Repeatability and Reproducibility of Central Corneal Thickness Measurement With Pentacam, Orbscan, and Ultrasound

Lackner, Birgit; Schmidinger, Gerald; Pieh, Stefan; Funovics, Martin; Skorpik, Christian

doi:10.1097/01.opx.0000180817.46312.0a

Cited by 275 publications

(246 citation statements)

References 31 publications

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“…Ultrasonik yöntemler aras›nda ultrasonik pakimetre ve ultrasonik biyomikroskop (UBM), optik yöntemler aras›nda ise speküler mikroskopi, optik koherans tomografi, taray›c› slit kornea topografisi, konfokal mikroskopi ve Pentacam Scheimpflug sistem say›labilir. 1,[7][8][9][10][11][12][13][14][15][16][17] Ultrasonik pakimetri, ucuz ve kolay uygulanabilir bir teknoloji olmas›, ölçümlerinin yüksek tekrarlanabilirlikte ve güvenilirlikte olmas› nedeniyle klinik uygulamalarda yayg›n olarak kullan›lmaktad›r. 13,[18][19][20] Korneaya temas etmesi en önemli dezavantaj›d›r ve epitel defektlerine ve enfeksiyonlara yol açabilmektedir.…”

Section: Giriflunclassified

“…Son y›llarda kullan›ma giren OCULUS Pentacam cihaz› (Oculus Inc., Almanya), Scheimpflug prensiplerini kullanarak kornea ve lensin kesitsel görüntülerini almakta, ön segmentin 3 boyutlu katarakt yo¤unlu¤unu belirlemekte, kornea kurvatür ve kal›nl›¤›n› ölçmektedir. 1,11,17 Korneaya temas gerektirmemesi, h›zl› ölçüm almas›, kornean›n tüm lokalizasyonlar›nda-ki kal›nl›¤› belirlemesi ve yüksek tekrarlanabilirlikte olmas› en önemli avantajlar›ndand›r.…”

Section: Giriflunclassified

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Pentacam ile Ölçülen Santral Kornea Kalınlıklarının Karşılaştırılması

Büyük¹,

Bozkurt²,

Kamış³

et al. 2011

tjo

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ÖzetAmaç: Normal ve keratokonuslu gözlerde ultrasonik pakimetre (Ocuscan ® RxP) ve OCULUS Pentacam Scheimpflug kamera ile ölçülen santral kornea kal›nl›k (SKK) de¤erlerinin karfl›laflt›r›lmas› Gereç ve Yöntem: Prospektif çal›flmada 57 keratokonuslu, 62 sa¤l›kl› gözün s›ras›yla Pentacam ve ultrasonik pakimetre ile SKK ölçümleri yap›ld›. Her iki cihaz ölçümlerinin ortalamas› efllendirilmifl dizide t testi ile istatistiksel olarak karfl›laflt›r›ld› ve p<0,05 istatistiksel olarak anlaml› kabul edildi. Her iki cihaz ile al›nan SKK ölçümleri aras›ndaki iliflki Pearson testi ile de¤erlendirildi. Sonuçlar: Keratokonuslu gözlerin ortalama SKK ölçümleri Pentacam cihaz› ile 480,18±33,6 μm, ultrasonik pakimetre ile 465,67±34,5 μm olarak bulundu ve farkl›l›k istatistiksel olarak anlaml› idi (t=-5,87; p<0,001). Sa¤l›kl› gözlerde ise bu de¤erler s›ras›yla 573,8±35,7 μm ve 563,58±30,9 μm olarak ölçüldü (t=-4,32; p<0,001). Sa¤l›kl› grupta 15 gözün SKK de¤erleri ultrasonik pakimetre ile 585 μm üzerindeydi ve bu gözlerin Pentacam ve ultrasonik pakimetre ile al›nan ölçümleri s›ras›yla 619±13,1 μm ve 608,87±14,1 μm olarak bulundu (t=-3,3; p=0,005). Her iki cihaz ile al›nan ölçümler birbiriyle anlaml› korelasyon göstermekteydi (r=0,95, p<0,001). Material and Method:In this prospective study, CCT measurements were done in 57 keratoconic eyes and 62 healthy eyes by OCULUS Pentacam and ultrasonic pachymetry, consecutively. The measurements taken by the 2 instruments were compared with paired-samples t-test. A p value <0.05 was considered as statistically significant. The correlation between the measurements was evaluated using the Pearson test. Results: The mean CCT of keratoconic eyes was 480.18±33.6 μm with Pentacam and 465.67±34.5 μm with ultrasonic pachymetry, which demonstrates a statistically significant difference (t=-5.87; p585 μm (t=-3.3; p=0.005). There was a high correlation between the CCT readings done by the two methods (r=0.95, p<0.001). Discussion: The CCT measurements obtained by Pentacam in both keratoconic and healthy eyes highly correlated with the ultrasonic measurements. However, the CCT measurements taken by Pentacam were higher compared to the ultrasonic measurements; therefore, one and the same imaging technique should be used in follow-up measurements. (Turk J Ophthalmol 2011; 41: 104-7)

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Section: Giriflunclassified

Pentacam ile Ölçülen Santral Kornea Kalınlıklarının Karşılaştırılması

Büyük¹,

Bozkurt²,

Kamış³

et al. 2011

tjo

View full text Add to dashboard Cite

show abstract

“…It includes a rotating Scheimpflug camera with a monochromatic slit light source. The device makes real-time images from the anterior segment of the eye, giving data with high repeatability and interoperator reproducibility (Lackner et al, 2005). The image gives a complete representation of the anterior chamber, extending from the endothelium of the cornea to the posterior surface of the lens.…”

