Slit lamp

for eye care professionals.. will help them to understand slit lamp examination based on theory can co-relate with the practicals to gain more knowledge

1. SLIT LAMP By- ABHISHEK YADAV OPTOMETRIST COMMUNITY OPHTHALMOLOGY

2. Invented by Gullstrand in 1911 a lamp which emits a narrow but intense beam of light, used for examining the interior of the eye It enhances the examination by: Excellent image quality Flexible illumination and magnification Binocular stereoscopic view Providing room for different attachments for detailed examination INTRODUCTION

3. On the basis of illumination system it is of 2 types- ZEISS TYPE HAAG STREIT

4. On the basis of compound microscope system it is of 2 types- GRENOUGH TYPE GALILEAN CHARGE TYPE

5. HAND- HELD SLIT LAMP

6. Associated instruments- Applanation tonometer Gonioscopic lens Fundoscopy lens Laser delivery devices Optical pachymeter Image archiving devices Laser interferometer

7. OPTICS i t works on the same principle as a compound microscope. The objective lens(+22D) is towards the patient, whose eye forms the object. The objective lens consists of two planoconvex lenses with their convexities facing towards each other. The eyepiece is +10 to +14D and is towards the examiner. The illuminating system can be adjusted to vary the width, height and angle of incidence of the light beam.

8. Slit-lamp routine examination Patient adjustment. Instrument adjustment. Beginning slit-lamp examination. Semi dark room Starting with diffuse illumination(for short time) Minimum exposure of retina to light Corneal surface disturbances which can be mistaken for pathology Start with low magnification then high magnification.

9. METHODS OF ILLUMINATION DIFFUSE ILLUMATION Broad light Lid margins Bulbar conjunctiva Limbus Anterior segment evaluation DIRECT ILLUMIATION Slit beam and microscope focused on the same area Changes in corneal stroma and epithelium

10. 3. INDIRECT ILLUMINATION Slit beam focused just beside the area to be examined. Corneal microcysts and vacuoles. 4. RETROILLUMINATION Light is reflected off the irs or fundus while microscope is focused on the cornea. Corneal oedema , neovascularization , microcysts and infiltrates.

11. 5. SPECULAR REFLECTION Angle must be 60º ( ANGLE OF ICIDENCE=ANGLE OF REFLECTION). Changes in endothelium. 6. SCLEROTIC SCATTER Total internal reflection. Beam focused at the temporal limbusand as it passes through the cornea, it outlines any subtle stromal or epithelial opacities which may lie in its path. 7. OSCILLATORY ILLUMINATION OF KOEPPE Beam is given an oscillatory movement by which it is often possible to see minute objects or filaments especially I the aqueous.

12. FILTERS WHITE FILTER COBALT BLUE FILTER RED FREE FILTER

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