Outcomes of 35-year duration of type 1 diabetes and proliferative diabetic retinopathy on functional vision and quality of life: Benefits of good glycemic control.

Aims: To evaluate clinical outcomes, functional vision and quality of life (QoL) after 35-year duration of type 1 diabetes (T1D) and proliferative diabetic retinopathy (PDR).

Methods: A population-based cohort study of T1D. Data from laboratory tests, ophthalmic examinations, multifunctional vision-test, and 15D-QoL measurements were analysed.

Results: 35 % of the original cohort (n = 216) had PDR, and 48 % of them were re-evaluated. They were 41 ± 3 [34-46] years old and 62 % were males. The duration of T1D was 35 ± 4 [29-41] years. 76 % had transdermal glucose monitoring. HbA1c had decreased from 80.1 mmol/mol to 63.6 mmol/mol (p < 0.001). Visual acuity was 73-77 ETDRS-letters. Two patients had visual impairment. Visual field sensitivities were lower in PDR vs. healthy controls (23.2 ± 3.9 dB vs. 26.9 ± 1.0 dB, and 14.9 ± 5.6 dB vs. 21.0 ± 2.0 dB, respectively, p < 0.001). Contrast sensitivity was similar, but the reaction time was longer in the PDR group (490.5 ms vs. 462.8 ms, p = 0.004). QoL-parameters concerning sleeping, usual activities, discomfort and symptoms, and sexual activity had decreased, but improved for mobility and distress.

Conclusions: Long-term visual prognosis and QoL remained good despite the declined functional vision caused by PDR.