Refractive surgery and dry eye.

Refractive surgery is one of the most common elective surgeries performed worldwide. The incidence of dry eye disease (DED) after corneal refractive surgery varies among different studies. Pre-existing untreated DED has been identified as a risk factor for postsurgical dry eye symptoms. On the basis of both evidence and clinical experience, some recommendations for ocular surface and DED management pre- and post-refractive surgery are described. In aqueous deficiency Dry Eye Disease, preservative-free lubricating drops should be preferred, in addition to ointment and gel forms. Topical anti-inflammatory agents (Cyclosporine 0.1%, hydrocortisone phosphate, fluorometholone) should be used for 3-6 months in cases of ocular surface damage. The therapy of evaporative DED includes lifestyle modifications, lid hygiene (either performed by the patient or offered as professional lid hygiene by the physician), use of lubricating eye drops with lipid components, topical and/or systemic antibiotic treatment with anti-inflammatory properties and Intense Pulsed Light (IPL-) Treatment for meibomian gland dysfunction.

Bioengineered Human Stromal Lenticule for Recombinant Human Nerve Growth Factor Release: A Potential Biocompatible Ocular Drug Delivery System.

Small incision lenticule extraction (SMILE), is a surgical procedure for the myopia correction, during which a corneal stromal lenticule is extracted. Given that we have previously demonstrated how this discarded tissue could be repurposed as a bio-scaffold for stromal engineering, this study aimed to explore its use as an ocular drug delivery system of active molecules, using neurotrophic factor Nerve Growth Factor (NGF). We employed human stromal lenticules directly collected from healthy donors undergoing SMILE. Following a sodium dodecylsulfate (SDS) treatment, decellularized lenticules were incubated with a suspension of polylactic-co-glycolic-acid (PLGA) microparticles (MPs) loaded with recombinant human NGF (rhNGF-MPs). Fluorescent MPs (Fluo-MPs) were used as control. Data demonstrated the feasibility to engineer decellularized lenticules with PLGA-MPs which remain incorporated both on the lenticules surface and in its stromal. Following their production, the in vitro release kinetic showed a sustained release for up to 1 month of rhNGF from MPs loaded to the lenticule. Interestingly, rhNGF was rapidly released in the first 24 h, but it was sustained up to the end of the experiment (1 month), with preservation of rhNGF activity (around 80%). Our results indicated that decellularized human stromal lenticules could represent a biocompatible, non-immunogenic natural scaffold potential useful for ocular drug delivery. Therefore, combining the advantages of tissue engineering and pharmaceutical approaches, this in vitro proof-of-concept study suggests the feasibility to use this scaffold to allow target release of rhNGF in vivo or other pharmaceutically active molecules that have potential to treat ocular diseases.

Tear proteomics reveals the molecular basis of the efficacy of human recombinant nerve growth factor treatment for Neurotrophic Keratopathy.

Neurotrophic Keratopathy (NK), classified as an orphan disease (ORPHA137596), is a rare degenerative corneal disease characterized by epithelial instability and decreased corneal sensitivity caused by the damage to the corneal nerves. The administration of human recombinant nerve growth factor (rhNGF) eye drops, as a licensed-in-Europe specific medication for treatment of moderate and severe NK, has added promising perspectives to the management of this disorder by providing a valid alternative to the neurotization surgery. However, few studies have been conducted to the molecular mechanism underlying the response to the treatment. Here, we carried out tears proteomics to highlight the protein expression during pharmacological treatment of NK (Data are available via ProteomeXchange with identifier PXD025408).Our data emphasized a proteome modulation during rhNGF treatment related to an increase in DNA synthesis, an activation of both BDNF signal and IL6 receptor. Furthermore, the amount of neuronal Extracellular Vesicles EVs (CD171+) correlated with the EVs carrying IL6R (CD126+) together associated to the inflammatory EVs (CD45+) in tears. Such scenario determined drug response, confirmed by an in vivo confocal microscopy analysis, showing an increase in length, density and number of nerve fiber branches during treatment. In summary, rhNGF treatment seems to determine an inflammatory micro-environment, mediated by functionalized EVs, defining the drug response by stimulating protein synthesis and fiber regeneration.

