Visual functions and disability in diabetic retinopathy patients

Blindness among Patients with Type II Diabetes Mellitus Presenting to the Outpatient Department of Ophthalmology of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Diabetic retinopathy is a major microvascular complication of diabetes, and may progress to sight-threatening stages causing blindness with a consequent decrease in their quality of life. This study aimed to find out the prevalence of blindness among patients with type II diabetes mellitus attending the Outpatient Department of Ophthalmology of a tertiary care hospital.

Methods

A descriptive cross-sectional study was conducted among patients with type II diabetes mellitus presenting to the Outpatient Department of Ophthalmology of a tertiary care centre from 2 August 2021 to 30 June 2022 after receiving ethical approval from the Institutional Review Committee (Reference number: 74/2021). Diabetic patients underwent detailed eye examination including vision, slit lamp biomicroscopy examination, and fundus evaluation with full pupil dilation. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.

Results

Among 449 type II diabetic patients, blindness was seen in 17 (3.79%) (2.02-5.56, 95% Confidence Interval) patients. Among them, 1 (5.88%) had severe non-proliferative diabetic retinopathy, 3 (17.65%) had proliferative diabetic retinopathy and 8 (47.06%) had severe diabetic macular oedema.

Conclusions

 The prevalence of blindness among patients with type II diabetes mellitus was less than in other studies conducted in similar settings. Screening and timely management of diabetic retinopathy could reduce the prevalence of blindness due to diabetic retinopathy.

Keywords

blindness; diabetic retinopathy; prevalence.

Prevalence of Impairment of Visual Acuity and Severity of Retinopathy in Patients with Diabetes Mellitus

AIMS

No information exists on the frequency of visual impairment in people with diabetes mellitus (DM) in Germany. In this study, the prevalence of vision impairment in those individuals was investigated.

METHODS

We retrospectively analyzed a cohort of 295 people (14221 consultations) at a university outpatient clinic with any type of DM and an available ETDRS-Score and visual acuity. The primary outcome was the prevalence of visual impairment, the secondary outcome was the correlation of the ETDRS-Score and limitations of visual acuity and the prevalence of higher ETDRS-Score with a visual impairment defined as a decimal-visus</=0.3.

RESULTS

The prevalence of visual impairment in participants with DM was 11.2%; among these individuals, 81.8% had no or non-proliferative retinopathy. In the DM2 subgroup, 81.5% (n=22) of the visually impaired participants had no DR, in contrast to only 16.7% (n=1) in the DM1 subgroup. Progression in ETDRS-Score led to worse visual acuity (r=-0.209; p<0.001). A significantly related covariates with impairment of the visual acuity for individuals with DM1 was the duration of diabetes (B=-0.007; p=0.001) and for individuals with DM2, the age (B=-0.008; p=0.009).

CONCLUSIONS

The prevalence of impaired vision in people with diabetes in our cohort was 11.2%,<20% of visual impairment in people with diabetes is caused by diabetic retinopathy, and 69.7% of participants with visual impairment had no DR. In our study patients without visual impairment showed a similar distribution of DR severity levels regardless of the type of diabetes.

The effect of diabetic retinopathy on standing posture during optic flow stimulation

BACKGROUND

Diabetic retinopathy is a principal cause of visual damage and blindness, in which laser treatment offers proven therapy. The progressive degeneration of the retina, secondary to diabetes, is believed to cause postural instability although this is not well documented. The aim of this research was to assess how optic flow stimuli contribute to the control of stance in people with impaired retinal functions.

RESEARCH QUESTION

Does the different retinal functionality correspond to different specific patterns of movements and muscles recruitment?

METHODS

Postural mechanisms and motor strategies were measured by testing subjects in quiet stance on a force platform with surface electromyography under different optic flow stimulations. Root mean square values of the center of pressure time-varying signals and normalized EMG values were used to evaluate the postural sway.

RESULTS

People with diabetic retinopathy, and to a greater extent laser group, were more unstable than healthy subjects. The greater amplitude of the body sway observed in the retinopathy group, and especially in the laser group, could be an expression of the difficulty for this population in processing this kind of visual information.

SIGNIFICANCE

The increase in muscle activity indicates that there are musculoskeletal and postural changes in the lower limb musculature with increasing severity of diabetic retinopathy. An impaired retinal function might negatively affect postural control in a way that is dependent on the severity of retinal damage.

Visual functions and disability in Iranian adults: a population-based study

Background

Vision-related quality of life is related to severity of visual impairments and show the impact of eye diseases on daily activities. This study aims to assess visual functions and disability and its association with age, gender, education, marital status, and economic status in adults aged 45–69 years.

Methods

Data in this population-based study were from the second phase of the Shahroud eye cohort study and collected by using a Short-Form Visual Functioning Scale. The scores of visual function and disability were calculated based on Rasch-transformed scores of the National Eye Institute visual functioning questionnaire, where a more negative score indicates a better situation. Multiple linear regression was used to investigate the factors associated with visual functions.

