Femtosecond Laser-assisted Penetrating Keratoplasty Research Articles

A Predictive Model for Graft Failure in Femtosecond Laser-Assisted Penetrating Keratoplasty Among Chinese Patients: A 2-Year Study.

Graft failure is a major challenge in femtosecond laser-assisted penetrating keratoplasty (Fs-PKP). This study focuses on the development and validation of a clinical predictive model aimed at identifying the risk of graft failure in individuals undergoing Fs-PKP in China, offering a tailored approach to improve surgical outcomes. This retrospective cohort study at Nanjing First Hospital involved 238 patients and followed the TRIPOD statement. The cohort was divided into a training set (n = 166) and a validation set (n = 72) in a 7:3 ratio. It analyzed 23 predictor variables related to recipient, donor, and surgical factors, defining graft failure as "visually significant and irreversible corneal stromal edema, haze, or scarring." A comprehensive nomogram was created using univariate and multivariate Cox regression analyses and assessed by concordance index (C-index), time-dependent receiver operating characteristics (ROC) curve, calibration plots, and decision curve analysis (DCA). Five critical risk factors were identified: recipients' history of systemic autoimmune disorders, ocular trauma, prior penetrating keratoplasty (PKP) history, donors' diabetes history, and the endothelial cell density of the donor cornea. The nomogram showed a C-index of 0.72 (95% CI 0.65-0.79) in the training group and 0.66 (95% CI 0.55-0.76) in the validation group, indicating robust predictive accuracy. Time-dependent ROC curves, calibration plots, and DCA consistently validated the model's reliability, predictive power, and clinical utility across both training and validation cohorts. Our study developed and validated a model incorporating five key factors, enhancing preoperative prediction and management for Chinese patients with Fs-PKP graft failure.

Femtosecond Laser Applications in Ophthalmic Surgery

Femtosecond laser’s ultra-fast pulse duration results in a precise cut with low thermal energy. This precise and directed energy with low collateral tissue damage has been shown to be advantageous for ocular surgery with proven safety and reproducibility. The history and science, of femtosecond lasers as well as their evolution in eye surgery is discussed. The practical and current use of femtosecond laser in eye surgery is presented including its application in laser assisted cataract surgery, laser assisted ketatomileusis flap creation, intracorneal ring segment placement, femtosecond lenticle extraction, small incision lenticle extraction, creation of tunnels for presbyopic correcting corneal inlays, and femtosecond laser assisted penetrating keratoplasty. In each of these applications, the benefits and risks of the femtosecond laser procedure are reviewed and potential future applications of femtosecond in the field of Ophthalmic Surgery are discussed.

Comparing the efficacy and safety of femtosecond laser-assisted vs conventional penetrating keratoplasty: a meta-analysis of comparative studies.

To investigate the safety and efficacy of femtosecond laser-assisted penetrating keratoplasty (FLAK) versus conventional penetrating keratoplasty (CPK). A literature search of PubMed, Cochrane, Embase, Web of Science, and Clinicaltrials.gov was conducted for comparative studies published from January 2007 to October 2019. Studies that involved both FLAK and CPK groups and reported on the relevant efficacy and/or safety parameters were included. The Newcastle-Ottawa quality assessment scale was used to analyse the methodological quality of these studies. Further, weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated. From the screened articles, a total of 1991 eyes from nine comparative studies were included. FLAK was not statistically superior for twelve-month postoperative best corrected visual acuity (WMD = -0.06; 95% CI [-0.16, 0.04]; P = 0.22), corneal astigmatism (WMD = -0.81; 95% CI [-1.63, 0.01]; P = 0.05) or six-month postoperative uncorrected visual acuity (WMD = -0.11; 95% CI [-0.27, 0.06]; P = 0.21). There were no significant differences in corneal graft rejection rate and the graft failure between FLAK and CPK at twelve months postoperative. However, best-corrected visual acuity (BCVA) and corneal astigmatism corrected with FLAK were better than those with CPK six months postoperative after elimination of data heterogeneity. Visual outcomes improvement in FLAK was better than that in CPK at six months postoperative, but not twelve months postoperative. This review recommends selecting a technique based on patients' work demands and economic burdens.