Transcriptomic analysis revealed increased expression of genes involved in keratinization in the tears of COVID-19 patients.

Recent studies have focused their attention on conjunctivitis as one of the symptoms of coronavirus disease 2019 (COVID-19). Therefore, tear samples were taken from COVID-19 patients and the presence of SARS-CoV-2 was evidenced using Real Time reverse transcription polymerase chain reaction. The main aim of this study was to analyze mRNA expression in the tears of patients with COVID-19 compared with healthy subjects using Next Generation Sequencing (NGS). The functional evaluation of the transcriptome highlighted 25 genes that differ statistically between healthy individuals and patients affected by COVID-19. In particular, the NGS analysis identified the presence of several genes involved in B cell signaling and keratinization. In particular, the genes involved in B cell signaling were downregulated in the tears of COVID-19 patients, while those involved in keratinization were upregulated. The results indicated that SARS-CoV-2 may induce a process of ocular keratinization and a defective B cell response.

Face Mask-Related Ocular Surface Modifications During COVID-19 Pandemic: A Clinical, In Vivo Confocal Microscopy, and Immune-Cytology Study.

Purpose: The purpose of this study was to describe the face mask (FM)-related ocular surface changes using clinical tests, in vivo confocal microscopy (IVCM) and impression cytology (IC), and to investigate the Dry Eye-related Quality of life Score (DEQS). Methods: Sixty-six patients with dry eye disease (DED) and 62 healthy subjects (group 2) using FM were enrolled. Groups were divided into: groups 1A and 2A: < 3 hours of FM wear; groups 1B and 2B: 3 to 6 hours; and groups 1C and 2C: > 6 hours. Patients underwent DEQS questionnaire, break-up time (BUT), Schirmer test I (STI), fluorescein and lissamine staining (FS and LS), IVCM to determine corneal dendritic cell density (DCD) and goblet cell density (GCD), and IC to measure HLA-DR, at baseline and after 3 months. Results: FM use duration before enrollment was 27 ± 2.3 and 30 ± 4.1 (days ± SD) for groups 1 and 2 (P > 0.05). After 3 months, DEQS worsened in groups 1B and 1C, STI in groups 1A to 1C, FS and LS in group 1C (P < 0.05); in controls, BUT and FS worsened only in group 2C (P < 0.05). DCD significantly increased in groups 1A to 1C and HLA-DR in groups 1B and 1C (P < 0.05), whereas GCD did not significantly change. DCD and HLA-DR increased only in group 2C (P < 0.05). DEQS significantly correlated with DCD (P = 0.05, r = 0.698; P < 0.001, r = 0.832) and HLA-DR (P = 0.043, r = -0.687; P < 0.001, r = 0.861) at baseline and 3 months. Conclusions: Use of FM increases ocular surface inflammation and negatively impacts the quality of life in patients with DED. Translational Relevance: The study of the prolonged use of FM effects may be relevant to managing DED.

Epithelial and stromal remodelling following femtosecond laser-assisted stromal lenticule addition keratoplasty (SLAK) for keratoconus.

The purpose of this study was to evaluate corneal epithelium and stromal remodelling with anterior segment optical coherence tomography in patients who have undergone stromal lenticule addition keratoplasty (SLAK) for advanced keratoconus. This was a prospective non-comparative observational study. Fifteen eyes of 15 patients with advanced keratoconus underwent implantation with a cadaveric, donor negative meniscus-shaped intrastromal lenticule, produced with a femtosecond laser, into a stromal pocket dissected in the recipient cornea at a depth of 120 µm. Simulated keratometry, central corneal thickness (CTT), corneal thinnest point (CTP), central epithelial thickness (CET), central and peripheral lenticule thickness, anterior and posterior stromal thickness were measured. Regional central corneal epithelial thickness (CET) and variations in the inner annular area (IAT) and outer annular area (OAT) were also analysed. All parameters were measured preoperatively and 1, 3, and 6 months postoperatively. The average anterior Sim-k decreased from 59.63 ± 7.58 preoperatively to 57.19 ± 6.33 D 6 months postoperatively. CCT, CTP, CET, and OAT increased and IAT decreased significantly after 1 month. All parameters appeared unchanged at 6-months except that of OAT that further increased. Lenticule thickness was stable. In conclusion we observed that SLAK reshapes the cornea by central flattening with stromal thickening and epithelial thickness restoration.

