Abstract
Purpose: :
To investigate how age and LSI at baseline may better inform a 5 year prognosis of incidence and progression of opacity.
Methods: :
The 290 patients who participated in the Monzen Eye Study in 1997–2000 were reexamined 5 years later in 2002–2005. After excluding aphakic and pseudophakic cases, those with cortical opacities in the central 3mm zone of the pupil and low quality images, 213 subjects aged >50 yrs were selected (male: 85, female 128, average age 61.4±6.6 yrs). Only right eyes were analyzed. After maximum dilation of the pupil, Scheimpflug slit and retroillumination photographs were taken employing the anterior eye segment analysis system (EAS–1000, NIDEK). LSI in the anterior capsule (A), anterior cortex (B), adult nucleus (C), anterior inner stripe of fetal nuclear (D), central clear zone (E) and posterior inner stripe of fetal nuclear (F) were measured.
Results: :
At the 1997–2000 baseline, LSI of all six lens layers had increased with aging with no significant difference between males and females. After 5 years, LSI further increased significantly in all six lens layers. LSI increase in layer A was highest in the 70s age group followed by the 60s and then the 50s (p<0.01). The increase of LSI in deep cortical layer (C) in subjects aged in their 50s was significantly higher than in the 60s followed by that in the 70s (p<0.01). No significant differences in change of LSI by age were seen in layer B and nuclear lens layers (D, E and F). The increase ratio of LSI over 5 years in layers C, D, E and F was significantly higher in the 50s than the 60s and 70s age groups (p<0.01). The increase ratio of LSI in layer C was significantly higher in the eyes with lower half LSI in layers C, D, E and F at baseline than in those with higher half (p<0.05).
Conclusions: :
LSI increased with aging in all lens layers; however, the increase patterns differed by age. The increase ratio of LSI was high in subjects in their 50s compared with that in older groups. By further follow up of these cases, the results might prove useful for predicting the incidence and progression rates of lens opacities from LSI at baseline and increase patterns over short periods.
Keywords: crystalline lens • clinical (human) or epidemiologic studies: prevalence/incidence • cataract