P01-A120 Pre-dissected dmek stored in an active storage machine: feasibility study

PURPOSE

The number of endothelial grafts precut by eye banks increases. Their shelf life is limited to a few days. We previously demonstrated the superiority of an active storage machine (ASM) over organ culture (passive) for whole corneas.

AIMS

To measure the endothelial viability of pre-dissected DMEK after 3 and 10 days of storage in our ASM in a preclinical study.

METHODS

Pairs of human corneas were included. The endothelial cell density (ECD in cells/mm2), thickness and transparency of corneas were measured before graft preparation. Descemet's membrane (DM) was peeled using the no-touch technique leaving the graft attached to the center of the cornea (on approx. 1mm2). After randomization, one cornea was kept in organ culture (OC) and the other in the ASM (21 mmHg, 2.6 µL/min) in the same medium (CorneaMax, Eurobio). The final viable ECD was determined using the triple staining with Hoechst-Ethidium-Calcein-AM. In addition, the expression of CD166 and NCAM (lateral membranes), ZO-1 (apical junctions), Na+/K+ ATPase (endothelial pump function) and COX-IV (mitochondrial content) was studied by immunostaining to characterize endothelial cells after the storage.

RESULTS

Initial ECDs were comparable: 2185±232 cells/mm2 in the ASM versus 2276±328 in OC for the 3-day period and 2680±416 cells/mm2 in the ASM versus 2644±420 in OC for the 10-day period. The DMs did not fold back in either BR or OC. The viable ECD did not differ significantly between the ASM and OC for either storage period: 2378±501 (ASM) versus 2342±503 (OC) for the 3-day period (n=8 pairs and p=0.624) and 2482±288 (ASM) versus 2579±315 (OC) for the 10-day period (n=5 pairs and p=0.176). Corneas were more transparent and thinner in the ASM than in OC after 3 days (916±86 versus 1193±136µm, p=0.0001) and 10 days (957±128 versus 1220±105µm, p=0.0625). The functional and structural markers studied were expressed in both groups after 3 and 10 days, some better preserved in the ASM.

CONCLUSION

The storage of precut DMEKs is possible in ASM and OC for at least 10 days. Interestingly, a pre-dissected endothelium continues to partially exert its pump function into the ASM. In practice, this could allow the stroma to be used for DALK without further deswelling. In addition to improving the storage of whole grafts, the ASM allows the storage of precut DMEKs for up to 10 days with excellent endothelial survival.

P02-A121 Precut DSAEK stored in an active storage machine: feasibility study

PURPOSE

The number of endothelial grafts precut by eye banks increases. Their shelf life is limited to a few days. We previously demonstrated the superiority of an active storage machine (ASM) over organ culture (passive) for whole corneas.

AIMS

to measure endothelial viability of precut DSAEK after 3 or 10 days of storage in our ASM in a preclinical study.

METHODS

Human pairs of corneas were included. The endothelial cell density (ECD in cells/mm2), and central corneal thickness (CCT in μm) were measured to ensure their initial intra pair comparability. After deswelling (CorneaJet, Eurobio) grafts preparation was performed by cutting the anterior stroma with a Moria linear microkeratome and keeping the anterior lamellae attached during storage. After randomization, one cornea was kept in the corneajet bottle (CJ) and the other was inserted into the ASM allowing a renewal or storage medium (CorneaMax, Eurobio) at 2.6 µL/min with 21 mmHg of pressure in the endothelial chamber. Both group of corneas were stored for 3 or 10 days at 31°C. The final viable ECD (vECD) was determined using the triple staining with Hoechst-Ethidium-Calcein-AM by an independent experimenter in a masked fashion.

RESULTS

Initial ECDs were comparable: 2595±878 in ASM versus 2654±954 cells/mm2 in CJ for the 3-days period (n=5 pairs) and 2416±712 in ASM versus 2492±764 cells/mm2 in CJ for the 10-period (n=5 pairs). CCTs were also comparable. The anterior lamellae stayed attached in either the ASM or CJ. vECD was significantly higher in ASM than in CJ with respectively 2062±695 cells/mm2 versus 1632±633 cells/mm2 after 3 days either a cell loss of 20.5% and 38.5% respectively (p=0.0062) and 1082±649 versus 935±691 cells/mm2 for the 10-day period either a cell loss of 132% and 164% respectively (p=0.005). Grafts thickness did not differ after 3 days 219±25 µm in ASM versus 182±39 µm (p=0.063) or 10 days respectively 221±58 µm versus 189±48 µm (p=0.06).

