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

2021 ◽  
Vol 8 ◽  
Author(s):  
Emilio Pedrotti ◽  
Erika Bonacci ◽  
Adriano Fasolo ◽  
Arianna De Rossi ◽  
Davide Camposampiero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Femtosecond Laser ◽  
Basal Layer ◽  
Corneal Stroma ◽  
Lamellar Keratoplasty ◽  
Human Donor ◽  
Air Drying ◽  
Anterior Lamellar Keratoplasty ◽  
Corneal Structure ◽  
Donor Corneas

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.

scholarly journals Femtosecond laser-assisted anterior lamellar keratoplasty (FSALK) versus microkeratome-assisted anterior lamellar keratoplasty (MALK) for the treatment of anterior corneal dystrophy.

2016 ◽  
Vol 15 (2) ◽  
Author(s):  
Radwan Almousa ◽  
Sheraz M Daya
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Visual Outcome ◽  
Corneal Dystrophy ◽  
Lamellar Keratoplasty ◽  
Secondary Outcome ◽  
Clinical Recurrence ◽  
Corneal Scarring ◽  
Anterior Lamellar Keratoplasty

Purpose: To compare the visual outcome of femtosecond laser-assisted anterior keratoplasty (FSALK) and microkeratome-assisted anterior lamellar keratoplasty (MALK) in anterior corneal dystrophy.  Methods: retrospective comparative chart review of 7 eyes that underwent FSALK and 7 eyes that underwent MALK. The primary outcome was the visual outcome of both procedures. The secondary outcome was the recurrence of the corneal dystrophies.Results: Mean follow-up time was 30±14(7-51) months for the FSALK group and 127±28(80-127) months for the MALK group. In the FSALK group the preoperative best spectacle-corrected visual acuity (BSCVA) improved from 20/63 to 20/25 at 36 months. In the MALK group there was 1 eye with documented BSCVA over 36 months follow-up; it improved from 20/160 preoperatively to 20/32 at 36 months. Uncorrected visual acuity (UCVA) at 36 months improved from 20/100 preoperatively to 20/63 in the FSALK group and from 20/200 preoperatively to 20/63 in the MALK group. Five eyes with Reis-Bucklers showed a clinical recurrence at a mean of 142±13(125-152) months. Two eyes with granular dystrophy showed a clinical recurrence at 23 and 80 months of follow-up. One eye in the MALK group had epithelial ingrowth. One eye in the FSALK group with compromised ocular surface due to 2 previous penetrating keratoplasty, suffered bacterial keratitis that ended up with corneal scarring. Conclusion: Both procedures improve visual outcome for anterior corneal dystrophy. FSALK has theoretical advantages over MALK; however, larger prospective studies are needed to prove this.

Femtosecond laser-assisted deep anterior lamellar keratoplasty: A safer option in keratoconus surgery

2021 ◽  
pp. 112067212110590
Author(s):  
Cristina Monterosso ◽  
Marco Antonini ◽  
Antonio Di Zazzo ◽  
Daniele Gaudenzi ◽  
Luigi Caretti ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Persistent Epithelial Defect ◽  
Corrected Visual Acuity ◽  
Anterior Lamellar Keratoplasty ◽  
Best Corrected Visual Acuity ◽  
Persistent Epithelial Defects