Topical preservative-free ophthalmic treatments: an unmet clinical need.

Introduction: The main role of preservatives in eyedrops is to ensure sterility and microbiological integrity of the drug, and to facilitate the penetration of active compounds into the eye. However, several studies documented significant toxic effects induced by preservatives, especially on the ocular surface. Consequently, most of the ophthalmic medications became progressively available in preservative-free (PF) formulations.Areas covered: We analyzed pre-clinical and clinical studies on PF eyedrops with particular attention to common chronic diseases such as dry eye and glaucoma. We discussed about the pros and cons of using PF eyedrops, in terms of efficacy, safety, and social-economic aspects.Expert opinion: There are still unresolved issues that make hard for PF medications to definitively conquer the drug market. Despite robust pre-clinical evidences of less toxicity, the low number of randomized clinical trials does not permit to state that PF eyedrops have, in clinical practice, a similar efficacy or a higher safety compared to preserved forms. These aspects limit their use to chronic diseases requiring long-term therapies with multiple daily instillations, especially in the presence of concomitant ophthalmic diseases that expose to a risk of ocular surface worsening.

In Vivo Confocal Microscopy of Stromal Lenticule Addition Keratoplasty for Advanced Keratoconus.

PURPOSE: To investigate the in vivo corneal microscopic changes after femtosecond laser-assisted stromal lenticule addition keratoplasty in keratoconus by means of in vivo confocal microscopy. METHODS: Patients affected by advanced keratoconus were included in the study. Negative meniscus-shaped stromal lenticules, produced with a femtosecond laser (VisuMax; Carl Zeiss Meditec) from eye bank corneas were transplanted into a stromal pocket dissected in the recipient cornea at a depth of 120 µm. In vivo confocal microscopy was performed during the 12-month follow-up to investigate changes of the corneal and lenticule structure. RESULTS: Ten patients were enrolled in the study. No changes of the dendritic cell population were documented during the follow-up period. Mild edema and stromal keratocyte activation gradually decreased during the first month. Subbasal nerve density returned to preoperative values after 6 months. Donor-recipient interfaces appeared hyperreflective but gradually improved over time with significantly reduced reflectivity after 3 months. No evidence of stromal inflammatory cell migration or matrix opacification was observed. Endothelial and keratocyte density remained stable over time. A variable degree of stromal radially distributed folds, not visible on biomicroscopy, was observed in the lenticule and in the posterior recipient stroma. CONCLUSIONS: Stromal lenticule addition keratoplasty produces transitory nerve plexus density reduction and minor inflammatory reaction that rapidly decreases during the first month. Donor-recipient interface reflectivity is comparable to a femtosecond laser refractive procedure with no sign of stromal opacification or stromal rejection in 1 year of follow-up. [J Refract Surg. 2020;36(8):544-550.].

In Vivo Evaluation of Corneal Nerves and Epithelial Healing After Treatment With Recombinant Nerve Growth Factor for Neurotrophic Keratopathy.

PURPOSE: To evaluate the renewal of corneal nerve structure and function in patients with neurotrophic keratopathy (NK) treated with recombinant human nerve growth factor (rhNGF) eye drops. DESIGN: Prospective, interventional, before-and-after case series. METHODS: This study included 18 patients with NK with a persistent epithelial defect or corneal ulcer, treated with topical rhNGF, and age-matched healthy controls. Patients underwent clinical examination with corneal fluorescein staining, Schirmer 1 tear test, assessment of corneal sensitivity with the Cochet-Bonnet esthesiometer, and morphologic examination of the nerves by in vivo confocal microscopy (IVCM) at baseline and at 4 and 8 weeks of treatment. IVCM analysis was used to assess corneal sub-basal nerve density, number of nerve branches, and the diameter of nerve fibers. RESULTS: A complete resolution of the epithelial defect was observed in all patients within 8 weeks. Schirmer 1 test showed a significant improvement of tear film secretion. Change from baseline in corneal sensation was significant (P < .001) but did not approach that of healthy controls. After 8 weeks of treatment, there was a significant increase in the mean nerve density in affected eyes as compared to baseline (P = .007) as well as in the number of nerve branches (P = .008) and nerve fiber diameter (P = .007). CONCLUSIONS: Topical treatment with rhNGF was effective in promoting complete corneal healing of persistent epithelial defects and corneal ulcers in patients with NK. This was associated with an improvement of corneal sensitivity and an increase of sub-basal nerve density, diameter, and number of nerve branches, indicating improvement in structure and function of corneal nerves.

