Analysis of Cytokine and Chemokine Level in Tear Film in Keratoconus Patients before and after Corneal Cross-Linking (CXL) Treatment.

Keratoconus (KC) is a degenerative corneal disorder whose aetiology remains unknown. The aim of our study was to analyse the expressions of cytokines and chemokines in KC patients before and after specified time intervals after corneal cross-linking (CXL) treatment to better understand the molecular mechanisms occurring before and after CXL in KC patients process of corneal regeneration.; Tear samples were gathered from 52 participants immediately after the CXL procedure and during the 12-month follow-up period. All patients underwent a detailed ophthalmological examination and tear samples were collected before and after CXL at regular intervals: 1 day before and after the surgery, at the day 7 visit, and at 1, 3, 6, 9, and 12 months after CXL. The control group consisted of 20 healthy people. 10 patients were women (50%) and 10 were men (50%). The mean age was 30 ± 3 years of age. Tear analysis was performed using the Bio-Plex 3D Suspension Array System. Corneal topography parameters measured by Scheimpflug Camera included: keratometry values (Ks, Kf), PI-Apex, PI-Thinnest, Cylinder.; All the 12 months post-op values of the KC patients' topographic measurements were significantly lower than the pre-op. As for the tear cytokine levels comparison between the patient and control groups, cytokine levels of TNF-α, IL-6, and CXCL-10, among others, were detected in lower amounts in the KC group. The pre-op level of IL-6 exhibited a significant increase the day after CXL, whereas comparing the day after the procedure to 12 months after CXL, this showed a significant decrease. Both TNF-α and IL-1 showed a significant decrease compared to the day before and after CXL. We observed significantly higher levels of IL-1ß, IL-10, IFN-γ and TNF-α in moderate and severe keratoconus than in mild keratoconus (p < 0.05). We also demonstrated a statistically significant positive correlation between both pre-op and 12 months after CXL TNF-α, IFN-γ, IL-6 and Ks and Kf values (p < 0.05, r > 0); Alterations of inflammatory mediators in tear fluid after CXL link with topographic changes and may contribute to the development and progression of KC.

Comparison of Vision Correction and Corneal Thickness at 180-Day Follow-Up After Femtosecond Laser-Assisted In-Situ Keratomileusis (FS-LASIK), Photorefractive Keratectomy (PRK), and Small Incision Lenticule Extraction (SMILE): A Study from a Single Center in Poland of 120 Patients with Myopia.

BACKGROUND This study from a single center in Poland included 120 patients with myopia, and the aim was to compare vision correction and corneal thickness at the 180-day follow-up after femtosecond laser-assisted in-situ keratomileusis (FS-LASIK), photorefractive keratectomy (PRK), or small incision lenticule extraction (SMILE). MATERIAL AND METHODS The effectiveness and safety of laser vision correction (LVC) procedures were evaluated by determining pre- and post-procedure uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) values on the Snell chart. Twenty patients with diagnosed mild myopia (sphere maximum -3.0 diopters D; cylinder maximum 0.5 D) were qualified for PRK surgery. Fifty patients with diagnosed intolerance (sphere maximum -6.0 D; cylinder maximum 5.0 D) were eligible for the FS-LASIK procedure. Fifty patients with diagnosed myopia (sphere maximum -6.0 D cylinder 3.5 D) were qualified for the SMILE procedure. RESULTS Regardless of which procedure was performed, both UDVA and CDVA improved significantly postoperatively (P<0.05). In addition, the UDVA and CDVA values were similar in the postoperative period (P>0.05). For each procedure, the EI was no less than 0.94. Regardless of which type of LVC procedure was performed, CET at the center and 1.5 mm from the center in 4 meridians thickened, and this change was not statistically significant over the observation period (P>0.05). CONCLUSIONS Our analysis demonstrated similar effectiveness of the 3 methods - PRK, FS-LASIK, and SMILE - in patients with mild and moderate myopia.

Prospective Safety Evaluation of the Femtosecond Laser-Assisted Keratomileusis Procedure in Correcting Residual Ametropia in Patients After Deep Anterior Lamellar Keratoplasty.

