Ignite Creation Date:
2024-10-26 @ 3:36 PM
Last Modification Date:
2024-10-26 @ 3:36 PM
Study NCT ID:
NCT06522789
Status:
COMPLETED
Last Update Posted:
None
First Post:
2024-07-22
Brief Title:
Preoperative Corneal Measurements Estimate the Corrected Distance Visual Acuity After Corneal Cross-linking
Sponsor:
None
Organization:
None
Study Overview
Official Title:
Could Automated Objective Measurements Acquired at the Preoperative Stage Estimate the Corrected Distance Visual Acuity After Corneal Cross-linking in Keratoconus
Status:
COMPLETED
Status Verified Date:
2024-07
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
No
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study aims to determine if objective markers describing corneal optical density COD thinnest corneal thickness TCT anterior ARC and posterior PRC surface radii over the 3mm thinnest region of the cornea could provide a model for calculating corrected distance visual acuity CDVA after corneal cross-linking CXL in keratoconus
Detailed Description:
A prospective partially masked semi-randomised interventional clinical trial was undertaken between April 2018 and July 2023 in the refractive surgery department of the Sistina Ophthalmology Hospital in Skopje
The patients examination before the treatment and on every follow-up was a meticulous process that included assessment of CDVA Aitomu LCD Digital Vision Eye Chart Shanghai China refraction tonometry and corneal characteristics using Pentacam HR Oculus Optikgeräte GmbH Wetzlar Germany biomicroscopy and dilated fundus examination Corneal topography thickness distribution and COD profiles were captured for later analysis The COD profile which describes the turbidity of the cornea in the central apical region and the three concentric annular zones was a vital part of the examination The Pentacam software computed a figure ranging from 0 totally clear to 100 totally opaque along a grey scale describing the optical density in each of the 12 regions A higher number signifies increased turbidity and reduced transparency a lower number represents the opposite The software also averaged the total optical density in the apex each concentric zone each layer and the cornea A total of 20 COD values are generated for a single cornea COD values for the central 0-2mm region covering the anterior 0-2ant and central layers 0-2cent paracentral 2-6mm annulus covering the anterior 2-6ant and central layers 2-6cent total anterior region layer tot ant total central layer tot cent and whole cornea tot were recorded Separate COD values for the peripheral 6-10mm and 10-12mm annuli and posterior 60µ regions of the cornea were excluded as these regions are least likely to be affected by CXL On all occasions three consecutive Pentacam scans were taken in a dark room and the best-quality scan was selected for recording and analysis For each case the COD in greyscale units thinnest corneal thickness TCT µ anterior ARC and posterior PRC corneal radii of curvaturemm values measured over a 3mm diameter zone covering the cone of the cornea were sequestered from the best scan
The CXL procedure for group one adhered to the standard Dresden protocol All patients received topical anaesthetic Tetracaine HCL 05 Alcon Forth Worth Texas and a miotic Isopto Carpine 2 HCl Alcon Fort Worth Texas drops 30 minutes before the procedure The periocular region and conjunctival sac were washed with 10 povidone-iodine Betadine 10 Alcaloid Skopje Manual epithelial scraping with a crescent knife followed Pachymetry was kept over 400 μm during the procedure and measured with an ultrasound hand pachymeter Pocket II Quantel Medical Cournon dAuvergne France Riboflavin Peschke D Peschke Trade Huenenberg Switzerland was applied every 3 minutes for 30 minutes We performed corneal UV-A radiation with a wavelength of 370 nm and energy of 3mW using a UVA CXL lamp VEGA CBM-X-Linker Carleton Optical Chesham UK for 30 minutes 6 cycles of 5 minutes each Device testing was performed before every procedure and irradiance density measured between 27-and-33 mWcm2 was tolerated At the end of the corneal CXL procedure topical atropine 1 Atropine Sulphate Cooper Athens Greece antibiotic Tobrex Alcon Fort Worth Texas drops were instilled and a bandage soft contact lens Air Optix Night Day Aqua Alcon Texas was placed over the cornea Peschke D Riboflavin used in the study group was a standard Riboflavin solution consisting of 01 Riboflavin diluted into 20 dextran 500 The soaking time was 20-30 minutes or until microscopy showed riboflavin particles in the anterior chamber Tobradex Alcon Fort Worth Texas eyedrops a suspension of 03 Tobramycine and 005 Dexamethasone were prescribed for application after CXL The dosage was four times per day for the first two weeks then tapered twice daily for the next two weeks and then to one drop per day for the last two weeks All patients received topical steroids for a total of 6 weeks
The postoperative care was comprehensive ensuring the patients well-being and recovery It included a combination of antibioticcorticosteroid drops instilled four times daily for the next two weeks after which the drops were tapered off gradually over six weeks Postoperative examinations were scheduled for one day four days 1-week until epithelisation and bandage lens removal then 1-3-6-months and 1-year postoperatively After that the patients were advised to complete an ophthalmological examination at least yearly
