[Donation and harvesting of post-mortem corneas in the mortuary with a view to transplants]. / Don et prélèvements de cornées post-mortem en chambre mortuaire en vue de greffes.

The donation, removal and transplantation of corneas enable patients to improve or regain their sight. This treatment is possible thanks to deceased people who, during their lifetime, consent to or do not object to the donation. The operation is carried out according to a regulated medical-surgical process, initiated and organized by a specially-trained hospital coordinator.

An Efficient Technique for the Long-term Preservation of SMILE Lenticules Using Desiccation.

PURPOSE: To evaluate a desiccation protocol for the long-term preservation of human small incision lenticule extraction (SMILE) lenticules and to study their integration in an in vivo rabbit model. METHODS: Lenticules were retrieved after SMILE procedures in patients, then desiccated according to a novel protocol. Histologic and electron microscopic analyses were performed. Six rabbit eyes received grafts with an inlay technique, which consisted of inserting a desiccated lenticule into a stromal pocket. Rabbits were killed at different times between 6 and 24 weeks. Rabbit corneas were analyzed using optical coherence tomography, histology, and DAPI staining. RESULTS: Microscopic analysis of desiccated lenticules showed a preserved stromal architecture after rehydration. A decellularization of the lenticules after desiccation was observed without any chemical treatment. All rabbit corneas remained clear after grafting human lenticules and no rejection occurred. Optical coherence tomography showed regular lenticular implantation and no decrease in lenticule thickness. Histologic analysis showed no inflammatory infiltration around lenticules and no nuclear material inside lenticules after 6 months. CONCLUSIONS: A favorable integration of desiccated human SMILE lenticules in rabbit corneas was observed. The refractive issue of lenticular implantation must be investigated next. Clinical trials are needed to evaluate the use of desiccated SMILE lenticules to treat hyperopia or keratoconus in humans. [J Refract Surg. 2023;39(7):491-498.].

Tips and Tricks and Clinical Outcome of Cryopreserved Human Amniotic Membrane Application for the Management of Medication-Related Osteonecrosis of the Jaw (MRONJ): A Pilot Study.

Medication-related osteonecrosis of the jaw (MRONJ) is a complication of certain pharmacological treatments such as bisphosphonates, denosumab, and angiogenesis inhibitors. There are currently no guidelines on its management, particularly in advanced stages. The human amniotic membrane (hAM) has low immunogenicity and exerts anti-inflammatory, antifibrotic, antimicrobial, antiviral, and analgesic effects. It is a source of stem cells and growth factors promoting tissue regeneration. hAM acts as an anatomical barrier with suitable mechanical properties (permeability, stability, elasticity, flexibility, and resorbability) to prevent the proliferation of fibrous tissue and promote early neovascularization at the surgical site. In oral surgery, hAM stimulates healing and facilitates the proliferation and differentiation of epithelial cells in the oral mucosa and therefore its regeneration. We proposed using cryopreserved hAM to eight patients suffering from cancer (11 lesions) with stage 2-3 MRONJ on a compassionate use basis. A collagen sponge was added in some cases to facilitate hAM grafting. One or three hAMs were applied and one patient had a reapplication. Three patients had complete closure of the surgical site with proper epithelialization at 2 weeks, and two of them maintained it until the last follow-up. At 1 week after surgery, three patients had partial wound dehiscence with partial healing 3 months later and two patients had complete wound dehiscence. hAM reapplication led to complete healing. All patients remained asymptomatic with excellent immediate significant pain relief, no infections, and a truly positive impact on the patients' quality of life. No adverse events occurred. At 6 months of follow-up, 80% of lesions had complete or partial wound healing (30 and 50%, respectively), while 62.5% of patients were in stage 3. Radiological evaluations found that 85.7% of patients had stable bone lesions (n = 5) or new bone formation (n = 1). One patient had a worsening MRONJ but remained asymptomatic. One patient did not attend his follow-up radiological examination. For the first time, this prospective pilot study extensively illustrates both the handling and surgical application of hAM in MRONJ, its possible association with a collagen sponge scaffold, its outcome at the site, the application of multiple hAM patches at the same time, and its reapplication.

Face-to-face phacoemulsification using a slitlamp in patients who are unable to lie flat.

Phacoemulsification can be challenging in patients who are unable to lie flat or sit in a reclined position that exceeds 30 degrees to 45 degrees during surgery. We describe a new technique that we have used on 4 eyes of two patients. Both were operated on while sitting in a strictly upright position, resting their chin in front of a mobile slitlamp in the same manner as during a standard ophthalmologic examination. The surgeon sits on the other side of the slitlamp, facing the patient, and operates via a temporal corneal incision. The described operating conditions were deemed perfectly adequate by the experienced surgeon. Both patients recovered a corrected distance visual acuity of 20/20 in both eyes and said they would recommend this surgery to anyone who cannot lie flat. Surgeons should consider this technique when standard surgical positioning is not possible.

Endothelial quality of eye bank-prestripped DMEK prepared form organ-cultured corneas with the Muraine technique.

