Effects of femtosecond laser-assisted trephination on donor tissue in liquid interface as compared to applanated interface.

PURPOSE: To evaluate the effects of femtosecond laser-assisted keratoplasty using a liquid patient interface (L-PI) as opposed to an applanated interface (A-PI) on graft quality and functionality markers. METHODS: Pressure measurements during femtosecond laser-assisted trephination were performed using two groups of 10 porcine eyes. Trephination was performed either in an L-PI or in an A-PI setting. Pressure sensor needles placed intravitreally continuously recorded intraocular pressure during trephination. Twenty paired human donor eyes were used to test the morphological quality of donor tissue after trephination in L-PI and A-PI settings. Optical coherence tomography (OCT) scans were performed before and after trephination. Images were processed using ImageJ and pixel2 . RESULTS: During trephination, pressure measurements with an L-PI were significantly lower than with an A-PI (p = 0.0121). Mean pressure during trephination was 78.1 mmHg ± 37.6 mmHg with L-PI and 188.6 mmHg ± 17.7 mmHg with A-PI. Trephination in A-PI produced a significantly larger increase (p < 0.00001) in donor pachymetry than trephination in L-PI. Significantly lower areas of Descemet folds were achieved in L-PI trephination than in A-PI trephination (p < 0.01). There was no significant difference in circularity between A-PI and L-PI (p = 0.27). Total time required for trephination was comparable between L-PI and A-PI (p = 0.45). Time taken to reach working vacuum was achieved significantly more quickly in L-PI (p < 0.05). CONCLUSION: Femtosecond laser-assisted L-PI keratoplasty appears to be a promising method to decrease stress to donor and recipient tissue during femtosecond laser-assisted trephination. Results showed favourable donor tissue morphology markers after L-PI trephination.

Comparison of Excimer Laser Versus Femtosecond Laser Assisted Trephination in Penetrating Keratoplasty: A Retrospective Study.

INTRODUCTION: To compare the impact of non-mechanical excimer-assisted (EXCIMER) and femtosecond laser-assisted (FEMTO) trephination on outcomes after penetrating keratoplasty (PK). METHODS: In this retrospective study, 68 eyes from 23 females and 45 males (mean age at time of surgery, 53.3 ± 19.8 years) were included. Inclusion criteria were one surgeon (BS), primary central PK, Fuchs' dystrophy (FUCHS) or keratoconus (KC), no previous intraocular surgery, graft oversize 0.1 mm and 16-bite double running suture. Trephination was performed using a manually guided 193-nm Zeiss Meditec MEL70 excimer laser (EXCIMER group: 18 FUCHS, 17 KC) or 60-kHz IntraLase™ femtosecond laser (FEMTO group: 16 FUCHS, 17 KC). Subjective refractometry (trial glasses) and corneal topography analysis (Pentacam HR; Casia SS-1000 AS-OCT; TMS-5) were performed preoperatively, before removal of the first suture (11.4 ± 1.9 months) and after removal of the second suture (22.6 ± 3.8 months). RESULTS: Before suture removal, mean refractive/AS-OCT topographic astigmatism did not differ significantly between EXCIMER and FEMTO. After suture removal, mean refractive/Pentacam/AS-OCT topographic astigmatism was significantly higher in the FEMTO (6.2 ± 2.9 D/7.1 ± 3.2 D/7.4 ± 3.3 D) than in the EXCIMER patients (4.3 ± 3.0 D/4.4 ± 3.1 D/4.0 ± 2.9 D) (p ≤ 0.005). Mean corrected distance visual acuity increased from 0.22 and 0.23 preoperatively to 0.55 and 0.53 before or 0.7 and 0.6 after suture removal in the EXCIMER and FEMTO groups, respectively. Differences between EXCIMER and FEMTO were only pronounced in the KC subgroup. CONCLUSION: Non-mechanical EXCIMER trephination seems to have advantages regarding postoperative corneal astigmatism and visual acuity compared with FEMTO trephination, especially in KC. A bigger sample size and longer follow-up are needed to evaluate the long-term impact of EXCIMER and FEMTO trephination on postoperative topographic and visual outcomes.

