Recipient Cornea Research Articles

Artificial corneas versus donor corneas for repeat corneal transplants.

Individuals who have failed one or more full thickness penetrating keratoplasties (PKs) may be offered repeat corneal surgery using an artificial or donor cornea. An artificial or prosthetic cornea is known as a keratoprosthesis. Both donor and artificial corneal transplantations involve removal of the diseased and opaque recipient cornea (or the previously failed cornea) and replacement with another donor or prosthetic cornea. To assess the effectiveness of artificial versus donor corneas in individuals who have had one or more failed donor corneal transplantations. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2013, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2013), EMBASE (January 1980 to November 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to November 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 27 November 2013. Two review authors independently assessed reports from the electronic searches to identify randomized controlled trials (RCTs) or controlled clinical trials (CCTs). We resolved discrepancies by discussion or consultation with a third review author. For discussion purposes, we assessed findings from observational cohort studies and non-comparative case series. No data synthesis was performed. We did not identify any RCTs or CCTs comparing artificial corneas with donor corneas for repeat corneal transplantations. The optimal management for those individuals who have failed a conventional corneal transplantation is not known. Currently, in some centers, artificial corneal devices routinely are recommended after just one graft failure, and in others, not until after multiple graft failures, or not at all. To date, there have been no controlled trials comparing the visual outcomes and complications of artificial corneal devices (particularly the Boston type 1 keratoprosthesis which is the most commonly implanted artificial corneal device) with repeat donor corneal transplantation, in order to guide surgeons and their patients. It is apparent that such a trial is needed and would offer significant benefit to an ever-increasing pool of people with visual disability due to corneal opacification, most of whom are still in productive stages of their lives.

Microkeratome-assisted two-stage technique of superficial anterior lamellar keratoplasty for Reis-Bücklers corneal dystrophy.

The aim of this study was to describe a microkeratome-assisted 2-stage technique of superficial anterior lamellar keratoplasty (SALK) to manage Reis-Bucklers corneal dystrophy (RBCD). A microkeratome was used to create a 9-mm, 140-μm-thick corneal flap in the first stage. Four weeks later, in the second stage, a Hessberg-Baron suction trephine was used to perform a 7.0-mm central trephination up to a depth of 150 μm, within the corneal flap. Donor lamellar tissue was prepared using a microkeratome system, after which a vacuum punch was used to trephine a 7.0-mm lamellar button. This donor button was used to replace the central corneal flap in the recipient cornea without using any sutures. A bandage contact lens was applied for 2 weeks. This modified technique of staged sutureless SALK was used in 4 eyes of 2 patients with RBCD. Postoperatively, all eyes experienced an improvement in both uncorrected and best spectacle-corrected visual acuities. The average best spectacle-corrected visual acuity was 20/30 at the last follow-up (19 months, range 16-22 months). The cornea remained clear in all eyes until the last follow-up without any evidence of recurrence of RBCD. The staged technique of microkeratome-assisted SALK allows the replacement of superficial corneal stroma without the necessity for any sutures and seems to be a safe and effective method for the treatment of RBCD.

Corneal donor tissue preparation for Descemet's membrane endothelial keratoplasty.

Descemet's Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, along with its basement membrane (Descemet's membrane) is introduced onto the recipient's posterior stroma(3). Unlike Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), where additional donor stroma is introduced, no unnatural stroma-to-stroma interface is created. As a result, the natural anatomy of the cornea is preserved as much as possible allowing for improved recovery time and visual acuity(4). Endothelial Keratoplasty (EK) is the procedure of choice for treatment of endothelial dysfunction. The advantages of EK include rapid recovery of vision, preservation of ocular integrity and minimal refractive change due to use of a small, peripheral incision(1). DSAEK utilizes donor tissue prepared with partial thickness stroma and endothelium. The rapid success and utilization of this procedure can be attributed to availability of eye-bank prepared precut tissue. The benefits of eye-bank preparation of donor tissue include elimination of need for specialized equipment in the operating room and availability of back up donor tissue in case of tissue perforation during preparation. In addition, high volume preparation of donor tissue by eye-bank technicians may provide improved quality of donor tissue. DSAEK may have limited best corrected visual acuity due to creation of a stromal interface between the donor and recipient cornea. Elimination of this interface with transplantation of only donor Descemet's membrane and endothelium in DMEK may improve visual outcomes and reduce complications after EK(5). Similar to DSAEK, long term success and acceptance of DMEK is dependent on ease of availability of precut, eye-bank prepared donor tissue. Here we present a stepwise approach to donor tissue preparation which may reduce some barriers eye-banks face in providing DMEK grafts.

