Objective measurement of cortical and subcapsular opacification in retroillumination photographs.
An image analysis system has been developed for the objective analysis of cortical opacification. Lens photographs are obtained using a Neitz CTR retroillumination camera. The images are digitized using an IBM-PC-based imaging system. We have developed a program, called OPAC, through which the computer analyzes the image using a circular grid consisting of 93 sectors. The program outputs the percent of lens area which is opaque. Ninety-eight photographs, previously classified by the Lens Opacities Classification System (LOCS II), were analyzed using OPAC as well as a manual, square-grid counting system (GRID). The results show a linear correlation between OPAC and GRID with a correlation coefficient of 0.94. The results obtained with OPAC are also linearly correlated with the LOCS II classifications.
Wolfe
J K
JK
Brigham and Women's Hospital, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston.
Chylack
L T
LT
D002386:Cataract / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007903:Lens Capsule, Crystalline / Q000473:pathology*; D007904:Lens Cortex, Crystalline / Q000473:pathology*; D007908:Lens, Crystalline / Q000473:pathology*; D008029:Lighting / Q000379:methods*; D010781:Photography / Q000379:methods*; D012984:Software