Three-Dimensional Optical Coherence Tomography Imaging For Glaucoma Associated With Boston Keratoprosthesis Type I and II.

PRECIS: Three-dimensional (3D) spectral domain optical coherence tomography (OCT) volume scans of the optic nerve head (ONH) and the peripapillary area are useful in the management of glaucoma in patients with a type I or II Boston Keratoprosthesis (KPro). PURPOSE: The purpose of this study was to report the use of spectral domain OCT in the management of glaucoma in patients with a type I or II Boston KPro. MATERIALS AND METHODS: This study is an observational case series. Four consecutive patients with KPro implants were referred for glaucoma evaluation. A comprehensive eye examination was performed which included disc photography, visual field testing, and high-density spectral domain OCT volume scans of the ONH and the peripapillary area. 2D and 3D parameters were calculated using custom-designed segmentation algorithms developed for glaucoma management. RESULTS: Spectral domain OCT parameters provided useful information in the diagnosis and management of 4 KPro patients. OCT parameters which can be used in KPro patients included 2D retinal nerve fiber layer (RNFL) thickness, 3D peripapillary RNFL volume, 3D peripapillary retinal thickness and volume, 3D cup volume, and 3D neuroretinal rim thickness and volume. In 3 of 4 cases where the traditional 2D RNFL thickness scan was limited by artifacts, 3D spectral domain OCT volume scans provided useful quantitative objective measurements of the ONH and peripapillary region. Therefore, 3D parameters derived from high-density volume scans as well as radial scans of the ONH can be used to overcome the limitations and artifacts associated with 2D RNFL thickness scans. CONCLUSIONS: Spectral domain OCT volume scans offer the possibility to enhance the evaluation of KPro patients with glaucoma by using both 2D and 3D diagnostic parameters that are easily obtained in a clinic setting.

Management of Descemet Membrane's Folds After Deep Anterior Lamellar Keratoplasty: Descemet Membrane-Tucking Technique.

PURPOSE: To describe a surgical maneuver that allows for correction of central Descemet membrane (DM) folds at the end of a deep anterior lamellar keratoplasty (DALK) procedure. We term the present technique "DM tucking." METHODS: A blunt tip spatula is introduced vertically into the trephination cut, 90 degrees away from the main direction of the DM folds, and advanced until it touches the host layer. Gentle pressure is applied, resulting in tucking of the redundant host layer toward the periphery. The tucking maneuver is repeated at different clock hours until a regular graft-host interface is obtained. RESULTS: We applied the present technique to several DALK procedures performed for keratoconus, and found it to be safe and effective. CONCLUSIONS: DALK is the procedure of choice for the surgical treatment of corneal stromal diseases with a healthy endothelium, such as keratoconus. DM folds are a possible complication after DALK in patients with advanced corneal ectasia, arising from the compression of the redundant host DM by the donor graft, once it is sutured to the recipient. DM folds after DALK, when they involve the visual axis, cause permanent visual disturbances DM tucking allows the displacement of the central DM folds toward the graft margin, where they do not affect the patient's quality of vision.

Modified penetrating keratoplasty with Acell® bioscaffold implant in seven horses with deep full-thickness corneal stromal abscess.

