The Orphan Drug for Acanthamoeba Keratitis (ODAK) Trial: PHMB 0.08% (Polihexanide) and Placebo versus PHMB 0.02% and Propamidine 0.1.

PURPOSE: To compare topical PHMB (polihexanide) 0.02% (0.2 mg/ml)+ propamidine 0.1% (1 mg/ml) with PHMB 0.08% (0.8 mg/ml)+ placebo (PHMB 0.08%) for Acanthamoeba keratitis (AK) treatment. DESIGN: Prospective, randomized, double-masked, active-controlled, multicenter phase 3 study (ClinicalTrials.gov identifier, NCT03274895). PARTICIPANTS: One hundred thirty-five patients treated at 6 European centers. METHODS: Principal inclusion criteria were 12 years of age or older and in vivo confocal microscopy with clinical findings consistent with AK. Also included were participants with concurrent bacterial keratitis who were using topical steroids and antiviral and antifungal drugs before randomization. Principal exclusion criteria were concurrent herpes or fungal keratitis and use of antiamebic therapy (AAT). Patients were randomized 1:1 using a computer-generated block size of 4. This was a superiority trial having a predefined noninferiority margin. The sample size of 130 participants gave approximately 80% power to detect 20-percentage point superiority for PHMB 0.08% for the primary outcome of the medical cure rate (MCR; without surgery or change of AAT) within 12 months, cure defined by clinical criteria 90 days after discontinuing anti-inflammatory agents and AAT. A prespecified multivariable analysis adjusted for baseline imbalances in risk factors affecting outcomes. MAIN OUTCOME MEASURES: The main outcome measure was MCR within 12 months, with secondary outcomes including best-corrected visual acuity and treatment failure rates. Safety outcomes included adverse event rates. RESULTS: One hundred thirty-five participants were randomized, providing 127 in the full-analysis subset (61 receiving PHMB 0.02%+ propamidine and 66 receiving PHMB 0.08%) and 134 in the safety analysis subset. The adjusted MCR within 12 months was 86.6% (unadjusted, 88.5%) for PHMB 0.02%+ propamidine and 86.7% (unadjusted, 84.9%) for PHMB 0.08%; the noninferiority requirement for PHMB 0.08% was met (adjusted difference, 0.1 percentage points; lower one-sided 95% confidence limit, -8.3 percentage points). Secondary outcomes were similar for both treatments and were not analyzed statistically: median best-corrected visual acuity of 20/20 and an overall treatment failure rate of 17 of 127 patients (13.4%), of whom 8 of 127 patients (6.3%) required therapeutic keratoplasty. No serious drug-related adverse events occurred. CONCLUSIONS: PHMB 0.08% monotherapy may be as effective (or at worse only 8 percentage points less effective) as dual therapy with PHMB 0.02%+ propamidine (a widely used therapy) with medical cure rates of more than 86%, when used with the trial treatment delivery protocol in populations with AK with similar disease severity. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Corneal Biomechanical Evaluation After Meniscus-Shaped Stromal Lenticule Addition Keratoplasty (MS-SLAK) for Keratoconus.

PURPOSE: To evaluate corneal biomechanical changes after meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) performed for the treatment of keratoconus. METHODS: This interventional study included patients affected by advanced keratoconus (stage III and IV) who underwent examination with a dynamic Scheimpflug analyzer and non-contact tonometer (Corvis ST; Oculus Optikgeräte GmbH) at baseline and 12 months after MS-SLAK. The biomechanical parameters evaluated in this study were integrated inverse radius (1/R), deformation amplitude ratio (DA ratio), stiffness parameter at first applanation (SP-A1), biomechanical intraocular pressure (bIOP), central corneal thickness (CCT), and stress-strain index (SSI). RESULTS: Sixteen patients were enrolled in the study. The analysis was ultimately conducted on 15 patients. Comparative analyses showed an increase in corneal stiffness as demonstrated by a rise in SSI (P < .0001) and SP-A1 (P < .0001) and a decrease in DA ratio (P < .0001) and 1/R (P = .01). A significant increase in CCT was found (P < .0001). No statistically significant modification was found for bIOP (P = .43). CONCLUSIONS: The corneal biomechanical analyses evaluated by the Corvis ST showed that MS-SLAK for advanced keratoconus is able to increase corneal overall stiffness. This result is explained by the significant increase in thickness induced by MS-SLAK. [J Refract Surg. 2023;39(7):499-504.].

