. 2021 May 11;35(10):2685–2698. doi: 10.1038/s41433-021-01572-4

Table 5.

DR Screening strategy [8–15].

Question	Condition	Strategy	County guidelines
Question	Condition	Strategy	Canada	Latin Am	England	India	Kenya	NZ	AAO PPP
Who	All DM	Trained personnel	+	-	+	+	+	+	+
		Ophthalmologist	+	+	+	+	+	+	+
		Teleophthalmology	+	-	+	+	-	+	+
How	All DM	Fundus photo	+	+	+	+	+	+	+
		Ophthalmoscopy	+	+	+	+	+	+	+
		National screening	-	-	+	-	-	+
When	T2DM	At diagnosis	+	+	+	+	+	+
	T1DM	On basis of puberty			-	+			+
		Review on basis of age	+ (>15 years)	+ (>15 years)	12 years and above	+ (>10 years)		+ (>10 years)
		Review on basis of duration of DM(5- year interval)	+	+		+	+	+	+
	Pregnancy	Pre-existing DM only	+		+	+		+
	Pregnancy	All gestational DM		+			+	+	+
Basic tests	ALL DM	Visual acuity	+	+	+	+	+	+	+
		Fundus\camera preference	Non-mydriatic	Mydriatic	Non-mydriatic	Non-mydriatic	Mydriatic	Non mydriatc	Color
		Fundus field	7-field/UWF	NS	2 × 45⁰	Variable	NS	4–750	Not specified
		Mydraisis prefered	+	+	+	+	+	+	+
Referral	Disease severity	Non STDR	Annual	Annual	R0–R3^a	Annual	Annual	R0–R5^a M0-M6^a	Annual
Referral	Disease severity	STDR	Urgent	Urgent		Urgent	Urgent		Urgent
ICO	Referral by disease and county economics				Referral criteria by VA, disease, infrastructure
	No/mild NPDR. Referral	LMIC: 1–2 years	HIC-6–12 months		Vision	<20/40; VA reduction symptoms
	Mod- Severe NPDR & worse	LMIC-Urgent	HIC-Urgent		Disease status	Mod/severe NPDR & worse
	Pregnancy. Pre-existing DM	LMIC-28 weeks	HIC- 16–20 weeks		Infrastructure	VA, retinal exam not obtained

DM diabetes mellitus, NS not specified, NZ New Zealand, UWF Ultra-widefield.

^aBased on disease severity of disease.