Anterior Segment Examination for Optometrists: Grading Scales (Efron, CCLRU), Staining and van Herick
Last updated: November 2026
RPC Rounds for Optometrists · B.Optom study guide
Grading scales turn "a bit red" into a number that can be compared at the next visit or by another clinician. Optometrists use them every day for contact lens complications, dry eye and angle assessment. Grade to the nearest 0.5 or 0.1 step and always record the scale used.
A systematic slit lamp routine
- Lids and lashes (blepharitis, Demodex collarettes, meibomian glands, lid position).
- Tear film (meniscus height, debris, lipid layer).
- Conjunctiva (bulbar and limbal redness, papillae and follicles after lid eversion).
- Cornea (clarity, staining, vessels, endothelium).
- Anterior chamber (depth by van Herick, cells and flare).
- Iris and lens.
Grading scales
| Scale | Format | Commonly graded |
|---|---|---|
| Efron grading scales | Painted images, grades 0 (normal) to 4 (severe); clinically significant usually at grade 2 or more (or change of more than 1 grade) | Bulbar and limbal redness, lid redness, papillary conjunctivitis, staining, neovascularisation, epithelial microcysts, endothelial polymegethism, blepharitis, meibomian gland dysfunction |
| CCLRU / Brien Holden Vision Institute | Photographs, grades 0–4 | Redness, papillae, staining (type, depth, extent) |
| Oxford scheme | Panels A–E (0–V) for dye staining | Dry eye staining of cornea and conjunctiva |
| NEI / Industry workshop | Five corneal zones each graded 0–3 | Corneal staining in dry eye trials |
Grade 0 normal, 1 trace, 2 mild, 3 moderate, 4 severe. Using decimals (for example 1.5) improves sensitivity for monitoring.
Staining
| Dye | Shows | Tips |
|---|---|---|
| Sodium fluorescein | Epithelial defects and loss of cell junctions; tear film break-up; contact lens fit | Cobalt blue light with a yellow (Wratten 12) filter; look within 1–3 minutes |
| Lissamine green | Dead and devitalised cells, especially conjunctiva (dry eye) | White light, view after 1–4 minutes; less stinging than rose bengal |
| Rose bengal | Unprotected cells (mucin-deficient) | Stings; largely replaced by lissamine green |
- Tear break-up time (TBUT): fluorescein, ask the patient to blink and then stare; time to the first dark spot. Under 10 seconds is abnormal (under 5 seconds clearly). Non-invasive TBUT uses a placido or grid reflection.
- Staining patterns: inferior (exposure, lagophthalmos, dry eye), superior (superior limbic keratoconjunctivitis, lens-related), 3 and 9 o'clock (RGP lenses), diffuse punctate (toxicity from drops or solutions), linear vertical (foreign body under the lid).
Van Herick angle grading
| Grade | Peripheral AC depth vs corneal thickness | Interpretation |
|---|---|---|
| 4 | Equal to or more than the corneal thickness | Wide open |
| 3 | ¼ to ½ corneal thickness | Open |
| 2 | ¼ corneal thickness | Narrow: gonioscopy needed |
| 1 | Less than ¼ | Very narrow: risk of closure, refer |
| 0 | Iridocorneal contact | Closed |
Use a narrow beam at 60° to the viewing axis at the temporal limbus, perpendicular to the cornea. Van Herick is a screening test only; gonioscopy is the reference for the angle.
Practical pearls
- Photograph or draw what you grade: comparing pictures is more reliable than remembering a number.
- Always evert the upper lid in contact lens wearers with itching or mucus: papillary conjunctivitis hides there.
- Check the van Herick before dilating every hyperope over 50.
Where students slip
- Not recording which grading scale was used.
- Assessing fluorescein staining too late, when the dye has diffused.
- Treating van Herick grade 2 as safe without gonioscopy.
Test yourself: flip cards
Quick quiz
Related: Keratometry and Slit Lamp Illumination Techniques for Optometrists, Ophthalmology Grading Systems: 77 Free Quick Tables, Dry Eye Treatment in Ahmedabad, TFOS DEWS III: What Changed in Dry Eye Diagnosis and Treatment, Contact Lens Quick Reference and Fitting Guide: Vertex, LARS, RGP Patterns, Irregular Cornea and Scleral Lenses. Back to the optometry curriculum.
Key sources
- Efron N. Grading scales for contact lens complications. Ophthalmic Physiol Opt. 1998;18:182-186
- Bron AJ, Evans VE, Smith JA. Grading of corneal and conjunctival staining in dry eye (Oxford scheme). Cornea. 2003;22:640-650
- Van Herick W, Shaffer RN, Schwartz A. Estimation of width of angle of anterior chamber. Am J Ophthalmol. 1969;68:626-629
📘 Want more exam-ready material? See Most Commons in Ophthalmology on Kindle, or browse all my books.
Looking for an eye specialist in Ahmedabad? Eye Department at Sadbhaav or book a consultation with Dr. Dhaval Patel.