Advances in refractive corneal lenticule extraction

Fuest, Matthias

doi:10.4103/tjo.tjo_12_21

Cited by 20 publications

(16 citation statements)

References 78 publications

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“…We used laser parameters that were consistent with our clinical practice, hence it shows the sensitivity of hydration of lenticule creation, with a low nJ-energy laser system. This is especially important with the newer lenticule procedures, e.g., CLEAR, SILK, and SmartSight that all use low nJ-energy laser systems (5).…”

Section: Discussionmentioning

confidence: 99%

“…The first commercially available femtosecond laser system capable of this was the VisuMax developed by Carl Zeiss Meditec (Jena, Germany), which trademarked their ReLEx procedure as Small Incision Lenticule Extraction (SMILE) (3,4). More recently Ziemer Ophthalmic Systems (Port, Switzerland), who developed the FEMTO LDV, introduced a similar procedure referred to as cornea Lenticule Extraction for Advanced Refractive-Correction (CLEAR) (5,6). Although the lasers have different technical specifications and employ different photodisruptive processes-VisuMax employs high nano Joule (nJ)-energy and low-frequency pulses, while FEMTO LDV employs low nJ-energy and highfrequency pulses (Table 1), both lenticule extraction procedures involve precise laser firings that photo-disrupt the stromal material creating a posterior and then anterior lenticular surface.…”

Section: Introductionmentioning

confidence: 99%

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Incisional surface quality of electron-beam irradiated cornea-extracted lenticule for stromal keratophakia: high nJ-energy vs. low nJ-energy femtosecond laser

Chan,

Han,

Lim

et al. 2023

Front. Med.

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IntroductionCorneal lenticules can be utilized as an additive material for stromal keratophakia. However, following extraction, they must be reimplanted almost immediately or cryopreserved in lenticule banks. Electron-beam (E-beam) irradiated corneas permit room-temperature storage for up to 2 years, enabling keratophakia to be performed on demand. This study aims to compare the performance of high nano Joule (nJ)-energy (VisuMax) and low nJ-energy (FEMTO LDV) femtosecond laser systems on the thickness consistency and surface quality and collagen morphology of lenticules produced from fresh and E-beamed corneas.MethodsA total of 24 lenticules with −6.00 dioptre power were cut in fresh human donor corneas and E-beamed corneas with VisuMax and FEMTO LDV. Before extraction, the thickness of the lenticules was measured with anterior segment-optical coherence tomography (AS-OCT). The incisional surface roughness of extracted lenticules was analyzed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Multiphoton microscopy was then used to assess the surface collagen morphometry.ResultsThe E-beamed lenticules that were cut using FEMTO LDV were significantly thicker than the fresh specimens as opposed to those created with VisuMax, which had a similar thickness as the fresh lenticules. On the vertex, they were ∼11% thicker than the fresh lenticules. The surface roughness (Rq) of E-beamed lenticules incised with FEMTO LDV did not differ significantly from the fresh lenticules. This contrasted with the VisuMax-fashioned lenticules, which showed notably smoother surfaces (∼36 and ∼20% lower Rq on anterior and posterior surfaces, respectively) on the E-beamed than the fresh lenticules. The FEMTO LDV induced less cumulative changes to the collagen morphology on the surfaces of both fresh and E-beamed lenticules than the VisuMax.ConclusionIt has been previously demonstrated that the low nJ-energy FEMTO LDV produced a smoother cutting surface compared to high nJ-energy VisuMax in fresh lenticules. Here, we showed that this effect was also seen in the E-beamed lenticules. In addition, lower laser energy conferred fewer changes to the lenticular surface collagen morphology. The smaller disparity in surface cutting quality and collagen disturbances on the E-beamed lenticules could be beneficial for the early visual recovery of patients who undergo stromal keratophakia.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Incisional surface quality of electron-beam irradiated cornea-extracted lenticule for stromal keratophakia: high nJ-energy vs. low nJ-energy femtosecond laser

Chan,

Han,

Lim

et al. 2023

Front. Med.

