Diabetic retinopathy among the elderly with type 2 diabetes: A Nationwide longitudinal registry study.

PURPOSE: To investigate the prevalence, incidence and risk factors of DR in elderly people living with type 2 diabetes. METHODS: Individuals >80 years, in the Swedish National Diabetes Register (NDR) between 2008 and 2017, were included. Prevalence and incidence were calculated and stratified by age. Estimates were assessed by longitudinal binary logistic regression models. RESULTS: One hundred forty-one thousand, one hundred fifty-eight individuals with type 2 diabetes were included, median age 83 years, 53.3% females and with a median HbA1c 52 mmol/mol. The DR prevalence was stable at 336.2 cases/1000 patients in 2008 (95% CI, 330.2-342.3), with no significant changes during the 10-year period. Crude DR incidence rate: 88.5 cases/1000 patient years (95% CI, 87.6-89.4). The incidence rate was lower at higher ages. The effect of age on incident DR varied by sex, with females having an increasingly higher risk than males from 83 years of age, OR 1.25 (1.11-1.42) at age 90 years. The risk of incident DR with longer diabetes duration increased more rapidly at worse glycaemic control. CONCLUSION: The growing population of elderly with type 2 diabetes shows a stable proportion of DR and proposes an increased need for DR screening and eye care. Established risk factors for DR, such as diabetes duration and level of glycaemic control, are also important in the elderly; however, age and sex should be considered.

Screening for Diabetic Retinopathy with Extended Intervals, Safe and Without Compromising Adherence: A Retrospective Cohort Study.

INTRODUCTION: Screening for diabetic retinopathy (DR) prevents blindness through the early detection of sight-threatening retinal microvascular lesions that respond to timely local treatment. However, the provision of easy and regular access to DR screening programs is currently being challenged by the increasing prevalence of diabetes. One proposed solution is to extend the screening interval for patients at low risk for progression of retinopathy. To date, most providers of screening programs have hesitated to implement a strategy of extended intervals due to the lack of data on whether adherence and safety are compromised when retinal examinations occur less frequently. In the study reported here, we investigated adherence to the screening program and progression of retinopathy in patients with type 2 diabetes participating in a DR screening program with extended intervals. METHODS: This was a retrospective study that included 1000 patients with type 2 diabetes mellitus who attended a screening program for DR. The patients were consecutively placed into a low-risk patient cohort with no retinopathy or into an intermediate-risk patient cohort with mild retinopathy (each cohort n = 500). Screening intervals were 36 months for the low-risk cohort and 18 months for the intermediate-risk cohort. RESULTS: The 1000 subjects enrolled in the study had a median age of 68 (interquartile range 12) years and 60.4% were men. At the follow-up screening visit, data on 102 subjects were not included in the analysis of adherence rate due to death, severe systemic illness, other concurrent eye disease or migration. Among the 898 remaining subjects, adherence to the screening program was 93.7% (413/443) in the 36-month group and 98.3% (449/455) in the 18-month group (p < 0.0001). Non-adherence decreased with increasing age (odds ratio 0.92, 95% confidence interval 0.888-0.954, p = 0.0005). At follow-up, 65 subjects showed progression of retinopathy; none had worse than moderate retinopathy. Risk factors for DR and treatment for hyperglycemia, hypertension and hyperlipidemia were compared among subjects in the low-risk cohort: non-adherent subjects did not differ from their adherent counterparts without progression of DR, but the former had a shorter duration of diabetes and higher diastolic blood pressure than adherent subjects with progression of DR (4.5 vs. 7.5 years, p = 0.007; and 80 vs. 75 mmHg, p = 0.02, respectively). CONCLUSION: The results suggest that screening DR at extended intervals can be achieved with high adherence rates without compromising patient safety. However, younger subjects and those at higher risk of progression may require extra attention.

Progression of early retinal dysfunction in diabetes over time: results of a long-term prospective clinical study.

We explored signs of retinal dysfunction over time in diabetic subjects before or early in the course of retinopathy. Patients with no, mild, or moderate retinopathy were consecutively recruited and underwent standard automated perimetry, visual acuity measurement, and fundus photography. These examinations and measurements of HbA1c and blood pressure were repeated for up to 5 years from baseline. Visual field improvement/deterioration in diabetic subjects was evaluated using significance limits for change. Progression or regression of retinopathy was defined as a two-step change on the Early Treatment Diabetic Retinopathy Study final severity scale. Seventy-four subjects completed at least 3 years of follow-up, and 22% showed visual field worsening, defined as repeated significant deterioration at ≥10% of the test points, whereas only 1% showed field improvement. Worsening occurred in subjects both with and without vascular lesions. The degree of retinopathy was stable throughout the observation period in 68 of 74 eyes, improved in 4, and worsened in 2. Visual field deterioration was not correlated with a change in retinopathy. By using perimetry with an analysis tailored for monitoring diabetic subjects, we were able to demonstrate progression of retinal dysfunction over time, which may represent early signs of retinal neurodegeneration.