BACKGROUND This prospective study, from a single center in Poland, aimed to evaluate the correction of residual ametropia, or refractive errors, after corneal grafting using femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) in 60 patients (96 eyes) who had previously undergone deep anterior lamellar keratoplasty (DALK) compared with that achieved in 60 patients (108 eyes) who underwent vision correction using Femto-LASIK alone. MATERIAL AND METHODS The study group included 60 patients (96 eyes) whose residual ametropia was corrected using the Femto-LASIK procedure after having previously undergone DALK. The comparison group consisted of 60 patients (108 eyes) who underwent vision correction with the Femto-LASIK procedure without previously having undergone DALK. Uncorrected vision acuity, best-corrected vision acuity, and intraocular pressure were measured for both groups before the procedures and at 3, 6, 12, and 24 months after the procedures. Corneal endothelial cell density was evaluated by non-contact specular microscopy before the procedures and at 6, 12, and 24 months after the procedures. RESULTS In the study group, within the 24-month observation period, no transplant rejection, transplant decompensation, or corneal ectasia were noted. Statistical analysis did not show any significant differences between the best-corrected vision acuity values in the study group in the preoperative and postoperative periods (P>0.05). In contrast, uncorrected vision acuity values were significantly higher in patients during the postoperative period than the preoperative period (P>0.05). CONCLUSIONS The effects of vision correction with the Femto-LASIK procedure after DALK demonstrate the safety and effectiveness of the procedure for patients.

Efficacy of Continuous-Wave Transscleral Cyclophotocoagulation Post-Pars Plana Vitrectomy in Glaucoma Patients: A Retrospective Study from Poland.

BACKGROUND Glaucoma, a vision-threatening condition, results from optic nerve damage and affects millions of people worldwide. Often asymptomatic, it is hereditary, with risk factors like hypertension, diabetes, and steroid use. Despite its link with intraocular pressure (IOP), not everyone with high IOP develops glaucoma. After pars plana vitrectomy (PPV), patients face increased IOP risks. Traditional treatment includes pharmacotherapy, and, when ineffective, surgical interventions. Continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) is an alternative for refractory glaucoma but can have complications. Our study compares the efficacy and safety of CW-TSCPC after PPV. MATERIAL AND METHODS The study group consisted of 18 patients diagnosed with glaucoma who underwent the CW-TSCP procedure as the first-choice therapy after conservative treatment of glaucoma proved ineffective. The comparison group consisted of 12 patients who underwent the CW-TSCP procedure after conservative drug treatment and in whom surgical treatment of glaucoma had been unsuccessful. All patients had inadequate control of IOP after PPV. RESULTS Study and comparison group patients showed a decrease in IOP during the follow-up, independent of the type of endotamponade used (P<0.05). When the indication for PPV was retinal detachment hemorrhage into the vitreous chamber, a significant decrease in IOP between 0 days and 180 days was only found in the study group (P<0.05). In contrast, when the indication for PPV was the state after uveitis or proliferative diabetic retinopathy, a significant decrease in IOP was found at 180 days in the study and comparison groups (P<0.05). CONCLUSIONS The analysis showed that the CW-TSCPC procedure can be recommended as the first-choice invasive treatment in patients with increased IOP after PPV.

Level of Secretion and the Role of the Nerve Growth Factor in Patients with Keratoconus before and after Collagen Fibre Cross-Linking Surgery.

