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Study on the Safety and Effectiveness of Ripasudil Eye Drops for Patients with Fuchs Dystrophy After Cataract Surgery

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying Fuchs Endothelial Corneal Dystrophy, a condition affecting the cornea, which is the clear front part of the eye. The study is investigating the safety and effectiveness of a treatment called Ripasudil, also known by its code name K-321. Ripasudil is administered as eye drops and is being tested to see if it can help improve vision after patients undergo cataract surgery and a procedure called descemetorhexis, which involves removing a layer of cells from the cornea.

The purpose of the study is to determine how well Ripasudil works in improving vision in patients with Fuchs Dystrophy after their surgery. Participants in the study will be randomly assigned to receive either the Ripasudil eye drops or a placebo, which looks like the real medication but does not contain the active ingredient. The study will last for a total of 12 weeks, during which time the participants will gradually reduce their dosage over a two-week period. After this, there will be a follow-up phase lasting 38 weeks to monitor the participants' progress.

Throughout the study, the main focus will be on how quickly participants' vision improves, measured by their ability to read letters on an eye chart. The study will also look at other factors, such as changes in the health of the cornea. This research aims to provide valuable information on whether Ripasudil can be a beneficial treatment option for those with Fuchs Dystrophy undergoing cataract surgery and descemetorhexis.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be required to provide written informed consent. This means you agree to participate and understand the study requirements.

  2. Step 2

    Initial assessment

    You will undergo an initial assessment to confirm your eligibility. This includes checking your age, diagnosis of Fuchs Endothelial Corneal Dystrophy, and the condition of your eye.

  3. Step 3

    Surgery and treatment

    You will have cataract surgery and a procedure called descemetorhexis on your study eye. This involves removing a small area of the cornea.

    After surgery, you will start using Ripasudil eye drops or a placebo. The eye drops are administered as one drop in the study eye, twice a day, for 12 weeks.

  4. Step 4

    Dose taper phase

    Following the initial 12 weeks, there will be a two-week period where the dosage of the eye drops is gradually reduced.

  5. Step 5

    Follow-up phase

    You will enter a follow-up phase lasting 38 weeks. During this time, your eye health and vision will be monitored regularly to assess the effects of the treatment.

Who can join the trial?

11 criteria

  • Is at least 18 years old at the first visit.
  • Has a diagnosis of Fuchs Endothelial Corneal Dystrophy (FECD) at the first visit.
  • Has a specific eye condition called confluent central guttae in the study eye that can be treated by a procedure called descemetorhexis in an area of 5.5 mm diameter or less at the first visit.
  • Has a study eye with a Best Corrected Visual Acuity (BCVA) of 75 letters or fewer, which is similar to a vision of 20/32 or worse, at the first visit.
  • Has a cataract in the study eye that affects vision at the first visit.
  • Can understand and sign a written consent form and agrees to follow the study requirements before any study-specific tests are done.
  • At the second visit, the study eye must have had a descemetorhexis procedure that removed a central area with confluent guttae and a diameter between 4.5 to 5.5 mm.
  • Has completed cataract surgery with the following conditions:
    • The new lens is placed correctly in the eye without complications like a broken capsule or the need for additional surgery.
    • No significant detachment or removal of the Descemet membrane outside the central area, except for a small area near the surgical wound that is 0.5 mm or less.
    • The surgeon confirms through a microscope that the new lens is in the correct position in the eye.
    • No adverse events were noted by the surgeon during the surgery.

Who cannot join the trial?

7 criteria

  • Patients who have any other eye disease that could affect the study results.
  • Patients who have had previous eye surgery that might interfere with the study.
  • Patients who are currently using medications that could affect the eyes or the study outcomes.
  • Patients with a history of severe allergic reactions to medications.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial within the last 30 days.
  • Patients with any medical condition that the study doctors believe could make participation unsafe.
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Investigated drugs

Ripasudil (K-321) is an eye drop medication being tested in this clinical trial. It is designed to help improve vision in people who have undergone cataract surgery and a procedure called descemetorhexis, specifically for those with a condition known as Fuchs Endothelial Corneal Dystrophy (FECD). The main goal of using Ripasudil is to see if it can help improve vision clarity, measured by a specific eye test, within the first 12 weeks after surgery. This medication works by potentially aiding the healing process of the cornea, which is the clear front part of the eye, and improving overall eye health after the surgical procedures.

What is already known about the treatment

Ripasudil (K-321) – Ripasudil is administered in the form of eye drops, applied directly to the eyes. It is currently being studied in a Phase 3 clinical trial to assess its safety and effectiveness for patients with Fuchs Endothelial Corneal Dystrophy, particularly after cataract surgery and a procedure called descemetorhexis. The main therapeutic use of Ripasudil in this context is to improve vision by increasing the number of letters a person can read on an eye chart. At the molecular level, Ripasudil works by inhibiting a specific enzyme, which helps to reduce pressure in the eye and improve fluid drainage. It is classified pharmacologically as a Rho kinase inhibitor.

Investigated diseases

Fuchs Endothelial Corneal Dystrophy – This is a progressive eye disease that affects the cornea, the clear front surface of the eye. It is characterized by the gradual deterioration of the endothelial cells, which are responsible for maintaining the cornea's clarity by pumping out excess fluid. As these cells deteriorate, fluid builds up in the cornea, leading to swelling and clouding of vision. In the early stages, individuals may experience blurred vision, especially in the morning, which improves throughout the day. As the disease progresses, vision may become consistently blurry, and sensitivity to light can increase. In advanced stages, painful blisters may form on the surface of the cornea.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-502643-35-00Protocol codeK-321-303Estimated enrolment105 patientsSponsorKowa Research Institute Inc.

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