Visual outcome after femtosecond laser-assisted keratoplasty versus conventional penetrating technique

Purpose To evaluate and compare the visual outcome after femtosecond laser-assisted keratoplasty (FLAK) versus conventional penetrating technique. Settings and design This is a nonrandomized prospective comparative study that included a total of 30 eyes of 30 patients (16 females and 14 males) who underwent keratoplasty at three private eye centers in Assiut city, Egypt. These patients were divided into two groups: group I included 15 patients who were subjected to femtosecond laser-assisted penetrating keratoplasty and group II included 15 patients who were subjected to conventional penetrating keratoplasty (PKP). Patients and methods Visual outcome and intraoperative and postoperative complications were evaluated over a 18-month follow-up period. Statistical analysis Statistical analysis was performed using SPSS program. Student t test, paired sample t test, and χ2 test were used for the comparisons. Results Both uncorrected and best-corrected visual acuity showed marked improvement in both groups at 1, 3, 6, 12, and 18 months postoperatively. However, FLAK group showed statistically better uncorrected and best-corrected visual acuity at 3, 6, 12, and 18 months compared with conventional PKP group (all P<0.01). The mean sphere improved significantly in both groups at all follow-up periods. Flattest K (K1), steepest K (K2), and K mean showed a significant reduction in both groups at all follow-up periods with no significant differences between groups. Lower occurrence of postoperative complications was noticed in FLAK group compared with PKP group, with a nonsignificant difference (P=0.255). Conclusion Both techniques are effective, but FLAK has been shown to result in faster and better visual recovery, with significantly less astigmatism and lower complications compared with conventional PKP.

Conventional Penetrating Keratoplasty Versus Femtosecond Laser Assisted Penetrating Keratoplasty

Purpose: due to introduction of femtosecond Laser technology as new tool in penetrating keratoplasty (PKP), this study aims to compare this new tool and conventional PKP, also aims to compare between different shapes of femtosecond Laser (FSL) assisted PKP. Patients and methods: 40 eyes with different corneal pathologies were included in this study and they were categorized in to 2 groups. 20 eyes underwent penetrating keratoplasty by using manual trephination (I) and 20 eyes underwent PKP by using FSL assisted trephination (II). Results: femtosecond Laser assisted penetrating keratoplasty (FLAK) substantially improved wound healing, speeds up visual recovery and improved BCVA as it decreased MRA and corneal steepening but consumed more operative time. Conclusion: FLAK is the future in corneal graft surgery, where healing may not be a problem in the postoperative period

Endothelial cell density and corneal graft thickness following excimer laser vs. femtosecond laser-assisted penetrating keratoplasty\u2014a prospective randomized study

PurposeThe study aims to compare the impact of non-mechanical excimer laser-assisted (EXCIMER) and femtosecond laser-assisted (FEMTO) trephinations on graft endothelial cell density (ECD) and graft thickness before and after suture removal following penetrating keratoplasty (PK).MethodsThe inclusion criteria for this prospective, randomized, clinical study were as follows: (1) surgeries performed by one surgeon; (2) primary central PK; (3) keratoconus (KC) or Fuchs’ dystrophy (FUCHS); (4) no previous intraocular surgery; (5) graft oversize, 0.1 mm; and (6) 16-bite double-running suture. In 68 eyes of 68 patients (mean age: 53.3 ± 19.8 years), PK was performed using either 193-nm MEL70 excimer laser (“EXCIMER”: 17 KC, 18 FUCHS) or 60-KHz femtosecond laser (“FEMTO”: 17 KC, 16 FUCHS) trephination. Specular microscopy (EM 3000) and pachymetry (EM 3000; Pentacam HR; Casia SS-1000) were performed before removing the first suture (11.4 ± 1.9 months) and after removing the second suture (22.6 ± 3.8 months), but before any additional ophthalmic surgery.ResultsECD did not differ significantly (P ≥ 0.436) between EXCIMER and FEMTO either with “all-sutures-in” (1887 ± 409 vs. 1886 ± 438) or with “all-sutures-out” (1703 ± 379 vs. 1737 ± 362). Central corneal thickness and corneal thickness at the thinnest point of the cornea did not differ significantly between EXCIMER and FEMTO either with all-sutures-in (P ≥ 0.096 and P ≥ 0.653) or with all-sutures-out (P ≥ 0.636 and P ≥ 0.717).ConclusionsEXCIMER and FEMTO trephinations from the epithelial side seem to have no disadvantages regarding endothelial cell loss after PK, and both surgical procedures are safe for the endothelium. A larger sample size and longer follow-up are needed to evaluate the long-term impact of EXCIMER and FEMTO trephinations on ECD.

