VISUAL PROGNOSIS IMPROVING FOR DIABETIC PATIENTS

An analysis of 30 years of data from the Finnish Register of Visual Impairment indicates the visual prognosis of diabetic patients has improved over time. However, some of the positive trends observed between the first and second decades of the study seem to have levelled off more recently, perhaps as a result of the worsening epidemiology of diabetes itself, said Hannu Uusitalo MD, PhD, at the annual meeting of the Association for Research in Vision and Ophthalmology. The Finnish Register of Visual Impairment is a government-funded national register organised by the National Institute of Health and Welfare in Finland and maintained by the Finnish Federation of the Visually Impaired. By law, healthcare providers must submit information about any patient who fulfils the WHO criteria for visual impairment (ie, corrected visual acuity permanently <0.3 in the better eye or diameter of the visual field <20 deg).

Between 1980 and 2010, 4,087 patients were entered into the registry with diabetic retinopathy (DR) listed as their primary cause for visual impairment. In order to assess changes over time in visual impairment due to DR, the patients were further divided as to whether the cause of their visual impairment was proliferative or non-proliferative disease (PDR or NPDR) and into three time cohorts by decade. Patient age at time of notification of visual impairment, impairment severity based on the proportion of individuals who met the WHO definition for blindness at registry entry, and mean age of death were analysed for each decade for each diagnostic group. For the PDR subgroup, the median age at the time of notification of visual impairment was 39 years for patients entered into the registry during the 1980s, 62 years for the 1990s cohort, and 59 years for those entered during the first decade of the 21st century. During these three time periods, the median age of death was 42, 72, and 68 years respectively, while the proportion of blind persons decreased continuously, albeit most dramatically between the first and second decades, from 42 per cent to 22 per cent and then to 15 per cent over the last 10 years, Dr Uusitalo reported.

For the NPDR subgroup, there was little change across the three time cohorts in the median age at the time of notification of visual impairment (71, 73, and 73 years) or in the age at death (76, 79, and 78 years). The proportion of blind persons also was relatively unchanged between the 1980s and 1990s (10 per cent and nine per cent), but decreased to four per cent in the most recent cohort. “This study showed that visual impairment due to PDR was less severe in the past 20 years than it was in the 1980s. However, the end of the favourable developments in notification age of visual impairment and age of death that occurred early is probably due to an unfavourable development in the incidence of diabetes itself,†said Dr Uusitalo, professor of ophthalmology, University of Tampere, Finland, and chief medical officer, Finnish Registry of Visual Impairment. Dr Uusitalo noted that Finland ranks number one in the world for incidence of Type 1 diabetes and the incidence of Type 2 diabetes is also relatively high.