Significance of dynamic contour tonometry in evaluation of progression of glaucoma in patients with a history of laser refractive surgery

2019 ◽  
Vol 104 (2) ◽  
pp. 276-281 ◽  
Author(s):  
Sang Yeop Lee ◽  
Eun Woo Kim ◽  
Wungrak Choi ◽  
Chan Keum Park ◽  
Sangah Kim ◽  
...  

AimsIn this study, we tested the hypothesis that intraocular pressure (IOP) parameters measured by dynamic contour tonometry (DCT) would be more relevant in progression of glaucoma when there is a history of laser refractive surgery (LRS) than the IOP parameters measured by Goldmann applanation tonometry (GAT) or calculated by correction formulae.MethodsNinety-eight eyes in 54 patients with open-angle glaucoma and a history of LRS were included in this retrospective study. IOP was measured by both GAT and DCT during follow-up. Baseline, mean, and peak IOP, IOP fluctuation, and IOP reduction were measured by each tonometry method. Corrected IOP parameters using central corneal thickness and mean keratometry values were also analysed. Clustered logistic regression was used to identify variables correlated with progression of glaucoma. Areas under the curve (AUCs) for correlated variables were also compared.ResultsThe mean DCT value (OR 1.36, p=0.024), peak DCT value (OR 1.19, p=0.02) and pattern SD (OR 1.10, p=0.016) were significant risk factors for progression. There was a significant difference in the predictive ability of the mean DCT and GAT values (AUC 0.63 and 0.514, respectively; p=0.01) and of the peak DCT and GAT values (0.646 and 0.503, respectively, p=0.009). The AUCs for corrected IOP did not exceed those of DCT.ConclusionsIOP measurements were more associated with progression of glaucoma when measurements were obtained by DCT than by GAT or correction formulae in eyes with a history of LRS.

2016 ◽  
Vol 15 (2) ◽  
Author(s):  
Satheesh Solomon T Selvin ◽  
Chris Elsa Samson Jacob ◽  
Thomas Kuriakose

Purpose: Goldmann applanation tonometry (GAT) is considered the gold standard for Intraocular Pressure (IOP) measurement. It has the disadvantages of being a contact device, need for a slit-lamp, non-portability and need of a skilled examiner. Many hospitals are using a Non Contact Tonometry (NCT) as a screening device to save clinician time, however the usefulness is not proved in terms of reliability. This study was aimed to determine the usefulness of the Air-puff tonometer (TONOREF NIDEK II, NIDEK CO., LTD., JAPAN) over a GAT in a tertiary care center. Design: Cross-sectional Study Methods: This was a cross-sectional, non interventional observational study conducted on 224 eyes (right eye) from 224 patients. All patients underwent the IOP measurement with both methods and a central corneal thickness (CCT) measured. The data was analyzed using SPSS 20.0 software. Results: The mean age of the patients was 40.3±11.29 years. There was a statistically significant difference (p<0.001) between the mean NCT and GAT readings which persisted even after correction for central corneal thickness. The correlation between NCT and GAT using Pearson’s correlation coefficient was strong irrespective of the corrections for their corneal thickness (r = 0.751 and 0.718 for uncorrected and corrected values respectively). The correlation of the individual clinicians for the readings varied from moderate to strong. The ROC curve showed the best sensitivity and specificity to occur at around 13 to 14 mmHg. Conclusion: NCT seems to overestimate the IOP at low ranges as compared to the GAT and underestimate at higher ranges. The crossover of the values is seen between 12 to 13 mmHg.  The clinician should do an individualized analysis of his/her GAT measurements to the readings of the NCT machine at the clinic to obtain clinician specific nomogram. 


2021 ◽  
Vol 9 (2) ◽  
pp. 127-133
Author(s):  
Annamary Stanislaus ◽  
Ntsilane Susan Mosenene ◽  
Celina Mhina ◽  
John Stanslaus Kisimbi ◽  
Frederick Robert Burgess ◽  
...  

Background: Central Corneal Thickness (CCT) is an indicator of corneal health status as well as being an essential tool in assessment and management of corneal diseases. It is an important factor in the diagnosis and management of glaucoma as it affects the measurement of intraocular pressure. However, the pattern of central corneal thickness in our population is not known. Our study aimed to describe the CCT measurements and their variation with age and sex among patients attending the eye clinic at Muhimbili National Hospital (MNH), in Dar es Salaam, Tanzania. Methodology: A hospital-based descriptive, cross-sectional study used convenient sampling to recruit adult patients aged 18 years and above, presenting to the MNH between August 2016 and January 2017.Visual acuity assessment, Goldman applanation tonometry and CCT assessment using an ultrasound pachymeter were performed. Patients with previous intraocular surgery were excluded. Results: A total of 398 patients (208 males and 190 females) were recruited. The mean CCT was 526.64±38.30 µm; being 523.99±38.20 µm for males and 529.7±38.3 µm for females. 226 (56.85%) had CCT of less than 520 µm.There was no statistically significant difference in CCT between gender. The proportion of patients with thinner CCT increased with increasing age from 25.8% in those < 30 years to 75% in those aged 71years and above. The mean CCT decreased with increasing age with P-value<0.001. Conclusion: The average CCT in patients attending Muhimbili National Hospital is 526.64 µm (SD 38.30) which is generally thin, inversely proportion to age and similar that of other Africans and African-Americans. This finding has implications for the management of glaucoma in this population.