OBJECTIVE: To describe and evaluate a modified penetrating keratoplasty technique utilizing ACell® for management of equine deep stromal or full-thickness corneal stromal abscesses (SA). METHODS: Cases presenting to the University of Georgia Ophthalmology service for surgical management of SA necessitating penetrating keratoplasty (PK) were included in the study population. Surgery entailed the use of an ACell® disk sutured within the deep level of a stepped full-thickness corneal incision with an overlying conjunctival pedicle flap placed in the superficial step incision. Patients were evaluated for success as defined by a comfortable, visual outcome. RESULTS: Surgery was performed in seven horses. Conjunctival flap incorporation and globe retention occurred in all patients. Functional vision was maintained in six of seven eyes (85.7%) at last follow-up examination (mean of 87.6 days [range 41-251 days]). Mean size of ACell® implant was six millimeters (range 4-8 mm). Postoperative complications included moderate to severe anterior uveitis (n = 2), diffuse keratitis (n = 1), incipient cataract formation (n = 3), and anterior and posterior synechiae (n = 1). CONCLUSIONS: This technique is a viable option for treatment of equine SA requiring PK. The use of bioscaffold implant is an alternative to frozen and fresh donor cornea transplantation.

[Objective assessment of donor material for penetrating corneal transplantation]. / Ob''ektivizatsiia otsenki donorskogo materiala dlia skvoznoi peresadki rogovitsy.

Reliable suitability evaluation of donor material is the crucial issue of penetrating corneal transplantation. The main parameter to be considered is endothelial cell density (ECD). However, when it comes to practice, one has to admit significant variation in ECD readings of cadaver corneas obtained by different methods. AIM: to investigate discrepancies in ECD measurements and to define objective criteria for the evaluation of a donor cornea before full-thickness grafting. MATERIAL AND METHODS: In a hundred cadaver eyes, discrepancies in ECD measurements by different methods (specular microscopy, confocal microscopy, and keratoanalyzer) were studied and objective evaluation criteria developed along with an optimal algorithm of pretransplantation assessment. Digital fluorescence microscopy was chosen as the reference method. RESULTS: It has been established that a triple measurement average obtained with any of the tested methods is informative enough as to the state of the donor cornea. CONCLUSION: The highest ECD values were obtained with specular microscopy, the lowest - with confocal microscopy. For reliable evaluation of donor corneas, we recommend that the average of a triple ECD measurement be taken using one of the mentioned methods.

Anterior Synechiolysis with Healon Needle and Ophthalmic Viscosurgical Devices after Anterior Lamellar Dissection in Penetrating Keratoplasty.

PURPOSE: We described a technique to perform anterior synechiolysis with a healon needle and Viscoat® ophthalmic viscosurgical devices (OVDs) through anterior lamellar dissection in penetrating keratoplasty. METHODS: OVDs were gently injected between iridocorneal adhesions with a healon needle to make a blunt dissection after anterior lamellar corneal dissection. Anterior synechiolysis at 360 degrees was completed with a healon needle and OVDs. Subsequently, the deep corneal lamella was cut with right and left Troutman-Katzin corneal scissors. 24 interrupted sutures were made with 10-0 nylon suture to implant the donor cornea. RESULTS: In two eyes from two patients, with corneal opacity and nearly total anterior synechiae, clear grafts and relatively deep anterior chambers were achieved. Penetrating keratoplasty with anterior synechiolysis was thus successful with a healon needle and OVDs through lamellar dissection. CONCLUSIONS: Anterior synechiolysis with a healon needle and OVDs through lamellar dissection is a safe and efficient technique for keratoplasty in patients with corneal opacity with anterior synechiae.

A Two-Piece Microkeratome-Assisted Mushroom Keratoplasty Improves the Outcomes and Survival of Grafts Performed in Eyes with Diseased Stroma and Healthy Endothelium (An American Ophthalmological Society Thesis).