Microscopic corneal epithelial changes and clinical outcomes in simple limbal epithelial transplantation surgery after treatment with amniotic membrane eye drops (AMED): A case report.

Purpose: To describe the microscopic epithelial changes and the clinical outcomes of a patient treated with amniotic membrane eye drops (AMED) because of a persistent epithelial defect (PED) and a partial limbal stem cell deficiency (LSCD) after simple limbal epithelial transplantation (SLET) and deep anterior lamellar keratoplasty (DALK). Observations: A 72-year-old patient, who had previously undergone SLET and DALK due to a total LSCD, presented with a PED related to a partial LSCD, and was treated with AMED for one month. We evaluated the patient's visual acuity, the Oxford grading scale, the Wong-Baker Pain Rating Scale, and in vivo confocal microscopy, both at baseline and 3 months after the end of treatment. Visual acuity improved from 0.5 to 0.4 LogMAR, the Oxford grading scale changed from grade III to grade I and the Wong-Baker Pain Rating Scale from grade 4 to grade 1. The corneal surface, which initially showed conjunctival characteristics over approximately 50% of the whole area, consisted mainly (75%) of mature corneal epithelium 3 months after the end of treatment. Conclusions and importance: While improving symptoms and clinical characteristics, AMED was also able to restore the normal corneal epithelium's morphology in a case of partial LSCD after SLET and DALK.

Meniscus-Shaped Stromal Lenticule Addition Keratoplasty for Corneal Regularization and Thickening in Advanced Keratoconus.

PURPOSE: The aim of this study was to investigate the outcome of the meniscus-shaped stromal lenticule addition keratoplasty (MS-SLAK) in corneal regularization and thickness. METHODS: Patients waiting for deep anterior lamellar keratoplasty for advanced keratoconus with an intolerance to contact lenses (CLs) underwent the MS-SLAK procedure by FSL 80 kHz ablation (VICTUS, Technolas Perfect Vision, DE). Customized positive meniscus-shaped stromal lenticules were obtained and implanted. Examination was performed at baseline and at 3-, 6-, and 12-month follow-up and included corrected distance visual acuity both with spectacles and CLs (spectacle CDVA and CL-CDVA), manifest refraction spherical equivalent, slit-lamp examination, anterior segment optical coherence tomography, corneal topography, and in vivo confocal microscopy. RESULTS: Fifteen patients completed the study. Statistical increases in corneal thickness values were found from the first follow-up ( P < 0.001). Improvement in the Surface Asymmetry Index ( P = 0.04), Symmetry Index ( P = 0.02), spherical aberration ( P < 0.001), coma ( P = 0.18), high-order aberration ( P = 0.37), and anterior asphericity index (Q) ( P = 0.31) were found at 12 months. At the 12-month follow-up, no improvement were found in spectacle CDVA ( P = 0.23); however, all patients reported CL wearing tolerance recovery, and significant improvement in CL-CDVA ( P = 0.002) was found. The confocal microscopy at 12 months showed a significant increase in keratocyte density within the lenticule and absence of fibrotic reactions in both anterior and posterior interfaces. CONCLUSIONS: MS-SLAK seems to be effective in regularizing the corneal surface as showed by the significant improvement in topographic symmetry indices, coma, and high-order aberration. The corneal regularization is also confirmed by the results in anterior Q and the recovery of the CL wearing tolerance.

Results of ultrathin Descemet stripping automated endothelial keratoplasty with donor corneas preserved in synthetic organ culture media.

