An observational study in Fuchs Endothelial Corneal Dystrophy, sponsored by Instituto Ramón y Cajal de Investigación Sanitaria. Recruiting at 1 site in Spain. Open to participants aged 40 Years and older. Per ClinicalTrials.gov, last updated 2025-12-04.
Sponsored by Instituto Ramón y Cajal de Investigación Sanitaria · Observational
This prospective multicenter diagnostic study aims to externally validate and extend the SUCCESS Score for predicting the need for endothelial keratoplasty after cataract surgery in patients with Fuchs endothelial corneal dystrophy (FECD). The model's performance and clinical utility are assessed using discrimination, calibration, and reclassification metrics.
Fuchs endothelial corneal dystrophy (FECD) is a progressive corneal disorder characterized by endothelial cell loss, corneal edema, and visual impairment. In patients with FECD and cataract, an important clinical challenge is to predict whether cataract surgery alone will suffice or whether endothelial keratoplasty (EK) will be required postoperatively. Accurate preoperative risk stratification is essential for surgical planning and patient counseling.
The SUCCESS Score, derived from Scheimpflug tomography, was proposed as an objective index to estimate the risk of postoperative corneal decompensation in FECD. However, its external multicenter validation and the potential contribution of corneal densitometry have not yet been fully established.
This ongoing prospective, observational, multicenter study aims to externally validate and extend the SUCCESS Score for predicting the need for EK after cataract surgery in patients with FECD. The study is being conducted across five tertiary referral centers in Spain. Eligible participants are adults with FECD grade ≥2 on the modified Krachmer scale and a visually significant cataract requiring phacoemulsification. Patients with epithelial edema, prior ocular surgery, corneal infection, or trauma are excluded.
Preoperative evaluation includes Scheimpflug tomography and corneal densitometry analysis. The primary outcome is the requirement for endothelial keratoplasty after cataract surgery, determined by postoperative visual function and corneal evaluation. Model performance will be assessed through discrimination (Harrell's C statistic), calibration, reclassification (IDI, NRI), and decision curve analysis to estimate clinical utility.
The primary analysis is scheduled for completion in October 2024. Extended follow-up will continue until June 25, 2026, to assess long-term predictive performance and generalizability of the extended SUCCESS model.
An interactive web-based calculator implementing both the original and extended SUCCESS models will be provided as a supplementary tool to facilitate clinical use and standardized patient counseling across participating centers.
92 studies on the registry are indexed under Fuchs' Endothelial Dystrophy; 27 are open to participants now.
This study's planned enrollment of 250 is above the median of 144 across 26 observational studies indexed under Fuchs' Endothelial Dystrophy.
Browse Fuchs' Endothelial Dystrophy studies →This is the only study on the registry with Instituto Ramón y Cajal de Investigación Sanitaria as lead sponsor.
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dults with clinically diagnosed Fuchs endothelial corneal dystrophy (FECD) and visually significant cataract who are scheduled to undergo phacoemulsification surgery at participating tertiary referral centers in Spain. Eligible participants present FECD grade ≥2 on the modified Krachmer scale and have available preoperative Scheimpflug tomography and corneal densitometry measurements. The study population represents a real-world clinical cohort of patients routinely evaluated in corneal and cataract units, allowing assessment of the predictive performance and clinical utility of the SUCCESS Score under standard care conditions.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with clinically diagnosed Fuchs endothelial corneal dystrophy (FECD) undergoing phacoemulsification cataract surgery at participating tertiary centers. All participants receive standard cataract surgery, and their preoperative data are used to calculate the SUCCESS Score with and without corneal densitometry parameters. Postoperative outcomes are monitored to determine the need for endothelial keratoplasty (EK).
Procedure: Phacoemulsification Cataract Surgery
Standard phacoemulsification cataract surgery performed in patients with Fuchs endothelial corneal dystrophy (FECD). All procedures are carried out according to institutional protocols at participating tertiary centers. Preoperative Scheimpflug tomography and corneal densitometry measurements are collected to calculate the SUCCESS Score and evaluate the risk of postoperative endothelial decompensation. Postoperative outcomes are monitored to determine whether endothelial keratoplasty (EK) is required during follow-up.
Need for endothelial keratoplasty (EK) after cataract surgery in patients with Fuchs endothelial corneal dystrophy
The primary outcome is the need for endothelial keratoplasty (EK) following phacoemulsification cataract surgery in patients with Fuchs endothelial corneal dystrophy (FECD). The endpoint is determined based on postoperative best-corrected visual acuity, corneal clarity, and presence of clinical signs of corneal decompensation. Each eye is evaluated using standardized follow-up visits and imaging criteria across participating centers. The decision to perform EK is made according to established clinical indications by the attending ophthalmologist, ensuring consistency across study sites.
Time frame: Up to 36 months after cataract surgery
Model discrimination (Harrell's C statistic) of the SUCCESS Score
Model discrimination will be assessed using Harrell's C statistic (concordance index) to quantify how accurately the SUCCESS Score predicts the need for endothelial keratoplasty after cataract surgery in patients with FECD.
Time frame: At primary analysis (October 2024)
Calibration and predictive accuracy of the SUCCESS Score
Calibration plots and Brier score will be used to evaluate the agreement between predicted and observed probabilities of endothelial keratoplasty. Goodness-of-fit will be assessed across deciles of predicted risk.
Time frame: At primary analysis (June 2026)
Reclassification and clinical utility of the extended SUCCESS model
The incremental value of adding corneal densitometry to the SUCCESS Score will be assessed using Integrated Discrimination Improvement (IDI), Net Reclassification Improvement (NRI), and Decision Curve Analysis (DCA) to determine potential clinical benefit.
Time frame: At primary analysis (June 2026)
Plan to share: Yes — Deidentified individual participant data (IPD) that underlie the results reported in this article will be made available to qualified researchers upon reasonable request. Access will be granted after publication of the primary results and upon approval of a methodologically sound proposal. Data will be shared through a secure institutional platform of the Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS).
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Beginning 12 months after publication and ending 36 months after publication.
Access criteria: Qualified researchers affiliated with academic or non-profit institutions may request access to the deidentified individual participant data (IPD), study protocol, statistical analysis plan, and analytic code. Requests must include a methodologically sound proposal describing the intended analyses and objectives. Data and supporting materials will be shared through a secure institutional data repository managed by the Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS). Access will be granted upon approval by the study's data governance committee and completion of a data use agreement ensuring appropriate data handling and confidentiality.
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