Assessing Ocular Health 2 Flashcards
what can you do to rule out open angle glaucoma?
by checking IOPs and visual fields
what is the posterior pole of the retina made up of?
-optic nerve head
-retinal vascular arcades
-the macula including the foveola, fovea, parafovea and perifovea
what are the 4 zones of the peripheral retina?
-The near periphery → a 1.5 mm ring adjacent to the 6 mm diameter macula (centred on the foveola and often defined as the posterior fundus)
-The middle periphery→ is the next 1.5mm ring
-The far periphery → measures the next 9mm to 10mm temporally and 16mm on the nasal side
-The extreme periphery or ora serrata → measuring the additional 2.1mm in the temporal and 0.7 mm on the nasal side
what kind of patient compalints require mandatory examination of the peripheral retina?
o Recent onset of floaters or increase in number of floaters
o Any floater that appears to reduce best-corrected acuity
o Flashes particularly if unaccompanied by headache and of an arcuate form arising with change of posture
o Any suggestion of vitreal haze during normal fundoscopy or if tobacco dust in the retrolental space
o History of blunt ocular trauma
o High myopia or family history of detachment
o Patients with lattice degeneration or retinal holes seen on normal fundoscopy
o Patients with a recent history of posterior vitreous detachment (PVD)
o Any patients for whom a wide-field view and stereoscopic imaging will enhance observation of a lesion
(examples are peripheral tumours, retinoschisis, diabetic retinopathy)
o All diabetic patients with any evidence of retinopathy
o Any patient taking tamoxifen (breast cancer), because of the possibility of secondary tumour in the eye
o Any patients taking chloroquine of hydroxychloroquine (malaria, rheumatoid arthritis, lupus)
give 11 differential diagnosis for flashes & floaters
- Retinal detachment
- Posterior vitreous detachment
- Optic neuritis
- Retinal vein occlusion
- Diabetes
- Inflammation of the eye panuveitis
- Visual migraines
- Tumour
- Trauma
- Ocular hypertension
- OAG (open angle glaucoma) suspect
what do you need to do for patients presenting with CC flashes and floaters?
-use the schaeffer’s sign technique to check for tobacco dust which could indicate retinal tear
-need to dilate the patient in order to check the peripheral retina.
what patients should you not dilate?
-Patients who have to drive immediately after
-Patients who do not want to be dilated on that day for x reason (clearly document that you advised to dilate them but they did not want to that day)
-History of penetrating injury
-Extremely narrow angles in VH
-very high IOP e.g. 29
what is shaeffers sign?
= tobacco dust, clumping of pigmented cells in the anterior vitreous and on the corneal endothelium which could indicate PVD or RD
what should you remeber to record if you dilate a patient?
-drug and concentration ‘
-batch number
-expiry date
-patient consent
what is primary open angle glaucoma characterised as?
an IOP beyond the normal range in the presence of an open anterior chamber angle
give 3 advantages of head mounted BIO
- stereoscopic, wide-angles, high resolution views of the entire fundus and overlying vitreous
- Its optical principles and illumination options allow for visualisation of the fundus regardless of high ametropia , hazy ocular media , central opacities
- It can be performed with patient upright or supine
how does head mounted BIO work?
- light beams are directed into the patients eye
- reflected observation beams are produced from the retina
- these beams are focussed to an aerial image following placement of a high plus-powered condensing lens at its focal distance in front of the patient’s eye
- The resultant image is real, magnified, upside down and laterally
reversed - image located between the examiner and condensing lens
- The observer views this image through the oculars of the head-
band indirect ophthalmoscope
what dilating agents are used for head mounted BIO?
0..5% or 1.0% tropicamide – for maximum dilation used in
conjunction with 2.5% phenylephrine
what does Goldmann-type 3- or 4 - mirror contact lens allow you to do?
allows the practitioner to see from the equator of the retina through to the ora serrata
what is the procedure for Goldmann-type 3- or 4 - mirror contact lens?
- Clean and disinfect lens
- Use local anaesthetic
- Coupling solution
- Determine the position of interest
- Select the appropriate mirror
- Rotate the lens such that the desired mirror is positioned 180° from the area of interest
- Direct the slit-lamp light into the mirror of choice
- Rotate the lens