PURPOSE: To evaluate outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) with donor corneas preserved at 31°C in Cornea Syn®, a medium formulated with recombinant human serum albumin (rHSA) to replace foetal calf serum, and deswelled-transported in the xeno-free medium Cornea Trans®. METHODS: Prospective, multicentre, open-label study. We evaluated the endothelial cell loss (ECL) as the percentage variation of the endothelial cell density (ECD, cells/mm2) between 6 and 12 months after surgery, corneal transparency and thickness at 12 months, and adverse events within 12 months. Endothelial lenticules of mean 89 µm, ECD ≥ 2300 cells/mm2, minimum signs of cell mortality or morphology alterations, were dissected by microkeratome in the eye bank, and grafted in patients ≥ 18 years without corneal neovascularisation, conjunctivalization, or blinking impairment. RESULTS: Thirty-five patients underwent UT-DSAEK, 3 showed primary failure, 1 late failure, and 2 skipped the 6-month visit. We analysed data from 29 patients, 27 with Fuchs endothelial corneal dystrophy (FECD) and 2 with pseudophakic bullous keratopathy (PBK). The median ECL between 6 and 12 months was 2.6% (p = .054, CI 0 to 12.5) and the absolute mean (SD) was 158.4 (364.1) cells/mm2. After 12 months, 96.5% of corneas were clear, with mean pachymetry of 585.9 (50.4) µm. CONCLUSIONS: The ECL rate after UT-DSAEK match overall that observed in DSAEK or UT-DSAEK models of endothelial survival and the overall safety compared that reported for similar follow-up. Corneas maintained in Cornea Syn® and Cornea Trans® did not affect the ECD and functional outcomes of UT-DSAEK up to 12 months.

Autologous simple conjunctival epithelial transplantation for primary pterygium.

PURPOSE: To evaluate the feasibility of a new method of conjunctival transplantation to achieve recovery of the normal conjunctival epithelium over the bare sclera after pterygium excision and prevent its recurrence. METHODS: After excision of the primary pterygium, we performed simple conjunctival epithelial transplantation (SCET) in which we glued an amniotic membrane patch pre-loaded with tiny autologous conjunctival tissue fragments over the scleral defect. Slit-lamp evaluation was performed at 2 and 7-10 days, and then at 1, 3, 6, and 12 months after surgery, together with confocal microscopy at 3, 6, and 12 months. RESULTS: Surgical excision and SCET for nasal primary pterygium were performed in 6 eyes (6 patients). No graft detachment occurred. An inflammatory granuloma was excised without sequelae in one patient 2 months after surgery. No signs of recurrence or sight-threatening complications were recorded at 12 months, and in vivo confocal microscopy showed progressive expansion of the conjunctival cell population and formation of a clear corneal-conjunctival transition. CONCLUSIONS: SCET takes advantage of the ability of the amniotic membrane and conjunctival cells to renew. Outcomes after SCET are comparable to conventional conjunctival flap surgery and can be achieved in less surgical time and with less donor tissue to be removed.

Glaucoma surgery during the first year of the COVID-19 pandemic.

PURPOSE: To summarize the actions taken to give continuity to the surgical treatment of glaucoma patients and to present the volume and characteristics of glaucoma surgery in the first year of pandemic at the Tertiary Glaucoma Center of the University Hospital of Verona (Veneto, Italy). METHODS: Demographical and surgical features of patients who underwent glaucoma surgery from March 9th, 2020 to March 8th, 2021 have been collected and compared to the same date range of the previous year. The analyzed data included age, gender, region of origin, glaucoma staging, type of anesthesia and surgical procedure. RESULTS: The surgical volume of glaucoma has dropped by 30.1%. In comparison with the previous year, we found a significant variation in the overall distribution of the performed surgical procedures (p < 0.001). There was a decline in Baerveldt tube implants (- 4.9%), and an increase of non-penetrating surgery (+ 2.6%), cyclo-photo ablative procedures (+ 4.2%) and MIGS (+ 5.7%). Only 24.3% of the procedures were performed under general anesthesia compared to 41.5% in the pre-pandemic period (p < 0.001). The number of procedures performed on eyes affected by advanced or end-stage glaucoma is doubled (p < 0.001). CONCLUSIONS: To give continuity to glaucoma surgery, we prioritized interventions on patients with poorer visual fields, rapidly progressing visual field deficit and elevated IOP uncontrolled by maximal medical therapy. Secondly, we have rescheduled the other interventions following the same priority criteria. Finally, we managed some lower priority cases with MIGS, minimizing the need for close post-intervention follow-up. Considering the negative consequences that a delay in the management of glaucoma can have in terms of visual loss, the closure of the operating rooms in the first quarter of the pandemic was detrimental. It appears that glaucoma surgery deserves urgencies that cannot be overshadowed and the greatest effort must be to give continuity to this type of eye surgery.