Femtosecond laser-assisted keratoplasty

To present our results on femtosecond laser-assisted penetrating keratoplasty. Twenty-five eyes of 25 patients underwent surgery with the following indications: pseudophakic bullous keratopathy (n = 10), keratoconus (n = 4), corneal dystrophy (n = 5), corneal scar (n = 4), band keratopathy (n = 2). Trephination of both the donor and recipient corneas were performed with VisuMax femtosecond laser device (Carl Zeiss Meditec AG, Jena, Germany). In each case, trephinaton of the donor tissue was performed first with an artificial anterior chamber (Moria, Antony, France). For the surgical plan and in the postoperative period we obtained different corneal imaging modalities. The corneal power was measured with corneal topography (TMS-4, Tomey, Nürnberg, Germany) and Scheimpflug tomography (Pentacam HR, Oculus, Wetzlar, Germany). The central corneal thickness was evaluated with Pentacam and corneal endothelial cell density was measured with specular microscopy (SP3000P, Topcon, Tokyo, Japan). The corneal structure was imaged with anterior segment optical coherence tomography (Visante, Carl Zeiss Meditec AG). All measurements were performed every 3 months in the first year and yearly thereafter. The follow-up period was 3 years in every case. The corrected decimal visual acuity showed an improvement from a preoperative 0.1 ± 0.1 to a postoperative 0.71 ± 0.18 value at the end of the follow-up period (p = 0.03). All corneal grafts maintained their transparency, there were no immunological rejection during the follow-up. Topographical astigmatism was 4.5 ± 3.1 D in the first month; it showed a decreasing tendency, but there was no significant change in the 3-year period. The mean central corneal thickness changed with 60 µm during the follow-up; there was no significant difference between the first month (564 ± 52 µm) and the third year (596 ± 64 µm) mean pachymetry values (p = 0.1). The mean endothelial cell density decreased first, then remained stable, but did not change significantly from the first (1641 ± 433 cells/mm2) to the last postoperative visit (1220 ± 391 cells/mm2, p = 0.1). In the case of femtosecond laser-assisted penetrating keratoplasty, trephination of the donor and recipient cornea is performed automatically in a highly precise fashion. The accurate cutting surface provides excellent wound apposition and healing. Both anatomical and functional rehabilitation of patients undergoing surgery are favourable and fast. Orv Hetil. 2018; 159(17): 671-676.

Does femtosecond laser assisted penetrating keratoplasty lead to less astigmatism in keratoconus patients, compared with conventional penetrating keratoplasy?

