![]() A posterior subcapsular cataract starts as a small, opaque area that usually forms near the back of the lens, right in the path of light. Cataracts that affect the back of the lens (posterior subcapsular cataracts).As it slowly progresses, the streaks extend to the center and interfere with light passing through the center of the lens. A cortical cataract begins as whitish, wedge-shaped opacities or streaks on the outer edge of the lens cortex. Cataracts that affect the edges of the lens (cortical cataracts).Advanced yellowing or browning of the lens can lead to difficulty distinguishing between shades of color. But with time, the lens gradually turns more densely yellow and further clouds your vision.Īs the cataract slowly progresses, the lens may even turn brown. A nuclear cataract may at first cause more nearsightedness or even a temporary improvement in your reading vision. Types of cataractsĬataracts affecting the center of the lens (nuclear cataracts). The cataract in one eye may be more advanced than the other, causing a difference in vision between eyes. As a result, your vision becomes blurred.Ĭataracts generally develop in both eyes, but not always at the same rate. A cataract scatters and blocks the light as it passes through the lens, preventing a sharply defined image from reaching your retina. Age-related and other medical conditions cause proteins and fibers within the lenses to break down and clump together, clouding the lenses.Īs the cataract continues to develop, the clouding becomes denser. The lens focuses light that passes into your eye, producing clear, sharp images on the retina - the light-sensitive membrane in the eye that functions like the film in a camera.Īs you age, the lenses in your eyes become less flexible, less transparent and thicker. The lens is positioned behind the colored part of your eye (iris). How a cataract formsĪ cataract is a cloudy lens. Long-term use of steroid medications, too, can cause cataracts to develop. Cataracts can also be caused by other eye conditions, past eye surgery or medical conditions such as diabetes. ![]() Some inherited genetic disorders that cause other health problems can increase your risk of cataracts. Proteins and fibers in the lens begin to break down, causing vision to become hazy or cloudy. This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.Most cataracts develop when aging or injury changes the tissue that makes up the eye's lens. The photopic PD of 3 technologies had a tendency to change in different age stage, which were decreased correspondingly with age more than 70 years old. OPD Scan-III and iTrace showed no statically difference for scotopic PD measurement in age-related cataract patents. There were significant differences of photopic PD measurements in age-related cataract patents(age<70y) among Lenstar LS 900,OA-2000 and OPD Scan-III. Comparison in photopic PD at different age: group 2 was larger than group 1, with statistical differences (P<0.05), and group 3 showed a significant decrease, with statistical differences (P<0.05). There were no statically differences of scotopic PD measurement using the 2 methods in each group. There were significant differences of photopic PD measurement using the 3 methods in group 1 and group 2(p<0.05). Statistical analysis of data using SPSS 23.0 software. The measurement of photopic PD was performed by OA-2000, Lenstar LS 900 and scotopic PD measurement was performed by iTrace and OPD Scan-III before operation. Patients were divided into 3 groups: group 1 age≤60y(78 eyes),group 2 60y70y(94 eyes). Prospective, instrument reliability analysis.To analyze PD of 267 eyes from 148 age-related-cataract patients in our hospital from Jan to Sep in 2017. The purpose of this study was to compare different methods of pupil diameter(PD) measurement using Lenstar LS 900 (Haag-Streit AG), OA-2000 (Tomey, Japan),iTrace (ray-tracing Tracey Technologies, Houston, TX) and OPD-Scan III (NIDEK, Inc., Fremont, CA) and analysis the pupil diameter changes of cataract patients.
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