Dynamic Contour Tonometry in Keratoconus and Postkeratoplasty Eyes

Meyenberg, Alexander; Iliev, Milko E; Eschmann, R.; Frueh, Béatrice E.

doi:10.1097/ico.0b013e31815dcf97

Cited by 21 publications

(21 citation statements)

References 35 publications

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“…DCT has been proposed to measure IOP irrespective of the corneal thickness 13,20 because DCT does not flatten the cornea, which allows the cornea to maintain its shape provoking minimal distortion during the measurement. This is similar to the previous reports about the effect of CCT on IOP measurements obtained by DCT in irregular corneas 15,16,21 and further confirm that DCT is less dependent on CCT than GAT. However, given DCT is designed to conform the shape of the cornea during IOP measurement, altered corneal geometrics and differences in corneal viscoelasticity in keratoconic corneas may interfere this function independent of CCT, as seen in our study.…”

Section: Discussionsupporting

confidence: 93%

“…[24][25][26] On the other hand, the agreement was weaker in irregular corneas. 15,21 It may be hypothesized that irregular corneal surface and differences in corneal biomechanical parameters, corneal rigidity and elasticity are disadvantageous factors for both GAT and DCT, leading to higher IOP variation and a weaker correlation. 15 In the current study, DCT and IOPcc, both were independent of CCT, did not show a good agreement in terms of IOP readings in Bland-Altman analysis.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Intraocular Pressure Values Obtained by Ocular Response Analyzer, Dynamic Contour Tonometry, and Goldmann Tonometry in Keratokonic Corneas

Bayer

Şahin

Hürmeriç

et al. 2010

Journal of Glaucoma

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Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Intraocular Pressure Values Obtained by Ocular Response Analyzer, Dynamic Contour Tonometry, and Goldmann Tonometry in Keratokonic Corneas

Bayer

Şahin

Hürmeriç

et al. 2010

Journal of Glaucoma

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“…20 Ismail et al 19 reported that in eyes that had undergone penetrating keratoplasty, GAT measurements may be less precise than non-applanation tonometry. Meyenberg et al 21 suggested that GAT could slightly underestimate IOP in postkeratoplasty eyes (3.1±2.5 mm), a fact which was confirmed in cases in which the procedure preserves the deeper corneal layers. 22 Regarding the effect of refractive surgery on GAT IOP measurements, there seems to be an agreement on the apparent IOP-lowering effect of the different modalities of surgery.…”

Section: Applanation Tonometers Goldmann Tonometer (Haag Streit Koenmentioning

confidence: 68%

“…15,16,66 It is a useful tool in situations where the clinician suspects inaccurate IOP measurements that could be caused by corneal biomechanical properties. It is particularly accurate in eyes with keratoconus, 20,21,67 corneal edema, 68 and those that have undergone penetrating keratoplasty 21,22,69 and refractive surgery. 25,70 The DCT provides a score (Q) representing the quality of the IOP measure.…”

Section: Dynamic Contour Tonometry -Pascal Tonometer (Smt Swiss Micromentioning

confidence: 99%

Modalities of Tonometry and their Accuracy with Respect to Corneal Thickness and Irregularities

Moraes

Prata

Liebmann

et al. 2008

Journal of Optometry

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Recent advances in tonometry have led to the development of a number of devices with differing clinical applications. Their role in cases of abnormal corneal thickness and surface irregularities is particularly important, as inaccurate estimation of the true intraocular pressure (IOP) in such cases may lead to suboptimal evaluation. The purpose of the present review was to evaluate the accuracy of the most widely used devices in cases of corneal thickness and surface irregularities, based on a survey of the published literature. The analysis was based on a Medline search focusing mainly on papers that have evaluated the devices' accuracy with respect to corneal thickness and irregularities. Nine device types (Goldmann tonometer, Tono-Pen, Perkins tonometer, Ocular Response Analyzer, non-contact tonometer, pneumatonometer, I-Care rebound tonometer, Pascal dynamic contour tonometer (DCT) and Phosphene tonometer) were described in detail. Moreover, the physical principles and major utility of each tonometer were compared. Each of the many different commercially available tonometers has specific advantages and disadvantages. New non-invasive technologies are getting closer to a precise estimation of the true IOP. However, among all tonometers, none is highly accurate when both corneal thickness and surface irregularities are present. Fifty years after its development, Goldmann tonometry remains the gold standard to which all other devices are compared. RESUMENAvances recientes en el campo de la tonometría han propiciado el desarrollo de diversos dispositivos con diferentes aplicaciones clíni-cas. Resulta de particular importancia el papel que juegan en el caso de espesores corneales anormales o en presencia de irregularidades en la superficie de la córnea, puesto que, en esos casos, una medida imprecisa de la presión intraocular (PIO) real puede traer como consecuencia una valoración incorrecta del caso. El objetivo de esta revisión es evaluar el grado de precisión de los dispositivos más utilizados hoy en día en casos en los que existen irregularidades en la superficie de la córnea o en el espesor corneal. Para ello, se llevó a cabo una búsqueda de datos entre los artículos publicados. El análisis estuvo basado en una búsqueda bibliográfica realizada dentro de Medline, centrándose principalmente en aquellos artícu-los científicos que habían estudiado el grado de precisión del dispositivo en función del espesor corneal del paciente y de la presencia o no de irregularidades corneales. Se describen en detalle nueve tipos de dispositivos: tonómetro de Goldmann, Tono-Pen, tonómetro de Perkins, Ocular Response Analyzer, tonómetro sin contacto, neumotonómetro, tonómetro de rebote I-Care, tonómetro de contorno dinámico Pascal y tonómetro de fosfeno. Además, se presentan de forma comparada los principios físicos en los que está basado cada tonómetro y las situaciones en las que cada uno resulta de mayor utilidad. Cada uno de los distintos tonómetros disponibles en el mercado presenta ventajas y desventajas respecto...

