KeratoconusNCT06243991
The Effect Of High And Low Molecular Weight Sodium Hyaluronic Acid Eye Drops After Crosslinking
An observational study of Keratoconus, run by Marmara University at 1 site in Turkey (Türkiye).
Trial summary
Purpose: The objective of this investigation was to assess the impact of eye drops containing high molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) on corneal nerve regeneration, dendritic cell (DC) density, corneal sensitivity (CS), and ocular surface parameters in patients… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Keratoconus
- What is being tested?
- in vivo Corneal Confocal Microscopy, Corneal Sensitivity and Non invasive tear break up time
- Type of treatment
- Medical device
- How many people
- 63 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Mar 2021to 1 Feb 2023
- How long will I take part?
- 12 Months
- Phase
- Observational
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Fifty-five patients with keratoconus were included in the study. All participants underwent accelerated epithelium-off CXL (A-CXL) for 10 minutes with 9 mW/cm² ultraviolet-A irradiation. A total of 63 eyes from 55 keratoconus patients were assigned into three groups: 17 patiens (20 eyes) in the HMW-HA group, 22 patient (23 eyes) in the LMW-HA group, and 20 patient (20 eyes) in the control group.
Who may be able to join
- Keratoconus patiens aged 18 and above who had been scheduled for corneal crosslinking
Who cannot join
- Dry eye disease, corneal thickness below 400 micrometer, pregnancy, breastfeeding, topical or systemic drug use, eye disease other than keratoconus, systemic diseases, active atopy or allergy, contact lens use, ocular surgery history.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effect Of High And Low Molecular Weight Sodium Hyaluronic Acid Eye Drops On Corneal Recovery After Crosslinking
Purpose: The objective of this investigation was to assess the impact of eye drops containing high molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) on corneal nerve regeneration, dendritic cell (DC) density, corneal sensitivity (CS), and ocular surface parameters in patients with keratoconus following corneal crosslinking (CXL).
Methods: Sixty-three eyes of 55 keratoconus patients were randomized to instill eye drops containing HMW-HA (n: 20) for 12 months, LMW-HA (n:23) for 12 months and polyvinyl alcohol (n: 20) until the epithelial defect closure in the control group after CXL. Subbasal nerve plexsus (SNP) was imaged with corneal confocal microscopy (CCM) and ACCMetrics program was used to quantify corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal nerve fiber branching density (CNBD) and corneal nerve fiber total branching density (CTBD). DC density was calculated with Image J software. CS was measured using the Cochet-Bonnet esthesiometer. Ocular Surface Disease Index (OSDI) questionnaire, non-invasive break-up time (NI-TBUT) were evaluated. All measurements were performed before CXL and postoperatively after 1, 3, 6 and 12 months.
Read the detailed description
This study assessed individuals aged 18 and above diagnosed with keratoconus and scheduled for epithelium-off CXL. A total of 63 eyes from 55 keratoconus patients were randomly assigned using computer-generated randomization (www.random.org/integers) into three groups: 20 eyes in the HMW-HA group, 23 eyes in the LMW-HA group, and 20 eyes in the control group without the administration of artificial tears.
Post-CXL, the HMW-HA group received topical HMW-HA (Comfort Shield®, i.com medical GmbH, Munich, Germany) three times daily for 12 months, the LMW-HA group received topical LMW-HA (Thealose Duo®, Thea, Clermont-Ferrand, France) three times daily for 12 months, and the control group received topical polyvinyl alcohol (Refresh, Allergan, Dublin, Ireland) three times daily until epithelial defect closure. All participants underwent accelerated epithelium-off CXL (A-CXL) for 10 minutes with 9 mW/cm² ultraviolet-A irradiation. The postoperative standard treatment regimen included topical moxifloxacin (0.5% Vigamox, Alcon Inc, USA) for one week, topical dexamethasone (0.1% Dexasine-SE, Kaysersberg Pharmaceuticals, France) for one week after epithelial closure, followed by topical loteprednol 0.5% (Lotemax, Bausch \& Lomb, USA) for three weeks.
Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and manifest spherical equivalent (SE) were recorded at all visits. The assessment was carried out in the following order: Ocular Surface Disease Index (OSDI) questionnaire, noninvasive tear break-up time (NIBUT), corneal tomography (Pentacam, OCULUS, Wetzlar, Germany), corneal sensitivity, corneal fluorescein staining, and CCM imaging. Examinations were conducted preoperatively and at the postoperative 1th, 3rd, 6th and 12th months.
- Conditions
- Keratoconus
- Being tested
- in vivo Corneal Confocal Microscopy, Corneal Sensitivity, Non invasive tear break up time, Ocular Surface Disease Index Qestionnaire, Corneal tomography
- Keywords
- Corneal crosslinking, corneal nerve regeneration, in-vivo corneal confocal microscopy, sodium hyaluronic acid,, high molecular weight hyaluronic acid
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
in vivo Corneal Confocal MicroscopyDevice
CCM was performed using the Heidelberg Retinal Tomograph 3 with the Rostock Cornea Module (HRT3-RCM, Heidelberg Engineering GmbH, Germany) under topical anesthesia. A viscous gel (Viscotears, Novartis Pharmaceuticals UK) served as a coupling agent between the cornea and the applanation cap. The subjects were instructed to focus on the fixation light with the unexamined eye to ensure proper positioning. Five high-quality images of the SNP were selected and analyzed using the automated tracing of nerve fibers program (ACCMetrics, M.A. Dabbah, Imaging Science and Biomedical Engineering, Manchester, England).
Corneal SensitivityDiagnostic test
Corneal sensitivity was evaluated using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartres, France), comprising a nylon filament measuring 60 mm in length and 0.12 mm in diameter. Participants were instructed to maintain a forward gaze while the esthesiometer gently made perpendicular contact. The procedure involved gradually decreasing the filament length in 5 mm increments, starting from 60 mm, until the initial response from the subject was detected.
Non invasive tear break up timeDevice
Noninvasive tear break-up time (NI-TBUT) was assessed using a Sirius Scheimpflug camera (CSO, Florence, Italy) and the device automatically provided the average NI-TBUT value
Ocular Surface Disease Index QestionnaireDiagnostic test
The Ocular surface disease index (OSDI) questionnaire consists of a total of 12 questions categorized into three subscales as follows: ocular symptoms, vision-related function, and environmental triggers. Each patient is asked to rate the symptoms on a 5-point scale ranging from never (0 score) to always (4 score) for every question in the questionnaire. The fourth and fifth questions in the first section, concerning blurred vision and reduced vision symptoms, were excluded from the questionnaire as these symptoms may already be present in patients with keratoconus disease. The total OSDI score was calculated according to the formula: OSDI = [(sum of scores for all questions answered) × 100] / [(total number of questions answered) × 4].
Corneal tomographyDevice
Scheimpflug-tomography device (Pentacam, OCULUS, Wetzlar, Germany) was used for measurement of keratometric values.
| Study group | Role | What they receive |
|---|---|---|
| Control group | Nineteen patiens (20 eyes) received topical polyvinyl alcohol (Refresh, Allergan, Dublin, Ireland) three times daily until epithelial defect closure after CXL in control group. Receives: Device: in vivo Corneal Confocal Microscopy; Diagnostic Test: Corneal Sensitivity; Device: Non invasive tear break up time; Diagnostic Test: Ocular Surface Disease Index Qestionnaire; Device: Corneal tomography | |
| LMW-HA group | Twenty-two patiens (23 eyes) received topical LMW-HA (Thealose Duo®, Thea, Clermont-Ferrand, France) three times daily for 12 months. Receives: Device: in vivo Corneal Confocal Microscopy; Diagnostic Test: Corneal Sensitivity; Device: Non invasive tear break up time; Diagnostic Test: Ocular Surface Disease Index Qestionnaire; Device: Corneal tomography | |
| HMW-HA group | Seventeen patiens (20 eyes) received topical HMW-HA (Comfort Shield®, i.com medical GmbH, Munich, Germany) three times daily for 12 months. Receives: Device: in vivo Corneal Confocal Microscopy; Diagnostic Test: Corneal Sensitivity; Device: Non invasive tear break up time; Diagnostic Test: Ocular Surface Disease Index Qestionnaire; Device: Corneal tomography |
What is being measured
The primary outcome is the main question the study is designed to answer.
