Cataract and IOL SurgeryAddOnNCT07452042
Postoperative Outcomes of a Toric AddOn Intraocular Lens After Keratoplasty and Cataract Surgery
An observational study of Cataract and IOL Surgery and Keratoplasty, run by Medical University of Vienna at 1 site in Austria.
Trial summary
The aim of this clinical study is to evaluate a toric add-on intraocular lens (IOL) for the correction of high astigmatism in patients who have undergone keratoplasty and cataract surgery. Read more about this study
- Who is it for?
- Ages 45 to 95 years
- Conditions the study is for
- Cataract and IOL Surgery, Keratoplasty, Toric Intraocular Lens Stability
- What is being tested?
- AddOn toric IOL implantation
- Type of treatment
- Surgery or procedure
- How many people
- 40 participants
- Where
- 1 siteAustria
- Study dates
- 27 Aug 2026to Feb 2029
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 95 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients scheduled for add-on toric intraocular lens (IOL) implantation due to high postoperative refractive cylinder after keratoplasty and cataract surgery at the University Department of Ophthalmology and Optometry are screened during the preoperative examination. Interested patients are informed about the study's objectives and procedures and, upon consent, are enrolled.
Who may be able to join
- Gender: female, male, or diverse
- Ophthalmological diagnosis: pseudophakic patients after keratoplasty
- Age: 45 to 95 years
- Complication-free cataract surgery using phacoemulsification and implantation of a posterior chamber lens.
- Complication-free keratoplasty and regular postoperative corneal astigmatism > 1 diopter (D)
- Pupil diameter in mydriasis > 5.5 mm
Who cannot join
- Uncontrolled glaucoma
- Proliferative diabetic retinopathy
- Iris neovascularization
- History of uveitis or iritis
- Microphthalmus
- Recurrent intraocular inflammation of unknown cause
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- Blindness in the other eye
- Uncontrolled systemic or ocular disease
- Pregnancy
- Breastfeeding
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Austria1 site, 1 recruiting
- Recruiting
Medical University of Vienna, Department of Ophthalmology and Optometry
Vienna, State of Vienna, 1090
Nikolaus Mahnert, M.D., 0043 140400 79450, nikolaus.mahnert@meduniwien.ac.at
About this study
Official title: Postoperative Outcomes of a Toric Add-On Intraocular Lens After Keratoplasty and Cataract Surgery
The aim of this clinical study is to evaluate a toric add-on intraocular lens (IOL) for the correction of high astigmatism in patients who have undergone keratoplasty and cataract surgery. As this patient group often suffers from significant preoperative residual astigmatism, there is a relevant clinical need for effective and safe refractive treatment options. The implantation of a toric add-on IOL in the ciliary sulcus is intended to significantly reduce postoperative astigmatism and improve visual rehabilitation.
The study is designed as a prospective, monocentric clinical trial with a limited number of cases, as this is a rare condition with limited availability of suitable patients. It is being conducted in accordance with Section 3 of the Austrian Medical Devices Act (MPG 2021) and is investigating a CE-marked add-on intraocular lens implant used within its intended purpose. The postoperative refractive cylinder serves as the primary endpoint, as it reflects the actual effectiveness of astigmatism correction. The rotational stability of the add-on IOL, which significantly influences refractive precision, is recorded as a secondary endpoint.
All study participants will be examined pre- and postoperatively in accordance with applicable medical standards. The results should contribute to the optimization of refractive care after keratoplasty and assess the clinical applicability of toric AddOn IOLs in this specific indication.
- Being tested
- AddOn toric IOL implantation
- Medical subject headings
- Cataract
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AddOn toric IOL implantationProcedure or surgery
Implantation of a toric AddOn IOL in the ciliary sulcus of patients after cataract surgery and keratoplasty with a high postoperative refractive cylinder.
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Postoperative Refractive Cylinder (Diopters)
The primary endpoint is the proportion of eyes achieving a ≥50% reduction in refractive cylinder postoperatively at the last visit (4 - 7 months). The postoperative refractive cylinder will be assessed by subjective refraction using a Snellen chart at 6 m.
A one-sided exact binomial test (α = 0.05) will be used to determine if this proportion is greater than 70%. The 90% two-sided Clopper-Pearson confidence interval will also be reported.
Measured: 4-7 months
Secondary outcomes (4)
Mean Absolute IOL Rotation from Intended Axis (Degrees)
The rotation of the IOLs over the first 4-7 postoperative months will be assessed with retroillumination photography (intraoperatively, 1 hour postoperatively, 1 week postoperatively, 1 month postoperatively, 6 months postoperatively). These images will be imported into the semi-automated evaluation software Rotix (labVIEW, National Instruments, Austin, Texas, USA). Two lines will be drawn to determine the IOL axis: one between two non-movable vessels serving as the reference axis, and a second one between the axis markings of the IOL. The Rotix software will then automatically calculate the axis difference between follow-up visits.
Measured: 4-7 months
Mean IOL Decentration (Millimeters)
Assessment of IOL decentration will be performed under mydriatic conditions using the AS-OCT Casia 2 (Tomey Corporation, Nagoya, Japan) preoperatively, as well as at 1 week, 1 month and 6 months postoperatively. Decentration will be calculated using the cataract module with semi-automatic correction.
IOL decentration will be defined as the horizontal and vertical distance from the center of the lens to the corneal vertex.
Measured: 4-7 months
Mean IOL Tilt (Degrees)
Assessment of tiltwill be performed under mydriatic conditions using the AS-OCT Casia 2 (Tomey Corporation, Nagoya, Japan) preoperatively, as well as at 1 week, 1 month and 6 months postoperatively. Tilt will be calculated using the cataract module with semi-automatic correction. IOL tilt will be defined as the horizontal and vertical angle of the lens relative to the corneal vertex.
Measured: 4-7 months
Mean Axial Position Change of IOL (Millimeters)
The aqueous depth (AQD) will be measured preoperatively and at 1 week and 6 months postoperatively using the AS-OCT Casia 2, all under maximum pupil dilation. Postoperative axial stability of the toric AddOn IOL will be calculated by subtracting the 1-week AQD from the 6-month AQD. Accordingly, a positive value will indicate a hyperopic shift and a negative value will indicate a myopic shift.
Measured: 4-7 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2026
- Study start27 Aug 2026
- Primary completionFeb 2029 (estimated)
- Study completionFeb 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cataract and IOL SurgeryStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Daniel Schartmüller, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07452042
- Sponsor's protocol ID
- 1710/2025
- Acronym
- AddOn
- Status last verified
- Feb 2026
- First submitted
- 23 Feb 2026
- Last updated
- 4 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No