Eight months follow-up of corneal nerves and sensitivity after treatment with cenegermin for neurotrophic keratopathy.

BACKGROUD: Cenegermin (Oxervate, Dompè Farmaceutici, Milan, IT), a recombinant human NGF, is a potentially healing new drug for neurotrophic keratopathy (NK), a rare but challenging disease affecting the cornea. To date, studies that evaluate its mid-term effect on corneal nerves and sensitivity are lacking. OBJECTIVE: To evaluate the recovery and morphology of subbasal corneal nerves in patients treated with Cenegermin for NK and assess their correlation with corneal sensitivity. METHODS: This prospective, observational case series study was carried out between May 2018 and August 2020 at the Ophthalmic Clinic of the University of Verona. Clinical evaluation, sensitivity, and in vivo confocal microscopy (IVCM) were performed in the central and all four corneal sectors at baseline, the end of therapy (8 weeks), and 2, 4, and 8 months after therapy. Consecutive patients with NK (stage 2-3), treated with Cenegermin (1 drop 6 times daily for 8 weeks), were enrolled. During each visit, Corneal nerve fiber length (CNFL), corneal nerve fiber total branch density (CTBD), corneal nerve fiber fractal dimension (CNFraD) and Cochet-Bonnet esthesiometry (CBE) were measured. RESULTS: We enrolled 18 patients. Complete NK healing was noted in 14/18(78%) patients after 8 weeks of treatment; then in 14(78%), 15(83%), and 13(72%) patients at 2-, 4-, and 8-months, respectively. Starting at 8 weeks through 4-month follow-up there was progressive improvement in CBE in all corneal sectors (p ≤ 0.01), which continued thereafter. There was significant corneal nerve regrowth especially in the peripheral cornea: centripetal progression starting at 8 weeks (CNFL and CNFrad) and significant branching starting at 2 months (CTBD), which continued through to the end of follow up. Sector-coupled IVCM and CBE findings correlated at all evaluations (all r ≥ 0.62 starting at 2 months, with highest values in the peripheral sectors). CONCLUSIONS: After Cenegermin we observed a subbasal corneal nerve regeneration, a recovery of sensitivity and a lasting epithelial healing, suggesting that the effect of its action persists several months after discontinuation in patients with NK.

The Role of Topical Povidone-Iodine in the Management of Infectious Keratitis: A Pilot Study.

The aim of this prospective explorative study was to evaluate the safety and the effectiveness of topical polyvinylpyrrolidone-iodine (PVP-I) administered during the time-to-results period for pathogen identification and susceptibility testing in patients with infectious keratitis (IK). A corneal swab (CS) for antimicrobial evaluation was performed at enrollment (T0) and topical 0.66%-PVP-I was administered until the laboratory results were available (T1). Ulcer and infiltrate areas and infiltrate depths were compared between T0 and T1 (i.e., time-to-result period). Patients were then shifted to a specific antimicrobial therapy and followed up until resolution of their infiltrates (Tlast-TL). Twenty-five eyes were enrolled, and none showed clinical worsening leading to protocol withdrawal. At T1, ulcer and infiltrate areas showed significant improvement in Gram-positive IK (n = 13-52%; p = 0.027 and p = 0.019, respectively), remained stable in fungal IK (n = 5-20%; both p = 0.98) and increased in those with Gram-negative bacteria (n = 4-16%; p = 0.58 and p = 0.27). Eyes with negative cultures (n = 3-12%) showed complete resolution at T1 and did not initiate any additional antimicrobial therapy. The administration of 0.66% PVP-I during the time-to-result period seems to be a safe strategy in patients with IK while often sparing broad-spectrum antimicrobial agents. In addition, it showed to be effective in eyes with a Gram-positive bacterial infection.

Early corneal and optic nerve changes in a paediatric population affected by obstructive sleep apnea syndrome.

