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Aim To investigate the interest of chromatic confocal microscopy (CCM) to characterise guttae in Fuchs endothelial corneal dystrophy (FECD). Methods Descemet's membranes (DM) were obtained during endothelial keratoplasty in patients with FECD and pseudophakic bullous keratopathy (PBK). They were compared with healthy samples obtained from body donation to science. Samples were fixed in 0.5% paraformaldehyde and flat mounted. Surface roughness of DMs was quantified using CCM and the AltiMap software that provided the maximum peak (Sp) and valley (Sv) heights, the mean square roughness (Rq) and the asymmetry coefficient (Ssk). Results The physiological roughness of healthy samples was characterised by an Rq of 0.12±0.05 µm, which was two times rougher than in PBK (Rq=0.06±0.03 µm), but both were still flat with a symmetrical distribution between peaks and valleys (Ssk close to 0, npeaks=nvalleys), smaller than 1 µm. In FECD, the maximum peak height was 5.10±2.40 µm, up to 5.8 and 8.3 times higher than the control and PBK, respectively. The maximum valley depth was half than the peak (2.28±0.89 µm). The surface with guttae was very rough (Rq=0.45±0.14 µm) and the Ssk=1.84± 0.43 µm, greater than 0, confirms an asymmetric surface with high peaks and low valleys (npeaks>nvalleys). Moreover, the CCM provided quantitative parameters allowing to distinguish different types of guttae from different patients. Conclusions CCM is an innovative approach to describe and quantify different morphologies of guttae. It could be useful to analyse the different stages of FECD and define subgroups of patients. [ABSTRACT FROM AUTHOR]

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. 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. [ABSTRACT FROM AUTHOR]

Objectives To assess to which extent the COVID-19 pandemic affected corneal transplantation by virtue of donor selection algorithms in different European countries. Design Survey. Setting 110 eye banks in 26 European countries. Participants 64 eye banks covering 95% of European corneal transplantation activity. Interventions A questionnaire listing the number of corneas procured and distributed from February to May 2018-2020 was circulated to eye banks. Main outcome measures The primary outcome was the number of corneal procurements. Additional outcomes were national algorithms for donor selection, classified according to their stringency (donors with COVID-19 history, suspected for COVID-19, asymptomatic, PCR testing) and the pandemic severity in each country. We calculated Spearman"s correlation coefficient to determine, two by two, the relationship between the 3-month decline in eye banking activity (procurement), the stringency of donor selection algorithm and the grading of pandemic severity (cases and deaths). A partial correlation was run to determine the relationship between decline and stringency while controlling for pandemic severity. Results Procurements decreased by 38%, 68% and 41%, respectively, in March, April and May 2020 compared with the mean of the previous 2 years, while grafts decreased, respectively, by 28%, 68% and 56% corresponding to 3866 untreated patients in 3 months. Significant disparities between countries and the decrease in activity correlated with stringency in donor selection independent of pandemic severity. Conclusions Our data demonstrate significant differences between countries regarding donor screening algorithms based on precautionary principles and, consequently, a decrease in the donor pool, already constrained by a long list of contraindications. Fundamental studies are needed to determine the risk of SARS-CoV-2 transmission by corneal transplantation and guide evidence-based recommendations for donor selection to justify their substantial medical and economic impact. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose To analyse the macula imaged with optical coherence tomography (OCT) in patients treated for acute postcataract endophthalmitis. Methods Patients presenting with acute postcataract endophthalmitis were included in this observational and multicentre study from January 2008 to December 2011. We recorded the following OCT data at the 3, 6 and 12-month visits: the central macular thickness, the perifoveal macular thickness, the central foveal point thickness and abnormalities of the outer retina, the macula and vitreoretinal interface. Results 46 patients were included in the OCT analysis. From month 3 to 12, epiretinal membrane (ERM) prevalence increased from 26% to 39%, vitreomacular traction prevalence decreased from 12% to 6%, non-tractional macular oedema (ME) prevalence varied between 7% and 13%. Only macular thinning remained stable at 10%. At month 12, a significant correlation was found between non-tractional ME and capsular rupture (at the time of cataract extraction, p=0.03). Eyes with an ERM exhibited increased central macular thickness (p=0.001) and lower visual acuity (VA) (p=0.02) at M12 in comparison to the group with normal macula. OCT analysis showed a significant association between ERM and the alteration of the ellipsoid band (p=0.02), as well as the external limiting membrane (ELM, p=0.07) at M12. Conclusions ERM and ME were the main macular abnormalities diagnosed after 1 year of follow-up, associated with VA less than or equal to 20/40 in 50% of the cases. Ultrastructural abnormalities of the ELM and the ellipsoid band were frequently observed in those patients. [ABSTRACT FROM AUTHOR]

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/mm2 (median (10°; 90° percentile, p=0.799)), whereas a significant difference of 755 (359; 1146) cells/mm2, 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. [ABSTRACT FROM AUTHOR]