Glaucoma ◽  
2012 ◽  
Author(s):  
Raghu C. Mudumbai

The development of glaucoma can occur postoperatively from corneal/refractive, cataract, and vitreoretinal surgery. Additionally, glaucoma may be noted after clinical procedures have been performed, including injections and laser procedures. This chapter is organized into two basic sections: postoperative and post-procedure glaucoma. Background: Currently little is known about the effect of refractive surgery in glaucoma patients or about patients who undergo refractive procedures and may go on to develop glaucoma. •IOP measurement •Measurement of IOP after refractive surgery can be challenging. Corneal properties that are altered after refractive surgery include corneal thickness, corneal curvature, the structural integrity (stiffness or hysteresis), as well as the overlying tear film that interacts with instruments that measure IOP. Photorefractive keratectomy (PRK) additionally ablates portions of Bowman’s layer, which may change corneal resistance. Nomograms have been developed to adjust for IOP change after corneal alteration but usually take only corneak thickness into account, which has led to little success in their use. •Goldmann applanation tonometry (GAT) assumes corneal thickness = 520 microns. Thicker corneas will overestimate IOP and thinner corneas, which result from refractive procedures such as PRK and LASIK, will underestimate IOP. Therefore, GAT may have limited value in measuring true IOP following refractive surgery. Other tonometric devices, like Pascal dynamic contour tonometry, pneumatonometry, and the Reichert ocular response analyzer, may be more accurate. There does not appear to be any simple conversion table that can be referenced in correcting measured IOP after the cornea is altered surgically. Preoperative IOP is probably the most important variable that should be recorded. •The intraoperative pressure spike associated with LASIK may occur in select patients, leading to the development of glaucomatous optic neuropathy. • Pressure-induced stromal keratitis (PISK) is a condition related to steroid-induced elevated IOP that may occur after LASIK. The clinical appearance is similar to diffuse lamellar keratitis (DLK), where there is a diffuse interlamellar haze covering the flap. DLK is an inflamatory response where IOP is not elevated and requires topical steroid treatment for resolution.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2338-2338
Author(s):  
Lena Coïc ◽  
Suzanne Verlhac ◽  
Emmanuelle Lesprit ◽  
Emmanuelle Fleurence ◽  
Francoise Bernaudin

Abstract Abnormal TCD defined as high mean maximum velocities &gt; 200 cm/sec are highly predictive of stroke risk and justify long term transfusion program. Outcome and risk factors of conditional TCD defined as velocities 170–200 cm/sec remains to be described. Patients and methods Since 1992, 371 pediatric SCD patients (303 SS, 44 SC, 18 Sß+, 6 Sß0) were systematically explored once a year by TCD. The newborn screened cohort (n=174) had the first TCD exploration between 12 and 18 months of age. TCD was performed with a real-time imaging unit, using a 2 MHz sector transducer with color Doppler capabilities. Biological data were assessed at baseline, after the age of 1.5 years and remotely of transfusion or VOC. We report the characteristics and the outcome in patients (n=43) with an history of conditional TCD defined by mean maximum velocities ranging between 170 and 200 cm/s in the ACM, the ACA or the ICA. Results: The mean follow-up of TCD monitoring was 5,5 years (0 – 11,8 y). All patients with an history of conditional doppler were SS/Sb0 (n=43). Mean (SD) age of patients at the time of their first conditional TCD was 4.3 years (2.2) whereas in our series the mean age at abnormal TCD (&gt; 200 cm/sec) occurrence was 6.6 years (3.2). Comparison of basal parameters showed highly significant differences between patients with conditional TCD and those with normal TCD: Hb 7g4 vs 8g5 (p&lt;0.001), MCV 82.8 vs 79 (p=0.047). We also had found such differences between patients with normal and those with abnormal TCD (Hb and MCV p&lt; 0.001). Two patients were lost of follow-up. Two patients died during a trip to Africa. Conditional TCD became abnormal in 11/43 patients and justified transfusion program. Mean (SD) conversion delay was 1.8 (2.0) years (range 0.5–7y). No stroke occurred. 16 patients required a treatment intensification for other indications (frequent VOC/ACS, splenic sequestrations): 6 were transplanted and 10 received HU or TP. Significant risk factors (Pearson) of conversion to abnormal were the age at time of conditional TCD occurrence &lt; 3 y (p&lt;0.001), baseline Hb &lt; 7g/dl (p=0.02) and MCV &gt; 80 (p=0.04). MRI/MRA was performed in 31/43 patients and showed ischemic lesions in 5 of them at the mean (SD) age of 7.1 y (1.8) (range 4.5–8.9): no significant difference was observed in the occurrence of lesions between the 2 groups. Conclusions This study confirms the importance of age as predictive factor of conditional to abnormal TCD conversion with a risk of 64% when first conditional TCD occured before the age of 3 years. TCD has to be frequently controled during the 5 first years of life.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Efstathios T. Detorakis ◽  
Emilia Grammenandi ◽  
Ioannis G. Pallikaris ◽  
Miltiadis K. Tsilimbaris