PURPOSE: The relation between OSAS and eye diseases is well known in adults, while very few and contradictory data can be found regarding paediatric ages. The aim of this study is to explore the early corneal, macular and optic nerve changes in paediatric patients with OSAS. METHODS: Prospective study that enrolled children aged ≥ 4 years referred to the Paediatric Pneumology Clinic in Verona for suspected obstructive sleep apnoea syndrome (OSAS) and investigated with the overnight respiratory polygraphy. Patients with apnoea-hypopnea index (AHI) > 1 were classified as OSAS, while those with AHI < 1 were classified non-OSAS. All patients underwent comprehensive eye examination including slit lamp, refraction, intraocular pression (Goldman applanation tonometry), corneal tomography (corneal astigmatism, corneal keratometry at the apex, surface asymmetry index, central corneal thickness and thinnest corneal thickness) and optical coherence tomography (central macular thickness, macular volume and retinal nerve fibre layer). RESULTS: Seventy-two children were enrolled in the study. The overall prevalence of OSAS was 48.6%. Statistically significant differences were found between OSAS and non-OSAS group for corneal asymmetry (0.9 ± 0.5 and 0.6 ± 0.3, respectively; p = 0.02), thinnest corneal thickness (551.8 ± 33.9 and 563.7 ± 32.5; p = 0.04), average retinal nerve fibre layer (102.8 ± 10.5 µm and 98.1 ± 12.3 µm; p = 0.012) and in nasal quadrant (76.2 ± 15.4 µm and 66.5 ± 12.6 µm; p = 0.0002). CONCLUSIONS: A comprehensive eye examination with corneal and optic nerve imaging showed early corneal and optic nerve changes in children newly diagnosed with OSAS. These could be prelude of the known ocular manifestations associated with OSAS in adult patients.

Gender Matching Did Not Affect 2-year Rejection or Failure Rates Following DSAEK for Fuchs Endothelial Corneal Dystrophy.

PURPOSE: To investigate whether donor to recipient gender or H-Y mismatching was associated with graft rejection or failure following Descemet stripping automated endothelial keratoplasty (DSAEK) in patients with Fuchs endothelial corneal dystrophy (FECD). DESIGN: Clinical cohort study. METHODS: This study used a multi-center registry including patients aged >18 years who had undergone their first DSAEK for FECD between January 2008 and March 2018. The impact of donor and recipient gender incompatibility (including H-Y mismatches) on corneal graft rejection and failure was evaluated using Kaplan-Meier curves and univariable and multivariable Cox models. RESULTS: Outcome data from 4341 eyes (3915 from the UK and 426 from Italy) were analyzed. Graft failure at 2-year follow-up occurred in 477 (11.0%) cases. Graft rejection at 2-year follow-up occurred in 175 cases (4.0%), 58 (1.3%) of whom developed graft failure. There was no significant effect of gender or H-Y mismatching on either rejection (P = .12, P = .06) or failure (P = .28, P = .14), respectively. CONCLUSIONS: In patients with FECD undergoing DSAEK, no significant influence of gender and or H-Y mismatch on graft rejection or failure was found.

In vitro establishment, validation and characterisation of conjunctival epithelium outgrowth using tissue fragments and amniotic membrane.

BACKGROUND/AIMS: To set up the in vitro conditions for renewal of the conjunctival epithelium using healthy fragments of conjunctival tissue glued over an amniotic membrane. METHODS: We evaluated the capability of conjunctival tissue fragments to generate conjunctival cell outgrowth after seeding them onto amniotic membrane and culture plates; we then assessed conjunctival molecular marker expression by immunofluorescence. We also evaluated the efficiency of glueing the fragments over the amniotic membrane to determine the best setting and the feasibility of shipping preloaded amniotic membranes. RESULTS: Epithelial outgrowth was detected in 65%-80% of conjunctival fragments starting 48-72 hours after glueing, without major differences between type of membrane preparation and fragment size. Within 6-13 days, a full epithelium covered the surface of the amniotic membrane. Specific marker expression (conjunctival epithelium, Muc1, K19, K13; stemness, p63; tight junctions, ZO-1) was detected. Results of the shipping test showed that only 31% of the fragments were still glued over the epithelial side of the membrane within 24 hours compared to more than 90% of fragments stayed attached in the remaining conditions. CONCLUSION: The in vitro regeneration of conjunctival epithelium following outgrowth from conjunctival tissue fragments glued over an amniotic membrane may offer a viable strategy to renew the epithelium in vivo once applied over the ocular surface at the recipient site.

Gram stain and addition of amphotericin B to improve the microbial safety of human donor corneas.

