1. OPTO 4101: Contact lens1- lab L01: Slit lamp microscope
Mohammed A.M Aljarousha
Department of Optometry
Faculty of Allied Health Sciences
Islamic University-Gaza

2. Slit lamp microscope part1

3. Definition of slit lamp
The slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye.
It is used in conjunction with biomicroscope.
The lamp facilities an examination of the anterior segment & posterior segment of the human eye.
The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions.

4. The practice of slit lamp

5. Prepare the instrument and patient
Switch on power & unlock base screw.
Cleaning the forehead band.
Changing paper strip from chinrest.
Adjust eyepieces to correct for examiner’s refractive error and interpupillary distance.
Comfortable sitting of patient and the examiner.
Give instructions to the patient to cooperate.
Proper positioning of the patient.
Target fixation.

6. Chronology for slit-lamp examination

7. Illumination techniques
Slit Width control knob
Narrow to fully open slit illumination achieved by rotating this knob

8. Slit height control knob
Short to long slit illumination achieved by rotating this knob

9. Direct illumination Direct diffuse illumination
Direct focal illumination
Beam
Conical section (pinpoint)

10. Direct diffused illumination
Illumination of the eye with a broad, unfocused light beam
Directed obliquely between 30-45
Magnification 6x to 10x
Light source
Biomicroscope

11. Direct diffused illumination
Light source
Biomicroscope
Application
General gross overview of eyelids, lashes, conjunctiva, sclera, pattern of redness, iris, pupil, gross pathology, ant capsule of lens.

12. Direct focal illumination
Illumination and observation are focused in the same plane
slit width narrow to broad
Illumination angle 45° to 60°
Magnification 10x-40x
Biomicroscope

13. Direct focal illumination
Application
Cornea in detail
Anterior chamber
Crystalline lens
Anterior part of vitreous
Grading cell and flare in anterior chamber

14. Beam direct illumination
The microscope is usually directed straight ahead but may also be moved to an angle opposite the illuminator.
The greater the angle between the illuminator and the microscope, the greater the width of the illuminated section.
A very narrow beam (optical section) directed onto the cornea can be used to evaluate corneal shape, elevation, and thickness.

15. Beam direct illumination
Application
Observe: cornea, iris, lens, vitreous

16. Conical section Application
Assessment of particles floating in the A/C
Narrow, short & bright slit of light
45°-60° light source directed to pupil
Magnification 16x-25x
Application
Inflammatory cells, flare, pigmented cells