PurposeVisual impairing including high irregular astigmatism is a well‐known problem after penetrating keratoplasty (PK). The femtosecond (FS) laser technique allows completely new trephination methods such as the zig‐zag, top hat or the mushroom cutting profiles, which result in a more rapid and stable wound healing. In the present study we compare conventional PK and FS laser PK concerning astigmatism and visual outcome in keratoconus patients 2 years postoperativelyMethodsA total of 67 patients were operated with PK between September 2013 and June 2015 at Oslo University Hospital, Norway. All patients were examined 2 years after surgery. Ten keratoconus patients who were operated with FS laser‐assisted PK (FS group) were included, using Alcon Wavelight FS200 Femtosecond Laser, and compared with a control group who underwent conventional PK (n = 20). Controls were matched for diagnosis, age, gender and time of operation. Postoperative results regarding astigmatism and visual outcome were compared.ResultsAt the 2 years follow‐up, the mean logMAR BCVA was 0.17 ± 0.14 in the FS‐group and 0.16 ± 0.19 in the control group (p = 0.89). The mean spherical equivalent was ‐1.91 ± 4.58 in the FS‐group, and ‐3.08 ± 2.81 in the control group (p = 0.39). The mean subjective and corneal cylinder was ‐6.08 ± 2.50 and 7.71 ± 3.78 in the FS‐group, compared to ‐4.89 ± 2.57 (p = 0.24) and 5.73 ± 3.84 in the control group (p = 0.21), respectively. K‐mean was 44.00 D ± 3.99 in the FS‐group and 44.98 D ± 1.63 in the control group (p = 0.50). ECD was 1456 cells/mm²± 325 in the FS‐group, and 1679 cells/mm²± 475 in the control group (p = 0.22).ConclusionsEven though the study included relatively few eyes, the findings confirm previous studies. No significant difference in astigmatism or visual outcome was found between the two groups 2 years postoperatively.

Comparison of Long-Term Outcomes of Femtosecond Laser-Assisted Keratoplasty with Conventional Keratoplasty.

Astigmatism is a significant problem in penetrating keratoplasty. Lower astigmatism and better visual outcomes had been expected from laser-assisted penetrating keratoplasty, that is, from the top-hat, mushroom, or zig-zag cutting profiles. We report the long-term outcomes of 141 femtosecond laser-assisted penetrating keratoplasties retrospectively. We compare these outcomes with those of penetrating keratoplasty using the guided trephine system (GTS). In all, 141 femtosecond laser-assisted penetrating keratoplasties had been performed in 119 patients. The results were compared with those of conventional keratoplasty (n = 1254; visual and refractive outcomes, graft rejections, and graft failure). Follow-up averaged 33 months. In eyes with keratoconus, the time to achieve a visual acuity of 10/20 (Snellen) was shorter in the mushroom than in the GTS group. However, there was no relevant long-term difference. Graft astigmatism was higher in the laser groups [keratometric astigmatism at the end of follow-up: -4.5 ± 4 (GTS), -5.8 ± 3.3 (top-hat), -5.9 ± 3.2 D (mushroom); P < 0.01]. In eyes with keratoconus, rates of graft rejection were highest in the mushroom group (55%). In the other groups, top-hat keratoplasty resulted in lower rates of rejection than GTS keratoplasty (31%). There is no significant difference in the refractive and visual outcomes after femtosecond laser-assisted penetrating keratoplasty compared with GTS keratoplasty. The benefits from the use of the femtosecond laser may be limited and should be weighed against an increased risk of immune reactions, higher surgical complexity, and higher costs.

In Vivo Confocal Microscopic Imaging of the Cornea After Femtosecond and Excimer Laser-assisted Penetrating Keratoplasty.

To examine the microstructure of the cornea after excimer and femtosecond laser-assisted penetrating keratoplasty (ELAK and FLAK) in eyes with Fuchs' dystrophy and keratoconus. Fifty-seven patients were divided into four groups according to corneal disease and surgical technique: Fuchs' dystrophy and ELAK (n = 9; mean age: 70.4 ± 10.6 years); Fuchs' dystrophy and FLAK (n = 13; mean age: 64.3 ± 11.2 years); keratoconus and ELAK (n = 9; mean age: 47.4 ± 13.9 years); and keratoconus and FLAK (n = 9; mean age: 43.5 ± 13.8 years). The control group comprised individuals without ocular disease (n = 17; mean age: 39.9 ± 17.3 years). In vivo investigation of the corneal graft and graft-host junction zone was performed with confocal corneal microscopy. All corneal grafts were transparent and no rejection reaction could be observed during the follow-up period. Confocal microscopy revealed no difference in basal epithelial cell density compared to controls. Anterior keratocyte density was lower than in the control group (818 ± 131 cells/mm(2)) in all four treatment groups (596 ± 174, 586 ± 113, 529 ± 75, 552 ± 91 cells/mm(2)). Langerhans cells could barely be seen; there was no difference in the cutting edge configuration and wound integrity. In vivo confocal microscopy provided evidence that good alignment of graft-host junction could be created with both techniques. The excimer laser was not inferior to the femtosecond laser in performing corneal cuts. The low density of Langerhans cells revealed well-controlled cellular immunological response and sustained corneal integrity in both laser groups.

