Long term follow-up of lenticular autofluorescence and transmittance in healthy volunteers.

This study was undertaken to assess long term changes in the lenticular autofluorescence and transmittance of healthy volunteers. Both eyes of 15 healthy volunteers aged 8 to 62 years were examined by slit-lamp examination and fluorophotometric measurements of lenticular autofluorescence (lambdaexc=415 nm-490 nm, lambdaem= 510 nm-550 nm) and transmittance (lambda=415 nm-550 nm) in 1983 and 1996. The changes in lenticular autofluorescence and transmittance between 1983 and 1996 were determined and compared with those calculated on the basis of age-dependence curves of a group of 56 healthy volunteers measured in 1983. These curves were obtained by approximation of the values of the 56 healthy volunteers by a linear, polynomial or exponential function of age, respectively. A mean yearly increase of lenticular autofluorescence of 8.69 ng . equivalent fluorescein . ml-1 . year-1 was observed in the 15 volunteers between 1983 and 1996 and this increase was significantly larger than that calculated on the basis of the three age-dependence curves in 1983 (6.36, 6.47 and 6.53 ng . equivalent fluorescein . ml-1 . year-1, P=0.0026, 0.0037 and 0.0044, respectively). The transmittance showed a mean yearly decrease of 0.508% . year-1 which was significantly larger than calculated on the basis of the three age-dependence curves in 1983 (0.153, 0.220 and 0.183% . year-1, P=0. 0033, 0.012 and 0.0059, respectively). One volunteer, i.e. the individual with the highest lenticular autofluorescence and lowest transmittance in 1983, had developed cataract in 1996. These measurements demonstrate for the first time, quantitative changes in lenticular autofluorescence and transmittance in a long term follow up. The at least 35% larger increase of autofluorescence and 130% larger decrease in transmittance in the follow-up group between 1983 and 1996 in comparison with the values based on age-dependent curves in 1983 could be caused by the increased solar UV radiation in The Netherlands during that period of time. Copyright 1998 Academic Press Limited.