How big is the foveal avascular zone?
The FAZ is an important anatomical landmark in fluorescein angiography. Its diameter is 0.5mm, the central 1.5 degrees of an individual’s visual field.
Is foveal avascular?
The absence of blood vessels and overlaying inner retinal tissue are thought to maximize the optical quality of the fovea pit by reducing light scattering. This central avascular region is known as the foveal avascular zone (FAZ).
What is normal fovea?
The fovea is a specialized retinal area that supports the highest visual acuity. Histologic features of a normal fovea comprise a central area exclusively containing cones with elongated outer segments (OS) underlying a capillary-free zone and surrounded by separation of inner retinal layers.
How wide is fovea?
Introduction. The fovea is a pitted structure in the center of the macula. At the center of the fovea lies the foveola, which is 0.35 mm in size with a depressed center known as the umbo.
What is CME of the eye?
Cystoid macular edema or CME, is a painless disorder which affects the central retina or macula. When this condition is present, multiple cyst-like (cystoid) areas of fluid appear in the macula and cause retinal swelling or edema.
What is the optimal pupil size for obtaining high quality fundus images?
between 2 and 8 mm
Thus the size of the pupil, usually between 2 and 8 mm in diameter, has been the primary technical challenge in fundus imaging.
What is capillary dropout?
Capillary dropout is characterized by the loss of capillary components that results ultimately in the degeneration or obliteration of capillaries.
What is normal foveal thickness?
The mean ± SD central foveal thickness was manually measured as 170 ± 18 μm, approximately 12 μm less than the value automatically obtained from the OCT3 software….Table 1.
| Region | Retinal Thickness in the Healthy Eves, Mean ± SD |
|---|---|
| Outer ring (3-mm radius) | |
| Superior | 239 ± 16 |
| Inferior | 210 ± 13 |
| Temporal | 210 ± 14 |
What is foveal thickness?
In A, foveal thickness is defined as the mean thickness within the central 1000-µm diameter area (the central blue circle on the Early Treatment Diabetic Retinopathy Study map).
What are the 6 layers of fovea?
CH, choroid; PE, pigment epithelium; OS, outer segment; IS, inner segment; ONL, outer nuclear or photoreceptor layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer. The subdivisions of the foveal region are indicated.