Early clinical research on the femtosecond laser assisted penetrating keratoplasty

Early clinical research on the femtosecond laser assisted penetrating keratoplasty

Laser welding in penetrating keratoplasty and cataract surgery in pediatric patients: Early results

To evaluate the efficacy of diode laser welding to close corneal wounds in penetrating keratoplasty (PKP) and cataract surgery in pediatric patients. Ophthalmology Department, Bambino Gesù Children's Hospital, Rome, Italy. Prospective observational study. Patients had surgery for congenital cataract (Group 1) or femtosecond laser-assisted PKP (Group 2). The surgery was followed by corneal wound closure using diode laser welding of the stroma. In Group 1, no standard suturing was used. In Group 2, the donor button was sutured onto the recipient using 8 single nylon sutures or a 10-0 nylon running suture (12 passages). Laser welding was then used as an adjunct to the traditional suturing procedure. Group 1 comprised 7 eyes (7 patients; mean age 8.1 years ± 5.3 [SD], range 1 to 15 years) and Group 2, 5 eyes (5 patients; mean age 10.6 ± 3.3 years, range 6 to 15 years). The adhesion of the laser-welded tissues was perfect; there were no collateral effects, and restoration of the treated tissues was optimum. Seidel testing showed no wound leakage during the follow-up. Postoperative astigmatism did not change significantly from the first day after cataract surgery and shifted moderately 3 months after PKP. Laser welding of corneal tissue appeared to be safe and effective in children for whom a sutureless surgical procedure is important to reduce the use of anesthesia for suture management, prevent endophthalmitis, and improve the antiamblyopic effect.

One-year follow-up of femtosecond laser-assisted penetrating keratoplasty

BackgroundThe purpose of this report is to describe the initial outcomes of femtosecond laser-assisted penetrating keratoplasty.MethodsThis retrospective surgical case series consisted of 10 eyes from 10 patients undergoing penetrating keratoplasty at a tertiary center. Femtosecond laser was used to perform a zig-square incision on the donor cornea with matched dimensions on the recipient cornea. Outcomes measured included: unaided visual acuity and best spectacle-corrected visual acuity preoperatively and at one, 3, 6, and 12 months postoperatively; manifest refractive and topographic astigmatism at 3, 6, and 12 months postoperatively; and endothelial cell density loss, calculated at the end of the one-year follow-up period.ResultsAt one-year follow-up, there was an improvement in unaided visual acuity from a mean preoperative logMAR of 1.67 to 0.44, and best spectacle-corrected visual acuity from a mean preoperative logMAR of 1.33 to 0.13. By postoperative month 3, mean manifest refractive and topographic astigmatism was 2.31 ± 1.41 D and 2.59 ± 1.57 D, respectively. The mean reduction in endothelial cell density was 20.7% after one year of follow-up.ConclusionFemtosecond laser-assisted penetrating keratoplasty provided a good visual outcome and early visual rehabilitation due to precise graft-host alignment and reduced astigmatism in the early postoperative months.

First Report of Traumatic Globe Rupture After Femtosecond Laser–Assisted Penetrating Keratoplasty

To describe the first reported case of traumatic globe rupture after femtosecond laser-assisted penetrating keratoplasty. A 21-year-old Hispanic man suffered a corneal laceration after blunt trauma leading to a visually significant corneal scar and aphakia. The patient underwent femtosecond laser-assisted penetrating keratoplasty using a zigzag-shaped wound with secondary intraocular lens placement. Eighteen months after surgery, he suffered another blunt trauma resulting in inferior dehiscence of his inferior penetrating keratoplasty wound, loss of uveal tissue, and extrusion of the scleral-fixated posterior chamber intraocular lens. The patient underwent repair of the wound dehiscence. Despite the theoretical advantages conferred by a shaped graft-host junction, a shaped penetrating keratoplasty wound created with femtosecond laser can still be subject to dehiscence from trauma.

