Anterior segment examination

A concise account of how to examine the anterior segment in a patient.

1. Examination of the Anterior Segment of the Eye Dr Udbuddha Dutta Post Graduate Trainee Dept Of Ophthalmology

2. General Inspection Head posture Examination of forehead Examination of eyebrows Examination of lids Lacrimal apparatus Eyeball

3. Techniques General inspection with diffuse light Examination in focal (oblique illumination) Examination of the recess of the angle of the eye Examination of IOP

4. Ophthalmological emergencies: R/O or R/I ruptured globe, retained foreign body, corneal abrasion, diagnose HSV corneal ulcer The Slit-lamp Exam: provides superior magnification & stabilizes pt’s head for removal of corneal FB tangential illumination aids in dx of uveitis/iritis “cells and flare”

5. Concept Works on the same principle as a compound microscope Objective lens Eye piece Illuminating system can be adjusted

6. filter rheostat magnification adjustment beam height slit-width adjustment slit-arm locking knob locking nut (horizontal) intensity locking bar (vertical) focus & lamp height

7. Magnification low power (~10x) is used for survey medium to high (16-40x) for optic section high (40x) for specular reflection normally, light is focused at same point as microscope (“ parfocal ”) Slit width Wide- survey globe/cornea Narrow- depth, width & position of small abnormalities beam as wide as cornea is thick a box of illuminated tissue is seen Thin (slit)- narrowest beam forms an optical section valuating small changes in clarity & pinpointing depth of pathology Light-source intensity Medium to high: most purposes High: optical section Filters neutral, cobalt blue (for fluorescein), red-free

8. Methods of Illumination Diffuse Focal Indirect Retro Specular reflection Scleral scatter

9. Slit lamp technique Start w/ 10x eyepieces & lower powered objective Use lowest voltage setting on transformer ensure open aperture Select the longest slit length Adjust chin rest Pt's eyes approx level w/ marker on head rest Slit arm in line w/ microscope Lamp height w/ slit beam centered vertically on Pt's medial canthus Focus by moving joystick

10. Forehead should be in contact w/ restraint Eyeline should be at level of indicator Angle of slit-arm ~ 60

11. Direct/Focal illumination Most common; focused slit; magnification 10x 40x wide beam for surface study; narrow beam for sections Broad beam section of cornea 2mm slit: corneal surface & stroma to ascertain depth (FB, abrasion) Narrow beam (optic section): easier to determine precise depth resolution improved by reducing slit width; clarity improved w/ increasing mag angle btwn slit-arm & scope ~ 45 - 60 increasing angle up to 90 will increase amnt of cross-section 4 layers of corneal section lens : opacities scatter & reflect more light - appear white (or pigmented) against gray background

12. SLE thru dilated pupil: light source cornea anterior chamber (AC) crystalline lens SLE lateral view showing intra-corneal lens anterior to native crystalline lens

13. “flare” in anterior chamber (AC) cornea iris                                                                                                                           keratic precipitates cornea

14. K eratic P recipitates (direct & retro-illumination )

15. “Rust ring” residual from metallic FB Hypopyon layering in AC

16. Conjunctiva Examined for congestion , presence of foreign bodies or inflammation, reactions in the form of papillae or follicles,cysts , concretions and tumours

17. Vernal Conjunctivitis

18. Sclera Shape Colour Nodules Staphylomas

19. The Cornea Size Surface Sensations Corneal Stains Corneal vessels Curvature Thickness

20. cells & flare cornea iris light source cornea iris no cells or flare

21. Anterior Chamber

22. Abnormal Contents of Anterior Chamber Plasmoid aqueous Pus Lens Vitreous Parasites FB Malignant cells Tumours and cysts Gas Silicone oil

23. Hyphaema

24. Hypopyon – pseudo, inverse

25. The Iris Colour Pattern Synechiae Iridodonesis Nodules Gap/hole Aniridia

26. Mysteries the iris reveals..

27. Pupil Number Location Size Shape Colour Pupillary reaction

28. The Lens Position Shape Colour Transparency Deposits

29. Gonioscopy Indirect Direct The angle structures Applications of gonioscopy

30. Applanation tonometer Based on Imbert Fick Law Goldmann tonometer – gold standard Perkin’s – hand held

31. Ultrasound Biomicroscopy Very high frequency ultrasound waves of 50-80 Mhz allow almost histological resolution of anterior segment Used in assessing anterior chamber depth and thickness of the intraocular mass

32. Thank you