The Influence of Type 1 Diabetes Mellitus on Amplitude of Accommodation

BCLA CLEAR Presbyopia: Epidemiology and impact

The global all-ages prevalence of epidemiologically-measured 'functional' presbyopia was estimated at 24.9% in 2015, affecting 1.8 billion people. This prevalence was projected to stabilise at 24.1% in 2030 due to increasing myopia, but to affect more people (2.1 billion) due to population dynamics. Factors affecting the prevalence of presbyopia include age, geographic location, urban versus rural location, sex, and, to a lesser extent, socioeconomic status, literacy and education, health literacy and inequality. Risk factors for early onset of presbyopia included environmental factors, nutrition, near demands, refractive error, accommodative dysfunction, medications, certain health conditions and sleep. Presbyopia was found to impact on quality-of-life, in particular quality of vision, labour force participation, work productivity and financial burden, mental health, social wellbeing and physical health. Current understanding makes it clear that presbyopia is a very common age-related condition that has significant impacts on both patient-reported outcome measures and economics. However, there are complexities in defining presbyopia for epidemiological and impact studies. Standardisation of definitions will assist future synthesis, pattern analysis and sense-making between studies.

Accommodative disorders in non-presbyopic subjects with type 1 diabetes without retinopathy: A comparative, cross-sectional study

PURPOSE

The purpose of this study was to assess accommodative function in non-presbyopic individuals diagnosed with type 1 diabetes (T1D) without any signs of retinopathy, to determine the existence of possible accommodative disorders related to this disease, and to determine the influence of T1D duration and glycosylated haemoglobin values on accommodative function.

METHODS

This comparative, cross-sectional study included 60 participants between 11 and 39 years old, 30 with T1D and 30 controls, with no previous eye surgery, ocular disease or medication that could affect the results of the visual examination. Amplitude of accommodation (AA), negative and positive relative accommodation (NRA and PRA), accommodative response (AR) and accommodative facility (AF) were assessed using the tests that showed the highest repeatability. Participants were classified based on normative values into 'insufficiency, excess or normal results', and a diagnosis of accommodative disorders (accommodative insufficiency, accommodative infacility and accommodative excess) was made.

RESULTS

Participants with T1D had statistically significant lower AA and AF and higher NRA values than the controls. Furthermore, AA was significantly and inversely correlated with age and the duration of diabetes; however, AF and NRA were only correlated with disease duration. In the classification by accommodative variables, a higher percentage of 'insufficiency values' was observed in the T1D group (50%) than in the control group (6%; p < 0.001). In terms of accommodative disorders, accommodative infacility was the most prevalent (15%), followed by accommodative insufficiency (10%).

CONCLUSIONS

Our findings indicate that T1D affects most accommodative parameters, with accommodative insufficiency being associated with this disease.

Modelling ocular ageing in adults with well-controlled type I diabetes

Purpose

To develop a paraxial eye model based on a previously collected cohort of adults with well-controlled type 1 diabetes mellitus (DM1) and a limited range of refractive errors.

Methods

The study used the previously published biometric data of 72 participants (Age: 41.5 ​± ​12.4 years) with DM1. Measurements included objective refraction, anterior and posterior corneal radii of curvatures, and internal distances. Moreover, phakometry was used to determine the lens radii of curvature and lens equivalent indices, from which the lens powers were calculated. A multivariate linear regression was performed for each biometric parameter with respect to current age (Age), the time since the onset of diabetes (Tdb), and current levels of glycated hemoglobin (HbA1c). The vitreous chamber depth was determined from other distances, and lens equivalent index was chosen to balance the models. These were compared with an existing model for non-diabetic eyes.

Results

Some dependent parameters were not affected by the independent variables (spherical equivalent, anterior corneal radius of curvature, central corneal thickness), some were affected by time since onset (the lens radii of curvatures, anterior chamber depth) and others were affected by both age and time since onset (posterior corneal radius of curvature, lens thickness, axial length). None of the dependent parameters were affected by current levels of HbA1c.

Conclusions

The proposed model accurately describes the age-related changes in the eyes of people with DM1. In this description the age of diabetes onset plays an important role, especially if the diabetes onset occurred during childhood.

Starting Time of Presbyopic Eyeglasses Wear and Lifestyle

Purpose

Presbyopia is a serious burden in the aged population, however, the factors affecting its progression have not been fully determined. The aim of this study was to explore the association between the time of starting to wear presbyopic eyeglasses and lifestyle, in participants aged from 40 to 59 years.

Methods

We selected the sample to be representative of sex and age for the age group 40 to 59 years. Participants completed a web-based survey on presbyopia-related questions, symptomatic dry eye, sleep habits, Pittsburgh Sleep Quality Index, subjective happiness scale (SHS), and other lifestyle-related questions including marital status, income, screen time, sun exposure, family history of myopia, and the frequency of regular visits to medical services.