Section: Measurement Of Ocular Parametersmentioning

confidence: 99%

Genetic Covariance Between Central Corneal Thickness and Anterior Chamber Volume: A Hungarian Twin Study

et al. 2014

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Background: Few, and inconsistent, studies have showed high heritability of some parameters of the anterior segment of the eye; however, no heritability of anterior chamber volume (ACV) has been reported, and no study has been performed to investigate the correlation between the ACV and central corneal thickness (CCT). Methods: Anterior segment measurements (Pentacam, Oculus) were obtained from 220 eyes of 110 adult Hungarian twins (41 monozygotic and 14 same-sex dizygotic pairs; 80% women; age 48.6 ± 15.5 years) obtained from the Hungarian Twin Registry. Results: Age-and sex-adjusted heritability of ACV was 85% (bootstrapped 95% confidence interval; CI: 69% to 93%), and 88% for CCT (CI: 79% to 95%). Common environmental effects had no influence, and unshared environmental factors were responsible for 12% and 15% of the variance, respectively. The correlation between ACV and CCT was negative and significant (r ph = -0.35, p < .05), and genetic factors accounted for the covariance significantly (0.934; CI: 0.418, 1.061) based on the bivariate Cholesky decomposition model. Conclusion: These findings support the high heritability of ACV and central corneal thickness, and a strong genetic covariance between them, which underscores the importance of identification of the specific genetic factors and the family risk-based screening of disorders related to these variables, such as open-angle and also angle closure glaucoma and corneal endothelial alterations.

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“…This is justified, in part, by the position of the second principal plane of the cornea, which is close to the anterior surface (actually about 0.05 mm in front of the cornea). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 [6][7][8] In this way, the Pentacam-measured anterior chamber diameter (measured from anterior chamber angle to anterior chamber angle, AG m ) and corneal height (measured from the internal cornea to the line connecting the anterior chamber angles, H m ) can be used to calculate the theoretical corneal radius (R rt ). 6 Ho et al reported that…”

Section: -3mentioning

confidence: 99%

Estimation of effective lens position using a method independent of preoperative keratometry readings

Dooley

Charalampidou

Nolan

et al. 2011

Journal of Cataract and Refractive Surgery

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Purpose To evaluate the validity of a keratometry-independent method of estimating effective lens position (ELP) prior to phacoemulsification cataract surgery. Setting Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland Methods The anterior chamber diameter (AGm) and corneal height (Hm) in 95 eyes (95 patients) scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Hm and AGm were used to estimate the ELP in a keratometry-independent method (using the SRK/T [ELPrs] and Holladay 1 [ELPrh] formulae). Results The mean (± SD) ELP was calculated using traditional (mean ELPs ± SD: 5.59 ± 0.52 mm and mean ELPh ± SD: 5.63 ± 0.42 mm) and keratometry-independent (mean ELPrs ± SD: 5.55 ± 0.42 mm and mean ELPrh ± SD: 5.60 ± 0.36 mm) methods. Agreement between ELPs and ELPrs and between ELPh and ELPrh were represented by Bland Altman plots, with mean differences (± 1.96 SD; range; student's t-test) of 0.06 mm (± 0.65 mm; -0.59 to +0.71 mm; p = 0.08) in association with ELPrs and -0.04 mm (± 0.39 mm; -0.43 to +0.35 mm; p = 0.08) in association with ELPrh. The mean absolute error (MAE) for ELPs versus ELPrs estimation and for ELPh versus ELPrh estimation were 0.242 ± 0.222 mm (range: 0.001 to 1.272mm) and 0.152 ± 0.137 mm (range: 0.001 to 0.814 mm), respectively. ConclusionThis novel study confirms that this keratometry-independent ELP estimation method is comparable to traditional keratometry-dependent methods and may be useful in post-refractive surgery patients. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 Running titleUtilising Scheimpflug imaging to estimate effective lens position in a keratometryindependent fashion. PresentationsThis work has been presented at the Irish College of Ophthalmologist's annual meeting May 2010. FundingNo author received any funding for this study. DeclarationThe authors declare that they have no conflict of interest. 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 4 Keywords Abstract PurposeTo evaluate the validity of a keratometry-independent method of estimating effective lens position (ELP) prior to phacoemulsification cataract surgery. SettingInstitute of Eye Surgery, Whitfield Clinic, Waterford, Ireland MethodsThe ResultsThe mean (± SD) ELP was calculated using traditional (mean ELP s ± SD: 5.59 ± 0.52 mm and mean ELP h ± SD: 5.63 ± 0.42 mm) and keratometry-independent (mean ELP rs ± SD: 5.55 ± 0.42 mm and mean ELP rh ± SD: 5.60 ± 0.36 mm) methods. ConclusionThis novel study confirms that this keratometry-independent ELP estimation method is comparable to traditional keratometry-dependent methods and may be useful in post-refractive surgery patients.

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Repeatability and Reproducibility of Central Corneal Thickness Measurement With Pentacam, Orbscan, and Ultrasound

Abstract: In the assessment of normal corneas, the Pentacam measured CCT values closer to ultrasound pachymetry and with less variability compared with Orbscan. The (interobserver) reproducibility with the Pentacam was highest of all 3 modalities.

Cited by 275 publications

References 31 publications

Pentacam ile Ölçülen Santral Kornea Kalınlıklarının Karşılaştırılması

Pentacam ile Ölçülen Santral Kornea Kalınlıklarının Karşılaştırılması

Genetic Covariance Between Central Corneal Thickness and Anterior Chamber Volume: A Hungarian Twin Study

Estimation of effective lens position using a method independent of preoperative keratometry readings

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