Data from the treated eye or just the right eye in bilateral cases were analysed Details of CDVA COD TCT ARC and PRC values were stored in Excel Microsoft Redmond WA and analysed to determine the significance of any differences between groups Mann Whitney U test or unpaired t-test and changes occurring within each group Friedman test or 1-way ANOVA for repeat measures Wilcoxon signed rank or paired t-test If significant changes were found then the analysis would be extended to determine the significance of any association between the change ie preop value-postop value in the parameter and the value at the start of the study Spearmans rho or Pearson correlation Depending on the outcome of this analysis the data would be further scrutinised to determine if a feasible model could be constructed linear and multiple regression analysis to predict the likely CDVA after CXL or after one year in untreated cases Non-parametric tests were applied when data were not normally distributed Kolmogorov-Smirnov test of normality The changes and differences were considered statistically significant when p005
The patients examination before the treatment and on every follow-up was a meticulous process that included assessment of CDVA Aitomu LCD Digital Vision Eye Chart Shanghai China refraction tonometry and corneal characteristics using Pentacam HR Oculus Optikgeräte GmbH Wetzlar Germany biomicroscopy and dilated fundus examination Corneal topography thickness distribution and COD profiles were captured for later analysis The COD profile which describes the turbidity of the cornea in the central apical region and the three concentric annular zones was a vital part of the examination The Pentacam software computed a figure ranging from 0 totally clear to 100 totally opaque along a grey scale describing the optical density in each of the 12 regions A higher number signifies increased turbidity and reduced transparency a lower number represents the opposite The software also averaged the total optical density in the apex each concentric zone each layer and the cornea A total of 20 COD values are generated for a single cornea COD values for the central 0-2mm region covering the anterior 0-2ant and central layers 0-2cent paracentral 2-6mm annulus covering the anterior 2-6ant and central layers 2-6cent total anterior region layer tot ant total central layer tot cent and whole cornea tot were recorded Separate COD values for the peripheral 6-10mm and 10-12mm annuli and posterior 60µ regions of the cornea were excluded as these regions are least likely to be affected by CXL On all occasions three consecutive Pentacam scans were taken in a dark room and the best-quality scan was selected for recording and analysis For each case the COD in greyscale units thinnest corneal thickness TCT µ anterior ARC and posterior PRC corneal radii of curvaturemm values measured over a 3mm diameter zone covering the cone of the cornea were sequestered from the best scan
The CXL procedure for group one adhered to the standard Dresden protocol All patients received topical anaesthetic Tetracaine HCL 05 Alcon Forth Worth Texas and a miotic Isopto Carpine 2 HCl Alcon Fort Worth Texas drops 30 minutes before the procedure The periocular region and conjunctival sac were washed with 10 povidone-iodine Betadine 10 Alcaloid Skopje Manual epithelial scraping with a crescent knife followed Pachymetry was kept over 400 μm during the procedure and measured with an ultrasound hand pachymeter Pocket II Quantel Medical Cournon dAuvergne France Riboflavin Peschke D Peschke Trade Huenenberg Switzerland was applied every 3 minutes for 30 minutes We performed corneal UV-A radiation with a wavelength of 370 nm and energy of 3mW using a UVA CXL lamp VEGA CBM-X-Linker Carleton Optical Chesham UK for 30 minutes 6 cycles of 5 minutes each Device testing was performed before every procedure and irradiance density measured between 27-and-33 mWcm2 was tolerated At the end of the corneal CXL procedure topical atropine 1 Atropine Sulphate Cooper Athens Greece antibiotic Tobrex Alcon Fort Worth Texas drops were instilled and a bandage soft contact lens Air Optix Night Day Aqua Alcon Texas was placed over the cornea Peschke D Riboflavin used in the study group was a standard Riboflavin solution consisting of 01 Riboflavin diluted into 20 dextran 500 The soaking time was 20-30 minutes or until microscopy showed riboflavin particles in the anterior chamber Tobradex Alcon Fort Worth Texas eyedrops a suspension of 03 Tobramycine and 005 Dexamethasone were prescribed for application after CXL The dosage was four times per day for the first two weeks then tapered twice daily for the next two weeks and then to one drop per day for the last two weeks All patients received topical steroids for a total of 6 weeks
The postoperative care was comprehensive ensuring the patients well-being and recovery It included a combination of antibioticcorticosteroid drops instilled four times daily for the next two weeks after which the drops were tapered off gradually over six weeks Postoperative examinations were scheduled for one day four days 1-week until epithelisation and bandage lens removal then 1-3-6-months and 1-year postoperatively After that the patients were advised to complete an ophthalmological examination at least yearly
Data from the treated eye or just the right eye in bilateral cases were analysed Details of CDVA COD TCT ARC and PRC values were stored in Excel Microsoft Redmond WA and analysed to determine the significance of any differences between groups Mann Whitney U test or unpaired t-test and changes occurring within each group Friedman test or 1-way ANOVA for repeat measures Wilcoxon signed rank or paired t-test If significant changes were found then the analysis would be extended to determine the significance of any association between the change ie preop value-postop value in the parameter and the value at the start of the study Spearmans rho or Pearson correlation Depending on the outcome of this analysis the data would be further scrutinised to determine if a feasible model could be constructed linear and multiple regression analysis to predict the likely CDVA after CXL or after one year in untreated cases Non-parametric tests were applied when data were not normally distributed Kolmogorov-Smirnov test of normality The changes and differences were considered statistically significant when p005
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None