The bioengineering of corneal endothelial grafts consists of seeding in vitro cultured corneal endothelial cells onto a thin, transparent, biocompatible, and sufficiently robust carrier which can withstand surgical manipulations. This is one of the most realistic alternatives to donor corneas, which are in chronic global shortage. The anterior capsule of the crystalline lens has already been identified as one of the best possible carriers, but its challenging manual preparation has limited its use. In this study, we describe a femtosecond laser cutting process of the anterior capsule of whole lenses in order to obtain capsule discs of 8 mm diameter, similar to conventional endothelial grafts. Circular marks made on the periphery of the disc indicate its orientation. Immersion in water for 3 days is sufficient to completely remove the lens epithelial cells and to enable the seeding of corneal endothelial cells, which remain viable after 27 days of culture. Therefore, this method provides a transparent, decellularized disc ready to form viable tissue engineered endothelial grafts.

Background/aim Rejection is the main cause of graft failure after penetrating keratoplasty (PK). Its prevention by repeated instillation of steroid eye-drops has not evolved in decades. Poor adherence and discontinuous nature of eye-drop treatment may explain some PK failures. In a rabbit model, we previously demonstrated that a subconjunctival dexamethasone implant was well tolerated and prevented rejection efficiently in the first 5–6 weeks. This clinical trial investigates its tolerance and safety after PK. Methods Single-centre, phase II non-randomised tolerance and safety pilot study (NCT02834260). Designed to analyse the risk of elevated intraocular pressure (IOP), discomfort and resorption time. Fourteen patients with a low rejection risk indication of PK were enrolled between January 2017 and August 2018. The implant was injected in the 12 o’clock position, 5 mm from the limbus, at the end of PK. A steroid eye-drop treatment was planned when implant resorption was complete. Patients were monitored regularly for 12 months: IOP (main outcome measure at 1 month), discomfort and redness scores, implant status, rejection episode and central corneal thickness by optical coherence tomography. An independent data safety monitoring committee verified safety aspects. Results No increase in IOP or other adverse event related to the implant was observed. Average resorption time was 6 weeks. The switch to steroid eye-drops was uneventful. One patient, included despite preoperative corneal neovascularisation (unintended protocol deviation) experienced a rejection. Conclusions This is the first proof of concept that dropless immunosuppression is possible after low rejection risk PK. Trial registration number NCT02834260.

With aging, the stiffening of the crystalline lens [K. R. Heys et al., Mol. Vision 10, 956 (2004); R. F. Fisher, J. Physiol. 212(1), 147–180 (1971)] can hinder accommodation and reduce near-vision in more than 75% of individuals above 40 year old [T. R. Fricke et al., Ophthalmology 125(10), 1492–1499 (2018)], an impairment known as presbyopia. Mapping lens elasticity using shear wave elastography holds significant promise for monitoring potential treatments for presbyopia. However, because of the transparency of the lens to ultrasound, the tracking of waves can be performed only on its boundaries. The goal of this study is to characterize the viscoelastic properties of in vitro crystalline lens samples with a curvilinear harmonic method based on noise correlation algorithms. This procedure consists of precise measurements of the dispersion of surface waves across a large frequency range (0.1–3.5 kHz), thus allowing for clear identification of the wave properties needed to correctly estimate the elasticity. The proposed method was applied to gelatin phantoms and excised porcine lens samples. This enabled the observation of two regions in the dispersion curves: a sharp decrease in dispersion at low frequencies (1 kHz), which was attributed to viscoelastic dispersion. In contrast to previous studies, shear elasticity and viscosity moduli were computed at higher frequencies with a Kelvin–Voigt model. If our approach confirms the shear viscosity of lenses, then the shear elastic moduli of lenses are almost an order of magnitude greater than the results of previous studies.

We present here in a historical focus on the first descriptions in the 1950's by Louis Paufique of Descemetorhexis without endothelial keratoplasty (DWEK) for the treatment of Fuchs' endothelial dystrophy. This article places the introduction of this surgical technique in the context of its time, describes its principles, and puts into perspective the place of this relevant treatment in the therapeutic arsenal of today and tomorrow.