CONCLUSION

The storage of precut DSAEKs into the ASM allows a better preservation of grafts without use on deswelling storage medium. Nevertheless, the cell loss remains high after 10 days, suggesting a significant cell stress.

Characterization of Femtosecond Laser and Porcine Crystalline Lens Interactions by Optical Microscopy

The use of ultrafast laser pulses for eye anterior segment surgery has seen a tremendous growth of interest as the technique has revolutionized the field, from the treatment of myopia, hyperopia, and presbyopia in the cornea to laser-assisted cataract surgery of the crystalline lens. For the latter, a comprehensive understanding of the laser-tissue interaction has yet to be achieved, mainly because of the challenge of observing the interaction zone in situ with sufficient spatial and temporal resolution in the complex and multi-layered tissue of the crystalline lens. We report here on the dedicated characterization results of the laser-tissue interaction zone in the ex vivo porcine lens using three different methods: in situ and real-time microscopy, wide-field optical imaging, and phase-contrast microscopy of the histological cross sections. These complementary approaches together revealed new physical and biological consequences of laser irradiation: a low-energy interaction regime (pulse energy below ~1 µJ) with very limited cavitation effects and a stronger photo-disruption regime (pulse energy above 1 µJ) with a long cavitation duration from seconds to minutes, resulting in elongated spots. These advances in the understanding of the ultrafast laser's interactions with the lens are of the utmost importance for the preparation of the next-generation treatments that will be applied to the lens.

Repeat corneal transplantation: indication, surgical technique, and early graft failures trends in France from 2004 to 2019

PURPOSE

To investigate the repeat corneal transplantation trend in France from 2004 to 2019.

METHODS

Review of the prospectively compiled French Biomedicine Agency electronic database containing all corneal transplantation records from 2004 to 2019. The surgical technique, demographic characteristics, diagnosis, and previous graft data were retrieved and analyzed using the Cochran-Armitage trend test.

RESULTS

A total of 66,584 corneal transplantations were performed, 51,260 of which were first grafts and 15,324 (23%) were regrafts. For regrafts, 77% were penetrating keratoplasties (PK) and 19.6% were lamellar keratoplasties (LK). Age, hypertonia, glaucoma, trauma, lens surgery, immune disorders, diameter > 8.5 mm, and neovessels in > 2 quadrants were associated with a higher rate of repeat keratoplasty. Keratoconus, secondary endothelial dystrophy, and Fuchs' dystrophy were the principal indications for regrafting. When a previous graft failed, it occurred earlier for patients with LK (4.6 years, median = 2, SD = 7.54) than PK (8.48 years, median = 5, SD = 9.51). Failure within a year was the reason why 28.3% of the LK regrafts and 12.5% of PK regrafts were performed, while for failure within two years these values were 49.9% and 27.8%, respectively. Graft survival decreased with the number of repeat keratoplasty, being more pronounced after a second LK regraft and after a first PK regraft.

CONCLUSION

The number of LK regrafts increased continuously, and 1/3 were performed for failure within the year. This rate increased until 2015, after which it stabilized until 2019, probably due to the better mastery of the technique.

Objective measurement of adherence to topical steroid medication after penetrating keratoplasty using an electronic monitoring aid: A pilot study

Objectives

Corneal transplantation is the most common transplant worldwide and its success critically depends on the management of corneal graft rejection through topical steroid therapy during the first 12 months after surgery. There is currently no published data on adherence after keratoplasty. This pilot study aims to explore the adherence to topical steroid after penetrating keratoplasty using a smart electronic device.

Methods

Thirty patients undergoing penetrating keratoplasty were included to evaluate the adherence to topical dexamethasone medication for 12 months after surgery. Patients received the usual post-transplantation treatment (topical dexamethasone) and follow-up after surgery (day 15, months 1, 2, 3, 4, 5, 6, 9, and 12). Adherence to treatment was monitored using the KaliJAR device (Kali Care, Santa Clara, CA, USA), which recorded the number of single-dose units (SDU) discarded. At control visits, data recorded by the device were compared to the manually count of SDU. Adherence ratio and individual adherence curve were explored for all patients.

Results

Data from 27 patients showed a high agreement between adherence ratio calculated based on the device data and obtained from manual counting of the discarded SDU (intraclass coefficient correlation of 0.87 [95% CI: 0.738–0.938]). Mean adherence to the treatment over the 12-month study period was 95.2 ± 4%.

