Femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty: 2-year outcomes of endothelial cell loss and graft survival

Purpose To assess 2-year endothelial cell loss and graft survival after femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty (FLS-DSEK). Methods In this prospective and noncomparative study carried out at Eye Hospital of Shandong First Medical University, 85 eyes (84 patients) with endothelial dysfunction receiving FLS-DSEK (n=62, 75.9%) or FLS-DSEK combined with phacoemulsification cataract surgery and intraocular lens implantation (n=23, 27.1%) from 2013 through 2016 were included. The graft endothelial cell loss, endothelial graft thickness, visual acuity, and complications after surgery were evaluated. Results Thin endothelial grafts were all successfully prepared, with no occurrence of perforation. The rate of endothelial cell loss was 17.4%, 18.8%, 19.9%, and 26.7%, and the central graft thickness was 113±54 μm, 102±40 μm, 101±28 μm, and 96±23 μm at 3, 6, 12, and 24 months, respectively. The median best-corrected visual acuity was 0.4 logMAR (range, 0–2 logMAR) at 24 months, demonstrating a significant difference from that before surgery (2 logMAR; range, 0.2–3 logMAR) (T=187.5, P<.001). Partial graft dislocation was the most common postoperative complication, with an occurrence rate of 14% (n=12), and it was associated with an abnormal iris-lens diaphragm (r=.35, P<.001). The other complications included a high intraocular pressure (n=5, 6%), endothelial graft rejection (n=4, 5%), and pupillary block (n=1, 1%). Endothelial graft decompensation occurred in the two eyes, and 98% (n=83) of the grafts survived at 24 months. Conclusions Data of the study suggest that the treatment using FLS-DSEK seems to be promising and might be considered a feasible choice in patients with endothelial dysfunction. Trial registration 1. Date of registration: 2021-02-18 2. Trial registration number: ChiCTR2100044091 3. Registration site: https://www.chictr.org.cn/

Nomogram for Single-pass Two-speed Automated Microkeratome Graft Preparation for Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

PurposeTo create a nomogram including the translational speed of the microkeratome blade, microkeratome head size and precut tissue thickness to predict the postcut thickness for Descemet stripping automated endothelial keratoplasty (DSAEK) to obtain the thinnest possible graft.MethodsThis prospective study incorporated 48 grafts for DSAEK from March 2017 to June 2020. Corneal tissue for DSAEK was prepared by 3 experienced physicians using the Moria Evolution 3E (Moria Inc, Antony, France) microkeratome with 400, 450 and 500 mm head sizes. Precut central corneal thickness was measured with a DGH 550 handheld pachymeter (Pachette 2), taking an average of 3 readings. The microkeratome head was selected according to precut tissue thickness. The target donor lamella thickness ranged from 70 to 120 μm, and the selected microkeratome head size was 150μm less than the donor cornea thickness. Two translational speeds were used for the microkeratome cuts. One month after surgery, the central lenticular thickness was measured with a Visante® Optical Coherence Tomography caliper (Carl Zeiss Meditec Inc, Germany). A descriptive analysis was performed.ResultsForty-eight donor grafts were prepared. Mean graft thickness was 97.58 ± 29.84 μm (range 39-176 μm). Of the 48 samples, central graft thickness was <120µm (81.3%) in 39, <100 µm (58.3%) in 28 and <80µm (37.5%) in 18 at 1-month follow-up. There were no statically significant differences between translational speeds. ConclusionsA nomogram with an automated microkeratome to obtain thin grafts for DSAEK provided good graft thickness results without donor waste.

