Riboflavin and ultraviolet A collagen crosslinking: In vivo thermographic analysis of the corneal surface

Abstract

PURPOSE: To assess the possible thermal damage to the cornea during combined riboflavin and ultraviolet-A crosslinking using in vivo surface thermographic analysis. SETTING: Department of Oto-Neuro-Ophthalmological Surgical Sciences, Eye Clinic, University of Florence, Florence, Italy. METHODS: Collagen crosslinking was performed on a day-surgery basis under aseptic conditions with traditional techniques. During the procedure, temperature measurements on the corneal surface were taken using an infrared thermocamera. The temperature values were detected in the area directly exposed to light irradiation, selecting it in the acquired thermographic image. Because the aim of the study was to consider the thermal damage that may be induced during the procedure, the maximum temperature value detected in the area studied was recorded and considered for successive analysis. RESULTS: Infrared thermocamera measurements of the corneal surface during crosslinking treatment showed that the temperature was constant during the entire procedure and remains under the threshold of thermal injury to corneal collagen. CONCLUSION: Corneal collagen crosslinking was a safe procedure that did not cause thermal injury to the corneal surface

Significance of the riboflavin film in corneal collagen crosslinking

“…6,24 Also the corneal in vivo temperature of 37 C might reduce the viscosity compared with our measurements reducing the film thickness of the viscous solutions. 25 In conclusion, this study shows the importance of a stable riboflavin film for the absorption and shielding of UVA. This is essential for the safety of the endothelium and also crucial to the CXL effect itself.…”

Biophysikalische Grundlagen der Kollagenvernetzung

“…Bei der Vernetzung der Hornhaut führt die Lichtenergie zu einer chemischen Modifizierung des Kollagens. Deshalb kommt es bei der Riboflavin/UV-Vernetzung hçchstens zu einer Temperaturzunahme von 2 -3 C [30] und ein thermischer Prozess ist ausgeschlossen. Diese Temperaturerhçhung liegt somit weit unterhalb der Schwelle für die thermische Schädigung des Kollagens.…”

Assessment of the Macula in Keratoconus: An Optical Coherence Tomography and Multifocal Electroretinography Study

“…It has been considered to progress until the third to fourth decade of life or may occur later, affecting both genders and all ethnicities [1,2,3,4,5]. Keratoconus typically manifests itself at puberty with an incidence of about 1/2,000 in the general population, progressing in approximately 20% to such an extent that penetrating keratoplasty is necessary [1,6]. Interestingly enough, its etiology remains elusive, although gene polymorphisms, degradative enzymes and proteinase inhibitors have been found to play a significant role in the etiopathogenesis of keratoconus [7,8,9,10,11,12,13,14,15,16].…”