BACKGROUND: The aim of this study was to analyse the concentration of the nerve growth factor (NGF-ß) in patients with keratoconus (KC) who are undergoing collagen fibre cross-linking (CXL) surgery in order to better understand the pathogenesis of this disease and observe the molecular changes occurring after the procedure. Among many cytokines, ß-NGF seems to play an important role in the healing processes of corneal damage. Therefore, its role in the regenerative process after CXL treatment may affect the course of treatment and its final results. Tear samples from 52 patients were collected in this prospective study. Additionally, the patients also had a number of tests performed, including corneal topography using optical coherence tomography. Flat (K 1), steep (K 2), cylindrical (CYL), and central corneal thickness (CCT) keratometry were assessed. The tear samples were collected, and other tests were performed before the CXL procedure and afterwards, during the 12-month follow-up period. The NGF concentration was measured using the Bio-Plex Magnetic Luminex Assay. Lower levels of NGF-ß were detected in the KC patients than in the control group (p < 0.001). The day after the procedure, the NGF-ß level was significantly lower (on average by 2.3 pg/mL) (p = 0.037) than before the procedure, after which, the level of the reagent increases, but only in the group with the advanced cone, one month after CXL it was significantly higher (p = 0.047). Regarding the correlation of NGF with topographic measurements, the following were found: NGF-ß correlates significantly (p < 0.05) and positively (r > 0) with K1 before the CXL procedure; NGF-ß correlates significantly (p < 0.05) and positively (r > 0) with K1 one month after CXL; NGF-ß correlates significantly (p < 0.05) and positively (r > 0) with CYL nine months after CXL; and, after twelve months, NGF-ß correlates significantly (p < 0.05) and positively (r > 0) with K2 and K1. Corneal sensitivity did not statistically and significantly correlate with the level of NGF-ß secretion. Our study suggests that NGF may be crucial in the development and progression of KC as well as in the repair mechanisms after CXL surgery. Further research is needed on the role of NGF and other inflammatory biomarkers for rapid diagnosis and selection of targeted therapy in patients with keratoconus.

Preventive Analgesia, Hemodynamic Stability, and Pain in Vitreoretinal Surgery.

Background and Objectives: Although vitreoretinal surgery (VRS) is most commonly performed under regional anaesthesia (RA), in patients who might be unable to cooperate during prolonged procedures, general anaesthesia (GA) with intraprocedural use of opioid analgesics (OA) might be worth considering. It seems that the surgical pleth index (SPI) can be used to optimise the intraprocedural titration of OA, which improves haemodynamic stability. Preventive analgesia (PA) is combined with GA to minimise intraprocedural OA administration. Materials and Methods: We evaluated the benefit of PA combined with GA using SPI-guided fentanyl (FNT) administration on the incidences of PIPP (postprocedural intolerable pain perception) and haemodynamic instability in patients undergoing VRS (p < 0.05). We randomly assigned 176 patients undergoing VRS to receive GA with SPI-guided FNT administration alone (GA group) or with preventive topical 2% proparacaine (topical anaesthesia (TA) group), a preprocedural peribulbar block (PBB) using 0.5% bupivacaine with 2% lidocaine (PBB group), or a preprocedural intravenous infusion of 1.0 g of metamizole (M group) or 1.0 g of paracetamol (P group). Results: Preventive PBB reduced the intraprocedural FNT requirement without influencing periprocedural outcomes (p < 0.05). Intraprocedural SPI-guided FNT administration during GA resulted in PIPP in 13.5% of patients undergoing VRS and blunted the periprocedural effects of preventive intravenous and regional analgesia with respect to PIPP and haemodynamic instability. Conclusions: SPI-guided FNT administration during GA eliminated the benefits of preventive analgesia in the PBB, TA, M, and P groups following VRS.

Metabolomic Signature Discriminates Normal Human Cornea from Keratoconus-A Pilot GC/MS Study.

The molecular etiology of keratoconus (KC), a pathological condition of the human cornea, remains unclear. The aim of this work was to perform profiling of metabolites and identification of features discriminating this pathology from the normal cornea. The combination of gas chromatography and mass spectrometry (GC/MS) techniques has been applied for profiling and identification of metabolites in corneal buttons from 6 healthy controls and 7 KC patients. An untargeted GC/MS-based approach allowed the detection of 377 compounds, including 46 identified unique metabolites, whose levels enabled the separation of compared groups of samples in unsupervised hierarchical cluster analysis. There were 13 identified metabolites whose levels differentiated between groups of samples. Downregulation of several carboxylic acids, fatty acids, and steroids was observed in KC when compared to the normal cornea. Metabolic pathways associated with compounds that discriminated both groups were involved in energy production, lipid metabolism, and amino acid metabolism. An observed signature may reflect cellular processes involved in the development of KC pathology, including oxidative stress and inflammation.