Improved Wound Stability of Top-Hat Profiled Femtosecond Laser-Assisted Penetrating Keratoplasty In Vitro

The femtosecond laser is a new option for cutting corneal tissue at high precision. The "top-hat" profile has an overlapping graft-host interface at the edge because of a larger inner trephination diameter. This may enhance graft fixation, thus improving the outcome and accelerating rehabilitation after penetrating keratoplasty. Femtosecond laser top-hat keratoplasties with overlaps of 0 and 3 mm between inner and outer trephination diameters were performed in vitro. After trephination, the excised corneal buttons were readapted by different suturing profiles. Pressure in the artificial anterior chamber was then raised until we observed wound leakage and ultimately wound prolapse. Better wound stability was found in conjunction with all profiled trephinations. When using 4 interrupted sutures, wound leakage occurred at a median of 13.0 cm H2O (mean, 12.3 cm H2O) and "zero overlap," at 19.0 cm H2O (mean, 20.8 cm H2O) and 1-mm overlap, at 32.0 cm H2O (mean, 32.8 cm H2O) and 2-mm overlap, and at 48.5 cm H2O (mean, 49.4 cm H2O) and 3-mm overlap. Comparing zero overlap with the mean values of 1- to 3-mm overlaps, wound leakage happened at 13.0 (mean, 12.3) versus 32.0 (mean, 34.3) cm H2O with 4 interrupted sutures, at 57.5 (mean, 58.3) versus 61.0 (mean, 70.8) cm H2O with 8 interrupted sutures, at 31.5 (mean, 32.0) versus >97.0 (mean, 75.5) cm H2O with 1 running and 4 interrupted sutures, and at 34.0 (mean, 32.3) versus 80.0 (mean, 69.9) cm H2O with 1 running suture. The analysis of variance revealed a statistically significant increase in wound stability for all overlaps independently from the size of the overlap. Femtosecond laser-assisted profiles with even small overlaps for penetrating keratoplasty may make fewer sutures and earlier suture removal possible because of better wound stability, contributing to earlier visual recovery and helping to prevent wound rupture after trauma. However, further study is required to identify the optimum profile including the various technical parameters.

Clinical results of 123 femtosecond laser-assisted penetrating keratoplasties

Postoperative astigmatism following penetrating keratoplasty is a major problem after corneal transplantation. The main goal of new trephination techniques such as femtosecond laser or excimer-laser trephination is to improve refractive and visual outcomes. The femtosecond laser technique makes profiled corneal trephinations such as the top hat or mushroom profile possible. We present the postoperative outcome of femtosecond laser-assisted penetrating keratoplasties. We performed 123 femtosecond laser-assisted penetrating keratoplasties in 119 patients. The main outcome measures were intraoperative specifics, astigmatism, and irregularity in Orbscan corneal topography, as well as the occurrence of immune reactions and side-effects. All sutures have been removed in 49 of these 123 eyes. Their mean follow-up was 13.9 ± 4.5 months. Time to complete suture removal (n = 49) was 12.0 ± 3.7 months in the mushroom group and 9.8 ± 2.1 months in the top hat group. Mean astigmatism in Orbscan topography was 6.4 ± 3.0 diopters in the mushroom and 5.8 ± 4.6 diopters in the top hat group (all sutures out). Femtosecond laser-assisted penetrating keratoplasty is a safe surgical technique. Due to the steps in profiled trephinations, the wound area is larger and theoretically the wound healing is, thus, faster and more stable. Complete suture removal is possible at an earlier time point compared to conventional penetrating keratoplasty. However, refractive results are not superior to those following conventional trephination.