Conclusions

Adherence to topical dexamethasone for 12 months after corneal transplantation was high. The connected device was able to record accurately the discarded SDU. This approach would be a particular interest in the early identification and personalized follow-up of poorly adherent patients.

Epithelial Regeneration in Human Corneas Preserved in an Active Storage Machine

Purpose

To characterize the corneal epithelium (CE) and limbal epithelium (LE) of human corneas stored in an innovative active storage machine (ASM) after a period of organ culture (OC).

Methods

Corneas unsuitable for graft and stored in a standard commercial OC medium for 2 to 5 weeks were transferred into our ASM for 14 days. The ASM actively maintained an overpressure on the endothelial side (20 mm Hg) while ensuring medium renewal. We compared three modalities of storage in the ASM's epithelial chamber: (1) alternating exposure to a supplemental hormonal epithelial medium (SHEM) and air (air-lifting), (2) continuous immersion in SHEM, and (3) continuous immersion in OC medium. Passive immersion of the whole cornea in OC medium or of the CE in SHEM with or without airlifting served as controls. Paired corneas were used for better comparability. Histology, differentiation (by immunolabeling), and ultrastructure were analyzed at the end.

Results

The ASM with air-lifting was most effective in regenerating a pluristratified and differentiated CE (apical ZO-1 and MUC16 staining and regeneration of the glycocalyx). In addition, the LE was stratified with preserved expression of ABCB5. The ASM with immersion in SHEM or OC medium gave a less stratified and differentiated CE. In the three control groups, the epithelia, when present, were paucistratified and less differentiated.

Conclusions

In human corneas previously stored in OC, the ASM regenerates a CE with differentiation characteristics close to normal.

Translational Relevance

Regeneration of the epithelium of human corneas discarded by eye banks will increase tissue availability for research.

Surgical Application of Human Amniotic Membrane and Amnion-Chorion Membrane in the Oral Cavity and Efficacy Evaluation: Corollary With Ophthalmological and Wound Healing Experiences

Due to its intrinsic properties, there has been growing interest in human amniotic membrane (hAM) in recent years particularly for the treatment of ocular surface disorders and for wound healing. Herein, we investigate the potential use of hAM and amnion-chorion membrane (ACM) in oral surgery. Based on our analysis of the literature, it appears that their applications are very poorly defined. There are two options: implantation or use as a cover material graft. The oral cavity is submitted to various mechanical and biological stimulations that impair membrane stability and maintenance. Thus, some devices have been combined with the graft to secure its positioning and protect it in this location. This current opinion paper addresses in detail suitable procedures for hAM and ACM utilization in soft and hard tissue reconstruction in the oral cavity. We address their implantation and/or use as a covering, storage format, application side, size and number, multilayer use or folding, suture or use of additional protective covers, re-application and resorption/fate. We gathered evidence on pre- and post-surgical care and evaluation tools. Finally, we integrated ophthalmological and wound healing practices into the collected information. This review aims to help practitioners and researchers better understand the application of hAM and ACM in the oral cavity, a place less easily accessible than ocular or cutaneous surfaces. Additionally, it could be a useful reference in the generation of new ideas for the development of innovative protective covering, suturing or handling devices in this specific indication. Finally, this overview could be considered as a position paper to guide investigators to fulfill all the identified criteria in the future.

[Corneal perforation with tyrosine kinase inhibitor chemotherapy: REGORAFENIB]

INTRODUCTION

Tyrosine kinase inhibitors (TKIs) are active in a variety of metastatic cancers. They have a good general tolerance with mainly hepatic and dermatological side effects. Rarely, ophthalmologic side effects may occur: eyelash abnormalities, eyelids abnormalities, disorders of the ocular surface with ocular dryness or even corneal erosions that can even lead to perforation. Regorafenib is a new oral multi-targeted tyrosine kinase inhibitor that inhibits multiple protein kinases, including those involved in tumor angiogenesis, oncogenesis and tumor microenvironment.

CASE DESCRIPTION

We describe, to the best of our knowledge, the first case of complicated bilateral ulcers of corneal perforation in a patient under REGORAFENIB.

OBSERVATION

20-year-old patient with metastatic chondrosarcomas of the pelvis, mandible and thorax received chemotherapy with REGORAFENIB. A few weeks after initiation of treatment, he experienced an increased dry eye syndrome associated with bilateral corneal ulcers complicated by perforation. Despite discontinuation of chemotherapy and maximal medical and surgical treatment (iterative amniotic membrane grafts and corneal transplantation), the progression was unfavorable.

