ELITE OPTICIANS Jamhuri/India street, Opp. Ministry of Science & Technology Bldg., P.O. Box 1737, Dar Es Salaam, Tanzania.

  19. Thank you for your review of Diaton tonometer clinical trials, reviews and testimonials. For any additional information about Diaton tonometer please visit : http://www.TonometerDiaton.com Or contact BiCOM Inc at Phone: 1-877-DIATONS (877-342-8667) Email: contact@tonometerdiaton.com Social Media - to connect with Diaton team – please connect: https://plus.google.com/+TonometerDiatonPen/ http://www.linkedin.com/company/tonometer https://www.facebook.com/Tonometer http://www.pinterest.com/Tonometer/ https://twitter.com/TONOMETER

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