From the Guidelines
The three most common types of cataracts are nuclear, cortical, and posterior subcapsular, with each having distinct characteristics and effects on visual function, as reported in a 2022 study published in Ophthalmology 1. The classification of cataracts is based on their location and cause, with the main types including:
- Nuclear cataracts, which form in the center of the lens and often cause progressive opacification or discoloration, affecting distance vision more than near vision
- Cortical cataracts, which develop in the lens cortex as opaque spokes or oil droplets, commonly causing glare symptoms
- Posterior subcapsular cataracts, which form at the back of the lens and can cause substantial visual impairment, particularly affecting near vision and causing glare symptoms in bright light Less common types of cataracts include anterior subcapsular, anterior polar, and posterior polar cataracts. The characteristics and symptoms of each type of cataract can vary, with some types progressing slowly and affecting certain aspects of vision more than others, as noted in the study published in Ophthalmology 1.
From the Research
Types of Cataracts
- Nuclear cataracts: This type of cataract is characterized by the clouding of the central part of the lens, which affects vision by scattering light and reducing the sharpness of images 2.
- Cortical cataracts: These cataracts are marked by white, wedge-like opacities that start in the periphery of the lens and work their way to the center in a spoke-like fashion, affecting vision by causing glare and scattering light 2.
- Posterior subcapsular cataracts: This type of cataract starts as a small, opaque area that usually forms in the back of the lens, right in the path of light, and can cause glare and halos at night, as well as significant vision problems in bright light conditions 2.
Characteristics and Diagnosis
- The study used the lens opacities classification system III (LOCS III) to grade the cataracts and found statistically significant differences when comparing the objective scatter index (OSI) of eyes without cataracts and those with different LOCS III grades 2.
- The comparison between the OSI and LOCS III reported good percentages of agreement regarding the number of eyes classified in equivalent levels: 72.4% (nuclear cataracts), 86.6% (cortical cataracts), and 84.3% (posterior subcapsular cataracts) 2.