Diabetic retinopathy, cataracts and glaucoma are common complications of type 2 diabetes mellitus (T2DM), and rank among the leading causes of visual impairment and blindness in Australia.  The aim of the present study was to determine the modifiable and non-modifiable factors associated with poor visual acuity (VA) in T2DM in an urban Australian population.

The Fremantle Diabetes Study Phase II (FDS2) recruited 1551 residents with T2DM between 2008 and 2011 from a postcode defined area of 157,000 people. All but 16 had valid VA and other data. VA was ascertained using the ETDRS chart and coded as normal or near normal vision (≤6/19) or poor vision or blindness (>6/19), using the best corrected eye as per World Health Organisation guidelines. Multiple logistic regression was used to identify independent associates of poor VA.

The mean±SD age of participants was 65.7±11.6 years, 52.1% were male and their median [IQR] diabetes duration was 8.8 [3.0-15.8] years.  Independent associates of poor VA are presented in the Table.

These associations are indicative of causes and consequences of poor VA. Poor VA was associated with diabetic nephropathy and its treatment (negatively) consistent with retinopathy as part of widespread microvascular disease. Those not fluent in English were at greater risk of poor VA, perhaps reflecting barriers to timely or adequate care.  Mobility problems and major hypoglycaemia may result from poor VA. The risk of hypoglycaemia may be increased by difficulties with self-blood glucose monitoring which was inversely associated with VA.

Health professionals need to be aware that older people, especially those from a non-English speaking background and with impaired renal function, may have poor VA, which has potentially serious consequences for their diabetes management.