Aims After keratoplasty, postoperative endothelial cell loss is calculated between the eye bank endothelial cell density (ebECD) and the postoperative specular microscopy (SM). To elucidate the very early cell loss, always described after penetrating keratoplasty (PK), we designed two complementary studies. Methods (1) Clinical prospective study of 90 consecutive PKs (keratoconus, Fuchs' corneal dystrophy, lattice dystrophy, bullous keratopathy) with organ-cultured corneas and postoperative follow-up by SM at day 5 (D5), D15, month 1 (M1) and M3. This series provided a quantification of the difference between ebECD performed 2 days before graft and very early postoperative ECD. (2) Ten pairs of corneas with comparable ebECD in both corneas and same organ-culture (OC) duration were randomised: one cornea was grafted, and, at the same time, the viable ECD (vECD) of the other was measured after labelling with Hoechst/ethidium/calcein-AM. The relationship between vECD and very early postoperative ECD was studied.Results vECD at the time of graft did not differ from ECD 5 days after PK, with a difference of 39 (−356; 355) cells/mm 2 (median (10°; 90°percentile, p=0.799)), whereas a significant difference of 755 (359; 1146) cells/mm 2 , corresponding to 28% (95% CI 26 to 30) of cells, was measured between ebECD and ECD 5 days after PK ( p<0.001). Conclusions In OC, ebECD provided to surgeons significantly overestimate the number of viable ECs grafted to patients. The absence of difference between the vECD at D0 and ECD at D5 indicates that the very early endothelial cell loss is almost negligible in recipients.
APOLLON (NCT02924311) was a prospective observational study to evaluate the effectiveness of intravitreal aflibercept (IVT-AFL) treatment of diabetic macular edema (DME) over 24 months in routine clinical practice in France. The primary endpoint was mean change from baseline in best-corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study letters) by 12 months, and safety was monitored throughout the study. Of 402 patients enrolled across 61 participating clinics and hospitals in France, 168 patients were followed for at least 24 months and included in the effectiveness analyses (79 treatment-naïve and 89 previously treated). After 24 months of IVT-AFL treatment, the mean (± standard deviation [SD]) change in BCVA from baseline was + 6.5 (± 10.7) letters in treatment-naïve patients (p < 0.001) and + 1.6 (± 17.0) letters in previously treated patients (p = 0.415) from a baseline of 63.8 (± 13.6) and 60.5 (± 16.5) letters. The mean number of IVT-AFL treatments over 24 months was 11.3 (± 4.9) and 11.9 (± 4.7) for treatment-naïve and previously treated patients. This final analysis of the APOLLON study indicated that following 24 months of IVT-AFL treatment in routine clinical practice in France, treatment-naïve patients with DME achieved significant gains in visual acuity and previously treated patients maintained prior visual acuity gains.Trial registration number: NCT02924311.
Purpose Restoration of a trans‐corneal pressure (P) gradient and continuous circulation of fluids on both sides of the cornea could improve endothelial cell survival and reduce stromal swelling and Descemet folding during long‐term corneal storage. Aim: to present the technical requirements and the technical choices we made during the development of an innovative corneal bioreactor (BR) Methods Main functions were defined with a process of functional analysis of needs in collaboration with eye bankers. Successive prototypes were built using 3D printing with biocompatible resins, and machining of PMMA blocks, and windows made out of optical grade glass were glued. Different types of connecting tubes were assessed. Efficiency was analysed in term of capacity of maintaining the cornea perfectly tighten in order to create 2 hermetic endo and epi compartments. P (adjustable from 0 to 50 mmHg with a mini‐LCD screen for live display) was regulated by a continuous irrigation from a disposable infusion system associated with a P sensor and a micro‐solenoid valve driven by a customized microcontroller Results The 3 most challenging points were: 1/waterproofness between epi and endo chambers that require to use corneas with at least a 16 mm diameter regular scleral rim 2/ biocompatibility of glues 3/ oxidation and alcalinization of storage medium caused by materials permeable to atmospheric gases. Since 2 years, 9 successive prototypes allowed selection of efficient solutions Conclusion Our innovative BR will be useful for both laboratory research and corneal storage by eye banks in a next future. Grant: ABM 2012, EFS 2012, ANSM 2012. PG, GT and SA patented the BR
This difference between the autograft and allograft, both performed in corneas with a normal peripheral endothelial reserve, indicates that the typical very early postoperative decrease in the EC is not caused mainly by surgery-dependent overmortality. It may be mostly artificial, revealing the overestimation of eye bank ECD caused by the technical unfeasibility of strictly considering living ECs and by measuring the ECD several days before grafting. This exceptional case suggests a new paradigm: surgeons graft fewer ECs than they think.
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