Introduction to cataracts of the eye

Published on January 31, 2023   8 min

A selection of talks on Physiology & Anatomy

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Hello everyone. I'm Dr. Akshay Badakere. I'm a pediatric ophthalmologist working at Sankara Nethralaya Chennai and I will be talking about an introduction to cataracts.
The objectives of my talk are, I will be talking about what cataracts are. A brief anatomy and embryology of the lens. Why senile cataracts happen. I'll also be talking about cataracts in adults and children and the various types, and then I will conclude.
The lens is an optically clear structure located behind the iris and in front of the vitreous body and the retina. The shape, clarity, and the refractive index of the lens enables it to focus light onto the retina. Any loss of transparency of the lens is defined as a cataract.
Let's look at the basic anatomy of the lens. The lens essentially is made of a central nucleus surrounded by an anterior and posterior capsule and in between the nucleus and the capsule is the cortical layer.
Let's look at the embryology of the lens. The lens begins as a thickening of the surface ectoderm overlying the optic vesicle. This then invaginates to form the lens pit. This lens pit closes to form the lens vesicle. Primary lens fibres fill the lumen, followed by proliferation of epithelial cells, which continues throughout life, leading to development of secondary lens fibres. It is these secondary lens fibres which forms the nucleus of the lens.
To recollect the embryology, the lens is nothing but the surface ectoderm and optic vesicle interacting, which leads to formation of the lens placode, followed by formation of the lens pit, and finally formation of the lens vesicle.