Clinical Research Directory

Intacs Prescription Inserts for Keratoconus Patients

The US food and Drug Administration (FDA) originally approved INTACS prescription inserts in April 1999 for the correction of low levels of nearsightedness (-1.00 to -3.00 diopters). Additional clinical data have shown that INTACS are safe for the treatment of keratoconus, in July 2004, FDA approved INTACS inserts for the treatment of keratoconus as a Humanitarian Use Device (FDA approval letter attached). The statute and the implementing regulation of FDA (21 CFR 814.124 (aj) require IRB review and approval before a HUD is used.INTACS prescription inserts are composed of two clear segments, each having an arc length of 150°, they are manufactured form a biomedical material called polymethylmethacrylate (PMMA) and are available in three thicknesses. Two INTACS inserts ranging from 0.250mm to 0.350mm may be implanted depending on the orientation of the cone and the amount of myopia and astigmatism to be reduced.

A Randomized Clinical Trial of Ex Vivo Corneal Cross-Linking of Donor Keratoplasty Tissue for Keratoconus Used for Keratoplasty in Keratoconus Patients

This randomized clinical trial will assess corneal astigmatism and visual outcomes in participants who have undergone corneal transplantation for keratoconus with ex vivo cross-linked donor corneal tissue versus participants who have undergone corneal transplantation for keratoconus with non-cross-linked donor corneas. Crosslinking is a procedure that stabilizes the biomechanical properties of the cornea; as a result, the cornea stiffens. It has been shown that this procedure stabilizes the cornea of patients with keratoconus or corneal ectasias. The FDA currently approves crosslinking for patients with progressive keratoconus and corneal ectasia following refractive surgery. Ex vivo crosslinking of donor corneal tissue for patients with keratoconus undergoing PK or DALK could stabilize the cornea and reduce the risk of high astigmatism and improve vision in patient with keratoconus.

Artificial Intelligence-assisted Diagnosis in Ophthalmology

This is a retrospective, multicenter, observational study designed to develop and validate an artificial intelligence (AI) system capable of detecting and classifying major ophthalmic diseases (glaucoma, cataract, diabetic retinopathy, and other retinal pathologies) in the Costa Rican population. The study will use approximately 15,000 existing medical images from digital archives of two ophthalmic centers in Costa Rica, without active participant recruitment or capture of new images. The primary motivation is that AI systems developed in other countries (primarily Asian, European, or North American populations) do not necessarily perform with the same accuracy when applied to Latin American populations. This study seeks to establish a precedent for the importance of locally validating any medical AI technology before clinical implementation.

Dextenza Versus Topical Steroid Eye Drops for Postoperative Management Following Corneal Crosslinking

This study aims to compare the use of Dextenza, an FDA-approved intracanilular drug-eluting insert that is designed to deliver a tapered dose of dexamethasone to the ocular surface for 30 days, to the standard of care, or the use of a month-long topical prednisolone acetate 1% (PredForte) eye drops starting from four times daily. Following treatment, Dextenza resorbs and exits the nasolacrimal system without the need for removal. Three prior phase 3 clinical trials have demonstrated that Dextenza is equally efficacious to a month-long topical Pred Forte taper in the treatment of postoperative inflammation following cataract surgery. This proposed study strives to demonstrate the non-inferiority of using Dextenza to treat postoperative inflammation following corneal collagen crosslinking compared to standard of care eye drops in a randomized trial. By demonstrating Dextenza's non-inferiority to treatment postoperative inflammation, the investigators hope to provide an alternative modality of treatment to patients who are unable to cooperate with or tolerate postoperative topical eye drop regimens, allowing for improved adherence to necessary therapy and thus improved postoperative outcomes.

Outcomes of CTAK Surgery

Measuring quality of vision and quality of life outcomes using a validated questionnaire in participants undergoing CTAK surgery for corneal ectasia

Electrophysiological Changes in Cases of Different Stages of Keratoconus

Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity.A typical patient with keratoconus presents in the teens or early twenties with complaints of blurring or distortion in vision and having to change glasses frequently due to changes in refractive error. Corneal thinning frequently precedes ectasia. In moderate and advance cases, a hemosiderin arc or circle line, known as Fleischer's ring, is frequently seen around the cone base. Vogt's striaes, which are fine vertical lines produced by Descemet's membrane compression, is another characteristic sign. Most patients eventually develop corneal scarring. Munson's sign, a V-shape deformation of the lower eyelid in downward position; Rizzuti's sign, a bright reflection from the nasal area of the limbus when light is directed to the limbus temporal area; and breakages in Descemet's membrane causing acute stromal oedema, known as hydrops, are observed in advanced stages. Corneal blindness is one of the major causes of reversible blindness, which can be managed with transplantation of a healthy donor cornea. It is the most successful organ transplantation in the human body as cornea is devoid of vasculature, minimizing the risk of graft rejection. Preoperative clinical evaluation of visual potential after corneal transplantation in the patient with dense corneal opacity remains difficult using only history and biomicroscopic examination. Some studies found that electrophysiologic tests were good predictors of visual prognosis prior to corneal transplantation. Electrophysiology is an objective functional test of the visual pathway and allows the location of visual dysfunctions to be detected. Full-field electroretinography (ERG) is an established clinical technique used to evoke and record mass responses of the retina to flashes of light. The ISCEV Standard full-field ERGs assess generalized retinal function under dark-adapted (DA) and light-adapted (LA) conditions.The visual evoked potential (VEP) is a cortical response and serves as a functional test of the entire visual pathway from the eye to the visual system of the brain.