Results

We found 529 participants (26.5%) used near correction, with a mean age for first near correction of 47.8±4.8 years. An earlier commencement of near correction correlated with hyperopia (P = 0.013), late wake-up time (P = 0.010), a poor subjective sleep quality score (P = 0.019), and a low annual income score (P = 0.025), after adjusting for age and sex. Stratification by income demonstrated the low-income group exhibited more dry eye, later wake-up time, longer sleep latency, longer sleep duration, worse sleep efficacy, lower SHS score, and a higher prevalence of living alone compared with the high-income group. The usage of corrective devices did not differ between the two groups.

Conclusions

The current study suggests a healthy sleep habit may delay the need for near correction, in addition to myopia. Shift work and circadian rhythm disruption might exacerbate presbyopia progression.

Vision-related symptoms, accommodative and binocular vision performance in young diabetics vs. normal controls

PURPOSE

To compare accommodative and binocular vision performance between young diabetic subjects and normal controls, and to investigate the correlation of accommodative/binocular indices with the severity of diabetes.

METHODS

Thirty young subjects with diabetes mellitus (DM) and 30 age-matched normal controls were recruited in this hospital-based cross-sectional study. DM was diagnosed by a haemoglobin A1c (HbA1c) higher than 6.5%. The status of vision-related symptoms was examined by the convergence insufficiency symptoms survey (CISS). All participants underwent a complete optometric examination including visual acuity measurement, objective and subjective refraction, accommodative and binocular vision assessments.

RESULTS

All study participants were between 18 and 40 years of age. There were no statistically significant differences in best-corrected visual acuity (BCVA), sphere, cylinder and spherical equivalent refraction (SE) between the diabetes and control groups. The median near point of convergence (NPC) was significantly more remote in diabetics compared with the control group. Mean accommodative amplitude (AA) and vergence facility (VF) and the median monocular accommodative facility (AF) were significantly lower in diabetic subjects compared with normal controls. In addition, the median accommodative lag in the diabetic group was significantly higher than the control group. A significantly higher percentage of the diabetic group were symptomatic (26.6%), compared with the controls (6.6%). The NPC and accommodative lag showed a significant positive correlation with the HbA1c level, while VF, AA and AF exhibited a significant negative correlation with HbA1c.

CONCLUSION

Aspects of accommodative and binocular vision performance are strongly affected by DM. There is also a significant correlation between accommodative and binocular disorders with the severity of DM. A significant percentage of young subjects with DM have severe vision-related symptoms.

The thyroid hormone levels and glucose and lipid metabolism in children with type 1 diabetes: a correlation analysis

BACKGROUND

Type 1 diabetes mellitus (T1DM) is common in clinical setting, the relationship between thyroid hormone levels and glucose and lipid metabolism in patients with T1DM remains unclear. We attempted to analyze the correlation of thyroid hormone levels and blood glucose and lipid metabolism in children with normal thyroid function.

METHODS

Children with T1DM were selected, and 85 healthy children who underwent physical examinations in our hospital as control group. The characteristics and laboratory testing results were compared, the correlation of thyroid hormone levels with blood glucose and blood lipids was analyzed by Pearson correlation analysis.

RESULTS

A total of 167 participants were included. the low-density lipoprotein-cholesterol (LDL-C), triglyceride (TG), fasting blood glucose (FBG), and glycated hemoglobin (HbAlc) in T1DM patients were higher than those in healthy controls, while the high-density lipoprotein-cholesterol (HDL-C), thyroid stimulating hormone (TSH) and free triiodothyronine (FT3) in T1DM patients were lower than that of healthy children (all P<0.05). TSH was positively correlated with LDL-C (r=0.169, P=0.032), TC (r=0.182, P=0.017) and TG (r=0.197, P=0.008), negatively correlated with FBG (r=-0.196, P=0.023) and HbAlc (r=-0.328, P=0.002). FT3 was negatively correlated with TG (r=-0.182, P=0.011), FBG (r=-0.184, P=0.009) and HbAlc (r=-0.223, P=0.005). TG in the high TSH group and the middle TSH group is higher than that of low TSH group. However, FBG and HbAlc were lower than those in the low TSH group (all P<0.05). Compared with the low FT3 group, the TG, FBG and HbAlc decreased in the high and middle FT3 group (all P<0.05).

CONCLUSIONS

The serum TSH are closely associated with FT3 and glycolipid metabolism in children with T1DM, which may be the useful indicators to assess the severity of T1DM in clinical settings to provide insights into the management of T1DM.