Basics Of Biomicroscopes

Question 1

Zeus slit lamp

Answer 1

Lamp at base

Question 2

Haag-Streit

Answer 2

Lamp from top

Question 3

Greenough type slit lamp

Answer 3

Switch, 2 levels of magnification

Question 4

Galilean type slit lamp

Answer 4

Knob with multi levels (more than two) levels of magnification

Question 5

Direct illumination

Answer 5

Both oculars and light beam are focused at the identical location

Question 6

Diffuse direct illumination

Answer 6

Maximum beam width and height directed between 30-45 degrees. Low magnification, high illumination with 10% grey filter for patient comfort

Question 7

Direct focal illumination

Answer 7

Max beam height, width varies but mainly narrow. Illumination angle 45-60 degrees, magnification 6x - 40x

Observing detail of specific part of eye

Question 8

Parrallelepiped

Answer 8

Light beam between diffuse and optic section

Question 9

Direct focal illumination

Answer 9

Optic section illumination or conical beam, high illumination. Angled at 45-60 degrees or more

Allows for visual dissection of transparent tissue

Question 10

Conical beam

Answer 10

As short as is wide, used to asses anterior chamber

Question 11

Tyndall phenomenon

Answer 11

Illumination of “dust particles”

Question 12

Indirect illumination

Answer 12

Observation and illumination are not focused at the same point

Question 13

Retro-illumination

Answer 13

“Backlighting” formed by reflecting light of slit beam from a structure more posterior than structure being observed

Question 14

Direct retro illumination

Answer 14

Observed feature is viewed in direct pathway of reflected light

Infiltrations, small scars, corneal vessels, etc.

Question 15

Indirect retro illumination

Answer 15

Illumination angle is greatly reduced or increased (viewed against dark background)

Infiltration, small scars, corneal vessels, microcysts, vacuoles

Question 16

Iris trans illumination

Answer 16

Trans illumination of the iris by indirect light reflected from the fundus

Visualization of defects of pigmented layer of the iris

Question 17

Specula reflection

Answer 17

Angle of incidence = angle of reflection

Examine corneal endothelium, inspect surface of tear film, contact lens, or lens

Question 18

Sclerotic scatter

Answer 18

Light is transmitted within the cornea by total internal reflection creating a limbal glow around the cornea

Question 19

White filter

Answer 19

Overview of ocular structure and examine intraocular structures

Question 20

Cobalt blue filter

Answer 20

Cornea evaluation using sodium fluorescein

Corneal abrasions, ulcers, GAT, TBUT

Question 21

Red free filter

Answer 21

Differentiate pigment lesions
Obscure anything that is red
Fleisher ring viewing
Rose bengal staining