Novel method to avoid the open-sky condition in penetrating keratoplasty: covered cornea technique.

The aim of this study was to present a novel technique to avoid the open-sky condition in pediatric and adult penetrating keratoplasty (PK). Seventy-two eyes of 65 infants and children and 44 eyes of 44 adult patients were operated on using this technique. After trephining the recipient cornea up to a depth of 50% to 70%, the anterior chamber was entered at 1 point. Then, only a 2 clock hour segment of the recipient button was incised, and this segment was sutured to the recipient rim with a single tight suture. The procedure was repeated until the entire recipient button was excised and resutured. The donor corneal button was sutured to the recipient corneal rim. The sutures between the recipient button and the rim were then cut off, and the recipient button was drawn out. None of the patients operated on with this technique developed complications related to the open-sky condition. Visual acuities, graft failure rates, and endothelial cell loss were comparable with the findings of studies performed for conventional PK. The technique described avoids the open-sky condition during the entire PK procedure. Endothelial cell loss rates are acceptable.

Can we predict corneal graft rejection based on proangiogenic cytokines level at the time of transplantation?

AbstractPURPUSE: To evaluate the quantity of vascular endothelial growth factor (VEGF) and its receptors (VEGFR) in the recipient cornea at the time of penetrating keratoplasty (PK). METHODS: Study included 20 eyes scheduled for PK. Quantity of angiogenic growth factors and their receptors: VEGF, sVEGFR1 and sVEGFR3 were analysed using an enzyme‐linked immunosorbent assay. Postoperatively patients were followed‐up for 3 years. Frequency of corneal graft reaction and degree of corneal neovascularisation were recorded. Donor corneas obtained from cadaver eyes were controls (n=20). RESULTS: Overall quantity of VEGF‐A was 287.74 pg/ml (SD=129.181) in the inflammatory group, 115.37 pg/ml (SD=105.93) in non‐inflammatory group and 142.28 pg/ml (SD=93.081) in controls. sVEGFR1 and sVEGFR3 were significantly higher in non‐inflammatory as compared to inflammatory group. Eyes with graft reaction had significantly higher VEGF‐A (307.4 pg/ml, SD= 100.058) as compared to those without graft reaction (182.8 pg/ml, SD=124.987). Statistical analysis was done by t‐test. CONCLUSION: Graft reaction occurs more often in corneas with increased VEGF‐A. Elevated sVEGFR may act as a sink for VEGF and thus as suppressors of angiogenesis and graft reaction.

Femtosecond laser-assisted deep anterior lamellar keratoplasty for keratoconus and keratectasia.

To describe the initial outcomes and safety of femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) for keratoconus and post-LASIK keratectasia. In this non-comparative case series, 10 eyes of 9 patients underwent DALK procedures with a femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany). Of the 9 patients, 7 had keratoconus and 2 had post-LASIK keratectasia. A 500 kHz VisuMax femtosecond laser was used to perform corneal cuts on both donor and recipient corneas. The outcome measures were the uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal thickness, astigmatism, endothelial density count (EDC), and corneal power. All eyes were successfully treated. Early postoperative evaluation showed a clear graft in all cases. Intraoperative complications included one case of a small Descemet's membrane perforation. Postoperatively, there was one case of stromal rejection, one of loosened sutures, and one of wound dehiscence. A normal corneal pattern topography and transparency were restored, UCVA and BCVA improved significantly, and astigmatism improved slightly. There was no statistically significant decrease in EDC. Our early results indicate that femtosecond laser-assisted deep anterior lamellar keratoplasty could improve UCVA and BCVA in patients with anterior corneal pathology. This approach shows promise as a safe and effective surgical choice in the treatment of keratoconus and post-LASIK keratectasia.