Corneal nerve fiber density (CNFD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFD.
Measured: Baseline
Corneal nerve fiber density (CNFD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFD.
Measured: Postoperative 1st, 3rd, 6th and 12th months
Corneal nerve branch density (CNBD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNBD.
Measured: Baseline
Corneal nerve branch density (CNBD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNBD.
Measured: Postoperative 1st, 3rd, 6th and 12th months
Corneal nerve fiber length (CNFL)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFL
Measured: Baseline
Corneal nerve fiber length (CNFL)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFL
Measured: Postoperative 1st, 3rd, 6th and 12th months
Corneal nerve fiber total branching density (CTBD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CTBD.
Measured: Baseline
Corneal nerve fiber total branching density (CTBD)
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CTBD.
Measured: Postoperative 1st, 3rd, 6th and 12th months
Corneal Sensitivity
Corneal sensitivity was assessed using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartes, France).
Measured: Baseline
Corneal Sensitivity
Corneal sensitivity was assessed using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartes, France).
Measured: Postoperative 1st, 3rd, 6th and 12th months
Dendritic cell density
The Density of dendritic cells was calculated using ImageJ software (Image V.1.31; National Institutes of Health)
Measured: Baseline
Dendritic cell density
The Density of dendritic cells was calculated using ImageJ software (Image V.1.31; National Institutes of Health)
Measured: Postoperative 1st, 3rd, 6th and 12th months
Ocular surface disease Index (OSDI) questionnaire
The Turkish validated version of the OSDI, a questionnaire assesing the clinical symptoms of the ocular surface disease, was used. The 4th and 5th questions in the first section, which inquire about blurred vision and reduced vision symptoms, were excluded from the questionnaire as they could already be present in patients with keratoconus disease.
Measured: Baseline
Ocular surface disease Index (OSDI) questionnaire
The Turkish validated version of the OSDI, a questionnaire assesing the clinical symptoms of the ocular surface disease, was used. The 4th and 5th questions in the first section, which inquire about blurred vision and reduced vision symptoms, were excluded from the questionnaire as they could already be present in patients with keratoconus disease.
Measured: Postoperative 1st, 3rd, 6th and 12th months
Non invaziv tear break-up time (NI-TBUT)
The tear break-up time (TBUT) was evaluated non-invasively using a Sirius Scheimpflug camera (CSO, Florence, Italy).
Measured: Baseline
Non invaziv tear break-up time (NI-TBUT)
The tear break-up time (TBUT) was evaluated non-invasively using a Sirius Scheimpflug camera (CSO, Florence, Italy).
Measured: Postoperative 1st, 3rd, 6th and 12th months
Secondary outcomes (4)
Visual Functions
Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) by the Snellen chart, based on the logMAR scoring system and manifest spherical equivalent (SE) were assessed.
Measured: Baseline
Refractive Outcomes
Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) by the Snellen chart, based on the logMAR scoring system and manifest spherical equivalent (SE) were assessed.
Measured: Postoperative 1st, 3rd and 6th months
Keratometric Findings
Corneal tomography (Pentacam, OCULUS, Wetzlar Germany) was used to obtain the data for K1, K2, Kmean, Kmax, and the Thinnest point (TP).
Measured: Baseline
Keratometric Findings
Corneal tomography (Pentacam, OCULUS, Wetzlar Germany) was used to obtain the data for K1, K2, Kmean, Kmax, and the Thinnest point (TP).
Measured: Postoperative 1st, 3rd and 6th months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2024
- Study start1 Mar 2021
- Primary completion1 Dec 2022
- Study completion1 Feb 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- More trials run by Marmara UniversityThe 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 63 participants (actual)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- Marmara University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Semra Akkaya Turhan, Assoc. prof., Study chair, Marmara University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06243991
- Sponsor's protocol ID
- 09.2021.86
- Status last verified
- Jan 2024
- First submitted
- 29 Jan 2024
- Last updated
- 6 Feb 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Ozkan G, Turhan SA, Toker E. Effect of high and low molecular weight sodium hyaluronic acid eye drops on corneal recovery after crosslinking in keratoconus patients. BMJ Open Ophthalmol. 2025 Mar 29;10(1):e001890. doi: 10.1136/bmjophth-2024-001890.
