test 4 Flashcards
Only type of bacterial conjunctivitis associated with pseudomembranes
Neisseria Gonnorhhoeae (gram neg)
% of patients who get angle recession after hyphema
60%
This is why you should perform gonioscopy after the hyphema has resolved
Because of the near triad, esotropia could be due to
Hyperopia or over accommodating
Broca-Sulzer effect
Light with an intensity above threshold will appear brightest if the duration is 50=100msec.
Fencher’s Law
Assumes that Weber’s law will hold true for stimuli above a given brightness threshold.
Point focal lenses completely correct for what type of aberration
Radial astigmatism
Point focal correct radial astig at the cost of offering no correction for curvature of field
Percival form lenses completely correct for what type of aberration
Curvature of field without offering any correction for radial astigmatism.
Orthoscopic doublet lenses
Minimize the effects of chromatic aberration.
How to find the ideal index of an anti-glare coating for a polycarbonate lens
Square root of polycarbonate index: 1.586
What fat soluble vitamin is least toxic
E
does a chemical burn result in decreased or increased IOP
Increased
Angle lambda
the angle between the pupillary axis and the line of sight. Usually 0.5mm nasal to the center of the pupil.
a 1mm shift in corneal reflex corresponds to how many pd
22
Temporal = eso nasal = exo
Is brinzolamide a suspension
yes, must shake
Do oral steroids increase or decrease BP
Increase
What is the aperture stop in a telescope
Objective lens
What causes RCE
Malformation or loss of hemidesmosomes between the basal layer of the K epi and BM.
Could also be due to increase in thickness of BM or age
What 3 things are attached to the scleral spur
Corneoscleral meshwork
Longitudinal and radial muscle fibers of the ciliary muscle
Only test that measures associated phoria
Fixation disparity
Very small misalignment of the eyes that allows for single binocular vision
Parks 3 step
- Which eye is hyper
- Worse with what gaze
- Worse with what tilt
When does stereo develop
6 months
AREDS 1
ACE !
Vitamin A / Beta carotene- 15mg Vitamin C- 500mg Vitamin E- 400 UI 80mg zinc 2mg copper
IgG
Most common antibody found in circulation
Only Ab that can cross placenta
Pyramidal pathway
Begins in the motor cortex in the precentral gyrus of the frontal lobe.
Provide motor innervation to the distal muscles through the lateral corticospinal tract and proximal muscles through the anterior corticospinal tract
What can be used to produce ketone bodies during starving conditions
Acetyl CoA can either go to TCA cycle or to form ketone bodies as an alternative source
What arteries form the minor circle of the iris
Formed by a remnant of the embryological development
How does cyclopentolate treat anterior uveitis
- Cyclo immobilizes the inflamed iris–> reduced pain
- Mydriasis prevents PS
- Vasoconstriction stabilizes the BAB
Which system has better absolute sensitivity?
scotopic has better ability to detect dim lights.
Why does a vitamin C deficiency result in scurvy
Scurvy= defective collagen synthesis and weak CT
Vitamin C is an essential cofactor to convert pro collagen to collagen.
CN most likely to be damaged from trauma
4 bc thinnest and longest
What age range does the VA of a child approach adult
3-4 years
Which type of muscle contains multinucleated cells
Skeletal
The inner layer of the optic cup gives rise to
Iris posterior pigmented epi, NPCE, neural retina
The outer layer of the optic cup gives rise to the
RPE
What causes Descemet’s folds?
Corneal stromal edema
- IK
- early post op cataracts
Distance for FT 28 and FT 35
28 is 5mm
35 is 3.5 mm
Respiratory acidosis is caused by
Hypoventilation –> increase in Co2 –> Acidic blood/decrease in PH
Another name for whorl keratopathy
Corneal Verticillata
Collateral vessels are most commonly observed with what condition
retinal vein occlusions
Others: advanced glaucoma, ON tumors
2 broad causative mechanisms of dry eye
Tear hyperosmolarity
Tear instability
How to calculate convergence demand
Pd in cm x accommodative demand in diopters
What wavelengths do rods and cones maximally absorb?
Rods- 507
Cyanolabe (blue) - 426
Chlorolabe (green) - 530
Erythrolabe (red) 557
4 uses for Nd: YAG
SLT
LPI
Cyclodestruction of the CB
Posterior capsuloptomy
3 uses for argon laser
ALT
PRP
Barrier laser treatment for retinal holes
What delays wound healing
DM Infection Tissue ischemia Malnutrition Cortisol/stress Decreased platelet aggregation
Keratocytes
Fibroblasts within the cornea that produce collagen and extracellular matrix
Which 3 structures in the eye store glycogen
Muller cells
K epi cells
Vitreous
What are the best ways to measure VA in infants/children?
Preferential looking
- Broken wheel cards
- TAC
