Deep anterior lamellar keratoplasty with dehydrated, 4 °C-stored, and rehydrated lenticules

Bonci, Paolo; Valle, Vincenzo Della; Bonci, Paola; Lodi, Roberto; Russo, Alessandra

doi:10.5301/ejo.2010.5972

Cited by 5 publications

(6 citation statements)

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“…The acceptable conditions for PK donors are donor age varying from 1 to 96 years [9][10][11][12][13][14][15][16], endothelial cell density between 2000 and ≥ 3000 cells/mm In contrast to penetrating keratoplasty, donors with quality ranging from fair to excellent are employed for DALK [20,21]. Furthermore, long-term preserved donor tissues completely devoid of cells are also transplanted [22][23][24][25]. One DALK study used donor cornea tissues with age between 12 and 72 years, graft rating from fair to excellent, endothelial cell density (ECD) between 1128 and 4255 cells/mm 2 , death-to-preservation time up to 56 hours, and storage time up to 13 days in Optisol medium (-4°C) [20].…”

Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

“…Another DALK study used donors with the following features: age between 28 and 88 years, ECD between 100 and 3300 cells/mm 2 , and storage time up to 35 days in organ culture medium (31°C) [21]. Long-term preserved corneas with mean storage time between 2.7 and 9.6 months are also used for DALK by some surgeons [22][23][24][25]. Frequently, lyophilization or chemical agents are used to dehydrate corneas before cryopreservation [22][23][24].…”

Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

“…Long-term preserved corneas with mean storage time between 2.7 and 9.6 months are also used for DALK by some surgeons [22][23][24][25]. Frequently, lyophilization or chemical agents are used to dehydrate corneas before cryopreservation [22][23][24]. However, it is possible to employ cryopreservation without dehydration before freezing as indicated by one study [25].…”

Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

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Donor Graft Quality Used for Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty

Feizi¹

2016

Advances in Eye Surgery

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Deep anterior lamellar keratoplasty (DALK) has been recently introduced as an alternative to penetrating keratoplasty (PK) for corneal pathologies not involving corneal endothelium. DALK does not rely on donor endothelium and requires less rigid criteria for donor corneal tissue quality. Therefore, it provides a greater availability of donor corneas that do not need perfectly healthy endothelium and high endothelial cell density to be suitable for PK. Furthermore, as lamellar corneal surgery expands the potential use of acellular corneal tissue, long-term preservation techniques are being revisited as a way to increase availability of corneal tissue to alleviate constraints of availability, cost, storage, and transportation in many countries. The recent alterations in the technique of corneal transplantation and hence the type of donor cornea tissues used for each technique, may require eye banks and corneal surgeons to reassess their selection criteria but it is important for any changes to be evidence-based. The purpose of this chapter, therefore, is to present an updated analysis on the type and quality of donor corneas used for PK and DALK, to evaluate the impact of donor and eye bank variables on the suitability of corneas for transplantation and then go on to determine whether any of these donor factors affect clinical outcomes, complications, and graft survivals.

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Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

Section: Type and Quality Of Donors Used For Pk And Dalkmentioning

confidence: 99%

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Donor Graft Quality Used for Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty

Feizi¹

2016

Advances in Eye Surgery

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“…The conventional preservation times of whole corneas and stromal lenticules can be lengthened by cryopreservation/vitrification (5), dehydration without freezing (6), glycerolization (7)(8)(9), lyophilization (or freeze-drying) (10)(11)(12), and sterilization by gamma irradiation (13).…”

Section: Introductionmentioning

confidence: 99%

Ultrastructural Analysis of Rehydrated Human Donor Corneas After Air-Drying and Dissection by Femtosecond Laser