To determine the effectiveness of two methods to improve the microbial safety of human corneas preserved in organ culture. We compared the number of positive preservation solutions of corneas in organ culture in which the initial short-term hypothermic corneal maintenance solution was supplemented with amphotericin B 2.5 µg/mL and the historical data of microbial test results (2015-2019). In addition, we appraised the efficacy of Gram stain to detect bacterial or fungal contamination in the organ culture solutions of corneas from at-risk donors compared to the culture tests of corneas from not-at-risk donors. Statistical analysis was performed using STATA and statistical significance set at p < 0.05. The number of positive culture tests after preservation was 15 (0.5%) in 2020 compared to a mean of 37 (1.2%) in the period 2015-2019 (p < 0.01), with 10 (1.0%) positive samples in the cohort of 998 corneas from at-risk donors and 5 (0.2%) in the 2046 corneas from not-at-risk donors (p < 0.01). All corneas from at-risk donors tested positive at Gram stain and the results were available 1-3 days before those of the conventional culture tests. Amphotericin B supplementation in the short-term maintenance solution markedly reduced the number of positive microbial tests after organ culture and the early detection of contaminants, including slow-growing microorganisms, by Gram stain before the standard culture results. This meant fewer corneas being discarded and a greater likelihood of preventing post-graft infections.

22†Renewal of conjunctival epithelium over amniotic membrane to perform autologous simple conjunctival epithelial transplantation (SCET): in vitro validation and results of clinical application for primary pterygium.

BACKGROUND: Transplantation of ex vivo cultured conjunctival cell layers, generated on amniotic membrane or other scaffolds, provides a viable option in treating heterogeneous ocular surface conditions. By comparison, cell therapy is costly, labour-intensive and subject to good manufacturing practice requirements and regulatory approval; no conjunctival cell-based therapy is currently available. Several techniques are available after primary pterygium excision to recover the ocular surface anatomy by restoring healthy conjunctival epithelium and preventing recurrence and complications. However, application of conjunctival free autograft or transpositional flap to cover the bared scleral area is limited when the conjunctiva are to be spared for future glaucoma filtering surgery, in patients with large or double-headed pterygia, in recurrent pterygia, or when the harvesting of donor conjunctival is precluded by scarring. AIM: To develop a simple technique to obtain expansion of the conjunctival epithelium when applied in vivo in diseased eyes. METHODS: We evaluated in vitro the best way of gluing conjunctival fragments over the AM, the efficiency of the fragments to generate conjunctival cell outgrowths, the molecular marker expression, and the feasibility of shipping preloaded AM.We performed simple conjunctival epithelial transplantation (SCET) in which we glued an amniotic membrane patch pre-loaded with autologous conjunctival tissue fragments over the scleral defect after pterygium excision and evaluated the recovery of the normal conjunctival epithelium and the disease recurrence up to 12 months after surgery. RESULTS: 65-80% of fragments generated outgrowth 48-72h after gluing, without differences between type of AM preparation and fragment size. Within 6-13 days, a full epithelium covered the surface of the amniotic membrane. Specific marker expression (Muc1, K19, K13, p63, ZO-1) was detected. The shipping test showed after 24h the 31% of the fragments glued over the AM epithelial side, compared to more than 90% of fragments stayed attached in the remaining conditions (stromal side, stromal without spongy layer, epithelial side without epithelium).Surgical excision and SCET for nasal primary pterygium were performed in 6 eyes/patients. No graft detachment and recurrence occurred within 12 months. In vivo confocal microscopy showed progressive expansion of the conjunctival cell population and formation of a clear cornea-conjunctiva transition. CONCLUSIONS: We established the most suitable conditions for a novel strategy based on in vivo expansion of conjunctival cells from conjunctival fragments glued over the AM. The application of SCET seems to be effective and replicable for the renewal of conjunctiva in patients requiring ocular surface reconstruction.

Corneal transplantation during the COVID-19 pandemic: An operational guide.