PURPOSE: To test the hypothesis that a new microkeratome-assisted penetrating keratoplasty (PK) technique employing transplantation of a two-piece mushroom-shaped graft may result in better visual outcomes and graft survival rates than those of conventional PK. METHODS: Retrospective chart review of 96 eyes at low risk and 76 eyes at high risk for immunologic rejection (all with full-thickness central corneal opacity and otherwise healthy endothelium) undergoing mushroom PK between 2004 and 2012 at our Institution. Outcome measures were best-corrected visual acuity (BCVA), refraction, corneal topography, endothelial cell density, graft rejection, and survival probability. RESULTS: Five years postoperatively, BCVA of 20/40 and 20/20 was recorded in 100% and over 50% of eyes, respectively. Mean spherical equivalent of refractive error did not vary significantly over a 5-year period; astigmatism averaged always below 4 diopters, with no statistically significant change over time, and was of the regular type in over 90% of eyes. Endothelial cell density decreased to about 40% of the eye bank count 2 years after mushroom PK and did not change significantly thereafter. Five years postoperatively, probabilities of graft immunologic rejection and graft survival were below 5% and above 95%, respectively. There was no statistically significant difference in endothelial cell loss, graft rejection, and survival probability between low-risk and high-risk subgroups. CONCLUSIONS: Refractive and visual outcomes of mushroom PK compare favorably with those of conventional full-thickness keratoplasty. In eyes at high risk for immunologic rejection, mushroom PK provides a considerably higher probability of graft survival than conventional PK.

A new technology for applanation free corneal trephination: the picosecond infrared laser (PIRL).

The impact of using a Femtosecond laser on final functional results of penetrating keratoplasty is low. The corneal incisions presented here result from laser ablations with ultrafast desorption by impulsive vibrational excitation (DIVE). The results of the current study are based on the first proof-of-principle experiments using a mobile, newly introduced picosecond infrared laser system, and indicate that wavelengths in the mid-infrared range centered at 3 µm are efficient for obtaining applanation-free deep cuts on porcine corneas.

Novel spatula and dissector for safer deep anterior lamellar keratoplasty / Uso de espátula e dissector para otimização da ceratoplastia lamelar anterior profunda (DALK)

Objective: We describe a novel spatula and dissector to facilitate the big-bubble technique in deep anterior lamellar keratoplasty (DALK). Methods: A 29-year-old man who was diagnosed with bilateral keratoconus underwent deep anterior lamellar keratoplasty (DALK). After 350μm partial thickness incision of the recipient cornea, the Bonfadini dissector was inserted at the deepest point in the peripheral incision and could be advanced to the center of the cornea safely because of its "semi-sharp" tip. After achieving the big-bubble (BB) separation of Descemet membrane (DM) from the overlying stroma, the anterior stromal disc was removed. Viscoelastic material was placed on the stromal bed to prevent uncontrolled collapse and perforation of DM during the paracentesis blade incision into the BB. We could detect the safe opening of the BB using the Bonfadini dissector by the leakage of air bubbles into the viscoelastic material. After injecting viscoelastic material into the BB space, we inserted the Bonfadini spatula into the bigbubble safely because of its curved profile and blunt edges. The groove along the length of the Bonfadini spatula enables safe and efficient incision or the residual stromal tissue using the pointed end of a sharp blade while protecting the underlying DM. After removal of posterior stroma, the donor button was sutured with 16 interrupted 10-0 nylon sutures. Results: This technique and the use of the Bonfadini spatula and dissector facilitate exposure of Descemet membrane. Conclusion: The smooth Bonfadini DALK spatula and dissector facilitate safe and efficient completion of DALK surgery. .

