Slit lamp

SlitLamp - History, Optics, types, Methods & Uses

1. SLIT LAMP Biomicroscopy

2. HISTORY Purkinje 1823 De Wecker 1863 Albert & Greenough 1891 Czapski 1897

3. Gullstrand 1911 Henker 1916

4. Parts of a Slit Lamp Observation System Illumination System Mechanical support System

5. Observation System Eyepiece +10D Objective lens +22D Prisms

6. Magnification systems Czapskiscope with rotating Objectives Haag Streit model, Bausch and Lomb, Thorpe model Littman-Galilean telescope principle Zeiss,Rodenstock and American optical slit lamps Zoom system Nikon photo SL, Zeiss 75 SL

7. Classical Haagstreit type

8. The Galilean Magnification changer

9. Illumination System

10. Zeiss Type

11. Haag Streit type

12. Mechanical Support System Joy stick arrangement Patient support system Fixation target Mechanical coupling

13. Techniques of Biomicroscopy Patient education Patient positioning Adjust Ocular eye pieces & IPD Fixation Magnification

14. Manipulating the Light source Focusing Examination & Special procedures Documentation

15. Methods of Illumination Diffuse illumination Direct focal illumination Inirect illumination Retroillumination Specular reflection Sclerotic scatter Oscillating illumination of koeppe

16. Diffuse illumination General view of anterior eye and the palpebral conjunctiva. Contact lens fitting.

17. 2.Direct focal Illumination

18. Optical section Parallelopiped of cornea Conical Beam Tangential Illumination

19. Optical Section Narrow slit beam focused obliquely Knife like histological section

20. Corneal optical section Tear layer – Bright anterior most Epithelium – Dark line Bowman’s membrane – Bright line Stroma – Wide granular and Grayish Descemet’s membrane & Endo – Bright zone

21. Lens Optical Section

22. ii. Parallelopiped of Cornea Corneal scars or infiltrates- bright Water clefts - black

23. iii. Conical Beam To examine presence of aqueous flare and cells Magni - 25x

24. iv. Tangential illumination Observe surface structure Medium wide beam Magni 10, 16 or 25x Anterior and posterior cornea,anterior iris, anterior lens ( pseudoexfoliation )

25. 3.Indirect llumination Uses : Corneal infiltrates Corneal microcysts Corneal vacuoles Epithelial cells

26. 4.Retroillumintion Direct Indirect

27. Direct Retroillumination 16-25x

28. Indirect Retroillumination

29. Graves divided the Pathologies Obstructive – pigment, blood filled vessel. Repersive – epithelial oedema , precipitates Refractile - vacuole Vacuole I.D.R – Black area with bright surface D.R- illuminated area with black line

30. Solid / opaque precipitate Retroilluminaition from Fundus (Red Glow ) lamp & microscope coaxial 10- 16x Cornea,lens,vitreous pathologies D.R- Dark area I.D.R – Bright area away from illumination

31. Transillumination Pupil- mid dilated Circular beam of light equal to size of pupil Microscope focused on iris Magni 10- 16x Use- Iris defects

32. 5.Specular Reflection Integrity of cornea or Lens Start from 10-16x Endothelial mosaic & Lens surface

33. 7.Sclerotic Scatter Faintest corneal pathology 6-10x

34. 7.Oscillating illumination of Koeppe Slit beam given oscillatory movement . Minute particles and filaments

35. SLIT LAMP EXAMINATION Suggested Power 6X or 10X external ( lids,tear film,conjunctiva ),contact lenses 16X angles,cornea,iris,lens,foreign bodies,corneal abrasions 25x aqueous flare,corneal endothelium 40X corneal endothelium Beam Width 1. narrowest angles,cornea,anterior chamber 2. a bit wider cornea,lens,etc 3. a bit wider yet external,contact lenses 4. full width external,applanation tension (with blue filter) Beam Height Full most areas and structures short checking anterior chamber for cells & flare Color /Filter White most areas and structures Blue (use fluorescein dye) applanation tensions,corneal staining,tear film,staining patterns of rigid contact lenses Green (red-free) evaluating blood vessels ,iron lines , fleischer ring

36. Uses of Slit Lamp Routine examination of ocular adnexa , anterior segment and anterior vitreous face Confirm fitting of contact lens Foreign body removal Suture removal Epilation Removal of membrane,crusts

37. Accessory Devices Gonioscopy Fundus examination ( fundus non contact lenses) Pachymetry Applanation tonometry Ophthalmodynamometry As delivery system for argon,diode and YAG laser Laser interferometry Potential acuity meter test Slitlamp photography Slitlamp videography