Our aim was to measure the endothelial quality of prestripped Descemet membrane endothelial keratoplasty (DMEK) 48 h after preparation in an eye bank with the Muraine technique and shipping in a distant center. Ten pairs of human corneas with similar eye bank endothelial cell density (ebECD) were stored in organ-culture (OC) for 25 days (20, 28) [median (10-90 percentiles)]. One cornea was then randomized to DMEK preparation using the Moria Muraine trephine, the other served as control. The grafts were left attached to the center of the cornea, immersed in the OC medium (without Dextran) and shipped to a distant center. After 48 h, the viable ECD (vECD) was assessed by image analysis after staining with Hoechst/Ethidium/Calcein-AM. In addition, immunostaining was performed on flat mounted tissues for structural (ZO-1, NCAM, CD166) and functional (Na+/K+ ATPase) proteins of ECs, and for collagen I. Just before stripping, ebECD was 2428 (2268-2669) cells/mm2 for DMEK and 2471 (2135-2714) for controls (P = 1). Forty-eight hours after stripping, vECD was 2057 (1829-2463) cells/mm2 for DMEK and 2119 (1496-2525) for controls (P = 0.508). The expression patterns of the 5 proteins were similar in ECs of both groups. Notably, the deep posterior folds observed in OC controls almost disappeared in prestripped DMEK due to the lack of a link between Descemet membrane and stroma. As a consequence of the elimination of mechanical stress in these zones, EC evenly covered the whole graft. In conclusion, DMEK prestripping with the Muraine technique and shipping away can be used safely by eye banks.

Novel technique for the preparation of corneal grafts for descemet membrane endothelial keratoplasty.

PURPOSE: To report a simple novel technique to facilitate preparation of Descemet membrane grafts for Descemet membrane endothelial keratoplasty (DMEK). DESIGN: Laboratory investigation and retrospective, single-center, consecutive case series. METHODS: Preparation of the endothelial graft is performed on an artificial anterior chamber, endothelial side up. After an incomplete circular superficial trephination, we describe a simple technique using a 27 gauge cannula to detach the Descemet membrane (DM). Endothelial cell density (ECD) was measured before dissection on 12 human corneas for research and 3 days after storage in organ culture. Histologic and electron microscopy analysis were performed. A DMEK was performed in 50 patients with Fuchs dystrophy. Visual acuity and ECD were evaluated 2 and 6 months after surgery. RESULTS: ECD was 2765 ± 256 cells/mm(2) on corneas for research before dissection and 2651 ± 305 cells/mm(2) after 3 days in organ culture (P < .01). Histologic and electronic sections confirm that the cleavage was between DM and posterior stroma. Clinically, preparation of 2 corneas from a single donor was unsuccessful; 48 corneas were clear at 2 months and 47 at 6 months. At 2 months 77% of the patients had recovered a visual acuity of at least 20/30. At 6 months, 91.5% of the patients had a visual acuity of at least 20/30. ECD was 2656 ± 28 cells/mm(2) (range: 2450-3100 cells/mm(2)) preoperatively, 1797 ± 41 cells/mm(2) (range: 1100-2700 cells/mm(2)) at 2 months, and 1658 ± 43 cells/mm(2) (range: 900-2600 cells/mm(2)) at 6 months. CONCLUSION: We report here a reliable and efficient technique for the preparation of pure Descemet membrane grafts.

Pan-corneal endothelial viability assessment: application to endothelial grafts predissected by eye banks.

PURPOSE: To present an experimental method for determining the viable cell pool of corneal endothelia and its application to assessing predissected endothelial grafts. METHODS: The endothelial cell density (ECD) of five pairs of human organ cultured corneas was determined using a standard counting method with a calibrated image analysis system. A thin posterior graft (30-50 µm) was manually predissected from a cornea chosen at random. Predissected and control corneas were shipped to the remote center, where standard ECD determination was repeated and was immediately followed by a triple Hoechst/ethidium/calcein labeling coupled with image analysis of the whole graft surface. Numeration of nuclei (H+), dead cells (E+), and total area covered by viable cells (C+) allowed the calculation of viable ECD corresponding to the cell density that the cornea may have after redistribution of viable cells over the whole Descemet surface. RESULTS: The median (range) viable ECD was lower than the standard ECD determined immediately earlier in predissected and control corneas: 1628 (1138-2379) and 2065 (1492-2876) cells/mm(2) (P = 0.043), corresponding to -20% (-1%-38%) and -12% (-3%-26%), respectively (P = 0.08). CONCLUSIONS: Standard counting by eye banks overestimates the actual pool of viable endothelial cells. This may be the main explanation for the initially rapid decrease in ECD universally described in patients after all types of keratoplasty. Early low postoperative ECD may indicate that surgeons graft fewer living cells than the eye banks' ECD let suppose, rather than a massive pre- and postoperative cell death. The novel concept of viable ECD can be useful for assessing all types of corneal processing.

Impact of new lamellar techniques of keratoplasty on eye bank activity.

BACKGROUND: Deep anterior lamellar keratoplasty (DALK) has become an increasingly popular alternative to penetrating keratoplasty in patients with stromal corneal pathologies. The main advantages of DALK are: prevention of long-term endothelial loss, elimination of allograft reaction and short topical steroid treatment with lower risks of glaucoma, cataract and infection. Because this technique enables surgeons to use corneal grafts with low endothelial density, the aim of this paper was to determine whether this type of innovation has had a significant impact on eye bank activity. METHODS: We reviewed our corneal graft activity over a 40-month period and assessed the proportion of deep lamellar and penetrating keratoplasties. During the same period, we also evaluated our eye bank activity and recorded the utilisation of grafts with endothelium abnormalities, which were only suitable for lamellar techniques. RESULTS: Deep lamellar keratoplasty represented 29.8% (85 out of 285) of corneal transplantations. Forty-eight percent of all corneas stored at the local eye bank were unsuitable for penetrating keratoplasty; 36.6% of those were not suitable for endothelial deficiencies. Among these, 72.7% were used for DALK and 27.3% were rejected. This permitted a 24.5% increase in corneal grafting activity. In contrast, Descemet's membrane was removed at the time of surgery in 12% of corneas with healthy endothelium, which was used for deep lamellar keratoplasty. CONCLUSIONS: Deep anterior lamellar keratoplasty development and close collaboration between eye banks and surgeons can induce a significant increase in corneal grafting. This could be a partial solution in countries confronted with corneal graft shortages.