Laser-Assisted Penetrating Keratoplasty: 1-Year Results in Patients Using a Laser-Welded Anvil-Profiled Graft

To describe a new laser-assisted penetrating keratoplasty technique combining a femtosecond anvil-like trephination pattern with the laser welding procedure. Cohort prospective study with 1 year of follow-up (June 2011 through January 2013). This study was performed at Misericordia e Dolce Public Hospital, Prato, Italy. Twenty-four eyes of 22 patients underwent penetrating keratoplasty: 4 had granular dystrophy, 12 had keratoconus in its final stages, 3 had post-herpetic leukoma, and 5 had corneal scars. A femtosecond laser was used to create anvil-profiled cuts in donor and recipient corneas. Diode laser welding was performed, supporting standard suturing. All patients were evaluated for corrected distance visual acuity, pachymetry, manifest astigmatism, and endothelial cell density after 1, 3, 6, and 12 months. Mean ± standard deviation postoperative corrected visual acuity was 0.48 ± 0.23 logarithm of the minimal angle of resolution (logMAR), 0.30 ± 0.18 logMAR, 0.18 ± 0.13 logMAR, and 0.13 ± 0.16 logMAR at 1, 3, 6, and 12 months, respectively. At the same follow-up times, mean pachymetry was 537 ± 57 μm, 533 ± 74 μm, 528 ± 72 μm, and 529 ± 58 μm, respectively; and mean endothelial cell density was 1945 ± 371 cells/mm(2), 1881 ± 410 cells/mm(2), 1781 ± 401 cells/mm(2), and 1730 ± 376 cells/mm(2), respectively. Mean manifest and topographic postoperative astigmatism were: 3.6 ± 2.5 diopters (D) and 4.65 ± 2.57 D at 1 month, 2.93 ± 2.34 D and 4.79 ± 2.85 D at 3 months, 2.82 ± 1.75 D and 3.44 ± 2.28 D at 6 months, and 2.08 ± 1.25 D and 2.73 ± 2.01 D at 12 months, respectively. All surgical operations were successful and without intraoperative complications. The use of the anvil trephination profile was effective for performing laser-assisted penetrating keratoplasty. The large donor-recipient interface enables the laser welding procedure and good preservation of the recipient's endothelial cell pool.

Vascular Endothelial Growth Factor in a Recipient Cornea Acts as a Prognostic Factor for Corneal Graft Reaction Development

Purpose: To evaluate whether the vascular endothelial growth factor A (VEGF-A) in the recipient cornea measured at the time of penetrating keratoplasty (PK) can act as a prognostic factor for corneal graft reaction development.Methods: The study included 25 eyes (of 25 patients) scheduled for PK. According to preoperative clinical finding, patients were divided into three groups: inflammatory with neovascularization (n = 11); inflammatory without neovascularization (n = 7); and non-inflammatory (n = 7). One half of the recipient cornea was analyzed for the levels of VEGF-A protein using a commercial enzyme-linked immunosorbent assay; the other half was analyzed to determine the loci of VEGF-A production by immunohistochemistry. The frequencies of corneal graft reaction and rejection were recorded, together with the improvement of visual acuity. Twenty-five donor corneas obtained from cadaver eyes represented the control group (n = 25).Results: There was a statistically significant difference in the levels of VEGF-A protein between the recipient corneal buttons obtained from eyes with inflammatory changes and neovascularization, and those from the non-inflammatory group and controls (p < 0.01). The level of VEGF-A was 287.74 pg/ml (standard deviation [SD] = 129.181) in the inflammatory with corneal neovascularization group, 227.64 pg/ml (SD = 85.590) in the inflammatory without neovascularization group, 115.37 pg/ml (SD = 105.93) in the non-inflammatory group, and 142.28 pg/ml (SD = 93.081) in the control group. Graft reaction/rejection rate was 54.5%/45.5% in the inflammatory with neovascularization group, 14.3%/0% in the inflammatory without neovascularization group, and 14.3%/14.3% in non-inflammatory group. Patients who developed clinical signs of graft reaction during the postoperative follow-up had a significantly higher level of VEGF-A (307.4 pg/ml, SD = 100.058) compared with those without any signs of graft reaction (182.8 pg/ml, SD = 124.987).Conclusion: Our results suggest that both graft reaction and final graft rejection occur more often in patients with increased levels of VEGF-A in a recipient cornea at the time of PK.