Purpose To evaluate postoperative safety of femtosecond laser deep anterior lamellar keratoplasty performed with an innovative anvil profile in keratoconus patients. Methods This is a single-center, retrospective cohort study. We reviewed medical records of 89 keratoconus patients that underwent femtosecond laser deep anterior lamellar keratoplasty surgery (46 eyes) and manual deep anterior lamellar keratoplasty (47 eyes). Inclusion criteria required: age > 18 years old, best-corrected visual acuity < 0.3 LogMAR, continuous suture of the graft, postoperative immunomodulant regimen with dexamethasone 0.1% for 6 months and at least 12 months follow-up. Previous eye surgery, hydrops, and other ocular disease were excluded. The main outcome measures were postoperative events: rejections, persistent epithelial defects, and graft failures. Results During the follow-up (20 ± 6 months) graft rejection was diagnosed in 0 of femtosecond laser deep anterior lamellar keratoplasty versus 6 (17%) of manual deep anterior lamellar keratoplasty [ p 0.027], persistent epithelial defect in 0 of femtosecond laser deep anterior lamellar keratoplasty versus in 4 (11%) of manual deep anterior lamellar keratoplasty [ p 0.048] and graft failure occurred in 4 (11%) of manual deep anterior lamellar keratoplasty. The best-corrected visual acuity, after removal of sutures, was better in the femtosecond laser deep anterior lamellar keratoplasty group 0.09 ± 0.08 LogMAR versus 0.16 ± 0.13 LogMAR in manual deep anterior lamellar keratoplasty [ p 0.035] group although refractive spherical equivalent and cylinder, topographic average keratometry and cylinder were similar. Conclusions Anvil-shaped femtosecond laser deep anterior lamellar keratoplasty in keratoconus surgery increases safety and readiness of recovery, decreasing the incidence of corneal rejection, epithelial defects, graft failures, and producing better best-corrected visual acuity after removal of sutures.

The Big-Bubble Full Femtosecond Laser-Assisted Technique in Deep Anterior Lamellar Keratoplasty

2015 ◽  
Vol 31 (12) ◽  
pp. 830-834 ◽  
Author(s):  
Luca Buzzonetti ◽  
Gianni Petrocelli ◽  
Paola Valente ◽  
Giancarlo Iarossi ◽  
Roberta Ardia ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Anterior Lamellar Keratoplasty ◽  
Big Bubble

scholarly journals Lamellar Keratoplasty: A Literature Review

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ladan Espandar ◽  
Alan N. Carlson
Keyword(s):  
Literature Review ◽  
Graft Rejection ◽  
Corneal Stroma ◽  
Surgical Instruments ◽  
Lamellar Keratoplasty ◽  
Endothelial Keratoplasty ◽  
New Techniques ◽  
Posterior Lamellar Keratoplasty ◽  
Acceptable Alternative ◽  
Anterior Lamellar Keratoplasty

The concept of lamellar keratoplasty (LK) is not new. However, newer forms of lamellar keratoplasty techniques have emerged in the last decade or so revolving around the concept of targeted replacement of diseased corneal layers. These include anterior lamellar keratoplasty (ALK) techniques that aim to selectively replace diseased corneal stroma and endothelial keratoplasty techniques aiming to replaced damaged endothelium in endothelial disorders. Recent improvements in surgical instruments and introduction of new techniques as well as inherent advantages such as preservation of globe integrity and decreased graft rejection have resulted in the reintroduction of LK as an acceptable alternative to conventional PK. In this review, indications, benefits, limitations, and outcomes of various anterior and posterior lamellar keratoplasty techniques are discussed.

scholarly journals Comparative Study of Corneal Endothelial Cell Damage after Femtosecond Laser Assisted Deep Stromal Dissection

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ting Liu ◽  
Jingjing Zhang ◽  
Dapeng Sun ◽  
Wenjie Sui ◽  
Yangyang Zhang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cell Damage ◽  
Endothelial Damage ◽  
Lamellar Keratoplasty ◽  
Control Group ◽  
Electron Microscopic ◽  
Anterior Lamellar Keratoplasty ◽  
Bed Thickness ◽  
Scanning Electron

Purpose.To find a relatively safe designed stromal bed thickness to avoid endothelial damage for lamellar keratoplasty with an Allegretto Wavelight FS200 femtosecond laser.Methods.Twelve rabbits were randomly divided into 50 μm and 150 μm groups according to the anticipated residue stromal bed thickness preparation with a femtosecond laser. Six rabbits without laser cutting were used as a control group. Central endothelial images were analyzed with in vivo confocal microscopy and scanning electron microscopy. The apoptosis of endothelium was evaluated with Hoechst 33342 staining and a TUNEL assay.Results.The endothelium of the 50 μm group had extensive injuries upon in vivo confocal and scanning electron microscopic observation, and minor injuries were observed in the 150 μm group. Moreover, more apoptotic cells were observed in the 50 μm group.Conclusions.When using a FS200 femtosecond laser assisted anterior lamellar keratoplasty, there was minor endothelium damage with a 150 μm stromal bed, and a more than 150 μm thickness stromal bed design may prevent the damage of corneal endothelium.

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