SLIT-LAMP-BIOMICROSCOPY-pt.1.pdf

SLIT-LAMP BIOMICROSCOPY Parts of the Slit-Lamp The slit-lamp biomicroscope is composed of the following parts: Mechanical support Forehead rest Chin rest Fixation target Power supply unit Locking controls Observation system...

SLIT-LAMP BIOMICROSCOPY Parts of the Slit-Lamp The slit-lamp biomicroscope is composed of the following parts: Mechanical support Forehead rest Chin rest Fixation target Power supply unit Locking controls Observation system Binocular eyepieces Camera/video adaptor Observation tube (on demonstration/teaching slit-lamps only) Magnification changer Illumination system Lamp housing unit Slit width and height control Neutral density filter Cobalt blue light Red-free (green) filter Field size control Diffuser Prism Chronology of Anterior Segment Examination 1. Lids and Lashes 2. Conjunctiva 3. Cornea 4. Tear Film 5. Eversion of Eyelids 6. Anterior Chamber 7. Angle of AC 8. Iris 9. Crystalline Lens 10. Anterior Vitreous CADILLAC G. ALCARAZ, O.D.  SLIT-LAMP ILLUMINATION TECHNIQUES Magnification Illumination / Filters Slit Structures Conditions Evaluated Angle of Width Examined Illumination Lids and Blepharitis Moderate lashes Trichiasis Low to High Neutral height Conjunctiva Conjunctival Diffused Mag density Cornea Concretions Circular Sclera Pterygium 45° Iris Pinguecula Pupil Corneal Vacuoles stroma Microcysts Med to High Medium to Dystrophies Mag Broad beam Epithelial Striae Parallel Neutral breakdown Folds epiped ~ 30 ° density Thickness of Variable Slit (2mm- Lens 3mm) surface and Endotheliu Direct m Variation in Nerve Fibres Focal corneal Blood Vessels curvature Infiltrates Cataracts Med to High Narrow Corneal Angle Closure Mag beam thickness Glaucoma Optic Neutral Section density Full height Depth of visible 60° features within the cornea Conical Med to High Neutral Small, Anterior Aqueous flare, Beam density circular Chamber pigmentation or cell > 50° debris Layers of Vascularization Cornea Epithelial edema Med to High Microcysts Mag Crystalline Vacuoles Neutral Small, Lens Dystrophies Retro-illumination density Circular Crystalline lens Coaxial opacities (~ 0.5°) Contact lens deposits Indirect Localized Central Corneal epithelial Clouding oedema Medium to (CCC) Low to Med Broad beam Corneal Mag Neutral scars Sclerotic Scatter density Thickness of Foreign Decentered Slit (2mm- bodies in 3mm) the cornea CADILLAC G. ALCARAZ, O.D.  Endothelial Endothelial blebs Medium cell layer High Mag broad beam Tear film Specular Neutral debris Reflection 25°/30° density Thickness of Tear film i=R Slit (2mm- lipid layer 3mm) thickness Low to Med Iris Iris freckles Mag Cornea Tumors Tangential Neutral Wide Open General integrity of density cornea and iris Special 70°- 80° Illumination Techniques Anterior Lens Opacities Low to Med Medium to Chamber Aqueous Flares Mag Neutral broad beam Crystalline Oscillatory Beam density Lens ~ 60 ° Maximum Variable Height Slit – Lamp Magnification and Observed Area Low 7X - 10X General Eye Medium 20x – 25x Structure Layers High 30x – 40x Detail CADILLAC G. ALCARAZ, O.D.