PURPOSE: To provide an operational guide for corneal transplantation during the COVID-19 pandemic aimed to maintain surgery and avoid spreading of SARS-CoV-2. METHODS: Prospective observational case series study in patients requiring corneal graft manage toward separate free and restricted pathways for those COVID-19 negative or positive, respectively. RESULTS: During the national lockdown, 30 consecutive patients underwent endothelial (n = 16), penetrating (n = 9), and anterior lamellar keratoplasty (n = 5). Two patients followed the COVID-19 restricted pathway, as they were considered positive while waiting for test results. Nine patients were hospitalized one night in the hospital. On admission to the hospital before surgery, at surgery, the day after surgery and at 7 and 30 days all patients and health-care personnel showed no symptoms and resulted negative at risks factors/exposure to the SARS-CoV-2 infection and occurrence of COVID-19. Nucleic acid testing resulted not detectable in all patients and SARS-CoV-2 antibodies quantification showed IgG and IgM below the positive predicted value in 29 patients. One patient showed IgM above the cut-off of significance (1.21 and 1.03 preoperative and 1-month postoperative, respectively) that were considered irrelevant because of the absence of symptoms and exposure risks. CONCLUSIONS: The concept of donor emergency (i.e. short-term availability of transplant tissues), makes corneal transplantation an always-urgent activity because it is related to the availability of the corneal tissue from a donor. Modest adjustments to ophthalmic clinic and eye surgery organization are required to maintain surgery and care of eye patients in a safe environment.

Femtosecond Laser-Assisted Big-Bubble Deep Anterior Lamellar Keratoplasty.

PURPOSE: To determine whether type 1 big-bubble (BB) formation is influenced by the sequence of incisions created with the Victus femtosecond laser (FSL) enabled with software version 3.4 (SV 3.4) during deep anterior lamellar keratoplasty (DALK). MATERIALS AND METHODS: Consecutive FSL-assisted DALK BB procedures were performed on 20 human donor corneas: 10 shaped by tunnel incision followed by lamellar incision (tunnel-lamellar group, TL) and 10 in the reverse order (lamellar-tunnel group, LT). The BB type was assessed by evaluating dynamic air movement during air inflation; bubble diameter and floor thickness were measured by anterior segment optical coherence tomography. RESULTS: Overall, a type 1 BB formed in 85% of eyes: 100% in the TL group and 70% in the LT group. In the LT group, a type 2 BB formed in 2 corneas and one cornea was perforated during cannula insertion. Type 1 BB was achieved after one attempt in 90% of eyes in the TL group and in 57% in the LT group. CONCLUSION: Shaping the tunnel before rather than after lamellar incision may be more effective for obtaining a type 1 BB by air injection.

Femtosecond laser-assisted implantation of corneal stroma lenticule for keratoconus.

PURPOSE: To review recent progress, challenges, and future perspectives of stromal keratophakia for the treatment of advanced keratoconus. METHODS: We systematically reviewed the literature in the PubMed database, last update June 30, 2020. No language restriction was applied. The authors checked the reference lists of the retrieved articles to identify any additional study of interest. RESULTS: Several techniques have been proposed for the treatment of keratoconus in order to avoid or delay keratoplasty. This was primarily due to the lack of accessibility to donor corneas in many countries. The ease and predictability of the more advanced femtosecond lasers used to correct ametropias by stromal lenticule extraction lead to hypothesize that generated refractive lenticules could be implanted into corneal stromal layers to restore volume and alter the refractive properties of the cornea in patients with corneal ectasias. At the same time, new techniques for preservation, customization, and cellular therapy of the corneal stromal have been developed, directing to the valorization of otherwise discarded byproducts such as donor corneas unsuitable for either lamellar of penetrating keratoplasty. CONCLUSIONS: Femtosecond laser-assisted stromal keratophakia could be a suitable therapeutic option for the treatment of corneal ectasias, especially in patients with advanced keratoconus, providing biomechanical support recovering the pachimetry to nearly normal value at the same time. The accuracy and predictability of the refractive outcome are yet a critical issue and the patient eligible for the procedure still has to be characterized.

Ultrastructural Analysis of Rehydrated Human Donor Corneas After Air-Drying and Dissection by Femtosecond Laser.