Background. To evaluate differences between Goldmann Applanation Tonometry (GAT) and Dynamic Controur Tonometry (DCT) following trabeculectomy.Methods. Thirty eight glaucomatous eyes with a history of trabeculectomy (Trabeculectomy group, TG), 20 eyes without a history of trabeculectomy but with a history of latanoprost use (Latanoprost group, LG), and 19 nonglaucomatous eyes (Control group, CG) were included. GAT-IOP, DCT-IOP, the difference between them (dIOP), the central corneal thickness (CCT), the axial length (AL), and the depth of the anterior chamber (ACD) were measured.Results. dIOP was significantly higher in TG (5.19 mmHg) than in LG (4.01 mmHg) and CG (1.98 mmHg). Correlations between AL and dIOP were statistically significant in both TG and LG but not in CG whereas correlations between dIOP and other clinical parameters examined were statistically not significant in all groups.Conclusions. The significantly higher dIOP in TG implies that the bio-mechanical properties of the ocular walls are altered following trabeculectomy.


2011 ◽  
Vol 22 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Ivano Riva ◽  
Luciano Quaranta ◽  
Andrea Russo ◽  
Andreas Katsanos ◽  
Eliana Rulli ◽  
...  

Purpose To compare intraocular pressure (IOP) measured using a dynamic contour tonometer (DCT) and a Goldmann applanation tonometer (GAT) with in vivo intracameral IOP, and establish the relationship between DCT, GAT and central corneal thickness (CCT) in patients with primary open-angle glaucoma (POAG). Materials and Methods We examined 50 eyes of 50 patients with POAG scheduled for glaucoma or cataract surgery. Immediately before surgery, CCT, GAT and DCT IOP were assessed, after which manometry of the anterior chamber was performed. A Bland-Altman plot was used to test the agreement among the 3 measurements of IOP, and univariate and multivariate regression analyses were used to evaluate the effect of CCT on DCT and GAT. Results On average, the DCT readings were 4.0±1.6 mmHg higher than the GAT readings and 2.3±2.4 mmHg higher than the manometric readings; the GAT measurements were generally a mean 1.7±1.8 mmHg lower than the manometric readings. The CCT had an almost similar influence on DCT and GAT measurements (p=0.84). Conclusions The DCT-measured IOP was significantly higher than that measured by means of GAT and anterior chamber manometry. The DCT and GAT readings were both influenced by CCT to the same extent.


2019 ◽  
Vol 12 (2) ◽  
pp. 12-17
Author(s):  
A. Sh. Zagidullina ◽  
B. M. Aznabaev ◽  
I. A. Lakman ◽  
R. R. Islamova ◽  
R. R. Sattarova

Purpose. To study tonometry parameters features, measured by different methods, taking into account individual morphometric eye parameters and biomechanical properties of the corneoscleral shell in patients with the initial and the advanced stages of primary open angle glaucoma (POAG).Material and methods. 51 patients (99 eyes) aged 48–82, with the initial (45 eyes) and advanced stages (54 eyes) of POAG were examined. The control group consisted of 31 patients (62 eyes) aged 47–83 without ophthalmic pathology. In addition to standard ophthalmologic examination, tonometry was performed using the Ocular Response Analyzer (ORA, Reichert Inc., the USA).Results. The main tonometry parameters of ORA revealed significant differences between POAG patients and the control group. No significant difference in the central corneal thickness (CCT) was found between the POAG and the control group. Patients with I and II stages of glaucoma taken separately showed differences in CCT and tonometry parameters.Conclusion. Dynamic bi-directional applanation tonometry enables to take into account the changes in viscoelastic properties of the corneoscleral eye shell, and definitely has diagnostic advantages in examining patients with various stages of POAG.


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