retinal disorders Flashcards
what are the methods of visualizing the retina ?
direct ophthalmoscope
indirect ophthalmoscope
the sit lamp biomicroscopy
poorly pigmented retina term ?
tigroid fundus
what are the anatomical parts that we divide the retina into ?
central retina
peripheral retina
what are the components of the central retina ?
the macula
the fovea
what are the features of the fovea ?
thinnest part
only has cones no rods
responsible for sharp vision
what are thee 10 layers of the retina ?
nerve fibre layer
ganglion cell layer
inner plexiform layer
inner nuclear layer
outer plexiform layer
outer nuclear layer
photoreceptor layer
RPE
Bruch’s membrane
Choroid
what are the 2 types of photoreceptors ?
RODs and CONES
what is the difference between RODS and CONES ?
cones are for day, color vision and there are three types of them that only exist in the fovea
rods exist outside of the fovea in the retina and are responsible for black and white vision and there are only one type
what are the feature of the retinal pigment epithelium ?
not light sensitive
regulates diffusion
keeps the retina dry from fluids in thee choroid
storing of vitamin A
what is the blood supply of the retina ?
the inner half of the retina - supplied by the central retinal artery
the outer half of the retina - non vascular and receives oxygen and nutrition from the choroid
what are the specific clinical investiigations for the retina ?
fundus fluorescein angiography
Optical coherence tomography
Ultrasound
what is using OCT useful for ?
seeing if there is any macular oedema
effect of glycemic control on retinopathy in DR ?
can delay retinopathy
this can be monitored by HbA1c
what can the findings in DR be attributed to ?
either microvascular leakage
or microvascular occlusion
what are the different presentations of diabetic retinopathy ?
Non proliferative retinopathy
severe non proliferative
proliferative diabetic retinopathy
Advanced diabetic eye disease
what are the other names that also refer to non proliferative retinopathy ?
background diabetic retinopathy
what are the features of non proliferative diabetic retinopathy ?
micro aneurysms
dot and blot hges
hard exudates
soft exudates/ cotton wool spots
intra retinal microvascular abnormalities
venous beading and sausaging
what is the etiology behind cotton wool spots ?
nerve fibre layer infarcts due to ischemia and not true exudates
what allows for the convesioin of non proliferative DR to proliferative ?
we reach this stage once the ischemic tissue begin to release VEGF allowing for new friable vessels to form
what are the two types of differentiated vascularization in proliferative diabetic retinopathy ?
NVD - neovascularization at the disc
NVE - neovascularization elsewhere
what is NVD what complication is NVD highly associated with ?
neovascularization at the disc massive vitreous hge
what are the features of advanced diabetic eye disease ?
massive vitreous hge
traction retinal detachement
neovascular glaucoma
what is the type of glaucoma associated with advanced diabetic eye disease ?
neovascular glaucoma
what is the most common cause of drop of vision in diabetic retinopathy ?
macular oedema
how can ischemic maculopathy be detected ?
FFA
how can macular oedema be treated ?
focal laser and/or anti VEGF
but nothing for macular ischemia
what is the treatment for diabetic retinopathy ?
in addition to control of blood glucose there are three main lines of management :
Focal laser
Intravitreal Injections
Pars plana vitrectomy
what is the aim of using focal laser in DR ?
directed at leaking micro aneurysms aiming at their occlusion with subsequent drying up of the retina