Optimization of femtosecond lasers using porcine and human donor corneas before in vivo use

Stoddard, Jenna E.; Marneris, Athanasios G.; Borr, Matthew J.; Keil, Michael

doi:10.1016/j.jcrs.2018.03.035

Cited by 2 publications

(1 citation statement)

References 5 publications

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“…We included 220 paired porcine eyes, freshly obtained from a local abattoir and macroscopically inspected for damage, haze, oedema or surface irregularities. Porcine corneas provide a well-established ex vivo animal model for preclinical research on corneal procedures, with reported central corneal thickness (CCT) ex vivo of approximately 920 µm, shown to remain stable for up to 24 hr after enucleation (Jay et al 2008;Nibourg & Koopmans 2014;Stoddard et al 2018).…”

Section: Ex Vivo Porcine Modelmentioning

confidence: 99%

Excimer laser‐assisted corneal epithelial pattern ablation for corneal cross‐linking

Brekelmans

Dickman

Verma

et al. 2021

Acta Ophthalmologica

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Purpose To determine corneal cross‐linking (CXL) efficacy and chromophore penetration after excimer laser‐assisted patterned de‐epithelialization. Methods Two‐hundred‐twenty porcine eyes were de‐epithelialized ex vivo, either fully (mechanical; n = 88) or patterned (excimer laser; n = 132). Consecutively, corneas were impregnated with hypo‐ or hyperosmolar riboflavin (RF; n = 20, RF‐D; n = 40, respectively) or water‐soluble taurine (WST11; n = 40, and WST‐D; n = 40, respectively), or kept unimpregnated (n = 80). Sixty corneas were subsequently irradiated, inducing CXL, with paired contralateral eyes serving as controls. Outcome measurements included strip extensiometry to assess CXL efficacy, and spectrophotometry and fluorescence microscopy to determine stromal chromophore penetration. Results All tested chromophores induced significant CXL (p < 0.001), ranging from 7.6% to 14.6%, with similar stiffening for all formulations (p = 0.60) and both de‐epithelialization methods (p = 0.56). Light transmittance was significantly lower (p < 0.001) after full compared with patterned de‐epithelialization. Stromal chromophore penetration was comparable between fully and patterned de‐epithelialized samples, with full penetration in RD and RF‐D samples and penetration depths measuring 591.7 ± 42.8 µm and 592.9 ± 63.5 µm for WST11 (p = 0.963) and 504.2 ± 43.2 µm and 488.8 ± 93.1 µm for WST‐D (p = 0.669), respectively. Conclusions Excimer laser‐assisted patterned de‐epithelialization allows for effective CXL. Stromal chromophore concentration is, however, reduced, which may have safety implications given the need for sufficient UVA attenuation in RF/UVA CXL. The different safety profile of near‐infrared (NIR) may allow safe WST11/NIR CXL even with reduced stromal chromophore concentration values. In vivo studies are needed to evaluate the benefits and further assess safety of excimer laser‐assisted patterned de‐epithelialization for corneal CXL.

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Section: Ex Vivo Porcine Modelmentioning

confidence: 99%

Excimer laser‐assisted corneal epithelial pattern ablation for corneal cross‐linking

Brekelmans

Dickman

Verma

et al. 2021

Acta Ophthalmologica

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Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus

et al. 2021

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Purpose To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus. Methods We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest. Results Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty. Conclusions Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.

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Optimization of femtosecond lasers using porcine and human donor corneas before in vivo use

Cited by 2 publications

References 5 publications

Excimer laser‐assisted corneal epithelial pattern ablation for corneal cross‐linking

Excimer laser‐assisted corneal epithelial pattern ablation for corneal cross‐linking

Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus

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