et al. 2021

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Purpose: To evaluate the efficiency of femtosecond laser (FSL) incision of rehydrated human donor corneas after air-drying and its effects on corneal structure.Methods: We compared the rehydrated and fresh-preserved corneas by microscopy following Victus-Tecnolas FSL treatment for straight-edge anterior lamellar keratoplasty (ALK). The corneas were dehydrated at room temperature under a laminar-flow hood.Results: To obtain the horizontal cut in rehydrated corneas, we increased the FSL pulse energy to 1.2 μJ from 0.80 μJ applied for the fresh corneas and obtained a clear-cut separation of the lamellar lenticule cap from the corneal bed. Light microscopy showed regular arrangement of stromal collagen lamellae, with spaces in between the fibers in the corneal stroma in the fresh and the rehydrated corneas, but the uppermost epithelial layers in the rehydrated corneas were lost. Transmission electron microscopy (TEM) revealed no signs of thermal or mechanical damage to the corneal structure. The epithelial basal membrane and Bowman's layer maintained their integrity. The epithelial basal layer and cells were separated by large spaces due to junction alteration in the rehydrated corneas. There were gaps between the lamellar layers in the stroma, especially in the rehydrated corneas. Keratocytes displayed normal structure in the fresh corneas but were devoid of microorganules in the rehydrated corneas. Minor irregularities were observed in the vertical incision and the horizontal stroma appeared smooth on scanning electron microscopy.Conclusion: The corneal stroma of rehydrated corneas maintained morphology and integrity, while corneal cellular components were generally altered. When corneas are intended for FSL-assisted ALK, effective stromal bed incision is best achieved at a laser power higher than that currently adopted for fresh corneas.

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“…Optical keratoplasty includes penetrating keratoplasty, deep anterior lamellar keratoplasty, and Descemet's membrane exposure full-bed deep anterior lamellar keratoplasty (FBDALK) (Yao et al, 2002;Yao, 2008;Bonci et al, 2011;Wu et al, 2012;Zhang et al, 2013;Javadi et al, 2014). The purpose of surgery is to restore the patient's visual function as much as possible.…”

Section: Introductionmentioning

confidence: 99%

Effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty

Wang

Xie

et al. 2018

J. Zhejiang Univ. Sci. B

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Objective: To investigate the effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty (FBDALK). Methods: This is a retrospective analysis of patients who were diagnosed with advanced keratoconus between 2011 and 2014 in our hospital. The base of the cone in all patients did not exceed the central cornea at a 6-mm range. The FBDALK was performed by a same surgeon. All patients had a complete corneal suture removal and the follow-up records were intact. Patients who had graft-bed misalignment or who were complicated with a cataract or glaucoma were excluded. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), and Pentacam examination data were recorded at two years postoperatively. The recorded data included the superior-inferior (S-I) and nasal-temporal (N-T) corneal thickness differences in 2, 4, 6, and 8 mm diameter concentric circles with the corneal apex as the center (S-I 2 mm , S-I 4 mm , S-I 6 mm , S-I 8 mm , N-T 2 mm , N-T 4 mm , N-T 6 mm , and N-T 8 mm), the linear, X-axis, and Y-axis distance between the corneal pupillary center and the cornea apex, total corneal astigmatism at a zone of 3 mm diameter from the corneal apex (TA 3 mm), the astigmatic vector values J 0 and J 45 , and the corneal total higher-order aberration for 3 and 6 mm pupil diameters (HOA 3 mm and HOA 6 mm). Statistical analysis was performed by SPSS 15.0. Results: A total of 47 eyes of 46 patients met the criteria and were included in this study. The mean follow-up time was (28±7) months. The mean UCVA was 0.45±0.23 (logMAR) (MAR: minimum angle of resolution) and the mean BSCVA was 0.19±0.15 (logMAR), which were all significantly positively correlated with postoperative TA 3 mm and HOA 3 mm. The mean S-I corneal thickness differences were (44.62±37.74) μm, and the mean N-T was (38.57±32.29) μm. S-I 2 mm was significantly positively correlated with J 0 (r=0.31), J 45 (r=0.42), HOA 3 mm (r=0.37), and HOA 6 mm (r=0.48). S-I 4 mm and S-I 8 mm were significantly positively correlated with HOA 3 mm (r=0.30, r=0.40) and HOA 6 mm (r=0.46, r=0.35). The X-axis distance between corneal pupillary center and corneal apex was significantly positively correlated with J 45 (r=0.29). Conclusions: In patients with advanced keratoconus after FBDALK, the unevenly distributed thickness at corneal pupillary area and the misalignment of corneal apex and pupillary center might cause significant regular and irregular astigmatism, which affected the postoperative visual quality.

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Deep anterior lamellar keratoplasty with dehydrated, 4 °C-stored, and rehydrated lenticules

Abstract: The results showed that the method of preservation and distribution of dehydrated, 4 °C stored, and rehydrated lenticules is safe, cheap, and simple. Furthermore, it does not appear to influence the outcomes of the DALK surgery.

Cited by 5 publications

References 0 publications

Donor Graft Quality Used for Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty

Donor Graft Quality Used for Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty

Ultrastructural Analysis of Rehydrated Human Donor Corneas After Air-Drying and Dissection by Femtosecond Laser

Effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty

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