In vivo and in vitro results of an automated preloaded delivery system for IOL implantation in cataract surgery.

PURPOSE: To compare the corneal tissue trauma after the use of an automated preloaded injector and a manual injector and assess scanning electron microscope (SEM) and atomic force microscope (AFM) features of both injector cartridges. SETTING: Ophthalmology Clinic and Laboratory of Stem Cells and Regenerative Medicine University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy; DESIGN: Prospective randomized clinical study METHODS: Forty eyes of 40 patients for phacoemulsification were divided into two groups: implantation of intraocular lens was performed with AutonoMe automated delivery system (AutonoMe group: 20 eyes) and Monarch III injector system (Monarch group: 20 eyes). In vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) were performed before surgery, at 1 h, 1 day and 1 month post-operatively. In addition, SEM and AFM were performed on cartridges of both injector systems after injection of the IOL. RESULTS: A greater increase in central corneal thickness and corneal thickness at the incision site were observed in Monarch group versus AutonoMe group 1 h and 1 day post-operatively (p < 0.05). Endothelial cell count loss was significantly higher in Monarch group compared with AutonoMe group (p < 0.05) at 1 and 24 h. AS-OCT showed less endothelial misalignment at 30 days (p < 0.05), and IVCM showed less tunnel inflammation at all time points (p < 0.05) in AutonoMe group compared with Monarch group; roughness analysis at AFM of the AutonoMe cartridge was significantly lower compared to Monarch D cartridge (p < 0.05). CONCLUSIONS: The AutonoMe injector provided less corneal tissue trauma compared with Monarch III injector. The AutonoMe cartridge showed lower roughness at AFM compared to the Monarch D cartridge.

In vivo microscopic and optical coherence tomography classification of neurotrophic keratopathy.

Neurotrophic keratopathy (NK) is a rare degenerative corneal disorder characterized by instability of epithelial integrity with consequent epithelial defects that can worsen up to persistent epithelial defects with stromal melting and ulceration. The pathogenesis of NK springs from a variable degree of damage to the trigeminal nerve plexus, leading to a reduction or total loss of corneal sensitivity. Mackie classification (1995) distinguishes three stages of NK, based on the severity of clinical presentation. The technological innovations in corneal diagnostic imaging allow clinicians to accurately study the morphometry and morphology of corneal structure with microscopic resolution. In this study, 45 patients affected by NK at different stages underwent in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) with particular attention to analyze subbasal nerve plexus fibers and the stromal structure. At the light of IVCM and AS-OCT observations, we propose a different staging of NK with respect to the Mackie's classification that takes into account the severity of subbasal nerve fibers damage and the extension in depth of stromal ulceration; this classification better defines, at the time of diagnosis, the cellular and structural alterations in the affected corneas, with possible prognostic and therapeutic values in the management of NK.

In vivo and ex vivo evaluation of cell-cell interactions, adhesion and migration in ocular surface of patients undergone excimer laser refractive surgery after topical therapy with different lubricant eyedrops.

