Postoperative follow up by dynamic light scattering: detection of inflammatory molecular changes in the cornea, the vitreous and the lens.

Objective: To detect post-op molecular changes and inflammatory processes by dynamic light scattering (DLS) in eye segments. To develop DLS parameters which are appropriate for the control of post-op course after ophthalmologic surgery. METHODS, DESIGN: Three new DLS devices were tested in different post-op clinical settings such as pseudoexfoliation syndrome (PEX), cataract surgery and retinal surgery. In a second step DLS was used to detect molecular changes in the cornea of 6 patients after photo refractive keratectomy (PRK) and 16 patients after photo astigmatic refractive keratectomy (PARK).
Results: In PEX-patients cataract surgery changed the DLS signals of the anterior chamber and the lens in a specific way compared to the pre-op situation. Cataract patients without PEX had more scattering particles post-op and retinal surgery modified the DLS signal of the vitreous. Furthermore it was shown that the length of the corneal scattering vector l correlated with the process of the corneal wound healing after PARK. One and three months after surgery the lengths of the scattering vectors had increased significantly but returned to pre-op values twelve months post-op.
Discussion: The post-op transparency of eye segments such as the cornea, the vitreous and the anterior chamber depends primarily on the wound healing mechanisms. DLS seems to be a suitable method to control the corneal recovery after refractive surgery.
Conclusions: The length of the scattering vector l correlates well with the wound healing after refractive surgery. However DLS-signals seem to contain information about the molecular composition of tissue too. Therefore further research is needed to refine the interpretation of the DLS signals.