Trial Outcomes & Findings for German Corneal Cross Linking Register (NCT NCT00560651)

NCT ID: NCT00560651

Last Updated: 2026-06-18

Results Overview

Corrected Visual Acuity after crosslinking at the latest follow up examination

Recruitment status

ACTIVE_NOT_RECRUITING

Target enrollment

356 participants

Primary outcome timeframe

172 to 3396 days

Results posted on

2026-06-18

Participant Flow

All eyes included with corneal crosslinking

Unit of analysis: eyes

Participant milestones

Participant milestones
Measure	PRK CXL Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL Crosslinked eyes with manual abrasion of epithelium
Overall Study STARTED	49 78	149 261	158 265
Overall Study COMPLETED	49 78	149 261	158 265
Overall Study NOT COMPLETED	0 0	0 0	0 0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	PRK CXL n=78 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=261 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=265 Eyes Crosslinked eyes with manual abrasion of epithelium	Total n=604 Eyes Total of all reporting groups
Age, Categorical Between 18 and 65 years	45 Participants n=49 Participants	125 Participants n=149 Participants	126 Participants n=158 Participants	296 Participants n=356 Participants
Age, Categorical >=65 years	0 Participants n=49 Participants	0 Participants n=149 Participants	0 Participants n=158 Participants	0 Participants n=356 Participants
Age, Categorical <=18 years	4 Participants n=49 Participants	24 Participants n=149 Participants	32 Participants n=158 Participants	60 Participants n=356 Participants
Sex: Female, Male Female	11 Participants n=49 Participants	32 Participants n=149 Participants	32 Participants n=158 Participants	75 Participants n=356 Participants
Sex: Female, Male Male	38 Participants n=49 Participants	117 Participants n=149 Participants	126 Participants n=158 Participants	281 Participants n=356 Participants
Race and Ethnicity Not Collected	—	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Corrected Visual Acuity	0.7 letters read per line STANDARD_DEVIATION 0.35 • n=78 Eyes	0.61 letters read per line STANDARD_DEVIATION 0.35 • n=261 Eyes	0.41 letters read per line STANDARD_DEVIATION 0.28 • n=265 Eyes	0.67 letters read per line STANDARD_DEVIATION 0.36 • n=604 Eyes
Sphere	-0.29 Diopters STANDARD_DEVIATION 3.17 • n=78 Eyes	-0.4 Diopters STANDARD_DEVIATION 3.48 • n=261 Eyes	-1.95 Diopters STANDARD_DEVIATION 3.33 • n=265 Eyes	-0.88 Diopters STANDARD_DEVIATION 4.38 • n=604 Eyes
Cylinder	-2.96 Diopters STANDARD_DEVIATION 1.79 • n=78 Eyes	-2.90 Diopters STANDARD_DEVIATION 2.28 • n=261 Eyes	-2.04 Diopters STANDARD_DEVIATION 4.52 • n=265 Eyes	-2.63 Diopters STANDARD_DEVIATION 3.12 • n=604 Eyes
Endothelial Cells	2866 cells/mm^2 STANDARD_DEVIATION 271 • n=78 Eyes	2796 cells/mm^2 STANDARD_DEVIATION 284 • n=261 Eyes	2834 cells/mm^2 STANDARD_DEVIATION 339 • n=265 Eyes	2818 cells/mm^2 STANDARD_DEVIATION 351 • n=604 Eyes
K1	45.11 Diopters STANDARD_DEVIATION 3.02 • n=78 Eyes	44.29 Diopters STANDARD_DEVIATION 3.93 • n=261 Eyes	49.7 Diopters STANDARD_DEVIATION 11.09 • n=265 Eyes	44.81 Diopters STANDARD_DEVIATION 3.98 • n=604 Eyes
K2	47.47 Diopters STANDARD_DEVIATION 3.31 • n=78 Eyes	47.34 Diopters STANDARD_DEVIATION 4.49 • n=261 Eyes	55 Diopters STANDARD_DEVIATION 14.33 • n=265 Eyes	47.38 Diopters STANDARD_DEVIATION 4.23 • n=604 Eyes
Kmax	53.2 Diopters STANDARD_DEVIATION 5.19 • n=78 Eyes	53.55 Diopters STANDARD_DEVIATION 6.08 • n=261 Eyes	61.06 Diopters STANDARD_DEVIATION 15.62 • n=265 Eyes	53.44 Diopters STANDARD_DEVIATION 6.21 • n=604 Eyes
Astigmatismus	2.35 Diopters STANDARD_DEVIATION 1.57 • n=78 Eyes	3.05 Diopters STANDARD_DEVIATION 1.92 • n=261 Eyes	5.29 Diopters STANDARD_DEVIATION 4.37 • n=265 Eyes	2.85 Diopters STANDARD_DEVIATION 2.21 • n=604 Eyes
Pachymetry Thinnest	480 µm STANDARD_DEVIATION 36 • n=78 Eyes	471 µm STANDARD_DEVIATION 39 • n=261 Eyes	434 µm STANDARD_DEVIATION 67 • n=265 Eyes	473 µm STANDARD_DEVIATION 40 • n=604 Eyes