Comparison of Corneal Surface Higher-Order Aberrations After Endothelial Keratoplasty, Femtosecond Laser–Assisted Keratoplasty, and Conventional Penetrating Keratoplasty

To evaluate and compare corneal higher-order aberrations (HOAs) after Descemet stripping automated endothelial keratoplasty (DSAEK), femtosecond laser-assisted penetrating keratoplasty (FLAK), and conventional penetrating keratoplasty (PKP). A retrospective comparison of consecutive surgical series of 67 eyes of 59 patients between 1.5 and 19 months after corneal transplant surgery (22, 34, and 11 corneas underwent DSAEK, FLAK, and PKP, respectively, by a single surgeon). The main outcome measures were anterior and posterior corneal surface HOAs (Zernike polynomials, third to eighth order) determined with Scheimpflug photography at 4.0- and 6.0-mm optical zones and best spectacle-corrected visual acuity (BSCVA) (logarithm of the minimum angle of resolution equivalents). DSAEK had fewer total anterior HOAs compared with FLAK [P = 5.27 × 10(-5) (4.0 mm) and P = 1.02 × 10(-5) (6.0 mm)] and PKP [P = 1.82 × 10(-4) (4.0 mm) and P = 1.56 × 10(-4) (6.0 mm)] but greater total posterior HOAs than FLAK [P = 0.001 (4.0 mm) and P = 0.007 (6.0 mm)] and PKP [at 4.0-mm optical zone (P = 0.047)]. FLAK had fewer total anterior and posterior HOAs than PKP, but differences were not statistically significant. DSAEK grafts exhibited statistically significantly greater posterior HOAs than either type of PKP. The magnitude of anterior and posterior HOAs weakly correlated with BSCVA. DSAEK induces fewer anterior surface HOAs but greater posterior surface HOAs than FLAK or PKP. Differences between FLAK and PKP are not statistically significant. Anterior and posterior HOAs correlate weakly with poorer visual outcome and likely contribute to decreased BSCVA after keratoplasty.

Femtosekundenlaserassistierte perforierende Keratoplastik

The femtosecond laser technique allows completely new trephination methods in penetrating keratoplasty with profiles in the graft and the host cornea. The most common so-called profiled trephinations are the top hat and mushroom profiles. Due to the profile it is easier to get a watertight wound closure intraoperatively and due to the larger wound surface the wound healing is faster and more stable. This will possibly allow an earlier suture removal with final visual rehabilitation. First clinical results show that femtosecond laser-assisted penetrating keratoplasty is a safe surgical procedure. The long term results after complete suture removal will show whether the astigmatism results are better than those of conventional trephination techniques.

Minimizing the Risk of Disease Transmission During Corneal Tissue Processing

Corneal transplantation is undergoing significant change because the dysfunctional portion of the cornea may now be selectively transplanted. After recovery of corneoscleral tissue, further processing of such tissue as in microkeratome preparation of endothelial keratoplasty lenticules is defined as "open-container processing" by the Eye Bank Association of America. Airborne bacterial contamination during preparation of corneal tissue is a potential source of postoperative infection. This review addresses ways to minimize the risk of disease transmission as corneal tissue is processed for lamellar keratoplasty, endothelial keratoplasty, or femtosecond laser-assisted penetrating keratoplasty and to minimize risk to eye bank personnel or physicians preparing the tissue. Secondly, quality assurance measures are described that qualify the environment in which corneal tissue is being processed. We propose that the environment in which corneal tissue is being processed must be able to demonstrate acceptable levels of airborne microbial contamination annually as measured by settle plates to estimate airborne bacterial sedimentation. It is recommended that any environment where corneal tissue is prepared should meet the minimum standard of a conventional operating room which is <25 colony-forming unit per 90-mm settle plate per 1-hour exposure.

Femtosecond-assisted keratoplasty with fibrin glue–assisted sutureless posterior chamber lens implantation: New triple procedure

Abstract We report a surgical technique for managing bullous keratopathy secondary to anterior chamber intraocular lens (AC IOL). The technique comprises femtosecond laser–assisted penetrating keratoplasty and AC IOL exchange with fibrin glue–assisted sutureless posterior chamber intraocular lens (PC IOL) implantation (“glued IOL”). This new triple procedure combines the unique benefits of the femtosecond laser and the glued IOL, leading to stable wound configuration, decreased open-sky time, and less pseudophacodonesis, and there is less risk for the suture-related complications of transscleral suture fixation.