Background/aims To report the incidence, risk factors and prognosis of retinal detachment (RD) in patients who had vitrectomy for acute bacterial endophthalmitis after cataract surgery. Methods 123 patients with acute postcataract endophthalmitis, consecutively treated with pars plana vitrectomy (PPV) were included by the French Institutional Endophthalmitis Study group, in a prospective multicentre cohort study. Risk factors of RD were analysed using logistic regression. Results At the 6-month follow-up, the rate of post-PPV RD was 13% (n=16). The risk factors of post-PPV RD were diabetes (OR=4.7 (1.4-15.4), p=0.01) and visualisation of retinal vasculitis on the posterior pole (OR=3.8 (1.1-13.9), p=0.03) at the time of PPV. Postoperative RD occurred in 56% (n=9) of cases in the first month, in 31% (n=5) in the second month and in 6% (n=1) in the third month, with a mean delay of 47 ±71 days after PPV. The macula was detached in 12 cases (75%) and proliferative vitreoretinopathy grade C was present in seven cases. Final successful reattachment of the retina was obtained in 60% (n=9/15) of cases, with one (7/9) or two surgeries (2/9). Final visual acuity after surgical repair was ≥20/40 in 19% of cases, compared with 43% in patients without RD (p=0.05). Conclusions RD is a major and severe complication of PPV performed in patients with acute postcataract endophthalmitis. Retinal vasculitis is a major risk factor of RD after PPV. Anatomical and functional outcome remain poor. [ABSTRACT FROM AUTHOR]

Background The targeted delivery of drugs or genes into corneal endothelial cells (ECs) during eye banking could help improve graft quality and quantity. Physical methods raising less safety concerns than viral ones, we previously adapted, for in vitro ECs, a recent innovative technique of drug delivery based on the activation of carbon nanoparticles (CNPs) by a femtosecond laser (fsL). The aim of the present pilot study was to adapt this method to enable molecule delivery into the intact endothelium of ex vivo human corneas. Methods ECs from 40 organ-cultured corneas were perforated by photoacoustic reaction induced by irradiation of CNPs by a fsL. This enabled intracellular delivery of Alexa Fluor 488 dextran, a 4000 Da fluorescent macromolecule. The influence of increasing laser fluences (15, 20, 30 and 40 mJ/cm2) and of protective additives (ROCK inhibitor and poloxamer 407) on delivery and mortality rates was quantified using ImageJ. Results No dextran was delivered with a fluence lower than 20 mJ/cm2. Dextran was delivered into 3% (range 0%-7%) of cells at 20 mJ/cm2, 7% (range 2%-12%) at 30 mJ/cm2 and reaching a median 13% (range 3%-24%) for 40 mJ/cm2, showing that dextran uptake by ECs increased significantly with fluence. Induced mortality varied from 0% to 53% irrespective of fluence, but likely to be related with the endothelial status (EC density and morphometry, donor age, storage duration and presence of Descemet's folds). ROCK inhibitor slightly increased uptake efficiency, unlike poloxamer. However, none of them decreased the mortality induced by laser. Conclusions This study shows that a macromolecule can be delivered specifically into ECs of a whole organ-cultured human cornea, using fsL-activated CNPs. The delivery rate was relatively high for a non-viral method. Further optimisation is required to understand and reduce variability in cell mortality. [ABSTRACT FROM AUTHOR]

Aim To compare early versus delayed intravitreal betamethasone as an adjuvant in the treatment of presumed acute postoperative endophthalmitis after phacoemulsification. Methods Patients with presumed postcataract surgery endophthalmitis were included in this prospective, randomised, multicentre study. On admission, patients received intravitreal vancomycin and ceftazidime, and were randomly assigned to intravitreal betamethasone injection (early-IVB) group or no immediate injection (delayed-IVB) group. After 48 h, a second intravitreal antibiotic injection associated with intravitreal betamethasone was given to all patients. In patients with severe endophthalmitis or clinical deterioration, a prompt or delayed vitrectomy was performed. The primary outcome was the proportion of patients achieving a visual acuity (VA) of 20/40 or better at 12 months. The secondary outcomes were the rate of delayed vitrectomy and the rate of complications (retinal detachment and phthisis). Results Ninety-seven eyes of 97 patients were included, 45 in the early-IVB group and 52 in the delayed-IVB group. Overall, 62.9% of patients achieved a VA ≥20/40 at 1 year. There was no statistically significant difference in the visual outcome between the two groups at 1 year, whatever their baseline VA or light perception or hand motion or more (p=0.55 and p=0.10, respectively). The rates of delayed vitrectomy, retinal detachment and phthisis bulbi were not significantly different between the two groups (p=0.42, p=0.37 and p=0.44, respectively). Conclusions Early intravitreal betamethasone had no clear advantage versus delayed injection in the management of presumed postoperative endophthalmitis. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented about endothelial cell density (ECD) assessment with two non-contact specular microscopes, Topcon SP2000P and Rhine-Tec.