Intraoperative optical coherence tomography guided corneal sweeping for removal of remnant Interface fluid during ultra-thin Descemet stripping automated endothelial keratoplasty

Background Remnant interface fluid following Descemet stripping automated endothelial keratoplasty (DSAEK) is associated with postoperative detachments. The aim of this study was to assess outcomes of intraoperative optical coherence tomography (iOCT) guided meticulous peripheral corneal sweeping for removal of interface fluid during ultra-thin (UT) DSAEK. Methods This retrospective study included all eyes underwent iOCT guided UT-DSAEK from October 2016 to February 2018 at the Hanusch Hospital, Vienna, Austria. Peripheral meticulous corneal sweeping was performed to remove excess fluid. Central graft thickness (CGT) was measured prior to surgery, after graft bubbling and after corneal sweeping. Remnant interface fluid rates were compared between eyes that underwent rebubbling and those that did not. Results Overall, 28 eyes of 28 patients with a mean age of 73.9 ± 10.0 years were included. An iOCT guided meticulous peripheral sweeping was performed in 89.3% (n = 25) of the cases. Following 84% (n = 21) of the peripheral sweeping performed, remnant fluid was no longer identified. Following peripheral sweeping the interface fluid height was reduced from 17.31 ± 15.96 μm to 3.46 ± 9.52 μm (p < 0.001) and CGT was reduced by 7% (p < 0.001). Rebubbling was performed in 17.9% (n = 5) of the cases. The rebubbling group had a greater proportion of patients that had remnant fluid identified with iOCT at the end of surgery despite meticulous peripheral sweeping (60.0% versus 4.4%, p = 0.01). Conclusion The iOCT identified subclinical remnant fluid in nearly 90% of UT-DSAEK cases. An iOCT guided peripheral corneal sweeping led to resolution of interface fluid in a majority of cases. Eyes with persistent remnant fluid despite peripheral corneal sweeping are more likely to require subsequent rebubbling.

The Effect of Perichondrium and Graft Modification on the Viability of Conchal Cartilage Graft: An Experimental Study in Rabbit

Objective: Cartilage grafts are widely used in reconstructing nasal deformity for structural and aesthetic purposes. Despite being immunologically privileged, cartilage grafts are susceptible to volume loss with high risk of resorption over time. Therefore, experts opt for cartilage handling modification to resolve this issue through graft dicing, wrapping, or perichondrium preservation. This study will evaluate the effect cartilage graft preparations on graft viability. Design: Single-randomized post-test-only study design. Setting: Animal Hospital at Bogor Agricultural Institute. Participants: Six New Zealand, male, Hycole rabbits. Intervention: Conchal cartilage grafts were retrieved from 6 experimental rabbits and distributed into 3 treatment groups: diced cartilage graft (DC; control), one-sided perichondrium-attached scored cartilage (OPSC), and tube-shaped perichondrium-wrapped diced cartilage (TPDC). Main Outcome Measures: Macroscopic (weight and contour) and microscopic (chondroblast proliferation, graft thickness, apoptotic cells) evaluation through histological measures were recorded on week 12. Statistical analysis was done to compare between groups. Results: Diced cartilage and OPSC groups showed significant weight changes on week 12 ( P < .05) with OPSC presenting with the biggest difference. Diced cartilage and OPSC group showed moderate cell proliferation on week 12 while TPDC displayed most abundant apoptotic cells (5.8%; P < .05). Diced cartilage group had the highest cartilage thickness ratio ( P < .05). Discussion: Bare DC technique promoted graft thickness while perichondrium-attached scored cartilage showed the most abundant chondroblast proliferation and the least apoptotic cells. Perichondrium contributes to enhanced new cartilage formation. Conclusion: Diced cartilage graft is suitable for masking irregularity and volume augmentation, while perichondrium-attached cartilage graft is better for structural support in nasal reconstruction.

The effects of laser displacement on femtosecond laser-assisted conjunctival autograft preparation for pterygium surgery