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“…21,22 Dinamik kontür tonometre düzensiz kornealardaki biyomekanik değişikliklerden en az etkilenir. 23,24 Penetran keratoplasti sonrası gelişen ektazi / keratokonus nüksü tedavisinde gözlük ve kontakt lens kullanımından, ikinci penetran keratoplastiye kadar çeşitli yöntemler yer alır. 2,9 Kornea CxL tedavisinin keratokonusun ilerlemesini durdurmada etkili olduğu birçok çalışmada gösterilmiştir.…”

Section: Discussionunclassified

Penetran Keratoplasti Sonrası Ektazi Nüksü

Ayşe¹,

Akkaya²,

Budak³

et al. 2013

Tjo

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Ge lifl Ta ri hi/Re cei ved: 26.04.2012 Ka bul Ta ri hi/Ac cep ted: 04.07.2012 ÖzetPenetran keratoplasti sonrası kornea ektazisi veya keratokonus nüksü nadir görülen bir tablodur ve bu tablo ile ilgili literatürde az sayıda vaka sunuları vardır. Bilgisayarlı topografi kullanımı hastalığın tanı ve tedavisinde oldukça yararlıdır. Tedavide gözlük ve kontakt lens kullanımından, tekrarlanan penetran keratoplastiye kadar birçok yöntem yer alır. Bu makalede penetran keratoplasti sonrası ektazi gelişen iki vakanın klinik ve bilgisayarlı topografi bulguları sunuldu. 45 ve 25 yaşında sağlıklı iki erkek hasta penetran keratoplasti sonrası görme keskinliklerinde azalmadan yakınmaktaydı. Oftalmolojik ve topografi bulguları kornea ektazisi nüksü ile uyumluydu. 45 yaşındaki hasta rekeratoplasti sonrası 0,7 Snellen sırası düzeltilmiş görme keskinliği elde etti. Diğer hastaya kollajen çapraz bağ tedavisi uygulandı, antiglokomatöz tedavi verildi ve görme keskinliği 0,5'e ulaştı. Takip süreleri boyunca ektazide ilerleme olmadı. (Turk J Ophthalmol 2013; 43: 124-8) Anahtar Kelimeler: Penetran keratoplasti, keratokonus, nüks Sum maryCorneal ectasia or recurrent keratoconus after penetrating keratoplasty is rare, and few case reports exist in the literature concerning this condition. Computerized corneal topography is quite useful to identify and manage this disorder. Management consists of several methods ranging from spectacle and contact lens correction to repeated penetrating keratoplasty. Clinical and computerized topography findings of two patients with keratectasia following penetrating keratoplasty are presented in this article. Two healthy 45-year-old and 25-year-old male patients complained of decreased visual acuity following penetrating keratoplasty. Clinical and topographical data were consistent with recurrence of corneal ectasia. After repeated penetrating keratoplasty, best-corrected distance Snellen visual acuity of 0.7 was obtained in the 45-year-old patient. The other patient underwent collagen cross linking, received antiglaucomatous therapy, and his visual acuity reached 0.5. During the follow-up period, ectasia progression did not occur. (Turk J Ophthalmol 2013; 43: 124-8)

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Dynamic Contour Tonometry in Keratoconus and Postkeratoplasty Eyes

Abstract: DCT measured significantly higher intraocular pressures than GAT in keratoconus and postkeratoplasty eyes. DCT and GAT measures varied considerably, and DCT was not less dependent on biomechanical properties of irregular corneas than GAT.

Cited by 21 publications

References 35 publications

Intraocular Pressure Values Obtained by Ocular Response Analyzer, Dynamic Contour Tonometry, and Goldmann Tonometry in Keratokonic Corneas

Intraocular Pressure Values Obtained by Ocular Response Analyzer, Dynamic Contour Tonometry, and Goldmann Tonometry in Keratokonic Corneas

Modalities of Tonometry and their Accuracy with Respect to Corneal Thickness and Irregularities

Penetran Keratoplasti Sonrası Ektazi Nüksü

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