Keratoplasty

Researchers are studying the accuracy of measuring total corneal astigmatism compared to the actual corneal astigmatism under different regional measurement settings. This observational study focuses on patients who have undergone phacoemulsification surgery, with or without the implantation of toric intraocular lenses (IOLs), and have a certain degree of corneal astigmatism. The goal is to find the best region setting for measuring corneal astigmatism accurately. Participants with corneal astigmatism will have various eye measurements taken using specialized devices. These include total corneal astigmatism and anterior chamber depth measured by a Scheimpflug tomographer, pupil size assessed by the itrace and MONCV3 devices, and residual astigmatism evaluated through subjective refraction. The study observes these measurements at least one month after their cataract surgery. During the study, participants will undergo eye exams and tests to collect the necessary data. Researchers will analyze differences in vectorial measurements, pupil sizes, residual astigmatism, and anterior chamber depth to determine measurement accuracy. The study monitors these outcomes to optimize corneal astigmatism measurement methods. Participation duration varies depending on individual schedules and follow-up visits.

Researchers are investigating the immediate effects of cigarette smoking on the cornea's structure and measurements in healthy adults aged 18 to 60 years. This prospective, controlled study compares smokers and non-smokers to see if short-term smoking causes measurable changes in corneal tomography and biometric parameters. The study includes 46 smokers and 46 non-smokers to better understand how acute smoking exposure might affect eye health. Participants are divided into two groups: active smokers and non-smokers. Both groups undergo initial full eye examinations and measurements using a Pentacam device focused on the right eye to avoid data overlap. After baseline measurements, participants spend 10 minutes outdoors under standard conditions; smokers smoke during this period while non-smokers do not. The same eye measurements are taken immediately after this exposure period to compare changes within and between the groups. Throughout the study, participants undergo detailed eye exams and Pentacam imaging to measure corneal thickness and densitometry at the pupil center before and after the smoking or non-smoking exposure. Researchers monitor changes in these parameters to assess the acute impact of smoking on eye structures. The study duration includes baseline assessment, the 10-minute exposure period, and immediate post-exposure measurements to capture short-term effects.

Phacoemulsification is a common cataract surgery performed under topical anesthesia, which is generally safe but can cause pain, anxiety, and discomfort for some patients. This research evaluates the effect of oral anti-anxiety medication, specifically Alprazolam, on improving patient satisfaction during second eye cataract surgery. The study aims to clarify whether oral sedation can reduce pain, anxiety, and side effects like nausea and dizziness compared to no sedation during phacoemulsification. Patients will receive either a single oral dose of Alprazolam or a placebo tablet 30 minutes before surgery. The dose of Alprazolam is 0.5 mg for most patients, with a reduced 0.25 mg dose for those over 65 years or with liver disease. The study compares these groups to assess how oral sedation affects anxiety, pain, and surgical satisfaction. This is an extension study involving patients undergoing surgery on their second eye with topical anesthesia. During the trial, participants will complete questionnaires assessing pain, anxiety, and overall satisfaction before and after surgery. Researchers will monitor intraoperative discomfort and postoperative anxiety levels. Data from approximately 250 patients will be collected and analyzed for these outcomes. This study runs from March 2025 to December 2027, focusing on improving cataract surgery experiences safely and conveniently.

This research aims to analyze the factors influencing high-order aberrations following Small Incision Lenticule Extraction (SMILE) surgery, focusing on patients with lenticule retained. High-order aberrations are key indicators used to assess visual quality after refractive surgery. While previous studies have explored complications related to these aberrations, there is limited high-quality research on patients with covert residual lenticule, which complicates clinical decisions about additional surgery. The study compares high-order aberrations between patients with and without peripheral residual lenticule to provide a detailed evaluation of postoperative visual quality. It involves two groups: the lenticule retained group and the non-lenticule retained group. This observational study does not involve treatment interventions but collects data to understand the relationship between residual lenticule and visual outcomes. Participants will be followed up with assessments of higher-order aberrations at 90 days post-surgery. The study includes clinical evaluations and wavefront analysis to measure visual quality objectively. The findings aim to guide improvements in SMILE surgical techniques and postoperative care. The total participation involves initial assessment and follow-up visits as per the study plan.

Researchers are investigating how glaucoma and the medications used to treat it affect the thickness of the corneal and limbal epithelium, which reflects the health of limbal stem cells important for eye surface protection. This observational study focuses on glaucoma patients with various treatment durations and aims to understand the link between tear fluid proteins and limbal function. The goal is to provide insights for early detection and future drug development to protect limbal stem cells. Participants include healthy controls without glaucoma, newly diagnosed glaucoma patients using medication for less than 3 months, glaucoma patients on long-term medication for over a year, and patients with treatment in only one eye. The study will measure corneal and limbal epithelial thickness and analyze tear fluid proteomics at enrollment and again after 6 months for newly diagnosed patients. During the study, participants will undergo eye thickness measurements and tear sample collection at specified times. Researchers will review changes in limbal epithelial thickness primarily, along with corneal thickness and tear protein profiles, to evaluate limbal function. The study starts in July 2025 and is expected to continue until December 2026, providing valuable data on glaucoma medication effects and ocular surface health.

