slitlamp examinations of Anterior Chamber.pptx

examining AC with slitamp

1. Slit lamp techniques Uses the slitlamp to assesses anterior chamber signs of ocular inflammation Indicators : Uses the appropriate slitlamp techniques in appropriate ambient lighting Slitlamp techniques should include viewing of ff : Corneal endothelium Aqueous humor Iris and Anterior lens surface

2. Describes and grades what they would expect to see in patient with anterior ocular inflammmation

3. Anterior chamber AC Is a fluid-filled space between the back of the cornea and the surface of the iris The fluid found hear is the Aqueous Humor Clear and transparent Helps to maintain pressure in the eye Provides nutrient to the surrounding structures

4. Other structures found close to AC The cornea Endothelium (anterior border) Iris and the pupil (post. border) Anterior lens surface Trabecular meshwork (at the periphery)

5. 3 main ocular pathologies assoc. with AC Hyphema : Pool of blood at AC due to blunt eye trauma Anterior uveitis: Inflammatory process affecting the iris and Cilairy Body Glaucoma (ACG): blockage of the trabecular meshwork Preventing normal flow of aqueous Leading to increase IOP

6. Signs of Anterior Uvietis Hyperamia (or circum-limbal injections) AC cells and flare Keratic precitate KP Posterior synechiae Others: hypopion , fibrins

7. Procedure for general slitlamp Exams Clean the slitlamp contact surface with alcohol wipes infront of the patients Focus the eyepieces Adjust the IPD so that the image is centred in the Field of view of each eye Set the patient comfortably on a stable chair Explain the procedure in lay terms to the patient

8. Instruct the patient to place his or her chin on the chin rest and the forehead against the forehead rest Align the lateral canthus to the aligner marker Dim the room light and ask the patient to look at a fixating target(your ear: right ear: exam righ eye)

9. Slit lamp technique needed to observe AC structures for signs of inflamm . Direct focal illumination: Retro illumination Specular reflection

10. Direct focal illumination parallelepide : broader view of the cornea Endothelium for irregularity Optic section: Assess the layers of the cornea or the lens Depth of foreign body *(KPS virs Abrassions ) Cornical beam: Assess the aqueous humor Flare and cells

11. Retroillumination Involves focusing the beam on surface behind the area to be observed RETINA: assess the iris IRIS: cornea for cornea oedema Keratic precipitates Blood vessels

12. Specular reflection technique Corneal Endothelium Anterior lens surface Red free filter : differentiate pigmented lesions from blood vessels and haemorrhages *(appears darker after filter)

13. Direct illumination using Parallelepide Low to moderate Mag ( 10x -16x) Illumm . System is set at 45 from the microscope From temporal side *(when examing lateral side ) Adjust the beam width to 2mm OBSERVATION: An illumm . Block of cornea tissue will be visible Examine the cornea for any abnormality

14. Optic section Illumn system is set at 45 from VS Start with low mag 10x Place illumn at temporal side (when viewing temporal cornea) Narrow the beam to approx 0.1-0.2mm Focus it sharply on the cornea*(lens) Increase the brightness of the illumination

15. OBSERVATION: A slice of the cornea will be visible epithelium, bowmans membrane, stroma descemets membrane, endothelium Increase the MAG once the object of interest is identify

16. Conical Beam The examiner and px must be dark adapted Illumn angle : 45 to 60 from VS Moderate mag 16x adjust beam width to 1mm x 1mm CB Using pupil as background direct the beam onto the aqueous Two beam will appear, one on cornea and other on the lens; pace b/n is the AC

17. Refocus the microscope in the AC OBSERVATION: Normal AC = dark Red blood cell= reddish yellow dots WBC n fibrin = greyish white Pigmented granules = brown Use Red free filter to diff between RBC and WBC *( RBC appears darker after the green filter )

18. Retro illumination Set the beam to 1-2mm parallelepide beam Low mag *( 10x) Illumn angle is set 45 from the microscope Direct the light onto the iris and view the cornea against light reflected from the iris Mag can be varied when clearer image is required RETINA: illumn angle is zero

19. SPECULAR REFLECTION It’s a monocular technique: one eyepiece may require focusing Assess cornea endothelium Anterior lens surface

20. Corneal endothelium Illumination system set at 45 to 60 from Viewing system Set Mag to approx 16 x Use 2-3mm parallelepide beam Find the image of the illumination bulb then Move the light beam until the image of the bulb is just behind the posterior surface of the parallelepide

21. Angle of incidence is equal to the angle of reflection when the bright mirror image is visible. Focus the back of the parallelepiped A mosaic of hexagonal endothelium cells will appear High mag x40 is require for proper view Check for polymegathism *(cell size v), pleomorphism *(cell shape v)

22. Same for the anterior lens surface OBSERVATION An orange peel appearance of the lens will be seen

23. Grading Anterior chamber inflammation Cells and flare in AC are graded using the Standardization of Uveitis N omenclature (SUN)classification procedure: Cornical beam is require Narrow the height and width of the beam to 1mm x 1mm Move the beam to the centre of the pupil and Focus in the AC midway between the anterior lens surface and cornea endothelium Count cells and grade the degree of obscuration of the Iris details.

24. AC cells Grade 0= < 1 cell Grade 0.5+ = 1-5 cells Grade 1+ = 6-15cells Grade 2+ = 16 -25 cells Grade 3+ = 26-50 cells Grade 4+ = >50 cells

25. Aqueous Flare Graded from 0- 4+ depending of the visibility of the iris details Grade 0 = no flare Grade 1+ = faint flare Grade 2+ = moderate *(iris and lens details remain clear) Grade 3+ = marked *(iris and lens are hazy) Grade 4+ = intense(fibrous and plastic aqueous) The presence or absence of hypopyon shd be nocted