Objetivo: Descrevemos o uso de novos instrumentais cirúrgicos para facilitar a técnica de "big-bubble" na ceratoplastia lamelar anterior profunda (DALK). Métodos: Paciente masculino, 29 anos, foi diagnosticado com ceratocone bilateral e submetido à ceratoplastia lamelar anterior profunda (DALK). Após incisão da córnea receptora numa profundidade de 350μm de espessura parcial, o dissector Bonfadini foi inserido no ponto mais profundo da incisão periférica e pode avançar para o centro da córnea com segurança devido à sua ponta semiafiada. Depois de realizar a "big-bubble" (BB) e atingir a separação da Membrana de Descemet (MD) do estroma sobrejacente, o disco corneano de estroma anterior foi removido. Um viscoelástico foi colocado sobre o leito do estroma remanescente para impedir o colapso não-controlado e perfuração da MD durante a incisão na BB com lâmina de paracentese. Verificamos segurança no rompimento do estroma remanescente com o auxílio do dissector Bonfadini, para liberação da bolha de ar da BB através do viscoelástico. Depois de injetar o viscoelástico no espaço da BB, inserimos a espátula Bonfadini neste espaço, o que demonstrou-se seguro devido ao formato curvo e das bordas arredondadas do instrumental. A chanfradura ao longo do comprimento da espátula Bonfadini permite a incisão pela ponta de uma lâmina afiada, protegendo assim a MD subjacente. Após a remoção do estroma posterior, o botão doador foi suturado com 16 pontos interrompidos de fio nylon 10.0. Resultados: Esta técnica e o uso da espátula Bonfadini e dissector facilitam a exposição de membrana de Descemet. Conclusão: A superfície lisa da espátula Bonfadini e dissector, facilitam a realização segura e eficiente da ceratoplastia lamelar anterior profunda (DALK). .

[Perspectives of laser-assisted keratoplasty: current overview and first preliminary results with the picosecond infrared laser (λ = 3 µm)]. / Perspektiven der laserassistierten Keratoplastik: Eine aktuelle Übersicht und erste experimentelle Erfahrungen mit dem Pikosekundeninfrarotlaser (λ = 3 µm).

BACKGROUND: This article provides a review of the current state of laser-assisted keratoplasty and describes a first proof of concept study to test the feasibility of a new mid-infrared (MIR) picosecond laser to perform applanation-free corneal trephination. METHODS: The procedure is based on a specially adapted laser system (PIRL-HP2-1064 OPA-3000, Attodyne, Canada) which works with a wavelength of 3,000 ± 90 nm, a pulse duration of 300 ps and a repetition rate of 1 kHz. The picosecond infrared laser (PIRL) beam is delivered to the sample by a custom-made optics system with an implemented scanning mechanism. Corneal specimens were mounted on an artificial anterior chamber and subsequent trephination was performed with the PIRL under stable intraocular pressure conditions. RESULTS: A defined corneal ablation pattern, e.g. circular, linear, rectangular or disc-shaped, can be selected and its specific dimensions are defined by the user. Circular and linear ablation patterns were employed for the incisions in this study. Linear and circular penetrating PIRL incisions were examined by macroscopic inspection, histology, confocal microscopy and environmental scanning electron microscopy (ESEM) for characterization of the incisional quality. Using PIRL reproducible and stable incisions could be made in human and porcine corneal samples with minimal damage to the surrounding tissue. CONCLUSION: The PIRL laser radiation in the mid-infrared spectrum with a wavelength of 3 µm is exactly tuned to one of the dominant vibrational excitation bands of the water molecule, serves as an effective tool for applanation-free corneal incision and might broaden the armamentarium of corneal transplant surgery.

Stimulated penetrating keratoplasty using real-time virtual intraoperative surgical optical coherence tomography.

An intraoperative surgical microscope is an essential tool in a neuro- or ophthalmological surgical environment. Yet, it has an inherent limitation to classify subsurface information because it only provides the surface images. To compensate for and assist in this problem, combining the surgical microscope with optical coherence tomography (OCT) has been adapted. We developed a real-time virtual intraoperative surgical OCT (VISOCT) system by adapting a spectral-domain OCT scanner with a commercial surgical microscope. Thanks to our custom-made beam splitting and image display subsystems, the OCT images and microscopic images are simultaneously visualized through an ocular lens or the eyepiece of the microscope. This improvement helps surgeons to focus on the operation without distraction to view OCT images on another separate display. Moreover, displaying the OCT live images on the eyepiece helps surgeon's depth perception during the surgeries. Finally, we successfully processed stimulated penetrating keratoplasty in live rabbits. We believe that these technical achievements are crucial to enhance the usability of the VISOCT system in a real surgical operating condition.

Eye-tracker-guided non-mechanical excimer laser assisted penetrating keratoplasty.

