1. INSTRUCTION COURSE ON SLIT LAMP EXAMINATION Part II

2. M.P. STATE OPHTHALMIC CONFERENCE UJJAIN

4. The science of examination with a slit lamp is called Biomicroscopy as it allows in vivo study of living tissues at high magnification.

6. Examination of Various Ocular Structures

7. 1. LIDS 7. Mites and Parasites 6. Regurgitation on Pressure over sac 5. Punctal Occlusion Papillae on lid margin 4. Tumours and Naevi Cilium 3. Hordeolum externum Meibomian gland orifice 2. Diffuse inflammation (Edema) Individual hair follicle 1. Hyperaemia – Capillary engorgement and suffusion of superficial vessels Direct Focal Illumination Diffuse Illumination

8. 2. CONJUNCTIVA - As the conjunctiva is transparent it is mainly studied by light reflected from sclera. - Eversion of lid – Examination of upper tarsal conjunctiva - Double eversion of lid – Upper fornix examination.

11. (b) Direct Focal Illumination : - Detailed examination of all lesions - Depth of any lesion. - Papillae - Follicles - Blood Vessels over a tumour - Neovascularization - Extent of subconjunctival haemorrhage

12. (c) Specular Reflection - Zones of intensely brilliant reflexes - Conjunctival elevated zones - Mucus and Waxy meibomian gland secretions - Elevated papillae (d) Indirect Illumination : - Vessels - Conjunctival scars. (e) Sclerotic Scatter Technique : - Pannus in Trachoma

13. 3. CORNEA Diffuse Illumination - Generalised view of surface of cornea - Size - Shape - Transperancy - Foreign Body - Opacity - Staining of Cornea

14. Direct Focal Illumination Integrity of corneal epithelium Thickness of cornea Depth of lesion Vascularisation-superficial/deep Folds in Descemet's membrane Rupture in Descemet's mvmebrane

15. Hypopyon Ulcer seen in Direct Focal Illumination

17. Specular Reflection - Endothelial cell count (average 2800 cells/ Sq.mm) - Morphology of endothelium - Endothelial dystrophics - Hassall Henle bodies which are warts in descemet's membrane. - Bullae - Blood staining of endothelium

18. Sclerotic Scatter - Central nebular corneal opacity - Dystrophies - Corneal oedema - Rupture in descemet's membrane

20. Corneal Staining Fit of contact lens Break up time Applanation tonometry Siedel's test Double staining Ulcers Abnormal and Devitalised epithelium Epithelial defect Keratin Corneal erosion Mucus Corneal abrasion Mucus Seen in red free filter Seen with cobalt blue filter Alcian Blue Rose Bengal 1% Fluorescein 2%

21. 4. SCLERA AND EPISCLERA On Diffuse Illumination : - Deep, red, dusky congestion of episcleral vessels On Direct Focal Illumination - Episcleritis – Raised congested nodule - Deep Scleritis – Conjunctival congestion associated with episcleral vessel congestion with peripheral keratitis and uveitis.

22. 5. AQUEOUS HUMOUR Diffuse Illumination : - Depth of Anterior Chamber - Contents of Anterior Chamber - Foreign Body - Hypopyon - Hyphaema - Vitreous prolapse in AC - Traumatic Catractous material in AC - Micro Filareae - Cyst and Tumours

23. Direct Focal Illumination - Attachment of pupillary membrane - Cells - Flare - Foreign bodies - Depth of Anterior Chamber

24. AQUEOS FLARE Flare is the ability to see the path of light when slit beam is obliquely aimed across the AC. It is due to light scattering by suspended colloid particles causing TYNDALL effect.

27. Cells : Indication of active inflammation of iris and ciliary body. Slit beam is directed across the AC and beam is focused posterior to cornea. 2 x 1 mm slit beam is focused with maximum light intensity. 0 - 0 1+ - 5 – 10 2+ - 10 – 20 3+ - 20 – 50 4+ - > 50

28. ANTERIOR CHAMBER Van Herrick Method : For assessment of peripheral anterior chamber depth using a slit lamp. A comparison of depth of peripheral anterior chamber to the peripheral corneal thickness is used to determined the degree of shallowness of the anterior chamber.