Factors affecting DSAEK graft lenticle adhesion: an in vitro experimental study.

The aim of this study was to evaluate different factors that affect Descemet stripping automated endothelial keratoplasty (DSAEK) donor graft lenticle adhesion to the recipient cornea. This experimental study included 10 eye bank recipient corneas and 10 donor DSAEK lenticles. Recipient corneas were mounted on an artificial anterior chamber (AC), whereas donor lenticles were placed beneath the host cornea. Using optical coherence tomography and imaging software, the interface gap (IG) between the donor and recipient cornea was quantified to evaluate the effect of variations in AC air fill pressure, AC air fill duration, corneal massage, and corneal venting incisions on DSAEK donor graft lenticle adhesion. Different intraocular pressures (IOP) under air for the same time intervals, do not significantly correlate with the IG; nevertheless, it was noticed that the IG decreases as the IOP increases. With respect to the magnitude of AC IOP, there was no statistically significant difference when comparing 10 mm Hg with 30 mm Hg and assessing IG (P = 0.4). Complete air-fluid exchange resulted in significantly higher IG when compared with AC air bubble of 10 and 30 mm Hg that was sustained for 1 hour (P < 0.05). Furthermore, corneal surface massage did not facilitate DSAEK graft adhesion (P = 0.59). Finally, paracentral venting incisions followed by interface fluid aspiration seemed to significantly decrease the IG (P = 0.014). Corneal venting incisions and higher AC IOP values seem to facilitate DSAEK donor graft lenticle adhesion to the recipient cornea.

A novel murine model for keratoprosthesis.

To establish a murine model for keratoprosthesis. A miniature keratoprosthesis (m-KPro) device was created consisting of a poly[methyl methacrylate] front part and a titanium back plate, designed after the Boston KPro, which is in widespread clinical use. BALB/c mice were used and a 2 mm in diameter donor cornea was punched out. After 2-mm trepanation of the syngeneic recipient cornea, extracapsular crystalline lens extraction was performed. The m-KPro was assembled onto the cornea button in a similar manner to human KPro implantation. The cornea-device complex was secured to the recipient bed with eight interrupted 11-0 sutures. All mice (n = 10) were followed up for 8 weeks postoperatively. All m-KPros were successfully implanted and retained in all 10 animals. There were no critical complications such as endophthalmitis, corneal melting, device extrusions, leakage, extensive inflammation, or weight loss in the animals. We observed mild to moderate donor and host corneal neovascularization in all cases throughout the follow-up period. We have established a novel murine model of KPro implantation that we anticipate will serve as a good experimental system for evaluating host responses after KPro surgery.

Histologic findings of recipient corneas obtained via deep anterior lamellar keratoplasty

We sought to investigate the histologic findings of recipient corneasobtained via deep anterior lamellar keratoplasty (DALK). The histology of three recipient corneas obtained from patients during DALK was investigated. In all cases, the Descemet membrane was successfully exposed without any perforation during surgery. The isolated corneal tissue was stained with hematoxylin-eosin and periodic acid-Schiff. In two cases, the tissues were examined using a transmission electron microscope. In one cornea obtained via DALK, only the corneal stroma was observed, and the Descemet membrane was not confirmed. In another case, the recipient cornea was detached within the Descemet membrane. In the third cornea, the banded layer membrane was partially confirmed. These findings suggest that the recipient corneas separated at different layers during the DALK procedure. With our surgical technique, the detachment of the Descemet membrane may occur at a mechanically weak segment. This separation site may not be between the Descemet membrane and the corneal stroma.

