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 ~ 600

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 ~ 450 - 600
• increasing angle up to 900 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 lensSLE lateral view showing intra-
corneal lens anterior to native
crystalline lens

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

14. Keratic Precipitates (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 corneairis 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