Thickness and Curvature Changes of Human Corneal Grafts in Dextran-Containing Organ Culture Medium Before Keratoplasty

Hamon, Loïc; Daas, Loay; Mäurer, Stephanie; Weinstein, Isabel; Quintin, Adrien; Schulz, K.; Langenbucher, Achim; Seitz, Berthold

doi:10.1097/ico.0000000000002543

Cited by 15 publications

(13 citation statements)

References 30 publications

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“…However, potential inter-individual differences in de-swelling of donor corneas should be considered. Significant changes in curvature up to 24 hours after conversion to medium II could be excluded [15].…”

Section: Discussionmentioning

confidence: 99%

“…For this reason, donor corneas were tomographically screened from as early as 12 hours after transfer. This results in a relative tissue de-swelling of 82.9 % of total de-swelling after 24 hours [15]. However, potential inter-individual differences in de-swelling of donor corneas should be considered.…”

Section: Discussionmentioning

confidence: 99%

“…Transportation of donor corneal tissue at temperatures of > 10°C complies with the applicable regulations for transport [14]. Preoperative tomography of donor corneas was performed at least 12 hours after transfer of the donor cor- neas into medium II to enable reliable measurement of the donor corneal tissue after de-swelling [15].…”

Section: From Storage To Donor Tomographymentioning

confidence: 99%

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OCT Application for Sterile Corneal Graft Screening in the Eye Bank

Quintin

Hamon

Mäurer

et al. 2021

Klin Monbl Augenheilkd

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Background and Objective Sterile donor tomography enables the detection of corneal tissues with refractive anomalies. The aim of this study was to determine the curvature and thickness of donor corneas to support proper selection in the eye bank. Methods 704 donor corneas (Klaus Faber Center, LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz, in Homburg/Saar) were measured using the anterior segment optical coherence tomograph (AS-OCT) CASIA 2 (Tomey Corp., Nagoya, Japan). The corneoscleral discs were measured in their cell culture flask, which was positioned in a holder on the chin rest of the AS-OCT, after conversion to medium II (with 6% dextran T-500). The measured raw data were analysed and processed in MATLAB (MathWorks Inc., Natick, Massachusetts, USA), after which the refractive power of the steep and flat meridian at the anterior and posterior surface and the central corneal thickness (CCT) of the donor corneas were determined. Results values are expressed as mean x̅ ± standard deviation SD. Results The mean refractive power of the steep/flat meridian at the anterior surface was 45.4 ± 1.8 D/44.0 ± 1.3 D, the corresponding values for the posterior surface were − 6.2 ± 0.3 D/− 5.9 ± 0.2 D, and the mean CCT was 616.3 ± 85.1 µm. Of the 704 (100%) measured donor tissues, 590 (83.8%)/670 (95.2%) donor corneas showed no anomaly beyond respectively x̅ ± 2 SD/x̅ ± 3 SD among the 5 examined parameters. 72 (10.3%)/23 (3.3%) donor corneas had only 1 anomaly, 26 (3.7%)/10 (1.4%) had 2 anomalies, 10 (1.4%)/1 (0.1%), 3 anomalies, 5 (0.7%)/0 (0.0%), 4 anomalies, and 1 (0.1%)/0 (0.0%), 5 anomalies. Conclusions AS-OCT provides an objective and sterile screening method to identify corneal tissues with curvature anomalies in order to further optimise donor selection in the eye bank. To avoid postoperative refractive surprises, donor corneas with a total refractive power that deviates > ± 3 SD from the mean should not be used for penetrating or anterior lamellar keratoplasty, but may be suitable for posterior lamellar keratoplasty (DMEK or DSAEK). In the future, sterile donor tomography could enable: (1) the harmonisation of donor and recipient tomography, which may minimise residual astigmatism for a particular donor-recipient pair; and (2) the improvement of IOL power calculation in a classical triple procedure by means of regression analysis between pre- and postoperative total refractive power of corneal grafts.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: From Storage To Donor Tomographymentioning

confidence: 99%

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OCT Application for Sterile Corneal Graft Screening in the Eye Bank

Quintin

Hamon

Mäurer

et al. 2021

Klin Monbl Augenheilkd

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“…They were individually preserved and tested in a hydration preserving culture media containing 5% Dextran (Fig. 1) (Hamon et al, 2021).…”

Section: Experimental Set Upmentioning

confidence: 99%

Orientation and Depth Dependent Mechanical Properties of the Porcine Cornea: Experiments and Parameter Identification

Nambiar¹,

Liechti²,

Müller³

et al. 2022

SSRN Journal

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“…The possibility of qualifying CD in eye banks using topo- or tomographs had already been considered since 1999 (Terry et al 1999 ) but has made significant progress in recent years. Nowadays, donor tomography can be used in clinical routine as a screening method prior to keratoplasty (Seitz et al 2021 ; Quintin et al 2021a ) and has already been used, amongst others, to tailor out the best timepoint for changing from MI to MII before penetrating keratoplasty (Wolf et al 2009 ; Hamon et al 2021 ) to improve the IOL power calculation in classical triple procedure (Quintin et al 2021b ) and to “harmonize” the donor and recipient tomography (Mäurer et al 2020). However, the corneal tomographs were not developed for this purpose and other challenges when measuring CD under sterile conditions are the optical distortions of the culture container and image deterioration with culture media.…”

Section: Introductionmentioning

confidence: 99%

Reliability and efficiency of corneal thickness measurements using sterile donor tomography in the eye bank

et al. 2021

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To evaluate the reliability and efficiency of sterile pachymetric measurements of donor corneas based on tomographic data using two different methods: a “manual” and a “(semi-)automated” method. Twenty-five (25) donor corneas (50%) stored in MI and 25 (50%) in MII were imaged 5 times consecutively using an anterior segment OCT (AS-OCT). The central corneal thickness (CCT) was measured both with the manual measurement tool of the AS-OCT (= CCTm) and with a MATLAB self-programmed software allowing (semi-)automated analysis (= CCTa). We analyzed the reliability of CCTm and CCTa using Cronbach´s alpha (α) and Wilcoxon signed-Rank Test. Concerning CCTm, 68 measurements (54.4%) in MI and 46 (36.8%) in MII presented distortions in the imaged 3D-volumes and were discarded. Concerning CCTa, 5 (4%) in MI and 1 (0.8%) in MII were not analyzable. The mean (± SD) CCTm was 1129 ± 6.8 in MI and 820 ± 5.1 µm in MII. The mean CCTa was 1149 ± 2.7 and 811 ± 2.4 µm, respectively. Both methods showed a high reliability with a Cronbach´s α for CCTm of 1.0 (MI/MII) and for CCTa of 0.99 (MI) and 1.0 (MII). Nevertheless, the mean SD of the 5 measurements was significantly higher for CCTm compared to CCTa in MI (p = 0.03), but not in MII (p = 0.92). Sterile donor tomography proves to be highly reliable for assessment of CCT with both methods. However, due to frequent distortions regarding the manual method, the (semi-)automated method is more efficient and should be preferred.

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Thickness and Curvature Changes of Human Corneal Grafts in Dextran-Containing Organ Culture Medium Before Keratoplasty

Cited by 15 publications

References 30 publications

OCT Application for Sterile Corneal Graft Screening in the Eye Bank

OCT Application for Sterile Corneal Graft Screening in the Eye Bank

Orientation and Depth Dependent Mechanical Properties of the Porcine Cornea: Experiments and Parameter Identification

Reliability and efficiency of corneal thickness measurements using sterile donor tomography in the eye bank

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