Primary function of DFE
Eval peripheral retina for rhegmatogenous (retinal detachment) conditions
These are missed w/ direct/indirect monocular
Adv of BIO? 2 main ones
Quick assessment of ENTIRE retina & vitreous; helpful in pediatric/challenging Pts
Stereoscopic exam - high resolution, binocular, large FOV, unaffected by Pts refractive error
Disadv. of BIO? 3 main reasons
- 1)Low mag (SLEx & direct)
- -3x w/ 20D; not reccommended to move closer to Pt to inc mag
2) Very bright
3) Requires dilation
Indications of BIO. 4 main ones
- Every Pts needs one, esp
- Flashes/Floaters complaints
- High Myopia >4.00D
- Systemic Dz: DM, HTN, Lupus, Sickle Cell Anemia, Sarcoidosis, HIV/AIDs, Cancer
Contraindication of BIO
Narrow angles due to angular closure 2ndary to pupil dilation.
Caution w/ Tropicamide. Sensitive Down Syndrome Pts.
Dilation at 4pm Friday?
Hellz to the NO! danger period is 2-4 hrs and most Ophthalmologist offices are closed.
Dilation of Questionable Angles procedures and cautions
- Check IOP 45-60mins after instillation.
- Rise in IOP might be an ascending spike.
- IOP pressures will be highest at mid-dilation (1-2 hrs post dilation)
Tropicamide. %'s, eye color correction, does what? Generic names.
- 1% for brown eyes
- 0.5% for blue/green eyes
Is an Anticholinergic drug that blocks sphincter mm of iris -> dilation & moderate cycloplegia
Generic names: Tropicacyl & Spectro-Cyl
%'s, does what?, Brand names.
- 2.5% and 10%
- Sympathomimetic drug for mydriasis & vasoconstrictor
Brand names: Ak-Dilate, Mydfrin, Neo-synephrine, Neofrin
Name the 3 drugs used for dilation in order.
- 1) Proparacaine; anesthetic
- 2) Phenylephrine 2.5%; mydriasis/penetration
- 3) Tropicamide; disables sphincter
Attributes, benefits over 10%
- 2.5% Phenylephrine HCL is weak and slow-acting mydriatic drug.
- Does NOT induce blur.
- Less systemic risk than 10%
- Cannot be used as a dilator alone.
Side effects of Tropicamide and Phenylephrine
Head, heart, skin etc etc
- Trop: Stings
- Caution w/ overdosing kids
- OD includes: headache, tachycardia, dry mouth/skin, unusual drowsiness, warm/redness of skin
- Blurred Vision @ near
- Phenylephrine: Dizziness, fast/irregular/pounding heartbeat, inc sweating, inc BP, paleness, trembling
- High BP b/c vasoconstrictor properties esp for HTN Pts on 10% str. P.
Condensing lens: Increasing dioptic power will?
What lenses can be used?
- Inc FOV
- Dec Mag
- dec Working Distance
- 14D, 20D, 25D, 28D, 2.2 pan-retinal
- 20D is best of both worlds.
- 2.2pan0retinal is 25.5D, similar to 20D
Mag of condensing lenses
20D = ?
30D = ?
15D = ?
"2.2" = ?
- 20D = 3x
- 30D = 2x
- 15D = 4x
- "2.2" (25.5D)= 2.5x
DD (disc Diameter) of 20D Lens w/ BIO?
DD of direct ophthalmascope?
When tombonering, dist from lens to examiner is approx...?
Only works for which part of the retina?
Posterior pole & mid-periphery
When examining the retina how many peripheral and posterior views are there?
8 peripheral, 4 pole
Retina is divided into 3 concentric circles. What are they defined by?
- Inner = equator (4 vortex veins)
- Middle = ora serrata
- Outer = ciliary process