Aims To evaluate the effects of no-suction femtosecond laser (FSL) stability on conjunctival autograft (CAG) dissection in pterygium surgery. Methods Prospective analysis of 35 eyes from 34 subjects who underwent femtosecond laser-assisted pterygium surgery with the Ziemer Z8 laser (Ophthalmic Systems AG, Switzerland). Intraoperative absolute FSL displacements were measured and correlated with the duration and ease of CAG peel, CAG thickness, measured with intraoperative optical coherence tomography, and deviation from intended graft thickness. Results The median absolute FSL displacement was 22 μm (interquartile range [IQR] 14.7 to 60.8), while median vertical FSL displacement was 14.7 μm (IQR 7.3 to 44) and median horizontal FSL displacement was 22.0 μm (IQR 14.7 to 44). 65.7% had a grade 1 peel, 11.4% had grade 2 peel, 14.3% had grade 3 peel and 8.6% had grade 4 peel. The median duration of CAG peel was 5.4 seconds (IQR 3 to 21.4). The median CAG thickness was 69 μm (IQR 60.3 to 78.5), and the median deviation from targeted graft thickness was 9 μm (IQR 1 to 16). Eyes with more difficult peels and longer duration of CAG peels had significantly greater vertical FSL displacements (p = 0.04 and 0.02 respectively), but not horizontal displacement, age, ethnicity, CAG thickness or deviation from original thickness, compared to those with better quality and shorter duration peels. 1 eye (2.9%) had an incomplete CAG peel with a buttonhole and 2 eyes had graft tears (5.7%). Conclusion Micro-displacements during the suction-free CAG preparation are common but they did not affect the quality of the CAG peel, duration of peel, or CAG thickness. However, vertical globe displacement during FSL-assisted CAG creation was significantly associated with a more difficult and longer CAG peel duration. This highlights the importance of the cornea traction suture fixation to ensure stability of the eye during FSL application.

Results of posterior lamellar femto-keratoplasty using two different lasers

Purpose. To evaluate the results of treatment of patients with pseudophakic bullous keratopathy (PBK) by the method of posterior lamellar femto-keratoplasty with ultrathin graft (FS-DSEK) harvested using two different lasers. Material and methods. The results of surgical treatment of 82 patients (82 eyes) underwent posterior lamellar femto-keratoplasty for PBK were analyzed. In the 1st group included 43 patients (43 eyes) with PBK underwent FS-DSEK using FS laser Femto-Visum (Optosystems, Russia). In the 2nd group included 39 patients (39 eyes) with PBK underwent FS-DSEK using LDV Z8 (Ziemer, Switzerland). Observation period was 1 year. Before and after surgery following indicators were evaluated: uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), postoperative astigmatism, central corneal thickness (CCT), graft thickness, center-periphery (C:P) ratio, endothelial cell density (ECD), endothelial cell (EC) loss, optical density. Results. Transparent engraftment at 1-year observation period was observed in 88% of cases. In the 1st group UCVA=0.22±0.11, BSCVA=0.32±0.12, in the 2nd group UCVA=0.18±0.08, BSCVA=0.29±0.1 (p>0.05). The maximum BSCVA in both groups was 0.6. Postoperative astigmatism was comparative in 2nd groups – 1.43±1.1 and 1.38±1.0 D, respectively (p>0.05). In the 1st group, CCT=549±31, graft thickness in the central zone – 83±12, C:P ratio – 0.92±0.05; in the 2nd group CCT=546±28, graft thickness – 80±10, C:P ratio – 0.94±0.06 (p>0.05). In the 1st group ECD – 1326±282, EC loss – 55±6%; ECD in the 2nd – 850±230, EC loss – 70±7% (p<0.05). According to the results of densitometry, optical density of the posterior layers of the cornea and «donor–recipient» interface zone was higher in the 2nd group, both in the central and in the paracentral zones: in the 1st group in the posterior layers of the stroma – 16.4±1.2 (0–2 mm) and 15.8±1.0 (2–6 mm), in the interface zone – 14.5±0.9 (0–2) and 13.9±0.8 (2–6), in the 2nd group in the posterior layers – 18.3±1.3 (0–2 mm) and 17.9±1.1 (2–6 mm), and in the interface zone – 17.3±1.2 (0–2 mm) and 17.0±1.0 (2–6 mm, p<0.05). Conclusions. FS-DSEK showed high efficiency for treating patients with PBK. Functional results were comparative in 2nd groups. Statistical analysis showed highest safety of transplanted endothelium in the 1st group at 1-year observation period. Key words: pseudophakic bullous keratopathy, femtosecond laser, posterior lamellar keratoplasty, corneal endotheliumultrathin graft.