Plasma Polymer-Coated Contact Lenses for the Culture and Transfer of Corneal Epithelial Cells in the Treatment of Limbal Stem Cell Deficiency

Extensive damage to the limbal region of the cornea leads to a severe form of corneal blindness termed as limbal stem cell deficiency (LSCD). Whereas most cases of corneal opacity can be treated with full thickness corneal transplants, LSCD requires stem cell transplantation for successful ocular surface reconstruction. Current treatments for LSCD using limbal stem cell transplantation involve the use of murine NIH 3T3 cells and human amniotic membranes as culture substrates, which pose the threat of transmission of animal-derived pathogens and donor tissue-derived cryptic infections. In this study, we aimed to produce surface modified therapeutic contact lenses for the culture and delivery of corneal epithelial cells for the treatment of LSCD. This approach avoids the possibility of suture-related complications and is completely synthetic. We used plasma polymerization to deposit acid functional groups onto the lenses at various concentrations. Each surface was tested for its suitability to promote corneal epithelial cell adhesion, proliferation, retention of stem cells, and differentiation and found that acid-based chemistries promoted better cell adhesion and proliferation. We also found that the lenses coated with a higher percentage of acid functional groups resulted in a higher number of cells transferred onto the corneal wound bed in rabbit models of LSCD. Immunohistochemistry of the recipient cornea confirmed the presence of autologous, transplanted 5-bromo-2'-deoxyuridine (BrdU)-labeled cells. Hematoxylin staining has also revealed the presence of a stratified epithelium at 26 days post-transplantation. This study provides the first evidence for in vivo transfer and survival of cells transplanted from a contact lens to the wounded corneal surface. It also proposes the possibility of using plasma polymer-coated contact lenses with high acid functional groups as substrates for the culture and transfer of limbal cells in the treatment of LSCD.

Lamellar corneal lenticule graft to treat keratolysis after AlphaCor keratoprosthesis implantation.

Clinical assessment of AlphaCor keratoprosthesis and evaluation of surgical method to treat keratolysis in case of stromal necrosis occurrence. This is a noncomparative, retrospective, interventional case series. The medical records of 12 eyes of 12 patients who underwent consecutive AlphaCor keratoprosthesis implantations were reviewed. Patients with severe bilateral corneal pathology unsuitable for a conventional corneal graft, a best-corrected visual acuity (BCVA) from light perception (LP) to 20/200, with no active ocular surface inflammation, controlled intraocular pressure prior to the surgery, and an unstimulated Schirmer test of &gt;2.5 mm at 5 minutes were included. Postoperative medications included topical dexamethasone, ciprofloxacin, and 2% cyclosporine A. Main outcome measures included BCVA and complications occurrence. After a mean follow-up of 25 ± 12.3 months (range 2-38 months), 8 (66.7%) AlphaCor devices were retained. Postoperative BCVA ranged from LP to 20/63 (mean gain of 2.5 ± 3.1 lines). Seven cases of stromal melt (58.3%) occurred. Three were reversed to penetrating keratoplasty and 3 had a donor corneal layer fixated over the AlphaCor with satisfactory results (mean follow-up 23 ± 1.6 months). There were no instances of endophthalmitis, retinal detachment, or glaucoma exacerbation. AlphaCor showed a low incidence of the classic keratoprosthesis complications but a high occurrence of recipient cornea necrosis. Corneal melts were successfully managed in 3 cases by lamellar corneal lenticule graft, thereby increasing the retention of AlphaCor and maintaining BCVA.

Novel spatula and dissector for safer deep anterior lamellar keratoplasty

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.

