Stromal Demarcation Line in Pulsed Versus Continuous Light Accelerated Corneal Cross-linking for Keratoconus.

PURPOSE To compare the stromal demarcation line depth in pulsed versus continuous corneal cross-linking (CXL) for keratoconus. METHODS Seventy eyes underwent epithelium-off cross-linking, with 0.1% riboflavin applied during 10 minutes prior to ultraviolet irradiation at 30 mW/cm2. Thirty-six eyes received pulsed irradiation (1 second on, 1 second off) for 8 minutes and 34 eyes underwent continuous irradiation for 4 minutes. Total fluence was 7.2 J/cm2 for both groups. Patients were evaluated at 3 months after the procedure. RESULTS A significantly deeper stromal demarcation line was observed in the pulsed group compared to the continuous group (201.11 ± 27.76 vs. 159.88 ± 20.86 µm; P < .001). CONCLUSIONS The pulsed corneal cross-linking protocol induced a significantly deeper stromal demarcation line when compared to the 4 minutes of highly accelerated continuous CXL protocol. Neither CXL protocol induced a shallower demarcation line comparable to less accelerated CXL protocols previously reported.

[1]  Farhad Hafezi,et al.  Corneal cross-linking. , 2017, Survey of ophthalmology.

[2]  F. Hafezi,et al.  Establishing Corneal Cross-Linking With Riboflavin and UV-A in the Mouse Cornea In Vivo: Biomechanical Analysis. , 2015, Investigative ophthalmology & visual science.

[3]  Hassan Razmjoo,et al.  Corneal haze and visual outcome after collagen crosslinking for keratoconus: A comparison between total epithelium off and partial epithelial removal methods , 2014, Advanced biomedical research.

[4]  M. Rechichi,et al.  Pulsed vs continuous light accelerated corneal collagen crosslinking: in vivo qualitative investigation by confocal microscopy and corneal OCT , 2014, Eye.

[5]  Tukezban Huseynova,et al.  Accelerated versus conventional corneal collagen crosslinking , 2014, Journal of cataract and refractive surgery.

[6]  F. Hafezi,et al.  Corneal biomechanical properties at different corneal cross-linking (CXL) irradiances. , 2014, Investigative ophthalmology & visual science.

[7]  G. Kymionis,et al.  Corneal stroma demarcation line after standard and high‐intensity collagen crosslinking determined with anterior segment optical coherence tomography , 2014, Journal of cataract and refractive surgery.

[8]  F. Hafezi,et al.  The Biomechanical Effect of Corneal Collagen Cross-Linking (CXL) With Riboflavin and UV-A is Oxygen Dependent. , 2013, Translational vision science & technology.

[9]  F. Raiskup,et al.  Corneal crosslinking with riboflavin and ultraviolet A. I. Principles. , 2013, The ocular surface.

[10]  David Muller,et al.  Photochemical kinetics of corneal cross-linking with riboflavin. , 2012, Investigative ophthalmology & visual science.