An observational study in Cataract, sponsored by Johannes Kepler University of Linz. Not yet recruiting at 1 site in Austria. Open to participants aged 21 Years and older. Per ClinicalTrials.gov, last updated 2025-10-02.
Sponsored by Johannes Kepler University of Linz · Observational
The aim of this study is to investigate the lens diameter (LD) as a useful parameter in intraocular lens (IOL) power calculation by using several different non-invasive imaging techniques. The aim is to establish an accurate model for lens diameter estimation and subsequently evaluate the influence of the LD on the effective postoperative lens position. The comparability of the different devices in terms of variability between the biometric measurements will also be assessed.
By then combining these two approaches with artificial intelligence, the aim is to develop a new approach to effectively incorporate the LD in IOL power calculation and improve patient's outcome in the long run.
During uncomplicated cataract operation, the clouded natural lens is being removed and replaced with an artificial intraocular lens (IOL). To achieve optimal postoperative outcomes for patients, the power of the implanted artificial lens is calculated prior to surgery.
Significant progress has been made in calculation concepts over the past 20 years, including the introduction of regression, vergence and ray tracing. More recently, approaches incorporating artificial intelligence have emerged.
All these formulae are based on the biometric data of the eye. This includes parameters such as axial eye length, corneal curvature, central corneal thickness, anterior chamber depth and the refractive indices of the eye's optical segments. By including all these variables, modern formulas aim to deliver the best possible postoperative outcomes.
One variable that has not been included in the calculation thus far is the diameter of the natural lens. Large parts of the lens are covered by the iris. Even with medically dilated pupils the peripheral parts cannot be visualized, and subsequently not adequately reproduced using established imaging methods. This has made implementation in IOL power calculation difficult.
In everyday clinical practice, however, anterior segment OCT imaging devices are equipped with features that allow for an estimation of lens diameter. This is achieved by extrapolating the anterior and posterior curvature of the natural lens, which unfortunately makes this approach prone to error. Other imaging techniques, such as magnetic resonance imaging, are impractical in routine clinical practice due to time and cost considerations. However, they could be highly beneficial for future predictive approaches of the lens diameter The aim of this study is to develop a model for incorporating the lens diameter into IOL calculation. This will be achieved by using different imaging technologies to determine the actual lens diameter. The diameter will then be predicted using available biometric variables.
1,629 studies on the registry are indexed under Cataract; 235 are open to participants now.
This study's planned enrollment of 170 is above the median of 89 across 475 observational studies indexed under Cataract.
Browse Cataract studies →Johannes Kepler University of Linz is the lead sponsor of 33 studies on the registry; 12 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The participants will be selected at Kepler University Clinic Linz at the Departement of Ophthalmology and Optometry.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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 who are included in this study who additionally receive a cerebral MRI
Device: Swept-Source Anterior Segment OCT
Study cohort who doesn't receive an MRI
Device: Swept-Source Anterior Segment OCT
Device: Swept-Source Anterior Segment OCT The CASIA-2 (Tomey, Japan) is a high-resolution swept-source anterior segment OCT with CE certification. The device allows for incomplete visualization of the lens, including the anterior and posterior lens curvature. Device: AS-OCT + Placido disc corneal topography The MS-39 (CSO, Italy) is a non-invasive device that combines Placido topography with OCT-based anterior segment tomography. Device: Wave-front abberomtery The OSIRIS aberrometer is a standard tool for examining corneal aberration and measuring the ocular wavefront. Device: Swept-Source OCT The IOLMaster 700 (Carl Zeiss Meditec, Germany) is a standard swept-source OCT used for eye examinations. Device: AS-OCT The ANTERION (Heidelberg Engineering, Germany) is an anterior segment swept-source OCT. Diagnostic Test: Refraction Subjective Refraction evaluation using the cross-cylinder method
Prediction model to estimate lens diameter with different measurement tools (swept-AS segment OCT; anterior segment-OCT and Placido topography with OCT-based anterior segment tomography; wave-front abberometry; swept-source OCT and optical biometer)
Developing a prediction model to accurately estimate the lens diameter using biometric parameters (swept-source anterior segment Optical Coherence Topography (Casia-2), Placido topography combined with Optical Coherenece Topography-based anterior segment tomography (MS-39), wave-front abberometry (OSIRIS), Swept-Source Optical Coherence Tomography (IOLMaster 700) and anterior segment swept-source OCT (Anterion).
Time frame: preoperatively, 4 and 12 weeks post cataract surgery
Prediction model to estimate lens diameter with cerebral Magnetic Resonance Imaging
Developing a prediction model to accurately estimate the lens diameter using cerebral Magnetic Resonance Imaging to examine ocular configuration
Time frame: 12 weeks post cataract surgery
IOL calculation concept an artificial intelligence approach
Development of a new IOL calculation concept which includes the lens diameter using an artificial intelligence approach
Time frame: preoperatively, 4 and 12 weeks post cataract surgery
Different measurement modalities for the biometry of the eye
Comparison of different measurement modalities (swept-source anterior segment Optical Coherence Topography; anterior segment-Optical Coherence Tomography and Placido topography with Optical Coherenece Topography-based anterior segment tomography; wave-front abberometry; swept-source Optical Coherence Tomography and optical biometer) for the biometry of the eye
Time frame: 4 and 12 weeks post cataract surgery
Plan to share: Undecided
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This study is not yet recruiting, as verified in Oct 2025. You cannot join it, but the record below documents what was studied.
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Johannes Kepler University of Linz