Endogenous fluorescence can differentiate the keratoconic cornea.

The purpose of the study was to investigate the endogenous fluorescence of the keratoconic cornea in order to analyze changes in the spectra due to the keratoconic stroma abnormalities. Twenty-two corneal buttons obtained from patients with keratoconus (KC, N = 22) at the time of penetrating keratoplasty were used. As a reference, twelve normal corneas (N = 12): ten from the Eye Bank and two from enucleated eyes due to choroidal melanoma were used. The fluorescence excitation/emission matrices (EEM) in the ranges of 250-400/260-600 nm were recorded. Healthy cornea, keratoconic cornea and sclera showed three main EEM bands, which correspond to the following fluorophores: tryptophan residues in the proteoglycan fraction of corneal/scleral stromas, naturally occurring collagen cross-links and the NAD(P)H fraction present in the metabolically active cells. Relative intensity factors S1, S2 and S3 describing the contribution of each kind of fluorophore to the total fluorescence of the tissue were calculated. Normal and keratoconic corneas show qualitatively similar fluorescence matrices, but the statistically significant differences in the mean values of the S1, S2 and S3 parameters for the KC and normal corneas were observed indicating changes in contribution of different fluorophores to the whole fluorescence of the tissue. Moreover, differences between multidimensional distribution of the relative intensity factors S1, S2 and S3 between these groups were demonstrated (p < 0.001). In conclusions: Differences in the relative intensity factors calculated on a basis of the fluorescence spectra can correspond to the changes found in the KC stroma regarding natural collagen cross-links and the proteoglycan fraction. These parameters well differentiate the KC and normal corneas that could serve as an additional tool for the keratoconus characterization.

Comparison of Methods of Endotamponade Used During 23-Gauge Pars Plana Vitrectomy and the Risk of Raised Intraocular Pressure During 24-Month Follow-Up: A Retrospective Study of 196 Patients.

BACKGROUND Pars plana vitrectomy (PPV) is used to treat retinal conditions, including retinal detachment, and involves removal of the vitreous gel from the eye. Complications following PPV include raised intraocular pressure (IOP). This retrospective study aimed to compare methods of endotamponade used during 23-gauge PPV and the risk of raised IOP during 24-month follow-up at a single center. MATERIAL AND METHODS The study included 196 patients (age, 15-86 years; mean, 63.5 years) (196 eyeballs). There were 93 patients (47.45%) with a preoperative history of type 2 diabetes mellitus and 14 patients (7.14%) with a history of myopia. IOP was measured with Goldmann applanation tonometry at one-, three-, six-, 12-, and 24-month follow-up. The outcome was compared following endotamponade with silicone oil, sulfur hexafluoride (SF6), and balanced salt solution (BSS). RESULTS Mean IOP at one-month follow-up was 17.2 mmHg (±3.61 mmHg; range, 9-45 mmHg), and at 24-month follow-up was 17.3 mmHg (±3.23 mmHg; range, 7-30 mmHg). IOP following PPV was significantly associated with the indication for PPV (P=0.023), and the type of endotamponade used (P=0.049). In patients with silicone oil endotamponade, the risk of IOP at 24 months was increased by 2.3 times compared with SF6 or BSS endotamponade. Patients with SF6 endotamponade had a risk of IOP that was 3.3 times lower than for silicone oil tamponade or BSS tamponade. CONCLUSIONS Silicone oil endotamponade in PPV was associated with an increased risk of IOP at 24-month follow-up.

NMR spectroscopy of human eye tissues: a new insight into ocular biochemistry.

