Non–invasive method for the objective assessment of the intraocular scattering of the cornea and the crystaline lens

A new method has been developed for the assessment of the intraocular scat- tering generated in each structure of the human eye, i.e., the cornea and the crystalline lens. Based on a non-invasive recording of images of the light reflect- ed on the different surfaces of the eye (Purkinje images) and their posterior image processing allows the objective assessment of the intraocular scattering of the cornea and the crystalline lens separately. It is a simple and cost-effective method easy to use in clinics. Retinal image quality is the first limit to human visual performance, being affected by aberrations and scattering. The contribution of the latter has a great impact since it reduces the contrast of the retinal image and produces loss of vision, which is manifested in different diseases such as cataracts and some corneal disorders. Laser refractive surgery and intraocular lenses implantation can also increase the level of scattering. Nowadays, the most common tests used in clinical practice for the measurement of intraocular scattering are subjective, as the measurement of visual functions (Visual Acuity, Contrast Sensitivity Function) or the observation of the eye through a slit-lamp. Few instruments have been developed in the last years that allow the objective measurement of intraocular scattering as a whole, that is, that corresponding to the whole eye. Hence, there is a need for objective, non-invasive methods that permit to separate the contribution of the cornea and the crystalline lens to the overall intraocular scattering.