Tear levels of inflammatory markers increase in patients who wear corneal refractive therapy lenses, compared to those who wore silicone-hydrogel lenses or no lenses.

A team led by Dr Javier González-Pérez, Ocular Surface and Contact Lens Research Laboratory, Faculty of Optics and Optometry, University of Santiago de Compostela, Spain, compared 60 participants in a prospective, case-controlled study.

Of the subjects studied, 28 wore a silicone-hydrogel lens continuously for 30 nights and 32 wore a corneal refractive therapy lens on an overnight basis. There were also 32 control subjects included in the investigation.

Twelve months after initial lens fitting tear samples were obtained and assayed using ELISA cytokines IL-6 andIL-8, matrix metalloproteinase 9 (MMP-9) and epidermal growth factor (EGF).

EGF significantly rose after 12 months for both lenses and IL-6, IL-8 and MMP-9 only increased after corneal refractive therapy. Inflammatory response for corneal refractive therapy patients was linked to the degree of myopia and the presence of corneal staining.

An increased level of MMP-9 and EGF was associated with the presence of corneal-pigmented arch in those who wore corneal refractive therapy lenses.,/p>

The abstract was recently published in the British Journal of Ophthalmology.