BACKGROUND: The human eye is a complex organ whose anatomy and functions has been described very well to date. Unfortunately, the knowledge of the biochemistry and metabolic properties of eye tissues varies. Our objective was to reveal the biochemical differences between main tissue components of human eyes. METHODS: Corneas, irises, ciliary bodies, lenses, and retinas were obtained from cadaver globes 0-1/2 hours postmortem of 6 male donors (age: 44-61 years). The metabolic profile of tissues was investigated with HR MAS 1H NMR spectroscopy. RESULTS: A total of 29 metabolites were assigned in the NMR spectra of the eye tissues. Significant differences between tissues were revealed in contents of the most distant eye-tissues, while irises and ciliary bodies showed minimal biochemical differences. ATP, acetate, choline, glutamate, lactate, myoinositol, and taurine were identified as the primary biochemical compounds responsible for differentiation of the eye tissues. CONCLUSIONS: In this study we showed for the first time the results of the analysis of the main human eye tissues with NMR spectroscopy. The biochemical contents of the selected tissues seemed to correspond to their primary anatomical and functional attributes, the way of the delivery of the nutrients, and the location of the tissues in the eye.

General Treatment and Ophthalmic Management of Peters' Anomaly.

Peters' anomaly (PA) is a manifestation of complex disorders in the development of the anterior segment of the eye. The most recognizable feature of the disease is a doughnut-shaped central corneal opacity and adhesions between the opacity and underlying iris. Glaucoma is observed in 30-70% of patients, with up to 50% of the patients showing concomitant vision-threatening disorders. Up to 60% of patients have systemic abnormalities or developmental delays. Being a rare malformation, PA is one of the most common congenital indications for corneal transplantation in infants. Penetrating keratoplasty is used as the primary method of treatment in cases with corneal opacification of a degree that forbids visual development in both eyes. The heterogeneity of co-occurring ophthalmic and systemic malformations in the spectrum of PA determines the wide range of success, defined by various endpoints: graft clarity or visual acuity. Although surgical advancement has made corneal grafting possible in younger children, it has a higher graft failure rate and worse visual prognosis than adult keratoplasty. Optical sector iridectomy, pupil dilation, or cornea rotation can alternatively be performed. Satisfying results of pediatric keratoprosthesis in particular cases of PA have been described. Postoperative treatment of PA aims to maintain a clear optical pathway and prevent amblyopia. This article therefore aims at reporting the ophthalmic treatment and need for multidisciplinary management of PA, including pharmacological and surgical treatment.

Superficial Keratectomy Alone versus in Combination with Amniotic Membrane Transplantation in Aniridia-Associated Keratopathy and a Short-Term Clinical Outcome.

Background/Objectives: Aniridia-associated keratopathy (AAK) is a potentially vision-threatening pathology in congenital aniridia, for which both the underlying etiopathogenesis and effective treatment remain unclear. Methods:This prospective study was conducted to assess and compare the short-term outcome after superficial keratectomy (SK) alone or in a combination with an amniotic membrane transplantation (AMT). Here, 76 eyes were enrolled in 76 patients with grade 4 AAK. In all eyes, in order to assess preoperatively the efficiency of the limbal epithelial stem cells (LESC), the presence of corneal epithelial cells in confocal microscopy was established. The analyses included: best corrected visual acuity (BCVA), the stage of AAK and the number of corneal quadrants involved in corneal neovascularization (CNV). Results: Six months after surgery, the mean BCVA was 0.05 and ranged from 0.002 up to 0.1 in both groups. Improvement in BCVA occurred in 94.29% patients when *SK alone* was performed, and in 92.68% when in combination with AMT. There were no statistically significant differences in the effect of therapy depending on the type of surgery, regarding BCVA, stage of AAK and the number of quadrants with CNV. Conclusions: SK alone is an effective procedure in short outcomes limited to six months for advanced AAK in association with LESC partial efficiency.

Outcomes of Boston Keratoprosthesis Type I Implantation in Poland: A Retrospective Study on 118 Patients.