PURPOSE: The purpose of the study was to implement a new eye tracking mask which could be used to guide the laser beam in automated non-mechanical excimer laser assisted penetrating keratoplasty. MATERIALS AND METHODS: A new trephination mask design with an elevated surface geometry has been proposed with a step formation between conical and flat interfaces. Two recipient masks of 7.5/8.0 mm have been manufactured and tested. The masks have outer diameter of 12.5 mm, step formation at 10.5 mm, and slope of conical surfaces 15°. Its functionality has been tested in different lateral positions and tilts on a planar surface, and pig eye experiments. After successful validation on porcine eyes, new masks have been produced and tested on two patients. RESULTS: The build-in eye tracking software of the MEL 70 was always able to capture the masks. It has been shown that the unwanted pigmentation/pattern induced by the laser pulses on the mask surface does not influence the eye-tracking efficiency. The masks could be tracked within the 18 × 14 mm lateral displacement and up to 12° tilt. Two patient cases are demonstrated. No complications were observed during the surgery, although it needs some attention for aligning the mask horizontally before trephination. Stability of eye tracking masks is emphasized by inducing on purpose movements of the patient head. CONCLUSION: Eye-tracking-guided penetrating keratoplasty was successfully applied in clinical practice, which enables robust tracking criteria within an extended range. It facilitates the automated trephination procedure of excimer laser-assisted penetrating keratoplasty.

[Visual acuity and astigmatism after keratoplasty. Differences between the guided trephine system and motor trephine]. / Visus und Astigmatismus nach Keratoplastik. Unterschiede zwischen geführtem Trepansystem und Motortrepan.

BACKGROUND: The purpose of this study was to assess the differences in postoperative visual acuity, astigmatism, and selected postoperative complications between a guided trephine system (GTS) and motor trephine after penetrating keratoplasty. PATIENTS AND METHODS: In this retrospective analysis 74 patients who had undergone penetrating keratoplasty either by GTS (n = 53) or by motor trephine (Motortrepan) (n = 21) were included. Both patient groups included in this analysis were selected to ensure a homogeneous distribution of preoperative parameters to the greatest possible extent. However, some significant differences in patient selection between the two groups could not be avoided. Patients in the motor trephine group were older (mean age 68.4 years vs 56.4 years; p < 0.01) and had Fuchs' endothelial dystrophy more often (47.6 % vs 26.4 %) and significantly less keratoconus (14.3 % vs 32.1 %). RESULTS: No significant differences regarding visual acuity outcomes could be found between GTS and Motortrepan. In both patient groups there were no differences in the amount of preoperative astigmatism (1.36 vs. 2.0 dpt., p = 0.39). However, at the time of final corneal suture removal (2.23 vs. 3.5 dpt., p = 0.03) and at a postoperative control 1 year after final suture removal (2.29 vs. 3.85 dpt., p = 0.005) the amount of astigmatism in the motor trephine group was found to be significantly higher. CONCLUSION: In summary penetrating kerastoplasty using the motor trephine was found to result in significantly higher postoperative astigmatism than those performed with the GTS.

Penetrating keratoplasty using femtosecond laser-enabled keratoplasty with zig-zag incisions versus a mechanical trephine in patients with keratoconus.

BACKGROUND/AIMS: This paper will compare the visual outcomes of two different penetrating keratoplasty (PKP) techniques in patients with keratoconus. It is a retrospective comparative surgical case series of 116 keratoconus patients (137 eyes) who had PKP at the Cornea Eye Institute, Beverly Hills, California, USA. METHODS: 56 keratoconus patients (66 eyes) underwent femtosecond laser-enabled keratoplasty (FLEK) with a zig-zag incision configuration. Their visual parameters were compared with those of 60 patients (71 eyes) who had traditional blade mechanical trephination PKP. The range of follow-up was between 3 and 6 months. The main outcome measures included uncorrected visual acuity and best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent and topographically determined astigmatism. RESULTS: BSCVA was significantly better as early as 3 months postoperatively (p=0.001) in the FLEK group. Visual recovery to 20/40 after 3 months was significantly better in the FLEK group (p<0.001). Topographic astigmatism was lower in the FLEK group, but the difference between the two groups reached significance only at 3 months of follow-up (p=0.001). Postoperative complications noted were not different between the two groups. CONCLUSIONS: Faster visual recovery and better long-term outcomes were observed in keratoconus patients who had FLEK compared with those who had the mechanical PKP procedure with 6 months of postoperative follow-up.