Corneal Biomechanical Analysis Using Brillouin Microscopy

The objective of this study is to measure the Brillouin biomechanical properties in keratoconic corneas and characterize biomechanical alterations that occur after corneal procedures that inherently strengthen or weaken the cornea by evaluating the change in Brillouin metrics before and after treatments.

Placebo-controlled Study to Evaluate the Safety and Efficacy of GLK-221 Ophthalmic Solution in Subjects With Keratoconus

Multi-center, parallel-group, placebo-controlled trial designed to assess the safety and efficacy of twice-daily topically administered GLK-221 Ophthalmic Solution in subjects with keratoconus.

Study of TN-001 Topical Eyedrops for Keratoconus

The goal of this clinical trial is to learn if TN-001, a new eye-drop therapy, is safe and well-tolerated in adult patients with progressive keratoconus. It will also provide data on whether this therapy is effective in treating keratoconus. The main questions it aims to answer are: What medical problems do participants have when using TN-001 eyedrops? Does TN-001 eyedrop therapy stop keratoconus from progressing further? Participants will: Take TN-001 eyedrops twice a day, every day, for 3-6 weeks. Visit the clinic once every week for checkups and tests. Keep a diary of their symptoms.

Comparison of Epi-ON Corneal Collagen Crosslinking Performed Using an 18-Minute UVA Exposure vs. a 24-Minute UVA Exposure on Eyes With Ectatic Corneal Diseases

The goal of this clinical trial is to study the effects of an experimental (not Food and Drug Administration (FDA)-approved) treatment called corneal crosslinking (CXL) for conditions in which the cornea becomes progressively thin, steep, and misshapen, causing vision to be blurred. CXL is performed by putting riboflavin (vitamin B2) drops onto the eye and then exposing it to ultraviolet (UVA) light at about the same intensity as you get outdoors on a bright, sunny day. It is designed to stop the progression of disease by strengthening the cornea. Study participants will be at least 8 years of age or older and have a diagnosis of keratoconus, ectasia after LASIK, ectasia after PRK, pellucid marginal degeneration, progressive ectasia after previous CXL treatment or forme fruste keratoconus. The main question it aims to answer is: * Does CXL help prevent or slow the progression of someone's corneal condition and vision loss? Participants will: * Attend up to a total of 7 in office visits over the course of 6 months, where several eye and vision tests will be given. Receive CXL (applying riboflavin (Vitamin B2 eye drops) to the eye, then exposing the eye to ultraviolet (UV-A) light). * There will be two groups of participants. One group will receive the UVA treatment for 18 minutes and the other group will receive the UVA treatment for 24 minutes.

Compassionate Use Study of Epi-ON Corneal Collagen Crosslinking Performed Using UVA Exposure on Eyes With Ectatic Corneal Diseases for Subjects With Down Syndrome

The goal of this clinical trial is to study the effects of an experimental (not Food and Drug Administration (FDA)-approved) treatment called corneal crosslinking (CXL) for conditions in which the cornea becomes progressively thin, steep, and misshapen, causing vision to be blurred. CXL is performed by putting riboflavin (vitamin B2) drops onto the eye and then exposing it to ultraviolet (UVA) light at about the same intensity as you get outdoors on a bright, sunny day. It is designed to stop the progression of disease by strengthening the cornea. Study participants will be 8 years of age or older and have a diagnosis of Down syndrome. The main question it aims to answer is: * Does CXL help prevent or slow the progression of someone's corneal condition and vision loss? Participants will: * Attend up to a total of 7 in office visits over the course of 6 months, where several eye and vision tests will be given. Receive CXL (applying riboflavin (Vitamin B2 eye drops) to the eye, then exposing the eye to ultraviolet (UV-A) light for 20 minutes).

