Slit lamp biomicroscopy.

SLIT LAMP BIOMICROSCOPY

Course Content for OPT 562Department of Optometry,Faculty of Health Sciences

Imo State University, Owerri.

BYDR. EMEREOLE C.A.E (O.D)

FEB.2014.


TYPES OF SLIT-LAMP BIOMICROSCOPES

Zeiss and American optical association design

Haag-Streit Design. (Examiner is using the Hruby Lens here)


TYPES OF SLIT-LAMP BIOMICROSCOPES

Hand-held with an attached android or i-phone.

HAND-HELD SLIT LAMPS

Hand-held with an attached camera

Hand-held without attachments. Viewed normally.

NOTE: Hand-helds are preferable when the patient cannot be made to position erect to the normal slit-lamp. For example, bed-ridden patients, children whose heights do

not meet the table adjustment or who cannot maintain steadiness, newborns and also in animal studies.


PARTS OF A SLIT-LAMP BIOMICROSCOPE

1. Eyepieces

2. Reflecting mirror

3. Chin –rest adjustment knob

4. Joy stick

5. Slit width adjustment knob

6. Adjustment knob for aperture heightand slit tilt

7. Illumination system arm

8. Illumination system lock knob to obs. arm

9. Observation system arm

10. Observation system lock knob to base

11. Illumination system tilt adjuster

12. Filter selector switch13. Magnification selector14. Binoculars, adjustable for PD.15. Base axle

16. Axle rollers17. Rails18. Rolling pad/plate. Attached to table 19. Forehead rest20. Light compartment21. Chin-rest22. Fixation light

23. Adjustable table.24. Patient’s grip handle.


Comparison of schematic with real lifeparts. (Zoom-in to compare)

Goldmann Applanation tonometer attached

Hruby Lens being used for funduscopy


ATTACHMENTS TO THE USE OF THE SLIT LAMP

Perkin’s hand-held applanation tonometer

GOLDMANN SLIT-MOUNT APPLANATION TONOMETRY



APPEARANCE OF THE MIRES

GOLDMANN SLIT-MOUNT APPLANATION TONOMETRY



This more commonly presents as a highplus lens which will give a laterallyreversed image (almost like an indirectophthalmoscope which gives a laterallyreversed and inverted image)

The high minus form of the Hruby lensdoes not give a laterally reversed image

HRUBY LENS (POPULARLY KNOWN AS THE VOLK’S LENS)



View of the fundus wit a +90D Volk’s/Hruby Lens.

HRUBY LENS (POPULARLY KNOWN AS THE VOLK’S LENS)



The Variations of the Gonio-4-mirror Lens (Posner/Zeiss-type Lens); With handle (Left)

and without handle (Right).

The Optical principle of its use.

GONIOSCOPY (USING THE GOLDMANN 3-MIRROR LENS)



Placement of the Gonio contact-lens

(with handle)

View of the anterior chamber

angle through one of the

mirrors

View of the anterior chamber angle through all the mirrors at the same time

using the handless Gonio contact 4-mirror lens




Placement of the Gonioscope 3-mirror lens(without handle)

Other types of Goniolenses




A Zeiss and AOA’s slit-lamp design with inbuilt camera attachment, showing the view of the cornea and iris on the desktop using the

VISUPAC software. Video and Photos of test procedures and results can be recorded.

PHOTODOCUMENTATION



A Haag-streit slit-lamp design with external camera attachment, showing the view of the fundus on the desktop software. Videos and Photos of

test procedures and results can be recorded.

PHOTODOCUMENTATION



Camera cable attachment point on a Zeiss & AOA design TV attachment wit 3CCD

Camera

VISUPAC Software editing and analyzing

image.

PHOTODOCUMENTATION

External Camera attachment on a Haag-streit design.



CONTACT LENS FIT ASSESSMENT

An accessory second examiner observation probe for example during teaching.

Contact lens worn is being assessed.

SLIT LAMP BIOMICROSCOPYEXTERNAL EXAMINATION AND THE ILLUMINATION TECHNIQUES

Direct illuminationIndirect illumination

Oscillation

Specular reflection

Retro-illumination.Sclerotic Scatter

Diffuse illumination

SLIT LAMP BIOMICROSCOPYEXTERNAL EXAMINATION AND THE ILLUMINATION TECHNIQUES

TYPES OF ILLUMINATION TECHNIQUES

N.B: The Direct illumination technique IS NOT limited to when the illumination and

observation system are aligned (Direct focal). However an oblique technique applies

ONLY WHEN the structure illuminated IS NOT the structure being observed.

DIRECT OBLIQUE

The illumination and observation focus

on the same target

The illumination focuses on a target

behind and observation focuses on a

target infront


Direct illuminationMETHODS OF ILLUMINATION

PARELLELEPIPED

Area of Corneal Lesion. Is it an endothelial or

epithelial Lesion?

PARALLELEPIPED: Width: wide Slit beam (about 2mm). Separation 45 degree. Position. Illumination system should be on the temporal side. Magnification, approx. 10X.illumination: Medium.

A block of the cornea is revealed.



OPTIC SECTION

OPTIC SECTION: A narrow focal slit beam is projected at a 45° to 60° angle. It cuts an optical section through the cornea like a knife. With this technique it is possible to locate the layer of the pathological changes. Magnification: approx. 10X. Width . Narrow slit 1mm

The whitish area is the corneal abrasion (seen in the previous slide). Because it is on the outer surface, the lesion is therefore on the epithelium.

The thin outer reflection is seen to curve around the area of embedment. The posterior reflection is unaltered. This is a partially embedded foreign body.