[Results with the Boston keratoprosthesis]. / Ergebnisse nach Boston-Keratoprothese.

BACKGROUND: The Boston keratoprosthesis (BKP) is a surgical therapeutic option in patients with corneal disease and poor prognosis for penetrating keratoplasty. The purpose of this study was to summarize our results with this surgical technique which we have employed at our institution since November 2009. METHODS: All patients who underwent the BKP procedure at our institution between November 2009 and August 2011 were identified retrospectively and the data were analyzed. The surgical procedure and postoperative treatment were performed following the recommendations of the developers of the BKP. RESULTS: A total of 14 patients were included in the study and the patient age ranged from 36 to 78 years. All patients had superficial and stromal corneal opacification with loss of the normal corneal surface (conjunctivalization). In 13 patients the BKP was implanted after at least 1 penetrating keratoplasty (including 3 matched grafts) and in 1 patient it was performed as a primary procedure. The underlying diseases were Stevens-Johnson syndrome, chemical injury, chronic atopic dermatitis in neurodermitis, keratoconus, granulomatous uveitis, congenital glaucoma and eyeball injury/burn. The follow-up ranged from 1 to 21 months. Postoperative complications consisted of prolonged inflammatory anterior chamber reaction with synechia, deposits on the intraocular lens, posterior capsule opacification, secondary glaucoma, hypotension, conjunctival growth over the keratoprosthesis and cystoid macular edema. All cases had overall improvement of visual acuity at the last follow-up visit. The maximum improvement was from counting fingers to 0.7. CONCLUSION: Until now all BKPs have been preserved. At our institution the BKP is becoming increasingly more important even in such cases with a (very) poor prognosis for matched limbal and/or corneal grafts. Reimbursement for the BKP must, however be organized on a case by case basis.

Boston keratoprosthesis and Ahmed glaucoma valve for visual rehabilitation in congenital anterior staphyloma.

Congenital anterior staphyloma entails grave visual prognosis. The majority of reported patients have undergone enucleation. We report a promising result of staphylectomy with implantation of a keratoprosthesis and a glaucoma drainage device in a seven-month-old child with a large, congenital anterior staphyloma.

[Perspectives of excimer laser-assisted keratoplasty]. / Perspektiven der Excimerlaser-Trepanation für die Keratoplastik.

BACKGROUND AND PURPOSE: The purpose of this paper is to demonstrate the evolution of laser keratoplasty and to outline the potential future perspectives of this technique. METHODS: For non-contact donor trephination from the epithelial side an artificial anterior chamber has been used. Since 1989 more than 3,300 penetrating keratoplasty operations (PKP) have been performed successfully with the Zeiss-Meditec MEL60® excimer laser in Erlangen and Homburg/Saar. RESULTS: Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient decentration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism, higher regularity of the topography and better visual acuity. Besides less blood-aqueous barrier breakdown during the early postoperative course after PKP, excimer laser trephination does not induce cataract formation and does not impair the graft endothelium. Likewise, the rate of immunological graft rejections is not adversely affected by the excimer laser. In addition, trephination of an instable cornea is facilitated. CONCLUSIONS: Because of undisputed clinical advantages, especially in eyes with keratoconus, excimer laser trephination with orientation teeth/notches is still favored in Homburg/Saar in daily practice. The femtosecond laser (FSL)-assisted keratoplasty technique is very exciting but a prospective randomized study is required to determine potential benefits over excimer laser PKP.