A single quick-reference page for 77 grading, staging and classification systems used in ophthalmology, grouped by subspecialty. Each system is laid out as a table for fast revision before exams, ward rounds and clinics.
Looking for disease types rather than grades (IC3D dystrophies, ISGEO angle closure, CONAN, SUN, BETT, Chandler, NOSPECS)? See the companion page Classifications in Ophthalmology.
Revise with flip cards
77 cards, one per system. Recall the grades, then tap the card to check. Use Shuffle for random revision.
ADA Evidence Grading System for Clinical Practice Recommendations
Level
Description
A
Clear evidence from well-conducted, generalisable, adequately powered randomised controlled trials (including well-conducted multicentre trials and meta-analyses incorporating quality ratings); compelling non-experimental evidence (the Oxford Centre for Evidence-Based Medicine “all or none” rule); or supportive evidence from well-conducted, adequately powered RCTs at one or more institutions
B
Supportive evidence from well-conducted cohort studies (prospective cohort studies, registries, or meta-analyses of cohort studies), or from a well-conducted case-control study
C
Supportive evidence from poorly controlled or uncontrolled studies (RCTs with major or multiple minor methodological flaws, observational studies with high potential for bias, case series or case reports), or conflicting evidence with the weight of evidence supporting the recommendation
Nasal conjunctiva, cornea and temporal conjunctiva each graded 0–3; total 0–9
NEI/Industry Workshop
Cornea divided into five zones and conjunctiva into six areas, each graded on a 0–3 scale
Oxford scheme
Fluorescein or lissamine green staining matched to panels graded 0 to V
Lissamine green stains devitalised cells like rose bengal but is far less irritating.
Keratoconus: Belin ABCD staging
A = anterior radius of curvature (ARC, 3 mm zone); B = posterior radius of curvature (PRC); C = thinnest pachymetry; D = best-corrected distance acuity. Each parameter is staged separately, e.g. A2 B3 C1 D2.
Stage
ARC (mm)
PRC (mm)
Thinnest (µm)
BDVA
0
> 7.25 (< 46.5 D)
> 5.90
> 490
≥ 20/20 (6/6)
1
> 7.05 (< 48.0 D)
> 5.70
> 450
< 20/20
2
> 6.35 (< 53.0 D)
> 5.15
> 400
< 20/40 (6/12)
3
> 6.15 (< 55.0 D)
> 4.95
> 300
< 20/100 (6/30)
4
< 6.15 (> 55.0 D)
< 4.95
≤ 300
< 20/400 (6/120)
A scarring modifier is added: − no scar, + scar not obscuring iris details, ++ scar obscuring iris details. Unlike Amsler-Krumeich, ABCD includes the posterior surface, so it picks up early disease.
Angle grading by visible structures (RP Centre, AIIMS)
Grade
Deepest structure visible
0
Closed
1
Dipping of light only
2
Schwalbe's line
3
Anterior trabecular meshwork
4
Posterior trabecular meshwork / scleral spur
5
Ciliary body band
6
Root of iris
Trabecular meshwork pigmentation (Scheie)
Grade
Pigmentation
0
None
1+
Trace
2+
Mild
3+
Moderate (similar to iris pigmentation)
4+
Severe
Van Herick grading of peripheral anterior chamber depth
Peripheral chamber depth compared with peripheral corneal thickness (PCT) at the temporal limbus.
Grade
AC depth
Interpretation
4
≥ 1 PCT
Wide open
3
¼ to ½ PCT
Open
2
¼ PCT
Narrow; gonioscopy needed
1
< ¼ PCT
Very narrow; gonioscopy needed
Slit / 0
Iridocorneal contact
Dangerously narrow or closed
Limbal chamber depth (LCD) method: a modification with seven grades expressed as a percentage of corneal thickness (0%, 5%, 15%, 25%, 40%, 75% and ≥100%). It performs better for detecting established PACG and is widely used in epidemiological research.
Visual field severity: Hodapp-Parrish-Anderson
Stage
Mean deviation
Early
Better than −6 dB
Moderate
−6 to −12 dB
Severe
Worse than −12 dB
Additional criteria consider the number of depressed points and points within the central 5°.
Diabetic retinopathy: International (ICDR) classification
Grade
Findings
No apparent retinopathy
No abnormalities
Mild NPDR
Microaneurysms only
Moderate NPDR
More than microaneurysms but less than severe NPDR
Severe NPDR
Any one of the 4-2-1 rule (see below), and no PDR
PDR
Neovascularisation (NVD/NVE) and/or vitreous or preretinal haemorrhage
4-2-1 rule: severe intraretinal haemorrhages (≥ 20) in 4 quadrants, definite venous beading in 2 quadrants, or prominent IRMA in 1 quadrant. Two or more features = very severe NPDR.
Any of: retinal thickening within 500 µm of the foveal centre; hard exudates within 500 µm with adjacent thickening; a zone of thickening ≥ 1 disc area, part of which lies within 1 disc diameter of the centre
ICDR DME severity
Mild: thickening or exudates distant from the centre; Moderate: approaching but not involving the centre; Severe: involving the centre
The first system to correlate retinal findings with the severity and prognosis of hypertension.