Standardized pachymetry-assisted manual lamellar dissection for Descemet stripping endothelial keratoplasty

Purpose: To present an alternative technique (Pachy-DSEK) for the manual preparation of thin endothelial lamellae in Descemet stripping endothelial keratoplasty (DSEK), as well as to evaluate its visual and anatomic outcomes. Methods: A retrospective chart review was conducted in 15 cases who underwent DSEK at a private eye clinic in Brazil (INOB, Brasília) from June 2017 to December 2019. All patients had ocular comorbidities and relative contraindications to Descemet membrane endothelial keratoplasty (DMEK). All endothelial lamellae were manually prepared by using a standardized technique. Best corrected visual acuity (BCVA), tomographic parameters and graft’s thickness were evaluated preoperatively and at 6 months. Endothelial cell counts were evaluated preoperatively and at 12 to 24 months. Results: During preparation there was one case (6%) of peripheral tear and no tissue was lost. At 6 months, the median BCVA improved from 1.60 to 0.40 logMAR ( p = 0.0009). There was no significant change in anterior ( p = 0.507) and posterior astigmatism ( p = 0.483), anterior ( p = 0.683) and posterior mean keratometry ( p = 0.767), and total corneal power ( p = 0.952). The median central graft thickness at 6 months was 80 µm. Ultrathin grafts (<130 µm) were achieved in 80% of cases. At 12 to 24 months endothelial cell count decreased significantly. Graft’s detachment occurred in two cases (13%) and endothelial rejection in one case (6%). Conclusion: By using ultrasonic pachymetry intra-operatively and standardizing graft preparation, most manually dissected endothelial lamellae were ultrathin. Pachy-DSEK was safe and effective for treating endothelial disfunction in eyes with ocular comorbidities. It may be a cost-effective alternative to automated dissection methods.

Inverted Posterior Femto-Keratoplasty: Quality of the Surface of the Corneal Section and Preliminary Clinical Outcomes

Purpose. To evaluate the quality of the surface of an ultra-thin donor transplant prepared from the endothelial surface of the cornea using a femtosecond laser and to demonstrate the preliminary clinical results. Patients and Methods. 4 eyes were operated: 3 with Fuch`s endothelial dystrophy and 1 with pseudophakic bullous keratopathy. All patients were treated with DSEK with an ultrathin graft prepared by Alcon Wavelight FS 200 femtosecond laser (Germany). Before and after surgery UCVA, BSCVA, astigmatism, ECD were measured. EC death, graft thickness and CCT were evaluated at 12 months` observation. Atomic force microscopy was used for examination of 10 samples. Control group was 5 corneal flaps obtained by mechanical microkeratome (Moria SLK-2, France). Main group — 5 corneal flaps, obtained by femtosecond laser. Nonparametric Mann-Whitney test was used for statistical analysis. Coefficient of reliability p < 0.05 was considered to be significant. Results. RMS value of femto-laser group samples was 18.6 ± 7.8 um. RMS of microkeratome group samples was 22.3 ± 18.3 um. Statistical analysis did not reveal significant differences between the values of the studied parameter in these groups (p > 0.05). Transparent engraftment was observed in all cases, no corneal edema was identified. BSCVA ranged from 0.2 to 0.6, which was associated with the presence of concomitant pathology. Astigmatism was 1.35 ± 1.0 D. ECD = 1526 ± 434 cells/mm2. EC loss = 48.0 ± 12.8 %. Graft thickness in the central zone was 78.0 ± 18.1 µm. Center-Edge Index — 0.84 ± 0.12. CCT = 600 ± 31 um. No postoperative complications were found. Conclusion. The developed settings allowed to obtain high-quality ultra-thin graft with a sufficiently uniform surface without a risk of perforation. Preliminary clinical results showed the method potential for restoration of corneal transparency. ECD loss corresponded to the one achievable by DSAEK.