Researchers are evaluating the use of Autologous Cultured Corneal Epithelium (CECA) for treating corneal lesions caused by limbal stem cell deficiency, a condition affecting the eye's surface. This is the first clinical trial using a CECA product made at the LOEX laboratory. The study is a phase I/II trial designed to assess the safety and effectiveness of this graft in patients suffering from this condition. The trial includes participants of all genders, with plans to include five minors. The treatment involves surgical transplantation of the CECA graft, which is cultured corneal epithelium aimed at repairing damaged tissue caused by limbal stem cell deficiency. This procedure is the main intervention and is designed to restore the corneal surface by transplanting the reconstructed tissue to the affected eye. The trial does not involve additional treatment groups or placebo comparisons. Participants will be monitored for one year after the transplantation, with evaluations including anatomic assessments of the cornea, measurements of best corrected visual acuity, pain levels, and quality of life. These assessments help researchers understand the graft's impact on eye health and patient well-being. The study is sponsored by CHU de Quebec-Universite Laval and began in December 2012, with an estimated end date in December 2027.

Researchers are studying the relationship between clinical factors and the occurrence of adverse drug reactions in hospitalized patients who receive tropicamide/phenylephrine 8 mg/50 mg/mL. This study aims to identify which clinical determinants may increase the risk of these reactions and provide safety information for this commonly used ophthalmic drug combination. It also seeks to establish safety measures for patients undergoing eye examinations or surgery where these drugs are used. The study involves hospitalized patients scheduled for surgery who will receive two drops of tropicamide/phenylephrine 8 mg/50 mg/mL. Vital signs will be measured before administration and then at several time points afterward, including 5, 15, 30 minutes, and 1, 2, and 3 hours post-administration. Data will be collected using questionnaires and analyzed to find associations between clinical factors and adverse reactions. Participants will be monitored closely through vital sign checks and questionnaires during the study period. Researchers will evaluate adverse drug reactions and clinical determinants to understand their connection. The main outcome is to assess vital signs at set intervals following drug administration and identify any adverse reactions. The study is observational and aims to enhance the safety profile of this medication in hospitalized patients.

Researchers are evaluating the initial safety and effectiveness of the GORE Synthetic Cornea Device in treating loss of corneal clarity in patients who need corneal transplantation. This early feasibility study is prospective, open-label, single-arm, and conducted across multiple centers. It aims to assess clinical outcomes in patients with corneal opacity who are candidates for this procedure. Participants will receive treatment with the GORE Synthetic Cornea Device. After the procedure, they will have scheduled clinical follow-up visits over a 12-month study period to monitor their progress and device performance. The study may extend follow-up examinations up to 60 months if patients agree to continue. During the study, participants will undergo evaluations including visual acuity tests and assessments for adverse events related to the device and surgery. Researchers will track device retention, surgical complications, and any need for secondary interventions. Safety and effectiveness outcomes will be monitored through regular clinical exams, with the primary measures focused on safety events at the initial procedure and during the 12 months after treatment.

Researchers are evaluating a new treatment for total bilateral limbal stem cell deficiency (LSCD), a rare eye condition caused by severe burns or other ocular diseases that lead to blindness and poor quality of life. This condition results in loss of corneal epithelial stem cells, causing conjunctival invasion and corneal clouding. Currently, no proven effective treatments exist for total bilateral LSCD, and existing options have significant limitations and risks. The study involves transplantation of cultivated autologous oral mucosal epithelial sheets (FEMJA) directly onto the corneal stroma without sutures. The sheets adhere strongly and rapidly, protected by a soft contact lens during healing for 3 to 15 days. If the corneal stroma remains opaque due to scars, a complementary corneal graft may be performed 12 months after the FEMJA transplantation. This trial builds on earlier phase I/II studies that showed safety and effectiveness using a different culture method. Participants will have their oral mucosa cells cultured into epithelial sheets using a new enzymatic detachment process and grafted onto the eye. Researchers will monitor visual acuity improvement, transplant success, adverse events, and changes in eye signs and symptoms over 24 months. Safety assessments include monitoring for corneal graft rejection and correlations between biological characteristics of the transplanted sheets and visual outcomes. The total follow-up period is 24 months after transplantation.

Researchers are evaluating the ability of a deep convolutional neural network (CNN) to predict complications and outcomes related to Small Incision Lenticule Extraction (SMILE) surgery, which is used to correct refractive errors in the eye. This observational, multi-center study aims to assess the diagnostic accuracy of the AI algorithm in identifying intraoperative complications such as opaque bubble layer (OBL), negative pressure detachment, and black spots, which can affect surgery and recovery. The study is sponsored by the Second Affiliated Hospital of Nanchang University and focuses on improving prediction accuracy compared to human physicians. During the study, eyes that have undergone SMILE surgeries performed by experienced surgeons will be assessed using the AI diagnostic algorithm. The algorithm's performance will be evaluated by measuring accuracy, area under the curve (AUC), sensitivity, and specificity in predicting complications such as OBL area and progressive suction loss on the day of surgery, as well as postoperative outcomes including effective optical zone, refractive error, and central corneal thickness at day 7 and later timepoints. No treatment is administered as this is an observational study. Participants will be monitored through imaging and clinical data collected around the time of surgery and during follow-up visits up to day 90. Researchers will analyze the algorithm's ability to predict surgical complications and postoperative results to determine its real-world utility. The primary outcomes include the AUROC values for various predictions on days 0 and 7, while secondary outcomes focus on sensitivity and specificity at multiple time points. The study includes adults aged 18 to 45 years with stable myopia and excludes those with other eye conditions or systemic diseases. Total participation length varies by individual.