THE BLUE-GREEN AUTOFLUORESCENCE OF THE HUMAN OCULAR LENS AFTER THE WEAR OF PMMA CONTACT-LENS

The green ocular lens autofluorescence was determined in 30 Poly Methyl Meth Acrylate (PMMA) contact lens wearing volunteers and compared to that of 21 healthy non-contact lens wearing controls to determine whether a contact lens, reducing UV-A intensity reaching the eye, might protect the ocular lens against cataract formation. Increased autofluorescence was considered an indicator of increased probability for cataract formation. A multiple regression procedure revealed a significant yearly increase of autofluorescence with age (p < 0.01) which did not differ significantly (p > 0.86) from that in the controls. The regression procedure also revealed a decrease of the autofluorescence as a function of contact lens wear, but this decrease was not significant (p = 0.3). The order of magnitude of the decrease (-25%) corresponded to that of the calculated decrease in UV-A intensity at the ocular lens (-39%). This study could not support the thesis that cataract formation can be prevented by wearing PMMA contact lenses.