1926
The central posterior portion of the retina.
Has the densest concentration of photoreceptors of the retina and is responsible for high-resolution visual acuity.
Allows people to read, visualize fine details and recognize faces.
Posterior to its photoreceptors lies retinal pigmented epithelium.
Serves as a blood-ocular barrier providing photoreceptor phagocytes, transportation of nutrients and cytokine secretion.
Bruch’s membrane lies posterior to the retinal pigmented epithelium and it is a semi permeable exchange barrier separating the retinal pigment epithelium from the choroid.
The choroid supplies blood to the outer layers of the retina.
With age there is focal deposition of acellular debris between the retinal pigment epithelium and Bruch’s membrane, drusen.
Drusen are seen on fundoscopic examination as pale, yellow lesions and can be seen in the macula and the peripheral retina.
Drusen are categorized as small, medium or large ranging from less than 63-greater than 124 mm.
The diameter of a large drusen is nearly equivalent to the caliber of a retinal vein.
Drusen are categorized as hard of soft based on the appearance of their margins.
Hard drusen have discrete margins while soft drusen have indistinct margins.
Soft drusen are usually large and may be confluent.