P2 Flashcards
a notch, hole, or a fissure in any ocular structure from a congenital malformation and acquired process
Coloboma
a notch, hole, or a fissure in any ocular structure from a congenital malformation and acquired process
Coloboma
Refers to incomplete embryonic fissure closure during development
Coloboma
True or False: Coloboma is a bilateral condition
False; it can be unilateral or bilateral
True or False: Coloboma is a bilateral condition
False; it can be unilateral or bilateral
Coloboma came from the Greek word “Koloboma” which means
Curtailed or Multilated
Coloboma came from the Greek word “Koloboma” which means
Curtailed or Multilated
In Coloboma, a hole is present from birth due to…?
It happens when the choroid fissure, which is present during early stages of prenatal development, fails to close up completely before a child is born.
It is relatively uncommon, affecting less than one in every 10,000 births.
Ocular Coloboma
It is a classical description of Coloboma
Keyhole-shaped defect
Anomaly of lens shape
Lens Coloboma
It is a condition that results from the failure of fetal fissure during ocular development, usually unilaterally and is mainly a result of defects in zonules and ciliary bodies during ocular development
Lens Coloboma
What happens when a zonule or ciliary body fails to develop ?
It releases tension and the lens contracts segmentally a notch
True or False: Lens Coloboma is actually a coloboma of the zonule rather than a defect in the lens itself
True
Fill in the blanks: Lens Coloboma is a _______ problem and may a company other ______________ or ________ disorders . It is usually located in the _______ nasal quadrant, a lens coloboma is not a true coloboma. _____________ is required for visual improvement
Lens Coloboma congenital; ocular disorder; systemic; inferior; surgical treatment
Clinical Manifestation of Lens Coloboma
- Flattening of the equator of the lens in an area of absence of zonular fibers
- It is best visualized in dilated eyes and may be incidentally diagnosed as they are almost always asymptomatic.
Management for Lens Coloboma
- Refractive errors should be treated with CORRECTIVE LENSES.
- If severe and unable to correct with manifest refraction, LENS EXTRACTION is considered with iol placement to prevent an amblyopia from developing.
- Lens Coloboma can be treated by REMOVAL OF THE DEFECTIVE LENS.
- An intraocular lens can be placed in the CAPSULAR BAG along with a CAPSULAR TENSOR RING or position in the ciliary sulcus.
localized structural changes in the blood vessels and capillaries in the eye
Retinal Vascular Disease
health of the walls of small vessels and capillaries in the eye and retina depends on the 2 Q’s
- Quality of Blood Supply
- Quantity of Blood Supply
Fill in the blanks: in Retinal Vascular Disease, damage can result in a reduction in the ____________ which can cause _______ changes to the ___________ retina that may not have any symptoms at all.
if this damage happens centrally ______ and sometimes ________ vision loss can arise.
blood flow;irreversible;peripheral
severe;irreversible
True or False: Retinal Vascular Disease are a leading cause of blindness and require prompt diagnosis and treatment.
True or False: annual or bi-annual comprehensive eye exams for healthy adults’screens for early warning signs of these issues.
all are true
Common causes of retinal vascular disease that cause vision loss include:
- Diabetic Retinopathy (Proliferative DM, Diabetic Macular Edema)
- Hypertensive Retinopathy
- Hypercholesterolemia and clotting disease (vein and artery occlusion)
- Macular Degeneration (both wet and dry)
the top 3 retinal vascular diseases leading to severe sight impairment:
- Wet-ARMD
- Diabetic Retinopathy
- Retinal Vein Occlusion
Anatomy of the Retina
(in to out)
Internal limiting membrane
Nerve fiber layer
Ganglion Cell layer
Inner Plexiform layer
Inner Nuclear layer
Outer Plexiform layer
Outer Nuclear layer
External Limiting Membrane
Retinal Pigmented Epithelium
Rod and cone inner and outer segments and a single layer of cells
Retinal Pigment Epithelium
The only cells which are sensitive to light (for vision) and for entrainment and reflex responses to light.
Photoreceptor Cells
Photoreceptor Cells composed of:
Rods
Comes
Photosensitive ganglion Cells
True or False: Neural signals from the rods and cones are processed by other nerve cells in the Retina
True
the macula has a high density of:
Cones
Pigments
Gabglion Cells
the central 1.5 mm of the macula
fovea
it is located within the fovea, contains only cones and roughly circular avascular area
Fovea Avascular Zone