30. GONIOSCOPY It is done to see the structures in the recess of angle of anterior chamber. It is important in - Glaucoma - Foreign bodies entangled in angle of AC - Tumours arising in angle of AC. - Narrowing of angle can be identified by a steep configuration of iris and angulation of slit light reflex as it passes into the angle recess.

31. 6. IRIS Diffuse Illumination: Carried under low magnification : - Colour of Iris : - Heterochromia iridium - Heterochromia iridis - Gross structural abnormality - Iris Motility

32. Direct Focal Illumination - High Illumination - Light beam focused from temporal side - First periphery is inspected then pupillary zone to avoid dazzling. Observation : - Exudates - Vascular changes - Atrophic Changes - Neoplastic Changes Optical Section : - Narrow beam is made to see details of crypts and furrows.

33. Retro Illumination - Visualization of iris is via light reflected from the lens - Atrophic patches in iris. - Holes - Tears and dehiscences. - Patency of Peripheral iridectomy

34. Indirect Illumination - Outline of Crypts - Atrophic areas - Perforations - Cysts and Tumours - Haemorrhages

36. 7. LENS Diffuse Illumination : - To visualize anterior lens surface with part of its anterior capsule. - Surface and suture system of adult nucleus in older patients. - Embryonic Y suture. - Posterior Capsule when altered pathologically

37. Direct Focal Illumination : - Enables to see zone of discontinuity - Finer details of tissue stratification - Exact localization of minute changes. - Differentiate between congenital and developmental opacities, senile changes, traumatic opacities, complicated opacities.

38. Lens under direct focal illumination

39. Retro Illumination : 1. Used to observe whether the opacity is – - Obstructive – Opaque to light - Respersive – Scatters light - Refractile – Refracts, minimizes or distorts the views of background. 2. Observe anterior capsular changes - Deposits, Foreign bodies, Opacities Below Capsule.

41. Posterior Sub Capsular Cataract Seen in Direct Focal Illumination and Retro Illumination

42. Specular Reflection :- Mirror reflexes of anterior and posterior capsule can be seen as bright reflex, when the beam is moved from side to side across the surface of lens. It is due to irregular reflection caused by small irregularities of capsular surface known as SHAGREEN reflex. Any capsular opacity can be seen by this method.

43. Post Operative Evaluation of IOL Surgery : - IOL Centration and Stability. - Position of IOL - Pupillary Capture - Dislocated IOL - Early Uveitis - PCO : - Soemmerring Ring - Elschnigs Pears.

46. 9. VITREOUS - Examination of Anterior 1/3rd vitreous can be made using direct focal illumination. - Illumination is kept maximum - Slit very narrow. - Illumination is brought from largest angle possible, without disturbing the slit. - It is seen as optically clear space with delicate undulating fibrils and membrane like structures.

47. Direct Focal Illumination : - Shape - Rigidity - Vitreo retinal attachments - Vitreous opacities - Vitreous Bands and Membranes - Any pigmented Debris. - Foreign bodies in vitreous - Haemorrhages in vitreous

49. Goldmann Three Mirror Lens Examination : - Central planoconcave lens – 64 D. - It has 3 mirrors at 59°, 67° & 73°. - Central lens allows a magnified stereoscopic examination of central 30° of retina giving an erect image. - Oblong mirror gives a view of posterior retina. - Rectangular and anterior retinal mirrors examine corresponding retinal areas respectively.

50. Indirect Slit Lamp Biomicroscopy : - Carried out by hand held high plus condensing lenses. - + 90 D, + 78 D. - An inverted, stereo magnified image is formed between lens and slit lamp. - Lens is held 5 – 10 mm from patient's cornea. - Magnification is 10 X or 16 X. - Coaxial illumination for fundus examination. - Slit beam is angled 10° – 20° from axis of observation for vitreous examination.

51. Hruby Lens Biomicroscopy : - Planoconcave – high minus lens (–55D) - Neutralises the optical power of the eye. - Forms a virtual erect image of fundus.

52. Auxillary Devices : These can be used along with slit lamp. 1. Gonioscope for angle structure examination. 2. Applanation tonometer for IOP. 3. Endothelial cell counts using Eisner grid. 4. BUT 5. Staining Procedures.

54. Thanks