Background: Boston Keratoprosthesis Type I (BI-KPro I) is a synthetic cornea that can be used to restore vision in patients with corneal blindness. This retrospective study evaluated the outcomes of BI-KPro implantation in 118 patients. Material: The mean age of the patients was 56.76 ± 14.24 years. Indications for keratoprosthesis implantation were as follows: graft failure, 47 (39.83%); ocular burn, 38 (32.20%); neurotrophic keratopathy, 11 (9.32%), mucous membrane pemphigoid 9 (7.67%); autoimmune, 6 (5.08%); Stevens-Johnson syndrome, 4 (3.39%); and aniridia (2.54%). Methods: The surgeries were performed between March 2019 and June 2022 at a single clinical center in two locations. The postoperative visual acuity, complications, and need for additional surgical procedures were analyzed. Results: The Best Corrected Visual Acuity before surgery was 0.01 ± 0.006. After one year (V1), it was 0.30 ± 0.27; at two years (V2), it was 0.27 ± 0.26; and at three years (V3), it was 0.21 ± 0.23. The percentage of patients with visual acuity better than 0.1 on the Snellen chart was 37.29% after 1 year, 49.35% after 2 years, and 46.81% after 3 years of follow up. The most common complications were glaucoma (78 patients; 66.1%), corneal melting (22 patients; 18.6%), and retroprosthetic membranes (20 patients; 17.0%). Conclusions: The BI-KPro can significantly improve visual acuity. The worst long-term results were obtained in the group of patients with autoimmune diseases; therefore, careful consideration should be given to implanting BI-KPro in this group. The high incidence of de novo glaucoma or the progression of pre-existing glaucoma suggests the need for careful monitoring.

Assessment of Changes in Cap and Residual Stromal Thickness Values during a 6-Month Observation after Refractive Lenticule Extraction Small Incision Lenticule Extraction.

Background: In this study, the changes in corneal cap and residual stromal thickness (RST) values during a 180-day observation period after refractive lenticule extraction small incision lenticule extraction (ReLEx SMILE) were assessed. Methods: Fifty patients underwent ReLEx SMILE using the VisuMax 500 femtosecond laser, with corneal imaging conducted pre and post procedure via anterior segment optical coherence tomography (AS-OCT). Cap thickness in the center and 1.5 mm from the center in four meridians was measured at various intervals. Results: The results showed a significant decrease in cap thickness 180 days post procedure compared to earlier intervals (p < 0.05). Similarly, RST decreased gradually and significantly post procedure (p < 0.05). Notably, changes in cap thickness within the central 1.5 mm area were more dynamic than RST changes during the 6-month observation period following SMILE. Conclusions: The corneal cap thickness measured with swept-source AS-OCT within the central 1.5 mm area underwent more dynamic changes than the residual stromal thickness during the 6-month observation following SMILE.

Comparative Analysis of Corneal Parameters Performed with GalileiG6 and OCT Casia 2.

BACKGROUNDS: To compare keratometry (Ks and Kf), astigmatism (Ast.), and the astigmatism axes (Ax.) of the posterior surface of the cornea; the total, central cornea thickness (CCT); and the thinnest corneal thickness (TCT) measured using two different measurement methods. METHODS: Patients qualified for cataract surgery at the Chair and Clinical Department of Ophthalmology, Division of Medical Science in Zabrze, Medical University of Silesia, Katowice, Poland, were included in the study and monitored with the following two devices: OCT-CASIA2 and Dual Scheimpflug Analyzer GalileiG6. Our work was a randomized, prospective study in which compliance with the agreement of measurements between the devices was evaluated using the Bland-Altman method. RESULTS: A total of 110 patients (62 females and 48 males) were examined. Overall, 100 eyes of patients that qualified for cataract surgery were enrolled in the study. No statistically significant difference was observed for Total-Ks and Total-Kf. A significant difference was observable for the following parameters: total Ks-ax, total Kf-ax, the total power of astigmatism, and in all parameters of the part of the cornea and corneal thickness (CCT and TCT). CONCLUSIONS: The measurements obtained using Casia2 and the Dual Scheimpflug Analyzer GalileiG6 were significantly different and not interchangeable except for total Ks and Kf.

Clinical Evaluation of the Efficacy of Femtosecond Laser-Assisted Anterior Lamellar Keratoplasty.