Grade
Findings
1
Mild generalised arteriolar narrowing
2
More marked narrowing with focal constriction and arteriovenous nicking
3
Grade 2 plus flame haemorrhages, cotton-wool spots and hard exudates
4
Grade 3 plus optic disc swelling
Main limitation: grades 1 and 2 are hard to tell apart, which led to newer classifications.
Hypertensive retinopathy and arteriolosclerosis: Scheie (1953)
Grade
Hypertensive changes
Arteriolosclerotic changes
0
No changes
Normal
1
Barely detectable arteriolar narrowing
Broadened light reflex, minimal AV compression
2
Obvious narrowing with focal irregularities
Light reflex and crossing changes more prominent
3
Grade 2 plus retinal haemorrhages and/or exudates
Copper-wire arterioles, more prominent AV compression
4
Grade 3 plus papilloedema
Silver-wire arterioles, severe AV crossing changes
Hypertensive retinopathy: Wong and Mitchell (2004)
Grade
Signs
Systemic association
None
No detectable signs
None
Mild
Generalised or focal arteriolar narrowing, AV nicking, arteriolar wall opacity (silver wiring)
Modest association with stroke, coronary heart disease and mortality
Moderate
Haemorrhages (blot, dot or flame), microaneurysms, cotton-wool spots, hard exudates
Strong association with stroke, cognitive decline and cardiovascular mortality
Malignant
Moderate retinopathy plus optic disc swelling
Strong association with mortality
Arteriolosclerosis
Grade
Findings
1
Subtle broadening of the arteriolar light reflex, mild generalised attenuation, vein concealment
2
Obvious broadening of the light reflex; deflection of veins at AV crossings (Salus sign)
3
Copper-wiring; banking of veins distal to crossings (Bonnet sign); tapering of veins on both sides of crossings (Gunn sign); right-angled deflection of veins
Score each eye: 1 point for one or more large drusen (≥ 125 µm) and 1 point for any pigment abnormality. If neither eye has large drusen, intermediate drusen in both eyes count as 1 point. Advanced AMD in one eye scores 2 for that eye. Add both eyes (0–4).
Total score
5-year risk of advanced AMD
0
About 0.5%
1
About 3%
2
About 12%
3
About 25%
4
About 50%
Patients with intermediate AMD (or advanced AMD in one eye) benefit from AREDS2 supplements.
Medium tumours: brachytherapy and enucleation gave the same survival (COMS). The AJCC/TNM system (T1–T4 by thickness and diameter) is used for staging today.
Posterior to the equator: focal, diffuse or subretinal contraction; extent in clock hours
CA 1–12
Anterior to the equator: subretinal, circumferential or anterior-displacement contraction; extent in clock hours
Contraction types: 1 focal (posterior); 2 diffuse (posterior); 3 subretinal (posterior or anterior); 4 circumferential (anterior); 5 anterior displacement (anterior). Neither system accounts for the number and size of breaks, previous surgery, or the biological activity of PVR. Pathogenesis stages: cellular activation, proliferation, extracellular matrix formation and remodelling, contraction.
Demarcation line: thin, flat, white line between vascular and avascular retina
2
Ridge: the line gains height and width; isolated neovascular tufts (“popcorn”) may lie behind it
3
Extraretinal neovascular proliferation from the ridge into the vitreous
4
Partial retinal detachment: 4A extrafoveal, 4B including the fovea
5A
Total retinal detachment, optic disc visible (open funnel)
5B
Total detachment, disc not visible (closed funnel or retrolental tissue)
5C
Stage 5B with anterior segment abnormalities
Zones: I (circle with a radius twice the disc–fovea distance), posterior zone II (two disc diameters beyond zone I), II and III. Plus disease is a spectrum of dilation and tortuosity of posterior pole vessels, with pre-plus as the milder form. A-ROP (aggressive ROP) replaces AP-ROP. ICROP3 also defines regression, reactivation and persistent avascular retina.
Zone I any stage with plus; zone I stage 3 without plus; zone II stage 2 or 3 with plus
Treat
Type 2
Zone I stage 1 or 2 without plus; zone II stage 3 without plus
Monitor closely
Retinoblastoma: International Intraocular Retinoblastoma Classification
Group
Features
A
Small tumours (< 3 mm) confined to the retina, ≥ 3 mm from the foveola and ≥ 1.5 mm from the disc
B
All other tumours confined to the retina; subretinal fluid < 3 mm from the tumour base without seeding
C
Subretinal fluid 3–6 mm from the tumour, or vitreous/subretinal seeds < 3 mm from the tumour
D
Subretinal fluid > 6 mm from the tumour, or seeds > 3 mm from the tumour
E
Poor prognosis features: tumour > two-thirds of the globe, anterior segment or ciliary body involvement, iris neovascularisation or NVG, opaque media from haemorrhage, tumour necrosis with orbital cellulitis, or phthisis
1: punctum pointing upwards away from the globe; 2: partial lid eversion with scleral show; 3: conjunctival hyperaemia and mucosal thickening; 4: grade 3 plus exposure keratopathy
📘 Want the exam-ready deep dive? This topic, and much more is covered in Ophthalmology Explorer (A High-Yield Clinical Reference for Ophthalmology Residents, Fellows & Board Exams) — available on Kindle. See all my books.
Written and medically reviewed by Dr. Dhaval Patel, MD (Ophthalmology, AIIMS New Delhi) · Editorial policy
