1 - Diagnostics - Part 1 Flashcards
What is the transparent gel composed of collagen fibrils filled with?
Hyaluronan hydrated with water
What is the name of the ligament attached to the lens?
Wieger’s ligament
Name the space between lens zonules and vitreous?
Space of Garnier
Where is the Vitreous base located?
Ora serrata
2mm anterior and 3 mm posterior to the ora, ringlike area extends
Where is the most common area that may have an RD near the Ora serrata?
Meridional folds
What anatomical structures does the IS/OS junction tell you when observing the OCT?
Mitchondria (Ellisoid), Endoplasmic Reticulum (Myoid), cilia and inner discs
True or False. At the fovea there is no middle limiting membrane?
False. The middle plexiform layer is there area where photoreceptors reside.
(From Inner plexiform layer to the IS/OS junction)
Where is the greatest density of rods in the retina?
20 degrees from fixation
Person born with a cilioretinal artery, will have blood derived from what supply?
Ciliary circulation
Retinal vasculature, including its capillaries, retains the BBB with ___________ between ____________?
TIGHT JUNCTIONS and CAPILLARY ENDOTHELIAL CELLS
What is the percentage of vasculature provided by the choroid?
95%
Since the RPE villous processes wrap around the bottom of the photoreceptors, what is the name of the tight junctions holding onto the lateral surfaces?
Zonulae Occuldentes
Note: This is junction is only the Apical portion of the RPE. The basal surface shows rich infolding of the plasma membrane.
Which layer would you find PUFA, lipids or oxidatively damaged materials? Think of Drusen
Bruch’s membrane
RPE is generated from what layer of the optic layer?
Outer layer.
Pigmentation begins at 5 weeks
Secretion of the inner layer of Bruch’s membrane occurs by __ weeks.
6 weeks
What is present during the 7 month of gestation?
Bipolar, Amacrine, Ganglion cells and nerve fibers
When does macular development complete?
6 months
What occurs during 3 to 6 weeks, in regards to the Vitreous?
3–6 weeks: Fibrils from Cells and fibroblasts derived from mesenchyme at the rim of the optic cup or associated with the hyaloid vascular system, together with minor contributions from the embryonic lens and the inner layer of the optic vesicle: Ultimately, the primary vitreous comes to lie just behind the posterior pole of the lens in association with remnants of the hyaloid vessels (Cloquet’s canal).
What occurs during 6 to 10 weeks, in regards to the Vitreous?
Fibrils and cells (hyalocytes) originate from the vascular primary vitreous. Anterior: firm attachment to the internal limiting membrane of the retina constitutes the early stages of formation of the vitreous base. The hyaloid system develops a set of vitreous vessels as well as vessels on the lens capsule surface (tunica vasculosa lentis). The hyaloid system is at its height at 2 months and then atrophies from posterior to anterior
What occurs during 10 weeks, in regards to the Vitreous?
During the third month, the marginal bundle of Drualt is forming. This consists of vitreous fibrillar condensations extending from the future ciliary epithelium of the optic cup to the equator of the lens. Condensations then form the suspensory ligament of the lens, which is well developed by 4 months. The hyaloid system atrophies complete during this stage
How long after is AK-Fluor removed from the kidney’s?
24 to 36 hours
How long does the Choroidal flush take?
10 seconds
How much time has elapsed once Arterial phase has come?
12 seconds
How do you know the Arteriovenous phase has arrived?
The lining of the veins becomes illuminated
How much time has elapsed once the venous phase has arrived?
30 seconds
The mid phase or Recirculation phase indicates how much time has elapsed?
2 to 4 mins
The late phase, indicates how much time has elapsed?
7 to 15 mins
What are the two type of Hypofluorescence?
Vascular defect and Blocked fluorescence
What are the four type of Hyperfluorescence?
- Window Defect- Increased chorodial fluorescence
- Staining- increase in fluorescence but stays the same and margins are distinct
- Pooling - accumulation in a fluid filled space
- Leaking - margins are blur in late phase
ONH Drusen can be observed through what type of fluorescence?
Autofluoresence
Note: ON Hemartoma is also another type
If the Dye extravasates, what should be done to resolve it?
Ice cold compresses for 5 to 10 mins. Reassessed over hour or days, until edema, pain and redness resolve
When should you avoid giving fluorescein to pregnant women?
First trimester