BACKGROUND: To evaluate the clinical outcome, efficacy, and safety of femtosecond laser-assisted anterior lamellar keratoplasty. MATERIAL AND METHODS: In this prospective study, 21 males and 10 females aged from 15 to 62 years (mean 38.5) with different pathologies of the anterior corneal layers were enrolled for anterior lamellar keratoplasty using femtosecond laser VisuMax (Carl Zeiss, Germany). All patients were examined for uncorrected (UCVA) and best-corrected (BCVA) distance and near visual acuity, astigmatism, endothelial cell density, corneal thickness, and intraocular pressure. These examinations were performed before transplantation, at hospital discharge, and after 3 and 12 months. The mean follow-up time was 65.36 ± 28.54 months. RESULTS: A statistically significant improvement of both UCVA and BCVA for distance and near vision was registered. BCVA improved from 0.11 preoperatively to 0.168 (p = 0.03), 0.267 (p < 0.01), and 0.472 (p < 0.01) on the hospital discharge day, three months, and 12 months respectively. There were no statistically significant differences in astigmatism, intraocular pressure, endothelial cell density, and corneal pachymetry as compared to preoperative and postoperative values. Six patients (19%) had a graft failure with a rate of 33% at 26 months. CONCLUSIONS: Femtosecond laser-assisted anterior lamellar keratoplasty is a safe and effective surgical method, providing satisfactory graft survival rates.

Assessment of the Effectiveness of Glaucoma Treatment Using MicroPulse Transscleral Cyclophotocoagulation in Patients with Glaucoma Who Have Previously Undergone Vitreoretinal Surgery.

INTRODUCTION: This retrospective study aimed to assess the effectiveness of using MicroPulse transscleral cyclophotocoagulation (µP-TSCPC) in patients who had previously undergone pars plana vitrectomy (PPV), depending on the endotamponade used. METHODS: For the study, a total of 60 patients were enrolled who underwent PPV followed by tµP-TSCPC as a result of an increase in intraocular pressure (IOP) over the norm of 21 mmHg. In this group of patients, 20 received silicone oil endotamponade during PPV, 20 received sulfur hexafluoride gas SF6, and in another 20 a differentiated balanced salt solution (BSS) was used. RESULTS: The main indications for conducting PPV were (1) retinal detachment (silicone oil endotamponade was used; n = 12); (2) dislocation/subluxation of the patient's own or artificial intraocular lens (balanced salt solution (BSS) endotamponade was used; n = 11); (3) the presence of an epiretinal membrane and/or a macular hole (BSS endotamponade was used; n = 9, or SF6; n = 20); and (4) hemorrhage into the vitreous chamber (silicone oil endotamponade was used; n = 8). CONCLUSION: The choice of endotamponade used during PPV was not found to determine the effectiveness of µP-TSCPC treatment. The effectiveness of µP-TSCPC in patients after PPV depended, above all, on the etiology of the disease, for which PPV was previously performed. The lowest effectiveness of µP-TSCPC was noted in cases where the reason for conducting PPV was hemorrhage into the vitreous chamber and silicone oil endotamponade was used, while the highest effectiveness was noted in cases where PPV was conducted owing to the presence of an epiretinal membrane and/or a macular hole and SF6 endotamponade was used.

Adequacy of Anaesthesia for Nociception Detection during Vitreoretinal Surgery.