PURPOSE: To investigate, in vivo by means of in vivo confocal microscopy (IVCM) and ex vivo by impression cytology, epithelial cellular damage after excimer laser refractive surgery in patients under different topical lubricant therapies. METHODS: Two hundred eyes of 100 patients, undergone bilateral excimer laser refractive surgery for medium myopic error correction [spherical equivalent refraction from -1.75 to -3.50 dioptres (D) with refractive astigmatism under -0.75 D], have been recruited. All patients received, in addition to standard therapy for refractive surgery, high weight hyaluronic acid 0.2% eyedrops in one randomly selected eye and carboxymethylcellulose 1% eyedrop in the comparator eye (control eye) 4 times daily for 90 days. Follow-up included a baseline visit and further examination 7-, 30- and 90-day intervals [clinical evaluation with Schirmer test and tear break-up time (TBUT), IVCM and impression cytology]. RESULTS: No significant difference in Schirmer test and TBUT was observed during the follow-up period in eyes under different therapies. IVCM showed an improvement of conjunctival and corneal epithelial cells quality in eye in treatment with high weight hyaluronic acid 0.2% when compared to carboxymethylcellulose. Conjunctival impression cytology demonstrated an evident positivity for CD44 in eyes treated with both treatments in all follow-up controls. ICAM1 expression showed an increasing positivity starting at 30 days that became statistically significant after 90 days of high weight hyaluronic acid 0.2% therapy (p = 0.0167). CONCLUSIONS: In vivo and in vitro results showed the effectiveness of high weight hyaluronic acid 0.2% in facilitating cell-cell interaction, migration, cell proliferation, stabilizing epithelial barrier of the ocular surface. Moreover, use of high weight hyaluronic acid in treatment of corneal tissue damage after refractive surgery, in concordance with standard topical corticosteroids and antibiotics therapy, could be effective in promoting corneal epithelial wound healing with consequent good results in clinical outcome and patients' satisfaction.

Interference figures of polarimetric interferometry analysis of the human corneal stroma.

A rotating polarimetric 90°-cross linear-filter interferometry system was used to detect the morphological characteristics and features of interference patterns produced in in-vivo corneal stroma in healthy human corneas of 23 subjects. The characteristic corneal isogyres presenting with an evident cross-shaped pattern, grossly aligned with the fixation axis, were observed in all patients with centers within the pupillary dark area, impeding the exact determination of the center point. During the rotational scan in 78.3% of the eyes the cross-shaped pattern of the isogyre gradually separated to form two distinct hyperbolic arcs in opposite quadrants, reaching their maximal separation at 45 degrees with respect to angle of cross-shaped pattern formation. The corneal cross and hyperbolic-pattern repeated every 90° throughout the 360° rotational scan. While the interpretation of the isogyres presents particular difficulties, two summary parameters can be extracted for each cornea: the presence/orientation of a single or two dark areas in post-processed images and isochromes. However, the development of dedicated software for semi-quantitative analysis of these parameters and enantiomorphism may become available in the near future. The possible application of polarimetric interferometry in the field of both corneal pathologies and corneal surgery may be of great interest for clinical purposes.

Opaque bubble layer incidence in Femtosecond laser-assisted LASIK: comparison among different flap design parameters.

The purpose of this study was to evaluate the incidence of opaque bubble layer (OBL) in femtosecond laser-assisted in situ keratomileusis (LASIK) flaps created with the support of Visumax Carl Zeiss femtosecond laser, planned with different flap diameters (7.90, 8.0, and 8.20 mm) and the same laser energy and power settings. Incidence of intraoperative OBL in flaps of consecutive 108 patients (216 eyes) subjected to bilateral femtosecond-assisted LASIK was considered. Flap creation was performed with the same laser design parameters (spot distance and energy offset) and different presetting diameters of 7.90 mm (72 eyes, group 1), 8 mm (72 eyes, group 2), and 8.20 mm (72 eyes, group 3). The incidence of OBL was considered and its extension was reported measuring involvement of different four corneal flap quadrants in which was theoretically divided the entire flap area; based on these data, OBL presence was classified as none (no evidence of OBL), minimal (minimal presence in not more that one quadrants corneal flap), mild (OBL presence in almost two or three quadrants without tendency to invade central cornea), and moderate (OBL presence in almost three quadrants with tendency to invade central cornea). In group 1, the incidence of OBL was of 23.6 % (17 eyes) with a mild/moderate presence; in group 2, incidence was 20.8 % (15 eyes) with mild presence. Group 3 presented a reduced OBL incidence (4.1 %, 3 eye) with a minimal presence. No statistically significant difference was found between group 1 and 2 (p = 0.8414).We found statistically significant differences between group 1 and group 3 (p = 0.0012) and between groups 2 and 3 (p = 0.0044). A significant reduction and extension of OBL incidence were evident when LASIK flap settings diameter was increased, and flap edge was closer to the contact glass border; this is probably consequent to a more effective gas dispersion outside of corneal flap.

