LENS AUTOFLUORESCENCE

This study was carried out to investigate in vivo the changes of the human lens autofluorescen (AF) with aging and cataractogenesis. Measurements were performed in the blue-green AF (495 nm/ 520 nm) using a fluorometer designed, built and now clinically tested in our departme 43 random eyes of 43 healthy volunteers aged 6-86 years, five of each decade, were stud effects of aging and 84 eyes of 84 patients with cortical, nuclear, posterior subcapsular or m lens opacities were studied for differences of various cataract types. The results were com with the back light scatter values obtained by the commercially available Interzeag Lens Op Meter 701. Also AF and back light scatter of the lens were measured from 122 smoking males 57 to 76 years who participated in a cancer prevention study. The results were compared wi widely used subjective lens opacities classification system, LOCS III. In addition data was colle from 30 randomly chosen eyes of as many subjects with varying degrees of yellow-brown lens oration in an otherwise healthy eye. We studied the influence of lens yellowing expressed by m of lens AF on visibility of retinal nerve fiber layer in black-and-white images. Lens AF profile consists of anterior and posterior peaks and a central plateau. The height o anterior peak was used as a measure of the maximum AF value. The square root of the between the posterior and the anterior AF peaks was used for estimating the lens transmissio technique was highly reproducible. The coefficient of variation was 3.9% for maximum AF 2.9% for the lens transmission index. Both the maximum AF and light scatter were exponentially increased with age (r = 0.95 0.94, respectively; p<0.0001). According to the regression line of AF begins to increase in e childhood. It appears by extrapolation to be absent at birth. In contrast light scatter in the lens present even in young children. The lens transmission for blue-green light, determined from the AF curve, was almost unchanging with age up to 60 years. Thereafter it decreased rapidly an interindividual variation increased. In cataractous lenses the mean AF and scatter values differed statistically significantly those of age matched healthy controls. The highest AF values were measured in nuclear ca where AF was also related to visual acuity and an increasing yellow-brown colour of the nuc About half of the total variation of the transmission index values could be accounted for by cha in nuclear colour as assessed by the LOCS III grading system. The transmission index provi more precise prediction about nuclear colour and opalescence than age or light scatter did. In cortical cataracts the AF curve was low and flattened and the maximum AF value was sig cantly lower than in the age matched control eyes. The highest light scatter values were mea from cortical cataracts, but the correlation between LOCS III cortical grades and light scatter va was rather weak. Posterior subcapsular cataracts cannot be quantified either with AF or with light scatter mea ments. Lens yellowing, expressed as lens AF, had an actual effect on retinal nerve fiber layer vis AF measurements provided a better prediction about the visibility score than age or visual acuity di The results of the present study indicate that the lens autofluorescence measurement ma useful additional tool together with a subjective grading system in the follow-up of optical chan occurring in the nuclear region of the lens.