Clinical Outcome of Penetrating Keratoplasty in Patients 5 Years or Younger

To investigate and compare the clinical outcome of primary penetrating keratoplasty in pediatric patients with Peters anomaly and sclerocornea. Medical records of 20 eyes of 18 patients with Peters anomaly or sclerocornea who underwent primary penetrating keratoplasty when they were 5 years or younger were reviewed. The survival rates and median survival times of corneal grafts were evaluated to determine the surgical outcome. Demographics of patients, the preoperative characteristics of recipient eyes, surgical procedures, causes of graft failure, and postoperative complications were analyzed to identify the factors affecting graft survival. A total of 20 penetrating keratoplasties were performed in 18 patients. Eight patients had Peters anomaly, and 10 patients had sclerocornea. Overall, 50% of corneal grafts survived during the follow-up of 92.7 ± 10 months. The graft survival was 65% at 6 months and remained 50% at 12 months, 2 years, and 5 years after surgery. The mean survival time and survival rate were significantly different between patients with Peters anomaly and those with sclerocornea (the survival time, 135.6 ± 17.9 vs. 36.4 ± 16.1 months, P = 0.014; the survival rate, 87.5% vs. 25.0%, P = 0.02). The presence of opacity or vascularization in the limbus and in the peripheral cornea and the diameter of the recipient cornea were significantly correlated with graft failure. Penetrating keratoplasty in patients who were 5 years or younger had an excellent surgical outcome in patients with Peters anomaly, whereas the graft survival was poor in patients with sclerocornea.

Viable endothelial cell density by triple HEC staining of a failed Descemet stripping automated endothelial keratoplasty

AbstractPurpose The rate of DSAEK failure decreases during learning curve. It has been previously reported that one of the main cause of rapid DSAEK failure was endothelial cell (EC) loss (Zhang, Arch Ophthalmol 2010). Aim: to report a DSAEK immediate failure and its innovative assessment with determination of the viability of residual ECMethods In the eye bank, a cornea (donor: 44 years old, organ‐culture: 23 days, ECD the day before cut: 2963 cells/mm2, deswelling 21h) was precut with a single pass of a 350μm head (Moria microkeratome). Lamella thickness was 199μm (ultrasound). The recipient had a Fuchs dystrophy. In the operating room, trephination with a Baron punch was eccentric but insertion was uneventful. The graft failed despite 2 rebubbling. A penetrating keratoplasty was performed 2 months later. During surgery the explanted lamella was immediately incubated with Hoechst 33342‐Ethidium‐Calcein‐AM (HEC triple staining, Pipparelli, IOVS 2011) to determine the viability of residual EC. The thickness map of the lamella was then performed with an OCT (Casia, Tomey). The posterior surface of the recipient corneal button was observed with a macroscopeResults The eccentric trephination caused a important step on 90° of circumference. Unplanned retention of Descemet membrane with guttae was found on the posterior face of the recipient cornea. The viable ECD of the explanted lamella was 585 cells/mm2. Keratocytes of both the lamella and the recipient cornea were viableConclusion Allogenic EC and keratocytes survive on a detached lamella at least during 2 months in the anterior chamber of the recipient. Grant: AOL 2012

Use of bovine pericardium (Tutopatch®) graft for surgical repair of deep melting corneal ulcers in dogs and corneal sequestra in cats

To evaluate the efficacy of bovine pericardium (BP) graft in the treatment of deep melting corneal ulcers in three dogs and corneal sequestra in three cats. Three dogs with keratomalacia affecting the deep third of the stroma and three cats with corneal sequestrum were evaluated and underwent surgery. Following keratectomy, BP material was placed into the keratectomy bed and sutured to the recipient cornea with 9/0 polyglactin suture material. Postoperative treatment with topical and systemic antibiotics, systemic nonsteroidal anti-inflammatory agents, and topical atropine was prescribed. Follow-up examinations were carried out 1, 2 weeks, 1 and 2 months after the surgery and consisted of a complete ophthalmic examination. Optical coherence tomography (OCT) was performed 1 and 2 months after the surgery in one dog and in one cat. At 1 week, corneal neovascularization was present around the BP graft in all cases. Four weeks after the BP graft, in two dogs and in all cats, the vascularization was regressing and the graft was integrated into the cornea, which was regaining transparency. Topical treatment with anti-inflammatory agents was then prescribed for 2 weeks. Two months after the surgery, 5 of 6 corneas in two dogs and three cats had healed with focal corneal scarring. The remaining dog had progression of the keratomalacia involving the deep BP graft that required additional surgery, but became blind. Bovine pericardium graft offers a promising option for surgical reconstruction of the cornea following keratectomy for the management of corneal ulcers and sequestra.