PubMed 40157723
Study at a glance
From the registry record, last updated by the sponsor on 6 Feb 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect Of High And Low Molecular Weight Sodium Hyaluronic Acid Eye Drops On Corneal Recovery After Crosslinking
- ClinicalTrials.gov ID
- NCT06243991
- Acronym / sponsor ID
- 09.2021.86
- Conditions
- Keratoconus
- Keywords
- Corneal crosslinking, corneal nerve regeneration, in-vivo corneal confocal microscopy, sodium hyaluronic acid,, high molecular weight hyaluronic acid
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 63 participants (actual)
- Lead sponsor
- Marmara UniversityUniversity, hospital or other
- Study start
- 1 Mar 2021 (actual)
- Primary completion
- 1 Dec 2022 (actual)
- Study completion
- 1 Feb 2023 (actual)
- First posted
- 6 Feb 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Purpose: The objective of this investigation was to assess the impact of eye drops containing high molecular weight hyaluronic acid (HMW-HA) and low molecular weight hyaluronic acid (LMW-HA) on corneal nerve regeneration, dendritic cell (DC) density, corneal sensitivity (CS), and ocular surface parameters in patients with keratoconus following corneal crosslinking (CXL).
Methods: Sixty-three eyes of 55 keratoconus patients were randomized to instill eye drops containing HMW-HA (n: 20) for 12 months, LMW-HA (n:23) for 12 months and polyvinyl alcohol (n: 20) until the epithelial defect closure in the control group after CXL. Subbasal nerve plexsus (SNP) was imaged with corneal confocal microscopy (CCM) and ACCMetrics program was used to quantify corneal nerve fiber density (CNFD), corneal nerve fiber length (CNFL), corneal nerve fiber branching density (CNBD) and corneal nerve fiber total branching density (CTBD). DC density was calculated with Image J software. CS was measured using the Cochet-Bonnet esthesiometer. Ocular Surface Disease Index (OSDI) questionnaire, non-invasive break-up time (NI-TBUT) were evaluated. All measurements were performed before CXL and postoperatively after 1, 3, 6 and 12 months.
Detailed description
This study assessed individuals aged 18 and above diagnosed with keratoconus and scheduled for epithelium-off CXL. A total of 63 eyes from 55 keratoconus patients were randomly assigned using computer-generated randomization (www.random.org/integers) into three groups: 20 eyes in the HMW-HA group, 23 eyes in the LMW-HA group, and 20 eyes in the control group without the administration of artificial tears.
Post-CXL, the HMW-HA group received topical HMW-HA (Comfort Shield®, i.com medical GmbH, Munich, Germany) three times daily for 12 months, the LMW-HA group received topical LMW-HA (Thealose Duo®, Thea, Clermont-Ferrand, France) three times daily for 12 months, and the control group received topical polyvinyl alcohol (Refresh, Allergan, Dublin, Ireland) three times daily until epithelial defect closure. All participants underwent accelerated epithelium-off CXL (A-CXL) for 10 minutes with 9 mW/cm² ultraviolet-A irradiation. The postoperative standard treatment regimen included topical moxifloxacin (0.5% Vigamox, Alcon Inc, USA) for one week, topical dexamethasone (0.1% Dexasine-SE, Kaysersberg Pharmaceuticals, France) for one week after epithelial closure, followed by topical loteprednol 0.5% (Lotemax, Bausch \& Lomb, USA) for three weeks.
Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and manifest spherical equivalent (SE) were recorded at all visits. The assessment was carried out in the following order: Ocular Surface Disease Index (OSDI) questionnaire, noninvasive tear break-up time (NIBUT), corneal tomography (Pentacam, OCULUS, Wetzlar, Germany), corneal sensitivity, corneal fluorescein staining, and CCM imaging. Examinations were conducted preoperatively and at the postoperative 1th, 3rd, 6th and 12th months.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 12 Months
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Control group | – | Device: in vivo Corneal Confocal Microscopy, Diagnostic Test: Corneal Sensitivity, Device: Non invasive tear break up time, Diagnostic Test: Ocular Surface Disease Index Qestionnaire, Device: Corneal tomographyNineteen patiens (20 eyes) received topical polyvinyl alcohol (Refresh, Allergan, Dublin, Ireland) three times daily until epithelial defect closure after CXL in control group. |
| LMW-HA group | – | Device: in vivo Corneal Confocal Microscopy, Diagnostic Test: Corneal Sensitivity, Device: Non invasive tear break up time, Diagnostic Test: Ocular Surface Disease Index Qestionnaire, Device: Corneal tomographyTwenty-two patiens (23 eyes) received topical LMW-HA (Thealose Duo®, Thea, Clermont-Ferrand, France) three times daily for 12 months. |
| HMW-HA group | – | Device: in vivo Corneal Confocal Microscopy, Diagnostic Test: Corneal Sensitivity, Device: Non invasive tear break up time, Diagnostic Test: Ocular Surface Disease Index Qestionnaire, Device: Corneal tomographySeventeen patiens (20 eyes) received topical HMW-HA (Comfort Shield®, i.com medical GmbH, Munich, Germany) three times daily for 12 months. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Fifty-five patients with keratoconus were included in the study. All participants underwent accelerated epithelium-off CXL (A-CXL) for 10 minutes with 9 mW/cm² ultraviolet-A irradiation. A total of 63 eyes from 55 keratoconus patients were assigned into three groups: 17 patiens (20 eyes) in the HMW-HA group, 22 patient (23 eyes) in the LMW-HA group, and 20 patient (20 eyes) in the control group.
Key inclusion criteria (1 listed)
- Keratoconus patiens aged 18 and above who had been scheduled for corneal crosslinking
Key exclusion criteria (1 listed)
- Dry eye disease, corneal thickness below 400 micrometer, pregnancy, breastfeeding, topical or systemic drug use, eye disease other than keratoconus, systemic diseases, active atopy or allergy, contact lens use, ocular surgery history.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| in vivo Corneal Confocal MicroscopyCCM was performed using the Heidelberg Retinal Tomograph 3 with the Rostock Cornea Module (HRT3-RCM, Heidelberg Engineering GmbH, Germany) under topical anesthesia. A viscous gel (Viscotears, Novartis Pharmaceuticals UK) served as a coupling agent between the cornea and the applanation cap. The subjects were instructed to focus on the fixation light with the unexamined eye to ensure proper positioning. Five high-quality images of the SNP were selected and analyzed using the automated tracing of nerve fibers program (ACCMetrics, M.A. Dabbah, Imaging Science and Biomedical Engineering, Manchester, England). | Device | Control group, HMW-HA group, LMW-HA group |
| Corneal SensitivityCorneal sensitivity was evaluated using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartres, France), comprising a nylon filament measuring 60 mm in length and 0.12 mm in diameter. Participants were instructed to maintain a forward gaze while the esthesiometer gently made perpendicular contact. The procedure involved gradually decreasing the filament length in 5 mm increments, starting from 60 mm, until the initial response from the subject was detected. | Diagnostic test | Control group, HMW-HA group, LMW-HA group |
| Non invasive tear break up timeNoninvasive tear break-up time (NI-TBUT) was assessed using a Sirius Scheimpflug camera (CSO, Florence, Italy) and the device automatically provided the average NI-TBUT value | Device | Control group, HMW-HA group, LMW-HA group |
| Ocular Surface Disease Index QestionnaireThe Ocular surface disease index (OSDI) questionnaire consists of a total of 12 questions categorized into three subscales as follows: ocular symptoms, vision-related function, and environmental triggers. Each patient is asked to rate the symptoms on a 5-point scale ranging from never (0 score) to always (4 score) for every question in the questionnaire. The fourth and fifth questions in the first section, concerning blurred vision and reduced vision symptoms, were excluded from the questionnaire as these symptoms may already be present in patients with keratoconus disease. The total OSDI score was calculated according to the formula: OSDI = [(sum of scores for all questions answered) × 100] / [(total number of questions answered) × 4]. | Diagnostic test | Control group, HMW-HA group, LMW-HA group |
| Corneal tomographyScheimpflug-tomography device (Pentacam, OCULUS, Wetzlar, Germany) was used for measurement of keratometric values. | Device | Control group, HMW-HA group, LMW-HA group |
Primary outcome
Corneal nerve fiber density (CNFD)
Time frame: Baseline
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFD.