CONICAL SECTION “Tyndall Effect”.

CONICAL BEAM: Cells, pigment or proteins in the aqueous humour reflect the light like a faint fog. To visualize this the slit illuminator is adjusted to the smallest circular beam and is projected through the anterior chamber from a 42° to 90° angle. The strongest reflection is possible at 90°.

The whitish dust-like particles indicate the presence of aqueous flares


Diffuse illuminationMETHODS OF ILLUMINATION

DIFFUSE ILLUMINATION: Illumination is adjusted to wide beam with a diffusing filter in front of it. Magnification is low approx. 10X.

Diffuse illumination showing lens precipitates compared with direct illumination using the parallelepiped on the lens. Noticed the marked difference in perception.


Sclerotic ScatterMETHODS OF ILLUMINATION

SCLEROTIC SCATTER: Width: wide Slit beam (1 or 2mm). Separation 45-60 degree. Position. Illumination system should be on the temporal side of the temporal limbus. Magnification, approx. 10X. illumination: Medium.

Superficial puctate precipitates of the cornea revealed by sclerotic scatter

Halo formed by total internal reflection of the light at the sclerocorneal junction

Direction of illumination.


METHODS OF ILLUMINATION

DIRECT RETRO ILLUMINATION: A moderate slit beam is decentred and angled to project onto the iris directly behind the pathology. The light reflects and backlights the cornea. If there is some cataract present the lens can also be used to reflect light directly onto the area of interest.

Incident illumination through cornea to lens

Reflected illumination from lens toward the cornea parallel to the observer

Observed anomaly in corneal endothelium against the backdrop of the light reflection from the Crystalline Lens

DIRECT retro illumination

Retro illumination (from the Lens Vs. Cornea)



IRIS TRANSILLUMINATION: The moderate slit beam is now centered to project onto the fundus behind the area of interest. The background is red and reflects through any openings or areas of reduced pigmentations in the iris. The observation system is placed directly behind the illumination system.

Incident illumination through pupil to fundus

Reflected illumination of the fundus background (Red reflex as seen in ophthalmoscopy)

Observed anomaly of the Iris.

Retro illumination (from the Fundus Vs. Iris)

IRIS TRANSILLUMINATION



INDIRECT RETRO-ILLUMINATION: The moderate slit beam is now decentred even more and angled to project onto the iris adjacent to the area of interest. The background is dark and the edges of non-pigmented lesions are well defined by the diffuse light reflecting from the iris.

Incident illumination through cornea to Iris

Reflected illumination from Iris scattered dimly behind the cornea

Observed anomaly on the corneal (the layer affected may be unknown until an optic section is employed).

INDIRECT retro illumination

Retro illumination (from the Iris Vs. Cornea)



INDIRECT RETRO-ILLUMINATION: The moderate slit beam is now decentred even more and angled to project onto the medial lens cortex adjacent to the area of interest. The background is lit and the cortical opacity on the opposite end (temporal cortex) is well defined as a dark feature against a light background.

Incident illumination at the edge of the iris and the lens

Reflected illumination within the lens toward the temporal periphery

Observed anomaly on the lens cortex.

Retro illumination (from the Iris Vs. Cornea)

INDIRECT retro illumination


OscillationMETHODS OF ILLUMINATION

OSCILLATION: The moderate slit beam is used . Magnification is low approx. 10X. The observation is positioned at some angle while the illumination system is swept back and forth. After observing an area the observation could be repositioned and the illumination system sweeps the area again until the entire regions are systematically investigated.

A back and forth sweep between the direct and indirect techniques. Helps to reveal fine corneal scars, opacities and other lesions.


Specular Reflection (on the Cornea)


SPECULAR REFLECTION: Width: wide Slit beam (2 to 3mm parallelepiped). Separation 30-45 degrees. Position. Illumination system should be moved temporally until a bright reflection from the cornea is seen (this will happen when the angle of incidence equals the angle of reflection). Magnification, approx. 25X, or 40X to observe endothelial cells. Illumination: Medium

Endothelial reflection Epithelial Reflection

Purkinje Images Endothelial Cells

#1#2


METHODS OF ILLUMINATIONSpecular Reflection (on the Lens)

Anterior lens surface (displaying an orange-peel appearance).

SPECULAR REFLECTION: Width: wide Slit beam (2 to 3mm parallelepiped). Separation 30-45 degrees. Position. Illumination system should be moved temporally until a bright reflection from the lens is seen (this will happen when the angle of incidence equals the angle of reflection). Magnification, approx. 25X, or 40X to observe the orange-peel appearance of the anterior lens surface. Illumination: Medium

THE END

NEXT PRESENTATION: DISEASE CONDITIONS SEEN WITH THE SLIT LAMP AND PICTURES OF THEIR APPEARANCES.

REFERENCES

Elliott, D.B.(2007), Clinical Procedures in Primary Eye Care, 3rd Edition, Butterworth Heinemann, New York (2012). Pp. 236-247.

Schoster, J.V. (1999 )The Use of the Biomicroscope in Veterinary Ophthalmology for the Examination of the Anterior Segment.

Eye Examination with the Slit Lamp in O p h t h a l m i c I n s t r u m e n t s f r o m C a r l Z e i s sPublication No.: 000000-1152-355

Bhatti, S.S. Basics of slit lamp microscopy. www.bhattieye.com

The Vision Care Institute (2008). Slit-lamp Examination in Essential Contact Lens Practice. of Johnson & Johnson Medical Ltd.

Grosvenor T. (2007). Primary Care Optomtery, 5th Edition, Butterworth Heinemann, New York, pp. 140-145.

Slit lamp biomicroscopy.

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