Macrophage Depletion Impairs Corneal Wound Healing after Autologous Transplantation in Mice

PurposeMacrophages have been shown to play a critical role in the wound healing process. In the present study, the role of macrophages in wound healing after autologous corneal transplantation was investigated by depleting local infiltrated macrophages.MethodsAutologous corneal transplantation model was used to induce wound repair in Balb/c mice. Macrophages were depleted by sub-conjunctival injections of clodronate-containing liposomes (Cl2MDP-LIP). The presence of CD11b+ F4/80+ macrophages, α-smooth muscle actin+ (α-SMA+) myofibroblasts, CD31+ vascular endothelial cells and NG2 + pericytes was examined by immunohistochemical and corneal whole-mount staining 14 days after penetrating keratoplasty. Peritoneal macrophages were isolated from Balb/c mice and transfused into conjunctiva to examine the recovery role of macrophages depletion on wound healing after autologous corneal transplantation.ResultsSub-conjunctival Cl2MDP-LIP injection significantly depleted the corneal resident phagocytes and infiltrated macrophages into corneal stroma. Compared with the mice injected with PBS-liposome, the Cl2MDP-LIP-injected mice showed few inflammatory cells, irregularly distributed extracellular matrix, ingrowth of corneal epithelium into stroma, and even the detachment of donor cornea from recipient. Moreover, the number of macrophages, myofibroblasts, endothelial cells and pericytes was also decreased in the junction area between the donor and recipient cornea in macrophage-depleted mice. Peritoneal macrophages transfusion recovered the defect of corneal wound healing caused by macrophages depletion.ConclusionsMacrophage depletion significantly impairs wound healing after autologous corneal transplantation through at least partially impacting on angiogenesis and wound closure.

Interface Lamellar Keratitis Induced by a Post-Descemet Stripping Automated Endothelial Keratoplasty Corneal Trauma

A 78-year-old female patient suffering from Fuchs endothelial dystrophy had uneventful Descemet stripping automated endothelial keratoplasty (DSAEK) on the right eye. One and a half months postoperatively, she underwent a corneal foreign body trauma and was referred to our clinic, complaining about vision deterioration. Slit-lamp examination revealed a severe and diffuse interface lamellar keratitis between the DSAEK graft and the recipient's cornea without any signs of graft dysfunction. Intensive treatment with local corticosteroids was applied immediately, resulting in prompt improvement of both visual acuity and clinical condition. A new clinical entity, described as interface lamellar keratitis after corneal trauma in a DSAEK patient, is presented. Early diagnosis and appropriate intensive treatment with local corticosteroids are essential to successfully address this uncommon post-DSAEK complication.

Novel Maneuver Facilitating Descemet Membrane Unfolding in the Anterior Chamber

To describe a new technique for unfolding of the Descemet membrane (DM) during Descemet membrane endothelial keratoplasty. DM and endothelium were stripped from donor corneas submerged in corneal storage solution. Donor DM diameters were 8.5 mm. The central 8 mm of DM was stripped from the recipient cornea. After staining with trypan blue to improve visualization, donor DM was inserted through a 2.75-mm incision. Unfolding was achieved with simultaneous digital pressure in the equatorial region and tapping of the corneal surface. This technique was performed in Descemet membrane endothelial keratoplasty patients with Fuchs endothelial dystrophy (n = 6) and bullous keratopathy (n = 4). In all cases, a fast attachment of the DM was achieved. The recurling was successfully hindered because of the simultaneous equatorial pressurization and induced fluid currents inside the anterior chamber by appropriate corneal tapping. In all cases, a rapid corneal clearance was achieved with significantly increased visual acuity (logarithm of the minimal angle of resolution visual acuity preoperative = 0.90, logarithm of the minimal angle of resolution visual acuity final assessment = 0.19, P < 0.001; follow-up 14 ± 5 weeks). Simultaneous digital pressure with corneal tapping is a helpful maneuver to unfold the DM inside the anterior chamber. This technique may reduce the need for unnecessary instrumental and noninstrumental manipulation of the graft.