PRIMARY outcome

Timeframe: 172 to 3396 days

Population: Different numbers due to incomplete measurements during examination

Corrected Visual Acuity after crosslinking at the latest follow up examination

Outcome measures

Outcome measures
Measure	PRK CXL n=55 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=114 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=27 Eyes Crosslinked eyes with manual abrasion of epithelium
Visual Acuity	0.85 letters read per line Standard Deviation 0.33	0.83 letters read per line Standard Deviation 0.36	0.79 letters read per line Standard Deviation 0.35

PRIMARY outcome

Timeframe: 172 to 3396 days

K max after Crosslinking

Outcome measures

Outcome measures
Measure	PRK CXL n=55 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=107 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=16 Eyes Crosslinked eyes with manual abrasion of epithelium
Postoperative K Max	49.37 Diopters Standard Deviation 4.59	49.9 Diopters Standard Deviation 4.85	52.36 Diopters Standard Deviation 5.05

PRIMARY outcome

Timeframe: 172 to 3396 days

Sphere values after crosslinking at lastest-follow-up

Outcome measures

Outcome measures
Measure	PRK CXL n=55 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=114 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=27 Eyes Crosslinked eyes with manual abrasion of epithelium
Sphere	0.5 Diopters Standard Deviation 2.21	-0.06 Diopters Standard Deviation 2.72	-0.87 Diopters Standard Deviation 2.16

PRIMARY outcome

Timeframe: 172 to 3396 days

Refractive cylinder after Crosslinking at latest follow-up

Outcome measures

Outcome measures
Measure	PRK CXL n=55 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=114 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=27 Eyes Crosslinked eyes with manual abrasion of epithelium
Cylinder	-1.5 Diopters Standard Deviation 1.17	-2.23 Diopters Standard Deviation 1.92	-2.16 Diopters Standard Deviation 1.78

OTHER_PRE_SPECIFIED outcome

Timeframe: 172 to 3396 days

Endothelial cell density after Crosslinking at latest follow-up

Outcome measures

Outcome measures
Measure	PRK CXL n=55 Eyes Crosslinked eyes with previous photorefractive Keratectomy (PRK)	PTK CXL n=114 Eyes Crosslinked eyes with previous phototherapeutic keratectomy	Manual CXL n=26 Eyes Crosslinked eyes with manual abrasion of epithelium
Endothelial Cell Density	2886 Cells/mm^2 Standard Deviation 264	2841 Cells/mm^2 Standard Deviation 311	2786 Cells/mm^2 Standard Deviation 274

Adverse Events

PRK CXL

Serious events: 0 serious events

Other events: 6 other events

Deaths: 0 deaths

PTK CXL

Serious events: 0 serious events

Other events: 5 other events

Deaths: 0 deaths

Manual CXL

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	PRK CXL n=33 participants at risk Crosslinked eyes in combination with previous photorefractive Keratectomy (PRK)	PTK CXL n=70 participants at risk Crosslinked eyes in combination with previous phototherapeutic keratectomy (PTK)	Manual CXL n=20 participants at risk Crosslinked eyes with manual abrasion of epithelium
Eye disorders Sterile Infiltrates	18.2% 6/33 • Up until 3 month post corneal crosslinking	7.1% 5/70 • Up until 3 month post corneal crosslinking	0.00% 0/20 • Up until 3 month post corneal crosslinking

Additional Information

Anika Förster

Center for Refractive Surgery

Phone: +49 251 987789 0

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place