Purpose: To evaluate the efficiency of femtosecond laser (FSL) incision of rehydrated human donor corneas after air-drying and its effects on corneal structure. Methods: We compared the rehydrated and fresh-preserved corneas by microscopy following Victus-Tecnolas FSL treatment for straight-edge anterior lamellar keratoplasty (ALK). The corneas were dehydrated at room temperature under a laminar-flow hood. Results: To obtain the horizontal cut in rehydrated corneas, we increased the FSL pulse energy to 1.2 µJ from 0.80 µJ applied for the fresh corneas and obtained a clear-cut separation of the lamellar lenticule cap from the corneal bed. Light microscopy showed regular arrangement of stromal collagen lamellae, with spaces in between the fibers in the corneal stroma in the fresh and the rehydrated corneas, but the uppermost epithelial layers in the rehydrated corneas were lost. Transmission electron microscopy (TEM) revealed no signs of thermal or mechanical damage to the corneal structure. The epithelial basal membrane and Bowman's layer maintained their integrity. The epithelial basal layer and cells were separated by large spaces due to junction alteration in the rehydrated corneas. There were gaps between the lamellar layers in the stroma, especially in the rehydrated corneas. Keratocytes displayed normal structure in the fresh corneas but were devoid of microorganules in the rehydrated corneas. Minor irregularities were observed in the vertical incision and the horizontal stroma appeared smooth on scanning electron microscopy. Conclusion: The corneal stroma of rehydrated corneas maintained morphology and integrity, while corneal cellular components were generally altered. When corneas are intended for FSL-assisted ALK, effective stromal bed incision is best achieved at a laser power higher than that currently adopted for fresh corneas.

Gender medicine in corneal transplantation: influence of sex mismatch on rejection episodes and graft survival in a prospective cohort of patients.

To evaluate the effect of donor-to-recipient sex mismatched (male donor corneas to female recipients) on the incidence of rejection episodes and failures up to 1 year after corneal transplantation. Prospective observational cohort study, with donor corneas randomly assigned and surgeons blind to the sex of donor. A unique eye bank retrieved and selected the donor corneas transplanted in 4 ophthalmic units in patients with clinical indication for primary or repeated keratoplasty for optical reasons, perforating or lamellar, either anterior or posterior. Rejection episode defined as any reversible or irreversible endothelial, epithelial or stromal sign, with or without development of corneal edema, and graft failure as a permanently cloudy graft or a regraft for any reason detected or acknowledged during a postoperative ophthalmic visit at any time up to 1 year after surgery were recorded.156 (28.6%) patients resulted donor-to-recipient gender mismatched for H-Y antigen (male donor to female recipient). During the 12 months follow-up, 83 (14.7%, 95% CI 12.0-17.9) grafts showed at least 1 rejection episode and 17 (3.2%, 95% CI 2.0-5.0) failed after immune rejection, among 54 (9.6%, 95% CI 7.4-12.3) grafts failed for all causes. No significant differences between matched and mismatched patients were found for cumulative incidence of both rejection episodes (15.2% and 13.5%) and graft failures following rejection (3.2% and 2.6%), respectively. Multivariable analyses showed that H-Y matching either is not a predictive factor for rejection or graft failure nor seems to influence incidence of failures on respect to patient's risk category. The lack of influence of donor-to-recipient mismatched on the rate of rejections and graft failures resulting from this study do not support the adoption of donor-recipient matching in the allocation of corneas for transplantation.

In Vivo Confocal Microscopy of the Corneal-Conjunctival Transition in the Evaluation of Epithelial Renewal after SLET.

Examination of the corneal surface by in vivo confocal microscopy (IVCM) allows for objective identification of corneal and conjunctival cell phenotypes to evaluate different epithelialization patterns. Detection of a corneal-conjunctival epithelial transition could be considered as a sign of restored epithelial function following simple limbal epithelial transplantation (SLET). This is a prospective, interventional case series. We assessed patients with limbal stem cell deficiency (LSCD) by IVCM, preoperatively and at monthly intervals following SLET. Sectors in the central and peripheral cornea were scanned. Immediately upon detection of multi-layered cells with the epithelial phenotype in the central cornea and confirmation of epithelial transition in all corneal sectors, the decision for keratoplasty was taken. Ten patients were enrolled. After SLET, epithelial phenotype in the central cornea and an epithelial transition were identified within six and nine months in seven and one patients, respectively. One patient was a partial success and one failed. Five patients underwent keratoplasty, with stable results up to 12 months. Identification of the epithelial transition zone by IVCM permits assessment of the efficacy of SLET, enabling subsequent planning of keratoplasty for visual rehabilitation. The stability of the corneal surface following keratoplasty confirms that the renewal of the corneal epithelium was effectively retained.