Evaluation of Pachymetric Measurements with Scheimpflug Photography-Based System and Optical Coherence Tomography Pachymetry at Different Stages of Keratoconus

Akçay, Betül İlkay Sezgin; Ozgurhan, Engin Bilge; Bozkurt, Ercüment; Kurt, Tugba; Yıldırım, Yusuf; Coşar, Mediha Gülen; Yildirim, Aydın; Akkan, Julide Canan Umurhan; Demirok, Ahmet

doi:10.1155/2014/719205

Cited by 5 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, high correlation in CCT and TCT was reported between corneal thickness measurements using Visante and Sirrus among eyes with different stages of keratoconus (Sezgin Akcay et al. ). In a recent study, Visante OMNI (Carl Zeiss Meditec, Dublin, CA, USA), which is a combined Placido‐based topographer (Atlas) with a time‐domain OCT (Visante), was compared with Pentacam in keratoconic eyes (Viswanathan et al.…”

Section: Discussionmentioning

confidence: 80%

“…Although time-domain OCT had a slower acquisition speed and lower resolution compared to Fourierdomain OCT, high correlation was found between the two systems in keratoconic pachymetry values (Dutta et al 2013;Wang et al 2015). Similarly, high correlation in CCT and TCT was reported between corneal thickness measurements using Visante and Sirrus among eyes with different stages of keratoconus (Sezgin Akcay et al 2014). In a recent study, Visante OMNI (Carl Zeiss Meditec, Dublin, CA, USA), which is a combined Placido-based topographer (Atlas) with a time-domain OCT (Visante), was compared with Pentacam in keratoconic eyes (Viswanathan et al 2015).…”

Section: Agreement Of Measurements Between Devicesmentioning

confidence: 99%

“…Several studies have attempted to evaluate the precision of corneal imaging techniques in eyes with keratoconus (Nakagawa et al 2011;Savini et al 2011b;Szalai et al 2012;Fukuda et al 2013;Jhanji et al 2013;Montalban et al 2013;Sezgin Akcay et al 2014;Shetty et al 2014;Viswanathan et al 2015). Evidence appears to support a better measurement repeatability with OCT-based topography compared to other imaging modalities, although all techniques demonstrated high precision (Nakagawa et al 2011;Savini et al 2011b;Szalai et al 2012;Jhanji et al 2013).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comparison of corneal measurements in keratoconus using swept‐source optical coherence tomography and combined Placido–Scheimpflug imaging

Chan

Biswas

et al. 2016

Acta Ophthalmologica

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 80%

Section: Agreement Of Measurements Between Devicesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of corneal measurements in keratoconus using swept‐source optical coherence tomography and combined Placido–Scheimpflug imaging

Chan

Biswas

et al. 2016

Acta Ophthalmologica

View full text Add to dashboard Cite

show abstract

“…Scheimpflug imaging is sensitive to measuring corneal opacities, as it uses blue light at a wavelength of 475 nm. However, increased scattering at this wavelength can cause errors in corneal thickness measurements and may also hinder clear morphology description posterior to the opacities when compared to the OCT. 19 CM uses a 670 nm diode laser showing the benefit of reduced scattering, while AS-OCT uses red to near-infrared light (750-850 nm) exhibiting even deeper tissue penetration. In contrast to reports of some Scheimpflug imaging studies, we could not determine an increase in the posterior stroma.…”

Section: Discussionmentioning

confidence: 99%

Corneal optical density in Fuchs endothelial dystrophy determined by anterior segment optical coherence tomography

Wertheimer

Elhardt

Wartak

et al. 2020

European Journal of Ophthalmology

View full text Add to dashboard Cite

Purpose: In this study, we propose a method to grade corneal stromal opacity using optical density measurements by anterior segment optical coherence tomography (AS-OCT) and validate the approach in Fuchs endothelial corneal dystrophy (FECD). Methods: A retrospective analysis of human corneal OCT scans was performed on 48 eyes of 32 patients with FECD and 33 control eyes of 21 patients using the Carl Zeiss Cirrus HD-OCT 5000. In addition, corneal edema in fresh rabbit cadaver eyes was artificially induced by distilled water and imaged with the Thorlabs TELESTO-II spectral domain OCT at different time points during saturation. The increase of opacity due to corneal edema was proposed to directly correlate with enhanced reflectivity sites in the OCT images, corresponding to higher optical density. The increase was determined as the image area above a statistically established gray-scale value using ImageJ and correlated with other disease characteristics. Results: Optical densities in human corneas showed significant differences between FECD patients and the control group ( p = 0.002). The increased optical densities determined in FECD corneas correlated well with other disease characteristics such as corneal pachymetry or visual acuity. Likewise, rabbit corneas showed a time dependent increase in thickness and in corneal optical density during soaking in distilled water. Conclusion: This study presents corneal optical density by AS-OCT as an objective value for corneal changes in FECD. Complementing other diagnostic tools in FECD the assessment of corneal optical density may identify progression of FECD, gauge novel therapeutic strategies and support risk and benefit analyses for corneal surgery.

show abstract

Scheimpflug camera combined with placido-disk corneal topography and optical biometry for intraocular lens power calculation

et al. 2016

View full text Add to dashboard Cite

The purpose of this study was to compare the keratometry (K) values obtained by the Scheimpflug camera combined with placido-disk corneal topography (Sirius) and optical biometry (Lenstar) for intraocular lens (IOL) power calculation before the cataract surgery, and to evaluate the accuracy of postoperative refraction. 50 eyes of 40 patients were scheduled to have phacoemulsification with the implantation of a posterior chamber intraocular lens. The IOL power was calculated using the SRK/T formula with Lenstar K and K readings from Sirius. Simulated K (SimK), K at 3-, 5-, and 7-mm zones from Sirius were compared with Lenstar K readings. The accuracy of these parameters was determined by calculating the mean absolute error (MAE). The mean Lenstar K value was 44.05 diopters (D) ±1.93 (SD) and SimK, K at 3-, 5-, and 7-mm zones were 43.85 ± 1.91, 43.88 ± 1.9, 43.84 ± 1.9, 43.66 ± 1.85 D, respectively. There was no statistically significant difference between the K readings (P = 0.901). When Lenstar was used for the corneal power measurements, MAE was 0.42 ± 0.33 D, but when simK of Sirius was used, it was 0.37 ± 0.32 D (the lowest MAE (0.36 ± 0.32 D) was achieved as a result of 5 mm K measurement), but it was not statistically significant (P = 0.892). Of all the K readings of Sirius and Lenstar, Sirius 5-mm zone K readings were the best in predicting a more precise IOL power. The corneal power measurements with the Scheimpflug camera combined with placido-disk corneal topography can be safely used for IOL power calculation.

show abstract

Evaluation of Pachymetric Measurements with Scheimpflug Photography-Based System and Optical Coherence Tomography Pachymetry at Different Stages of Keratoconus

Cited by 5 publications

References 24 publications

Comparison of corneal measurements in keratoconus using swept‐source optical coherence tomography and combined Placido–Scheimpflug imaging

Comparison of corneal measurements in keratoconus using swept‐source optical coherence tomography and combined Placido–Scheimpflug imaging

Corneal optical density in Fuchs endothelial dystrophy determined by anterior segment optical coherence tomography

Scheimpflug camera combined with placido-disk corneal topography and optical biometry for intraocular lens power calculation

Contact Info

Product

Resources

About