PRoTECT: Corneal Wavefront Guided PRK + Epi-off CXL vs. PTK+Epi-off CXL in Keratoconus

Keratoconus causes irregular astigmatism and reduced vision. Epi-off corneal crosslinking (CXL) stabilizes the cornea but often leaves higher-order aberrations uncorrected. This randomized, parallel-group trial compares corneal wavefront guided photorefractive keratectomy (corneal wavefront guided PRK, 50 µm therapeutic ablation) combined with accelerated epi-off CXL versus epi-off CXL with epithelial removal by phototherapeutic keratectomy (PTK) using a Schwind AMARIS excimer laser, in adults with keratoconus. The primary endpoint is change in best-corrected distance visual acuity (logMAR) at 12 months. Key secondary endpoints include Kmax, corneal higher-order aberrations, manifest refraction, Scheimpflug densitometry (haze) and Fantes grade, Corvis ST biomechanics, NEI VFQ-25, and endothelial cell density by non-contact specular microscopy at 1, 3, 6 and 12 months.

First in Human Study to Assess Safety and Efficacy of an Implantable Nitinol Device in the Treatment of Keratoconus

This Study is a First In Human clinical investigation addressed to evaluate the safety and efficacy of a novel intra-corneal nitinol device (Investigational Medical Device: GROSSO® implant) for the treatment of advanced keratoconus disease of the eye.

Investigator Initiated, Prospective Study of Xenia Corneal Lenticule

Cornea ectatic conditions such as keratoconus and post-LASIK (Laser In situ Keratomileusis) ectasia are disorders of the eye that are notorious for its uncontrolled progression over time, leading to loss of vision. There are valuable treatment options for controlling disease progression in mild to moderate stages of such disease. However in advanced cases and / or when contact lenses cannot be worn, surgery remains the only treatment option to rehabilitate vision. Most treatment options are highly invasive and represent significant risks. This study evaluates a novel corneal implant, Gebauer™ Lenticule to treat severe keratoconus or post-LASIK ectasia. This implant is derived from porcine collagen and intended for intra-stromal insertion. The Gebauer™ Lenticule is expected to improve the stability of the cornea while not impairing the vision. The procedure is an additive procedure after other treatment options have been exhausted. The procedure is reversible with removal of the implant (in the unexpected case of an adverse reaction), and vision may be restored to baseline. The purpose of this study is to evaluate how well the implant is tolerated, it's safety profile, and how effective this new treatment option is in the treatment of keratoconus or post-LASIK ectasia.

fMRI and IVCM Cornea Microscopy of CXL in Keratoconus

Evaluation of neuroplasticity of pain pathways and corneal afferent nerve regeneration following corneal crosslinking (CXL) in keratoconus patients using fMRI and corneal In Vivo Confocal Microscopy (IVCM).

High Resolution, High-speed Multimodal Ophthalmic Imaging

Knowledge of the pathogenesis of ocular conditions, a leading cause of blindness, has benefited greatly from recent advances in ophthalmic imaging. However, current clinical imaging systems are limited in resolution, speed, or access to certain structures of the eye. The use of a high-resolution imaging system improves the resolution of ophthalmoscopes by several orders of magnitude, allowing the visualization of many microstructures of the eye: photoreceptors, vessels, nerve bundles in the retina, cells and nerves in the cornea. The use of a high-speed acquisition imaging system makes it possible to detect functional measurements such as the speed of blood flow. The combination of data from multiple imaging systems to obtain multimodal information is of great importance for improving the understanding of structural changes in the eye during a disease. The purpose of this project is to observe structures that are not detectable with routinely used systems.

A Study to Test the Diagnostic Potential of Brillouin Microscopy for Corneal Ectasia

We have developed novel Brillouin microscopy and we are testing its potential for keratoconus and ectasia diagnostics. We plan to perform axial scans of the cornea in human volunteers in order to compare biomechanical properties of Keratoconus vs. Normal corneas and compare biomechanical properties of post-LASIK ectasia vs. normal corneas.

Corneal Elastography and Patient Specific Modeling

The goal of this research is to develop measurement tools and simulation technology for characterizing and predicting individual responses to corneal treatments and for advancing understanding of corneal ectasia risk factors. Patients who either 1) have keratoconus and are being evaluated for corneal crosslinking or 2) have refractive error and are being evaluated for refractive surgery procedures such as LASIK will have their eyes imaged to assess their mechanical properties and will have computational simulations performed to predict the response to treatment. One aim of the study is to test the hypothesis that computational models can predict the cornea's shape changes within clinically acceptable limits of error.

Safety and Effectiveness of the PXL-Platinum 330 System for Corneal Cross-Linking in Eyes With Corneal Ectasia

To evaluate the safety and effectiveness of the PXL Platinum 330 system for performing corneal cross-linking (CXL) for the treatment of ectatic disorders.

