Unit 3 Flashcards

Question

Tengential map

Answer 1

Power and curvature at individual points Most accurate

Answer 2

Placedo disc - calculate elevation Scheimflug- actual elevation measure

Answer 3

Scheimflug and scanning slit primarily

Answer 4

Raise or lower the instrument until a bright ring refelection is centered in the cornea

Answer 5

Clear the circular images

Answer 6

Move the instrument or elevation knob

Answer 7

* Keratometry ◦ Automated ◦ Manual * Slit Lamp * Corneal Topography * Dry Eye Assessment ◦ Tear Break Up Time (TBUT) ◦ Schirmer’s test

Answer 8

* Handout: Procedure for Obtaining Keratometry Readings (Brightspace) 1. Calibrate instrument 2. Patient preparation ◦ Disinfect chin and head rest ◦ Occlude left eye ◦ Align reflected mires on patient’s cornea * Look into instrument * Plus sign in lower right circle * Focus mires Adjust horizontal power until plus sign tips are near each other * Rotate telescope until tips of plus signs align ◦ Determine the principal meridians * Superimpose plus signs ◦ Horizontal power * Superimpose minus signs ◦ Vertical power

Answer 9

* Record the power and axis for the horizontal meridian * Record the power and axis for the vertical meridian ◦ You may see the readings recorded with only one axis identified since the other is assumed to be 90 degrees away. ◦ There is a smaller chance of error when both axes are recorded. * Record whether the mires are clear and regular (MCAR), D0 * Distorted mires are often associated with poor tear quality or irregular astigmatism

Answer 10

43.50 @ 175 / 45.00 @ 085 D0 * Amount of astigmatism = 1.50 D

Answer 11

* Plays an essential role in the preliminary assessment and follow-up care of contact lens wearers * May also be used to assess: ◦ Posterior eye health Vitreous, lens, retina ◦ Anterior chamber angle ◦ Intraocular pressure

Answer 12

◦ An illumination system (the slit lamp) ◦ Viewing system (the biomicroscope) Joystick ◦ Focusing ◦ Lateral movements * Height control

Answer 13

* Brightness is controlled by a rheostat or multiposition switch ◦ Can be adjusted to obtain balance between patient comfort and optimal visibility * Filters can be incorporated to enhance the visibility of certain conditions ◦ Green filter (neovascularization) ◦ Neutral-density filter ◦ Polarizing filter ◦ Diffusing filter ◦ Cobalt blue filter* ◦ Wratten (yellow) filter

Answer 14

* Provides a clear image of the eye * Sufficient magnification to view all structures of interest ◦ Up to 40x should be possible

Answer 15

* Six areas of the anterior eye should be assessed in the preliminary examination ◦ Fig. 37.2 (Contact Lens Practice) * A normal technique is to use a variety of illumination methods – and cobalt blue light for fluorescein staining

Answer 16

* Lids = clear, uneven lid margin * Lashes = clear, Gr 1+ blepharitis * Conjunctiva = clear, Gr 1+ GPC, Gr 2+ injection * Cornea = clear, no staining, negative SPK, Grade 2+ SPK inferior * Angles = Gr 4+ open, narrow angles * Iris = flat and even, flat round pigment 1 mm at 6 o’clock * A/C = negative for cells or flare; Gr 3+ flare * Lens = Gr 1+ NS, clear, Gr 2+ brunescence

Answer 17

* There are six clinical techniques: Symptoms/history Dry-eye survey Slit-lamp Tear meniscus height Tear stability tests  Tear Break Up Time (TBUT) Ocular staining Fluorescein or lissamine green Lid surface assessment Blink rate Tear secretion/quantity Schirmer, Phenol red thread

Answer 18

◦ Test 1 – basal and reflex (no anesthetic) ◦ Test 2 – basal (with anesthetic)

Answer 19

◦ Parallelepiped ◦ Optic section ◦ Specular reflection ◦ Conical ◦ Retroillumination (Retro) * Indirect Illumination ◦ Retro ◦ Sclerotic scatter

Unit 3 Flashcards

(43 cards)