DISCUSSION

This is the first known case of corneal perforation under REGORAFENIB. The pathophysiology is multifactorial. On the one hand, this chemotherapy targets angiogenesis (VEGFR), oncogenesis (KIT, RET, RAF1, BRAF) and the tumor microenvironment (PDGFR, FGFR). On the other hand, other triggers are added, namely mixed dry eye syndrome, hypovitaminosis A (anorexia), the neurotrophic component, as well as the toxicity of chemotherapy via tears.

CONCLUSION

First described case of corneal perforation under REGORAFENIB, non-regressive at the end of chemotherapy, and despite medical and surgical treatments. Ophthalmologic surveillance is therefore necessary for patients under chemotherapy with tyrosine kinase inhibitors, as serious ocular complications, especially corneal ones, may occur.

Predictive factors for exudation of quiescent choroidal neovessels detected by OCT angiography in the fellow eyes of eyes treated for a neovascular age-related macular degeneration

BACKGROUND

To identify predictive factors for exudation for quiescent choroidal neovessels (qCNV) in the fellow eyes of eyes treated for a neovascular age-related macular degeneration (AMD).

METHODS

Prospective observational study. One hundred and forty-four contralateral eyes of 144 patients treated for wet AMD were analysed. At a baseline visit, multimodal imaging including dye angiographies and optical coherence tomography angiography (OCT-A) was performed in order to detect qCNV. Patients were followed up for 12 months with a monthly assessment. The manifestation of any type of exudation (either intra- or subretinal fluid or hyperreflective subretinal material) was monitored.

RESULTS

The prevalence of qCNV in the treatment-naive eyes was 15.9% with an incidence over a 12-month period of 2.8%. In total, 40.7% of the overall neovessels remained stable with no sign of exudation, while 59.3% presented some fluid during the follow-up. A statistically significant relationship was established for the following variables preceding the exudation: increase in central macular thickness (OR = 116; 95% CI [4.74; 50530] p = 0.038), increase in pigment epithelial detachment height (OR = 1.76; 95% CI [1.17; 3.18] p = 0.021) and width (OR = 1.53; 95% CI [1.12; 2.62] p = 0.042), increase in neovessels' surface on OCT-A (OR = 6.32; 95% CI [1.62; 51.0] p = 0.033), emergence of a branching pattern (OR = 7.50; 95% CI[1.37; 61.5] p = 0.032) and appearance of a hypointense halo surrounding the lesion (OR = 10.00; 95% CI [1.41; 206] p = 0.048).

CONCLUSIONS

The risk of exudation in the treatment-naive fellow eyes of eyes treated for neovascular AMD was notably increased in the presence of qCNV. The biomarkers identified will help to detect their activation in order to ensure prompt antiangiogenic therapy.

Innovative corneal active storage machine for long-term eye banking

Optimal ex vivo corneal storage in eye banks is crucial to increase both the number of corneas suitable for graft and their intrinsic quality, mainly the number of viable endothelial cells, which dictates graft survival in recipients. With both passive storage methods used worldwide (short-term cold storage in the United States, long-term organ culture in Europe), significant endothelial cell loss is inevitable. Here we show that, with an active storage machine, also called a bioreactor, which restores 2 fundamental physiological parameters, intraocular pressure and medium renewal, endothelial cell survival is improved by 23% compared with organ culture after 4 weeks' storage. Also observed in the bioreactor is a 4-fold higher expression of Na⁺ /K⁺ ATPase, which supports one of the major endothelial cell pumping functions. In addition, corneas remain thin and transparent, so they are suitable for surgery at any time. This new active eye banking method may help to reduce the severe global scarcity of donor corneas.

Long-term adverse event: inflammatory orbitopathy induced by pembrolizumab in a patient with metastatic melanoma

The recent advent of immune checkpoint inhibitors (ICI), including anti-programmed cell death 1 protein (anti-PD-1) agents has revolutionized the therapeutic approach of metastatic malignancies. Yet, ICI can disrupt immune tolerance resulting in enhanced immune activation in normal tissues with significant toxicity. A dysregulated activation of T-cells directed to normal tissues stands as the main mechanism of immune-related adverse events (irAE). To date, only two cases of immune-related inflammatory orbitopathy related to anti-PD-1 agents have been reported. This rare immune adverse event usually occurred early after ICI initiation. Here, we report the first case of late inflammatory orbitopathy occurring in a melanoma patient treated with pembrolizumab. Consequently, the occurrence of irAE under ICI should be monitored, even late after treatment instauration.