Corneal nerve fiber density (CNFD)
Time frame: Postoperative 1st, 3rd, 6th and 12th months
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFD.
Corneal nerve branch density (CNBD)
Time frame: Baseline
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNBD.
Corneal nerve branch density (CNBD)
Time frame: Postoperative 1st, 3rd, 6th and 12th months
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNBD.
Corneal nerve fiber length (CNFL)
Time frame: Baseline
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFL
Corneal nerve fiber length (CNFL)
Time frame: Postoperative 1st, 3rd, 6th and 12th months
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CNFL
Corneal nerve fiber total branching density (CTBD)
Time frame: Baseline
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CTBD.
Corneal nerve fiber total branching density (CTBD)
Time frame: Postoperative 1st, 3rd, 6th and 12th months
Automated tracing of nerve fibers program - CCMetrics (CCMetrics; M. A. Dabbah, ISBE, University of Manchester, Manchester, UK) was used to analyze CTBD.
Corneal Sensitivity
Time frame: Baseline
Corneal sensitivity was assessed using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartes, France).
Corneal Sensitivity
Time frame: Postoperative 1st, 3rd, 6th and 12th months
Corneal sensitivity was assessed using a Cochet-Bonnet esthesiometer (Luneau Ophtalmologue, Chartes, France).
Dendritic cell density
Time frame: Baseline
The Density of dendritic cells was calculated using ImageJ software (Image V.1.31; National Institutes of Health)
Dendritic cell density
Time frame: Postoperative 1st, 3rd, 6th and 12th months
The Density of dendritic cells was calculated using ImageJ software (Image V.1.31; National Institutes of Health)
Ocular surface disease Index (OSDI) questionnaire
Time frame: Baseline
The Turkish validated version of the OSDI, a questionnaire assesing the clinical symptoms of the ocular surface disease, was used. The 4th and 5th questions in the first section, which inquire about blurred vision and reduced vision symptoms, were excluded from the questionnaire as they could already be present in patients with keratoconus disease.
Ocular surface disease Index (OSDI) questionnaire
Time frame: Postoperative 1st, 3rd, 6th and 12th months
The Turkish validated version of the OSDI, a questionnaire assesing the clinical symptoms of the ocular surface disease, was used. The 4th and 5th questions in the first section, which inquire about blurred vision and reduced vision symptoms, were excluded from the questionnaire as they could already be present in patients with keratoconus disease.
Non invaziv tear break-up time (NI-TBUT)
Time frame: Baseline
The tear break-up time (TBUT) was evaluated non-invasively using a Sirius Scheimpflug camera (CSO, Florence, Italy).
Non invaziv tear break-up time (NI-TBUT)
Time frame: Postoperative 1st, 3rd, 6th and 12th months
The tear break-up time (TBUT) was evaluated non-invasively using a Sirius Scheimpflug camera (CSO, Florence, Italy).
4 secondary outcomes
Visual Functions
Time frame: Baseline
Refractive Outcomes
Time frame: Postoperative 1st, 3rd and 6th months
Keratometric Findings
Time frame: Baseline
Keratometric Findings
Time frame: Postoperative 1st, 3rd and 6th months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Feb 2024.
- Derived from this study: PubMed 40157723Ozkan G, Turhan SA, Toker E. Effect of high and low molecular weight sodium hyaluronic acid eye drops on corneal recovery after crosslinking in keratoconus patients. BMJ Open Ophthalmol. 2025 Mar 29;10(1):e001890. doi: 10.1136/bmjophth-2024-001890.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Semra Akkaya Turhan, Assoc. prof. study chair
Marmara University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Keratoconus, run by Marmara University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Feb 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Corneal nerve fiber density (CNFD) (time frame: Baseline). The study lists 16 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06243991, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Feb 2024.