Functional and structural change in diabetic eyes. Interim results from an ongoing longitudinal prospective study.

PURPOSE: To presents results after 18 months of follow-up of a longitudinal study aiming at exploring the correlation between diabetic retinal vascular lesions and functional change. METHODS: Patients were consecutively recruited from attendees to the screening program for diabetic retinopathy. Subjects are followed every sixth month for the first 3 years and thereafter annually up to 5 years. Progression of diabetic retinopathy is evaluated using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale and improvement/deterioration in visual fields by predefined significance limits for change. RESULTS: Of 81 subjects, with no/mild/moderate diabetic retinopathy included, 76 have passed the 18-month visit. At that time, retinal progression by two steps according to the ETDRS scale had occurred in two subjects. Visual acuity was -0.14 logMAR and had decreased with two letters (0.04 logMAR) (p < 0.001) from baseline. The global visual field index mean deviation was almost unchanged with a negligible improvement of 0.03 dB (p = 0.79). In 21 subjects, repeated significant deterioration was seen in ≥10% of all points tested in the field, while almost no improved points were noted. The two subjects with retinal progression were not among those 21 with indication of perimetric progression. CONCLUSIONS: This is, to our knowledge, the first longitudinal study evaluating change of visual fields in a representative diabetic cohort with no or mild/moderate retinopathy. In this interim report, we demonstrate deteriorated perimetric sensitivity in subjects already at 18 months of follow-up. The results will have implications for evaluating change in visual function in future clinical trials.

Stable refraction and visual acuity in diabetic patients with variable glucose levels under routine care.

PURPOSE: To investigate how refraction and visual acuity may vary in patients with diabetes under routine care. METHODS: Fifty-three eyes of 53 patients with various degrees of diabetic retinopathy were examined prospectively on four different occasions within a month. Refraction, best-corrected visual acuity (expressed as logMAR score) and blood glucose were measured on each occasion. Intraindividual variability was calculated as the range between the highest and lowest measurements. Associations between blood glucose levels and each of the other variables were tested by linear regression analysis for each patient. RESULTS: Refraction was completely stable in 43 patients and changed only slightly in 10, in whom the mean intraindividual variability of the spherical equivalent was 0.4 dioptres. Visual acuity test results were also highly reproducible. Mean intraindividual variability in visual acuity was 0.08 logMAR. Mean haemoglobin A1c (HbA1c) was 7.3 ± 1.5% but individual blood glucose levels ranged from 2.8 to > 22.2 mmol/l. Intraindividual variability ranged from 0.5 to 18.1 mmol/l, with a median of 6.0 mmol/l for the entire group. There were no associations between refraction or visual acuity and blood glucose levels or inter- or intraindividual glucose variations. CONCLUSION: Refraction and visual acuity test results were highly reproducible and stable in patients with reasonably well controlled diabetes but variable blood glucose levels under routine care.

Test-retest variability for standard automated perimetry and short-wavelength automated perimetry in diabetic patients.

PURPOSE: To assess limits for significant improvement or deterioration of visual fields in diabetic patients based on short-term test-retest variability in subjects with different degrees of retinopathy. METHODS: Fifty patients with diabetic retinopathy ranging from level 10 to 75 [according to the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale] were tested repeatedly with both standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with short intervals. The association between visual field loss and degree of retinopathy outside fovea was analysed. Test-retest variability of global and local visual field indices and prediction limits for significant change were calculated. RESULTS: The amount of visual field loss was significantly associated to the degree of retinopathy, with a correlation coefficient of -0.51 for SAP (P = 0.0003) and -0.45 for SWAP (P = 0.002). Global test-retest variability was smaller with SAP than with SWAP (P < 0.0001). For both SAP and SWAP, local test-retest variability was considerably smaller at test points with normal sensitivity than at test points with reduced sensitivity (P < 0.0001). Paracentral test points within 10 degrees of eccentricity had less variability than peripheral points (P < 0.0001), implying that smaller change is required to reach statistically significant improvement or deterioration at initially normal and paracentral points than at depressed points and peripherally located test points. CONCLUSION: Our results propose that SAP, as well as SWAP, can be useful for monitoring visual function outside fovea in diabetic patients with various degrees of retinopathy. We report a preference for SAP because of less variability generally. Limits for significant improvement or deterioration have been assessed but need future validation in a longitudinal study.