Corneal transplantation trends in France from 2004 to 2015: A 12-year review

Purpose:

The aim of this study was to report the 12-year longitudinal trends in indication and corneal transplantation techniques in France from 2004 to 2015.

Results:

The records of all corneal transplantations performed from 2004 to 2015 in France were retrospectively reviewed. The patient indications and types of transplant performed were analyzed. A total of 46,658 corneal transplantations were performed between 2004 and 2015, with 34,187 (73.3%) penetrating keratoplasty and 10,452 (22.4%) lamellar keratoplasty. The leading surgical indications were secondary endothelial failure (24.3%), keratoconus (18.8%), regraft (13.5%), and Fuchs endothelial corneal dystrophy (15.1%). Endothelial keratoplasty became the preferred technique for endothelial diseases and deep anterior lamellar keratoplasty the preferred technique for keratoconus, surpassing penetrating keratoplasty in 2013.

Conclusion:

Secondary endothelial failure is the top indication for performing a keratoplasty over the 12-year period. There was a shift from penetrating keratoplasty to endothelial keratoplasty performed for Fuchs endothelial corneal dystrophy and secondary endothelial failure, and to deep anterior lamellar keratoplasty, performed for keratoconus. This highlights an important shift in managing corneal diseases toward the application of selective and more conservative surgeries and changes in indications in corneal transplantation.

Immunosuppression by a subconjunctival implant releasing dexamethasone in a rabbit model of penetrating keratoplasty

AIMS

To evaluate the efficacy of a subconjunctival dexamethasone-releasing implant in preventing rejection of penetrating keratoplasty (PK) in an animal model.

METHODS

Twenty-two rabbits underwent allogenic PK. After randomisation, they received either a 700 µg dexamethasone implant under the conjunctiva at the end of surgery (n=10), one dexamethasone 1 mg/mL eye-drop thrice daily (n=6) or a placebo thrice daily (n=6). The suture was left in place. Animals were observed weekly by slit-lamp and optical coherence tomography with quantification of transparency, neovascularisation and central corneal thickness (CCT). At 5-6 weeks, they were euthanised for histology. The residual dexamethasone concentration in ocular tissues was measured with an ultra-performance liquid chromatography-tandem mass spectrometer.

RESULTS

Placebo group: early neovascularisation was systematic, penetrating the graft by 270-360° at 5-6 weeks. Rejection occurred in 50% of cases. Eye-drop and implant groups: similar course without rejection at 6 weeks and normal CCT. Neovascularisation was observed in 5/6 rabbits in the eye-drop group and in 6/8 in the implant group, with two cases of new vessels penetrating the graft from week 3. Neovascularisation scores did not differ significantly between the two treatments and were significantly lower than for the placebo. Histology was in agreement in all cases. Implants disappeared after 3-5 weeks. No local side effect was observed. Tissue concentrations were all higher at day 8 (n=2) in the implant group than in the eye drop group and lower at 6 weeks (n=8).

CONCLUSIONS

In this PK model characterised by a high rejection rate, a subconjunctival dexamethasone implant was for 6 weeks as effective as the topical form in preventing allograft rejection.

Cutting and Decellularization of Multiple Corneal Stromal Lamellae for the Bioengineering of Endothelial Grafts

Purpose

Engineered corneal endothelial grafts able to provide numerous functional endothelial cells for the restoration of corneal transparency would be a worthwhile way of replacing donor tissue, which is extremely scarce. The grafts are simply constructed: a biocompatible thin and transparent carrier colonized by a monolayer of cultured endothelial cells (ECs). Here we describe a process able to obtain appropriate carriers by recycling human corneas unsuitable for graft in their original state, but liable to provide multiple thin lamellae when cut with a femtosecond laser as used in refractive surgery.

Methods

We selected a robust method of stromal decellularization. To demonstrate that neither this process nor long-term storage hindered cell adherence, lamellae were endothelialized with an EC line.

Results

The constructs achieved up to very high EC density (the main quality criterion for regular donor corneas) while remaining transparent and thin. We verified that they could be inserted in the anterior chamber of a human eye, like a conventional endothelial graft. Human decellularized cornea will likely be directly compatible with the recipient cornea and comply with the requirements of health regulatory authorities.

Conclusions

This study demonstrates that thin human corneal lamellae could have high potential as carriers in next-generation therapy for endothelial dysfunctions.