Macular degeneration: Nursing

Macular degeneration is an eye condition in which the part of the retina that is responsible for clear vision, called the macula, degenerates. This causes blurred or reduced central vision, and is typically related to aging. There are two main types of macular degeneration: dry or nonexudative, which is the most common one; and wet or exudative.

Okay, but first, a bit of physiology. If we zoom into the wall of the eye, it is made up of three major layers. There's a fibrous outer layer, which contains the cornea and sclera, and helps shield excess light. The middle vascular layer is called the uvea and consists of the iris, pupil, ciliary body, and choroid. Finally, the neural layer consists of the retina, with its own outer pigmented layer, and an inner neural layer that’s composed of photoreceptor cells, called rods and cones, which convert light into neural signals that travel via the optic nerve to the brain for visual processing.

Now, there’s an oval spot in the middle of the posterior retina, called the macula, which contains the highest concentration of cones and is the part of the retina that offers the highest visual acuity.

Alright, now, even though the exact cause of macular degeneration is still unknown, several risk factors have been identified. Modifiable risk factors include smoking, diabetes, hypertension, and hyperlipidemia, whereas non-modifiable risk factors include aging and a family history of macular degeneration.

Now, let’s look at the pathology of macular degeneration. Dry macular degeneration typically develops slowly over time and is characterized by yellowish extracellular deposits of waste materials, known as drusen, that build up between the choroid and the retinal pigment epithelium. On the other hand, in wet macular degeneration, which develops rapidly, there is abnormal neovascularization, meaning that abnormal blood vessels grow from the choroid behind the retina and can leak intravascular fluid or blood.