45 year old patients with haemoglobin level of 11% had a 86.1% risk of any retinopathy, 22.4% risk of blindness with no screening and 10.1% risk of blindness with annual screening, and spent 8.1 years blind with no screening and 7.7 years with annual screening.

65 year old patients with haemoglobin level of 9% had a 49.4% risk of any retinopathy, 2.7% risk of blindness with no screening and 1.2% risk of blindness with annual screening, and spent 4.3 years blind with no screening and 4.2 years with annual screening.

75 year old patients with haemoglobin level of 7% had a 35.6% risk of any retinopathy, 0.8% risk of blindness with no screening and 0.3% risk of blindness with annual screening, and spent 3.0 years blind with no screening and 2.7 years with annual screening.

Risk of blindness varied by age and haemoglobin level. More frequent screening was more effective. For a 45 year old patient with haemoglobin level of 11%, screening every 5 years decreased time spent blind by 164 days. Screening every 3 years reduced time spent blind by 24 days and annual screening further reduced time spent blind by 21 days. For most groups, the marginal return on increasing screening frequency is small.

5.3 million people have been diagnosed as having type 2 diabetes. This population will accumulate 50,081,384 QALYs without any retinopathy screening and 50,216,915 QALYs with screening at 5-year intervals.