Skip to main content
OpenTrials
Completed

NCT Number: NCT07623720

CorVision® 4-year Follow-up

The objective of the study is to assess the long-term safety and effectiveness of the CorVision® microlens implanted in presbyopic patients for the management of management of presbyopia and near vision impairment. Approximately 100 patients in the Czech Republic will participate in this study. The study was reviewed and approved by an independent research ethics committee and also by the State Institute for Drug Control (SÚKL). The study will consist of a single visit during which standard, non-invasive, and painless examinations will be performed. This visit will correspond to the 4-year follow-up visit of the original clinical trial.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Presbyopia Eye Diseases Refractive Errors

Sex eligibility

All sexes

Study type

Observational

Primary location

Gemini Eye Clinic

Zlín, 760 01, Czechia

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subjects must have undergone implantation of CorVision microlens under study protocol CMG-PRT-002.
  • Provide informed consent
  • Willing to participate in the ophthalmological examinations

Exclusion criteria

  • Patients with severe ocular or general disorders that would prevent them from completed the visit.
  • Patients not being able to understand and give informed consent.

Treatment and study plan

Primary outcomes

  1. Uncorrected Near Visual Acuity of 0.3 logMAR or better

    Time frame: At least 4 years after the implantation

    More than 65% of the eyes should have an Uncorrected Near Visual Acuity (UNVA) of 0.3 logMAR or better at 4 years postoperatively.

  2. Implant removal

    Time frame: At least 4 years after the implantation

    The incidence of implant rejection leading to implant removal should occur in no more than 3% of implanted eyes.

Secondary outcomes

  1. Clinically significant corneal haze occurrence

    Time frame: At least 4 years after the implantation

    Clinically significant corneal haze is defined as any new stromal clouding in or near the laser-created pocket that leads to a reduction in central corneal clarity/transparency, is visible upon slit-lamp examination, and is graded as ≥ 2 on a standardized corneal haze grading scale.

Other outcomes

  1. Monocular Uncorrected Near Visual Acuity at Best Reading Distance

    Time frame: At least 4 years after the implantation

    Change in monocular uncorrected near visual acuity and best reading distance over time

  2. Monocular and Binocular Uncorrected Near Visual Acuity at 40 cm

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Uncorrected Near Visual Acuity (UNVA) at 40 cm.

  3. Monocular and Binocular Distance Corrected Near Visual Acuity

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Distance Corrected Near Visual Acuity (DCNVA).

  4. Monocular and Binocular Corrected Near Visual Acuity

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Corrected Near Visual Acuity (CNVA) over time.

  5. Monocular and Binocular Uncorrected Intermediate Visual Acuity (UIVA)

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Uncorrected Intermediate Visual Acuity (UIVA) over time.

  6. Monocular and Binocular Distance Corrected Intermediate Visual Acuity

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Distance Corrected Intermediate Visual Acuity (DCIVA) over time.

  7. Monocular and Binocular Uncorrected Distance Visual Acuity (UDVA)

    Time frame: At least 4 years after the implantation

    Change in monocular Uncorrected Distance Visual Acuity (UDVA) over time.

  8. Monocular and Binocular Corrected Distance Visual Acuity (CDVA)

    Time frame: At least 4 years after the implantation

    Change in monocular and binocular Corrected Distance Visual Acuity (CDVA) over time.

  9. Objective refraction

    Time frame: At least 4 years after the implantation

    Change in objective refractive sphere and cylinder magnitude measured by autorefractometry.

  10. Subjective refraction

    Time frame: At least 4 years after the implantation

    Change in manifest refractive sphere and cylinder magnitude, measured in diopters (D).

  11. Near addition

    Time frame: At least 4 years after the implantation

    Change in near addition values over time.

  12. Corneal Keratometry Measurements (K1, K2, and Kmean)

    Time frame: At least 4 years after the implantation

    Change in corneal keratometry values, including K1, K2, and mean keratometry (Kmean), as measured by corneal topography over time.

    Change in keratometry K1, K2 and Kmean measured in diopters over time.

  13. Central Corneal Thickness (Pachymetry) Measurement

    Time frame: At least 4 years after the implantation

    Change in central corneal thickness as measured by corneal pachymetry over time.

  14. Endothelial Cell Density (Study Eye)

    Time frame: At least 4 years after the implantation

    Change in endothelial cell density over time.

  15. Intraocular Pressure (Study Eye)

    Time frame: At least 4 years after the implantation

    Change in intraocular pressure over time.

  16. Tear Film Break-Up Time (TBUT) Test

    Time frame: At least 4 years after the implantation

    Change in tear film stability as measured by Tear Film Break-Up Time (TBUT) in units of seconds.

  17. Tear Production (Schirmer Test)

    Time frame: At least 4 years after the implantation

    Change in tear production as measured by the Schirmer test in units of mm.

  18. Corneal Thickness Measurement Using Optical Coherence Tomography (OCT)

    Time frame: At least 4 years after the implantation

    Change in corneal thickness measured at the corneal center in μm.

  19. Abnormal findings at OCT

    Time frame: At least 4 years after the implantation

    Incidence of abnormal findings on OCT.

  20. Slit-lamp findings

    Time frame: At least 4 years after the implantation

    Incidence of abnormal slit lamp findings (eyelid, conjunctiva, epithelium, stroma, central cornea clarity, cornea neovascularization, anterior chamber, iris, lens).

  21. Contrast sensitivity

    Time frame: At least 4 years after the implantation

    Determination of contrast sensitivity measured by CSV 1000 (Vector Vision) (changes from the pre-operative to the post-operative state and its stability over time will be investigated).

  22. Defocus curve

    Time frame: At least 4 years after the implantation

    Change in visual acuity measured at different defocus vergence levels during monocular defocus curve testing over time.

  23. Aberrometry measurements using iTrace

    Time frame: At least 4 years after the implantation

    Change in the total higher order aberrations (HOA) assessed by iTrace.

  24. Subjective questionnaire QoV - patient satisfaction

    Time frame: At least 4 years after the implantation

    Evaluation of patient satisfaction assessed on a scale

  25. Subjective questionnaire QoV

    Time frame: At least 4 years after the implantation

    Evaluation of patient satisfaction as assessed using the Quality of Vision (QoV) questionnaire scoring scale.

  26. Adverse events incidence

    Time frame: At least 4 years after the implantation

    Intraoperative and adverse events at each time point (numbers and percentages)

Sponsors and collaborators

Lead sponsor

Gemini Eye Clinic

Industry

Registry information

Official study title

Four Years Extended Follow-Up on CorVision® Bioengineered Corneal Microlens: Safety and Efficacy

Acronym: CorVision4yFU

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jun 3, 2026
Registry last updated
Jun 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.