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“…An experiment on enucleated porcine eyeballs found more total laser application, longer time on suction peak pressure and surgery, but smoother lenticule surfaces under scanning electron microscopy in CLEAR compared with SMILE. 25,26 Future studies are suggested.…”

Section: Historical Synopsis Surgical Procedures and Applicabilitymentioning

confidence: 99%

Comparison of clinical outcomes of LASIK, Trans-PRK, and SMILE for correction of myopia

Chang

Lin

Hsu

et al. 2022

Journal of the Chinese Medical Association

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Transepithelial photorefractive keratectomy (Trans-PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) are three mainstay refractive surgeries worldwide. The applicability, efficacy, safety, and predictability of these different techniques are quite similar. Trans-PRK has the strongest biostability, earliest return to normal corneal sensitivity but the longest recovery time, most uncomfortable postoperative experience, and possibility of corneal haze. LASIK possesses the fastest visual rehabilitation but the slowest corneal nerve reinnervation, and flap displacement is possibly lifelong. SMILE incurs no flap-related complications and has intermediate vision recovery time and biomechanics compared with Trans-PRK and LASIK. However, it lacks the cyclotorsion-compensation system, eye-tracking system, and customized treatment profile for high astigmatism or irregular corneal surface. This review aims to introduce the mechanisms, pros, and cons of these three types of refractive surgery. With full understanding, practitioners could advise patients on the most suitable treatment of choice.

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“…The major application is refractive eye surgery for short-sighted customers to get rid of glasses and contact lenses. [17][18][19] In 2001, we realized the prototype of a femtosecond laser two-photon imaging device with submicron spatial resolution and picosecond temporal resolution for clinical use as well as application in the cosmetic industry based on an 80 MHz titanium sapphire laser. We performed the very first clinical label-free multiphoton imaging studies in the University Hospital of Jena on patients diagnosed with skin cancer, including malignant melanoma.…”

Section: Introductionmentioning

confidence: 99%

Femtosecond fiber laser for medical one-photon confocal reflectance microscopy and multiphoton tomography

König

2024

Multiphoton Microscopy in the Biomedical Sciences XXIV

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So far, medical confocal reflectance microscopy is based on continuous wave (cw) laser diodes operating at 830 nm, and medical multiphoton tomography (MPT) is conducted with tunable water-cooled 80 MHz femtosecond titanium:sapphire lasers with mean powers less than 50 mW. The femtosecond laser beam is guided through an optical arm. The major application is high-resolution label-free skin imaging ("optical virtual biopsy") to detect skin cancer. MPT has also been used to test anti-aging and pharmaceutical components in situ.Here, we report on the use of an ultracompact femtosecond fiber laser for high-resolution tissue imaging. In particular, the development of the PRISM AWARD 2024 winning multimodal multiphoton tomograph based on an ultracompact air-cooled 50/80 MHz fiber laser operating at 780 nm is presented. The 18x9x3.5 cm 3 laser head, consisting of a pulse compression unit and a SHG crystal, is positioned inside the 360° imaging head. An optical arm or a fiber delivery for transmitting the ultrashort near-infrared laser beam is no longer required. Interestingly, the femtosecond laser pulses, used for two-photon autofluorescence and SHG imaging, are also employed to realize simultaneous high-resolution (submicron) one-photon confocal microscopy. In addition, optical metabolic imaging (OMI) by time-correlated single photon counting and fluorescence lifetime imaging (FLIM) of autofluorescent coenzymes can be performed. The fifth imaging modality of this multimodal device is white LED far-field imaging for dermoscopy and to define regions of interest for confocal and multiphoton analysis. The novel "green" 230 W femtosecond fiber laser tomograph can be operated by batteries and charged by sunlight due to the reduced power consumption by 75 % when using the fiber laser system compared to the tunable titanium:sapphire laser. High-resolution confocal and multiphoton imaging with compact fiber lasers in remote areas and on the bedside of the patient becomes a reality.

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Advances in refractive corneal lenticule extraction

Cited by 20 publications

References 78 publications

Incisional surface quality of electron-beam irradiated cornea-extracted lenticule for stromal keratophakia: high nJ-energy vs. low nJ-energy femtosecond laser

Incisional surface quality of electron-beam irradiated cornea-extracted lenticule for stromal keratophakia: high nJ-energy vs. low nJ-energy femtosecond laser

Comparison of clinical outcomes of LASIK, Trans-PRK, and SMILE for correction of myopia

Femtosecond fiber laser for medical one-photon confocal reflectance microscopy and multiphoton tomography

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