Confocal microscopy evaluation of stromal fluorescence intensity after standard and accelerated iontophoresis-assisted corneal cross-linking.

The aim of this study is to determine modifications in stromal fluorescence intensity after different corneal cross-linking (CXL) procedures and to correlate stromal fluorescence to corneal biomechanical resistance. For confocal microscopy study, 15 human cadaver corneas were examined. Three served as control (group 1), three were just soaked with iontophoresis procedure (group 2), three were treated with standard epi-off technique (group 3), and six underwent iontophoresis imbibition. Three of later six were irradiated for 30 min with 3 mW/cm2 UVA (group 4) and three for 9 min at 10 mW/cm2 UVA (group 5). Confocal microscopy was performed to quantify the fluorescence intensity in the cornea at different stromal depths. For biomechanical study, 30 human cadaver corneas were randomly divided into five groups and treated as previously described. Static stress-strain measurements of the corneas were performed. Iontophoresis imbibition followed by 10mW/cm2 irradiation proved to increase stromal fluorescence into the corneal stroma and significant differences were revealed between group 3 and 5 both at 100 (p = 0.0171) and 250 µm (p = 0.0024), respectively. Biomechanical analysis showed an improvement of corneal resistance in group 5. Iontophoresis imbibition followed by accelerated irradiation increased the stromal fluorescence and is related to an improvement of biomechanical resistance. This approach may represent a new strategy to achieve greater concentrations of riboflavin without removing corneal epithelium and improve clinical results while reducing the side effects of CXL.

In Vivo and Ex Vivo Evaluation of Inflammation and Apoptosis Induced after SMILE Procedures for Different Refractive Error Range.

PURPOSE: To detect corneal inflammation and apoptosis induced after small incision lenticule extraction (SMILE) at different refractive corrections for moderate to high values of myopia. METHODS: Fifty patients (50 eyes) suffering from medium to high myopia (spherical equivalent refraction from -3.75 to -10.00 diopters (D) with refractive astigmatism under -0.75 D) underwent SMILE in order to correct myopic error. In vivo evaluation was done by corneal confocal microscopy (IVCM) and ex vivo by immunohistochemistry. After surgery, all corneal lenticules were checked for regularity, entirety, and fixed in formalin for immunohistochemistry evaluation of apoptosis (TUNEL) and inflammation (CD11b) levels. Postoperative assessments took place during the first week and the first and third months after surgery. Patients returned for IVCM examination for analysis of the corneal stromal femtosecond laser treatment interfaces reflectivity. RESULTS: No correlation was observed between treated myopic refractive error and number of CD11b+ and TUNEL+ cell in all analyzed extracted lenticules. IVCM at 1 week and 1 month of follow-up showed numerous reflective particles at the laser treatment interface with a moderate light scattering. In semi-quantitative analysis of reflectivity intensity at the laser interfaces, a statistical difference was evident only between 1 week and 1 month (p = 0.0213). CONCLUSIONS: SMILE, as an innovative all-femto surgical procedure, results in a reduced tissue inflammation and apoptosis levels with a minimum tissue response, in terms of interface reflectivity, and there are no statistically significant differences among variable treated refractive error range.

In Vivo Distribution of Corneal Epithelial Dendritic Cells in Patients With Glaucoma.