AI-Orchestrated Workflow Versus Consultant Ophthalmologist for Refractive Surgery and Keratoconus Diagnosis (AEYE Trial)

Background and Rationale: Laser vision correction procedures, such as LASIK (Laser-Assisted In Situ Keratomileusis), PRK (Photorefractive Keratectomy), and SMILE (Small Incision Lenticule Extraction), are highly effective but require careful preoperative screening to ensure safety. One of the most critical aspects of screening is identifying keratoconus and other corneal ectatic disorders-conditions that cause progressive thinning and bulging of the cornea, often contraindicating surgery. Early detection is essential to avoid vision-threatening complications. Despite advanced corneal imaging tools such as Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), accurate diagnosis-particularly in borderline or early-stage cases-remains challenging and subject to variability in human interpretation. Artificial intelligence (AI) offers the potential to improve diagnostic precision, reduce oversight, and standardize surgical planning. Purpose of the Study: This study evaluates the performance of AEYE (Automated Evaluation for Your Eye), a multi-agent AI system designed to support ophthalmologists in diagnosing keratoconus and determining refractive surgery eligibility. AEYE simulates the clinical workflow of an anterior segment specialist by orchestrating three specialized agents: History \& Risk Agent: Reviews patient history and extracts risk factors. Imaging Agent: Analyzes corneal tomography, AS-OCT, and epithelial mapping scans. Surgical Decision Agent: Integrates all findings, assigns a diagnosis, and recommends appropriate treatment options, including surgical eligibility or corneal cross-linking (CXL). Study Design: The study includes 50 real-world patient cases, both retrospective (from 2020 onward) and prospective, who were evaluated for refractive surgery or keratoconus. Each case is analyzed independently by AEYE and a consultant ophthalmologist (blinded to AI output), using the same multimodal clinical and imaging data. Diagnostic accuracy, agreement in surgical recommendations, and workflow efficiency are assessed. Anticipated Impact: By comparing AI-derived decisions with expert clinical judgment, this study aims to validate whether structured AI workflows like AEYE can serve as reliable, safe, and explainable decision support tools. If successful, AEYE may offer a scalable solution to reduce diagnostic variability and enhance the safety and consistency of refractive surgery screening.

Scleral Lens Fitting Using Wide-Field OCT

The purpose of this study is to see if OCT technology can optimize scleral contact lens fittings. Subjects with keratoconus, post-penetrating keratoplasty (PK), post-LASIK ectasia, post-radial keratotomy (RK), or a variety of anterior surface disorders requiring scleral lens fittings will be considered for enrollment. For each study eye, a clinically-selected scleral lens fit will be compared against an OCT-selected lens fit. The quality of each lens fit will be determined by flourescein exam at the slit lamp. Apical clearance, limbal clearance, conjunctival compression, and lens edge lift will be assessed. A lens that satisfies all four criteria will be considered satisfactory.

OCT in Diagnosis of Irregular Corneas

This main goal of this study is to improve the detection, classification, monitoring, and treatment of irregular corneas due to keratoconus, warpage, dry eye, scar, stromal dystrophies, and other corneal conditions. The primary goal will be achieved by using optical coherence tomography (OCT) to: 1. Develop an OCT-based system to classify and evaluate corneal-shape irregularities. 2. Develop OCT metrics for more sensitive detection of keratoconus progression. 3. Develop OCT-and-topography guided phototherapeutic keratectomy (PTK) for irregular corneas.

Collagen Cross-linking in Keratoconus

Optical Coherence Tomography (OCT) devices are non-contact instruments that can measure the depth of scars, other causes of cloudiness of the cornea, and degree of corneal thinning in patients with keratoconus. Laser Custom Corneal Collagen Cross-linking (CXL) significantly decreases corneal aberrations and improves vision. This study will use OCT-guided setting for the lasers used in the corneal smoothing portion of the laser custom CXL procedure to assess the affect on visual outcomes.

Risk Factors and Progression of Keratoconus

Primary objective : Description of keratoconus at baseline and during progression in 200 participants followed by the ophthalmology departments of CHU Montpellier, CHU Bordeaux and CHU Toulouse during a 2-year period. Clinical outcome, histology of the cornea and tears proteomics will be assessed in 4 groups at different points in time: * At 6 months in participants with no intervention (risk reduction instructions: not to rub their eyes) * At 6 months in participants with no intervention that didn't comply with the risk reduction instructions * At 1 month in participants assigned to cross-linking surgery * At 1 month in participants assigned to intra corneal ring surgery If both eyes are affected, both will be evaluated with their own visit agenda. Visits for no surgery participants will be set at 6 months, 12 months and 24 months in the absence of intervention (apart from the behavioral risk reduction). Visits for surgery participants will be set at D7, 1 month, 6 months, 12 months and 24 months after the procedure: cross-linking or placement of the intra corneal ring. Secondary objective : Description of the association between clinical outcomes, histological progression of the cornea and tears proteomics in time, 2 years period. Comparison of tears proteomics in 36 participants with keratoconus followed at CHU of Montpellier and healthy participants at baseline .