Vitreoretinal surgery (VRS) is one of the most widely performed precise procedures in ophthalmic surgery; the majority of cases are carried out under regional anaesthesia (RA) only. However, in specific situations (such as when the patient fails to cooperate with the operator for various reasons), general anaesthesia (GA), alone or in combination with GA (combined general-regional anaesthesia, CGR), is the only safe way to perform VRS. While monitoring the efficacy of an intraoperative rescue opioid analgesia (IROA) during surgery (assessing the adequacy of anaesthesia (AoA)) may be challenging, the surgical pleth index (SPI) is a useful tool for detecting the reaction to noxious stimuli and allows for the rational titration of opioid analgesics (AO) during surgery. The current study investigated the influence of the SPI-based titration of fentanyl (FNT) in combination with various pre-emptive analgesia (PA) techniques on intraoperative pain perception during various stages of VRS performed under AoA. A total of 176 patients undergoing VRS under GA were enrolled in the study. They were randomly assigned to one of the five following study arms: Group GA (control group)-patients who received general anaesthesia alone; Group PBB-GA with preprocedural peribulbar block (with 0.5% bupivacaine and 2% lidocaine); Group T-GA with preventive, topical 2% proparacaine; Group M-GA with a preprocedural intravenous infusion of 1.0 g of metamizole; and Group P-GA with a preprocedural intravenous infusion of 1.0 g of paracetamol. The whole procedure was divided in four stages: Stage 1 and 2-preoperative assessment, PA administration, and the induction of GA; Stage 3-intraoperative observation; Stage 4-postoperative observation. the SPI values were monitored during all stages. The occurrence of nociception (expressed as ∆SPI >15) during various manipulations in the surgical field was observed, as were cumulative doses of rescue analgesia, depending on the PA administered. During the course of VRS, rescue FNT doses varied depending on the stage of surgery and the group investigated. The majority of patients, regardless of their group allocation, needed complementary analgesia during trocar insertion, with Group GA patients requiring the highest doses. Likewise, the highest cumulative doses of IROA were noted during endophotocoagulation in Group GA. Preventive PBB and topical anaesthesia were proven to be most efficient in blunting the response to speculum installation, while topical anaesthesia and paracetamol infusion were shown to be more efficient analgesics during endophotocoagulation than other types used PA. In the performed study, none of the PA techniques used were superior to GA with FNT dosing under the SPI with respect to providing efficient analgesia throughout the whole surgery; there was a necessity to administer a rescue OA dose in both the control and investigated groups.

Hydrogel membranes based on genipin-cross-linked chitosan blends for corneal epithelium tissue engineering.

Novel polymeric hydrogel scaffolds for corneal epithelium cell culturing based on blends of chitosan with some other biopolymers such as hydroxypropylcellulose, collagen and elastin crosslinked with genipin, a natural substance, were prepared. Physicochemical and biomechanical properties of these materials were determined. The in vitro cell culture experiments with corneal epithelium cells have indicated that a membrane prepared from chitosan-collagen blend (Ch-Col) provided the regular stratified growth of the epithelium cells, good surface covering and increased number of the cell layers. Ch-Col membranes are therefore the most promising material among those studied. The performance of Ch-Col membranes is comparable with that of the amniotic membrane which is currently recommended for clinical applications.

[Regeneration of corneal epithelium using keratin modified chitosan membranes]. / Regeneracja nablonka rogówki przy zastosowaniu membran chitozanowych modyfikowanych keratyna.

The cornea is a transparent front layer of the eye. It functions like a window that controls and focuses the light entering into the eye. The cornea contributes to 65-75% of the eye's total focusing power and it acts as a physical barrier against pathogenic microorganisms, dirt and other noxious physical factors. The corneal tissue is arranged in five basic layers. The outermost layer (epithelium) is made up of highly regenerative cells that allow for quick healing of superficial injuries. Eye infections, diseases, or mechanical injury can harm corneal epithelium and cause blindness. Under certain circumstances, to prevent that, it is recommended to perform complete corneal transplantation. However, due to lack of sufficient number of donors, researchers are searching for alternative solutions.. Regeneration of epidermal tissue can restore and ensure normal functioning of cornea. For that purpose proper grafts are needed. The goal of current research was to develop the material for scaffold preparation providing optimal conditions for the epithelium cornea cell culturing and to determine its chemical, physical, and biological properties. The scaffolds, which could be applied in ophthalmology should fulfill a lot of requirements, among them such as biocompatibility, biodegradability, restorability, non-toxicity. They should also have adequate mechanical strength, flexibility and porosity. The aim of this work was to synthesize and to determine the properties of polymeric material for ophthalmic surgery applications. A hydrogel scaffold in the form of membrane was obtained from chitosan - natural, biocompatible, biologically inert, stable in the natural environmental and antibacterial polysaccharide derived from chitin. Biodegradable chitosan films containing keratin were crosslinked with genipin - a naturally occurring and nontoxic agent. In this study we present physicochemical characterization of the scaffolds. Porosity, contact angle and swelling ratio (at different pH) were determined. The optical microscope technique was used to visualize the microstructure of the scaffolds. Atomic force microscopy (AFM) measurements revealed the topography of the surfaces of membranes. The biological tests have shown that epithelial cells seeded on the membranes proliferated efficiently.