PURPOSE: The purpose of this study was to evaluate dendritic cell (DC) distribution, morphology, and DC density in the entire cornea of medically controlled glaucoma patients (MCGP), using in vivo confocal microscopy (IVCM). METHODS: Fifty MCGP were enrolled, 15 patients with dry eye, and 15 healthy subjects served as controls. Patients were asked to complete the Ocular Surface Disease Index (OSDI) questionnaire and then underwent tear film break-up time (BUT), corneal staining, and Schirmer test (ST) I and then IVCM. In vivo confocal microscopy evaluated the limbal and central DC density, the DCs morphology and distribution. Relationships among DC density, OSDI score, and corneal staining were analyzed. RESULTS: Medically controlled glaucoma patients were divided into 2 groups; group 1 (29 eyes) was tested with one drug; group 2 (21 eyes) was tested with ≥2 drugs. Dendritic cells were significantly higher at limbus than at central cornea in both groups. Limbal DCs were found in the 86.7%, 89.7%, 90.4%, and 93.3% of eyes in controls, groups 1 and 2, and DED; central corneal DCs were found in the 26.6%, 75.9%, 80.9%, and 86.6% of eyes in controls, groups 1 and 2, and DED. Dendritic cell density was higher in glaucoma groups and DED than in controls (P < 0.001). Group 2 and DED presented DC density significantly higher compared with group 1 (P < 0.05). In group 1 DC density was higher in patients taking preserved drugs than in those taking preservative-free drugs (P < 0.05). Dendritic cell density was higher in DED than in group 2 (P < 0.05). Dendritic cell density significantly correlated with corneal staining and OSDI (P < 0.001). CONCLUSIONS: Dendritic cells increase in the entire cornea of MCGP, with a higher density at limbus. These modifications may take part in the induction of the glaucoma-related ocular surface disease.

In vivo confocal microscopy of the sclerocorneal limbus after limbal stem cell transplantation: Looking for limbal architecture modifications and cytological phenotype correlations.

PURPOSE: To correlate a biomicroscopic evaluation, an in vivo confocal microscopy examination, and impression cytologic findings of the corneal center and sclerocorneal limbus after cultured limbal stem cell transplantation and to test the effectiveness of in vivo confocal microscopy as a diagnostic procedure in ocular surface cell therapy reconstructive surgery. METHODS: Six eyes of six patients affected by limbal stem cell deficiency after chemical burns underwent ex vivo expanded limbal stem cell transplantation (two eyes) and ex vivo expanded limbal stem cell transplantation with subsequent penetrating keratoplasty (four eyes) to restore corneal transparency. One year after surgery, all patients underwent a biomicroscopic evaluation, central cornea impression cytology to detect cytokeratin 12 (CK12) positivity, and in vivo confocal microscopy of the central cornea and the sclerocorneal limbus to investigate the epithelial cellular morphology, limbal architecture, and corneal inflammation level. RESULTS: Impression cytology analysis showed CK12 positivity in five of six cases, in concordance with the biomicroscopic evaluation. Confocal microscopy pointed out irregular limbal architecture with the absence of the palisades of Vogt in all cases; the central epithelial morphology presented clear corneal characteristics in three cases and irregular morphology in the remaining three. CONCLUSIONS: After successful ex vivo expanded limbal stem cell transplantation, in the presence of a complete anatomic architecture subversion, documented by support of in vivo confocal microscopy, the sclerocorneal limbus seemed to maintain its primary function. In vivo confocal microscopy confirmed the procedure was a non-invasive, efficacious diagnostic ocular surface procedure in the case of cell therapy reconstructive surgery.

Small Incision Lenticule Extraction After Deep Anterior Lamellar Keratoplasty.

PURPOSE: Femtosecond laser-assisted small incision lenticule extraction (SMILE) was performed to correct myopic astigmatism in a 39-year-old patient who had previously undergone deep anterior lamellar keratoplasty (DALK) for keratoconus, with clinically significant anisometropia and contact lens intolerance. METHODS: Case report. RESULTS: SMILE was planned in the right eye to reduce the refractive error and to allow spectacle correction. The surgical procedure was centered on the visual axis, a 5.20-mm optical zone was used, and the refractive lenticule was extracted through a 3.25-mm incision located inside the graft edge. The refractive target was achieved 1 week after surgery and remained stable until the 3-month follow-up visit, while the corrected distance visual acuity improved from 20/100 to 20/40. Complications were not observed and the graft remained clear. In vivo confocal microscopy and anterior segment optical coherence tomography highlighted a regular wound healing and refractive interface profile. CONCLUSIONS: This case report highlights the feasibility of using SMILE as an alternative procedure for correcting refractive errors after keratoplasty, but further prospective studies are needed to prove the long-term refractive outcomes and safety of this technique.