Results

Among 4737 participants the visual function data for 4715 people were analyzed. The visual function of 75.3, 17.1 and 7.5% of participants were “ideal and good”, “moderate”, and “bad and very bad”, respectively, while 0.06% were unable for vision. The running mean of the visual function was calculated to be − 3.95 ± 0.02. The visual performance was worse in females than the males (β = 0.14, p = 0.005). Visual function improved with increasing levels of education (β = − 1.06, p < 0.001). It was worse in low-economic (β = 0.016, p = 0.005) and moderate-economic (β = 0.28, p < 0.001) participants than high-economic ones.

Conclusion

The visual function of Iranian adults aged 45–69 years was moderate. The male gender, higher education and the higher economic status had a better visual function.

Biologic Therapy and Treatment Options in Diabetic Retinopathy with Diabetic Macular Edema

Proliferative diabetic retinopathy and diabetic macular edema can be a potentially sightthreatening disease if not treated correctly. It is directly correlated to the duration of diabetes and how well managed the patients' diabetes is. In the last 15 years, the treatment of diabetic eye disease has taken a quantum leap in methodology due to the group of biological agents named antivascular endothelial growth factor (anti-VEGF). The introduction of the first biological agent has revolutionized the treatment, not only in diabetic eye disease but also across most inflammatory eye diseases, causing leakage of fluid from the blood vessels i.e., in age-related macular degeneration. The availability of these biological agents, despite their considerable costs, have significantly improved the outcomes measured in visual acuity compared to more traditional treatments of diabetic retinopathy in the form of sole laser treatment and glycemic control. The agents demonstrate a favorable safety profile, but if the rarest and most severe side effects occur, there is a potential total loss of vision. This review aims to make an overview of the current pharmaceutical therapeutic options in the treatment of diabetic macular edema. This includes laser therapy, intravitreal steroids, and a primary focus on intravitreal antivascular endothelial growth factors.

Inactivation of Endothelial ADAM17 Reduces Retinal Ischemia-Reperfusion Induced Neuronal and Vascular Damage

Retinal ischemia contributes to visual impairment in ischemic retinopathies. A disintegrin and metalloproteinase ADAM17 is implicated in multiple vascular pathologies through its ability to regulate inflammatory signaling via ectodomain shedding. We investigated the role of endothelial ADAM17 in neuronal and vascular degeneration associated with retinal ischemia reperfusion (IR) injury using mice with conditional inactivation of ADAM17 in vascular endothelium. ADAM17Cre-flox and control ADAM17flox mice were subjected to 40 min of pressure-induced retinal ischemia, with the contralateral eye serving as control. Albumin extravasation and retinal leukostasis were evaluated 48 h after reperfusion. Retinal morphometric analysis was conducted 7 days after reperfusion. Degenerate capillaries were assessed by elastase digest and visual function was evaluated by optokinetic test 14 and 7 days following ischemia, respectively. Lack of ADAM17 decreased vascular leakage and reduced retinal thinning and ganglion cell loss in ADAM17Cre-flox mice. Further, ADAM17Cre-flox mice exhibited a remarkable reduction in capillary degeneration following IR. Decrease in neurovascular degeneration in ADAM17Cre-flox mice correlated with decreased activation of caspase-3 and was associated with reduction in oxidative stress and retinal leukostasis. In addition, knockdown of ADAM17 resulted in decreased cleavage of p75NTR, the process known to be associated with retinal cell apoptosis. A decline in visual acuity evidenced by decrease in spatial frequency threshold observed in ADAM17flox mice was partially restored in ADAM17-endothelial deficient mice. The obtained results provide evidence that endothelial ADAM17 is an important contributor to IR-induced neurovascular damage in the retina and suggest that interventions directed at regulating ADAM17 activity can be beneficial for alleviating the consequences of retinal ischemia.

Impact of button position and touchscreen font size on healthcare device operation by older adults

In 1993, Taiwan officially became an aging society. Degradation of physiological function during aging is inevitable; visual and physical reactions are especially vulnerable. Given the popularity of electronic devices and their vigorous development in recent years, touchscreen use is now commonplace. As society ages, many people use devices to monitor their health. Some products have gradually eschewed their traditional interfaces, which have been replaced by touchscreens. Touchscreen operation and interpretation differ between older and younger populations. Here, we focus on healthcare equipment, exploring the effects of button position and touchscreen font size on operation by older people. To understand differences between older and younger people, we invited 32 people aged 18–35 years, and 32 people aged over 65 years, to participate in our experiment. Each subject tested four button positions and four font sizes, thus 16 test interfaces in all. We found that young people found no differences among the 16 interfaces, but the older group did. Larger fonts reduced operation time for older participants. At a font size of 22 pt, the older group performed as well as the young participants. When buttons were positioned at the top of the interface, the performance of the older participants improved. Overall, use of a font size of 22 pt and top-positioned buttons optimized the performance of the older participants while use of a font size of 10 pt and bottom-positioned buttons maximally degraded their performance. Our results can be used to design interfaces appropriate for older people, thus improving their autonomy.

Use of the King-Devick Variable Color Contrast Sensitivity Chart to differentiate stages of age-related macular degeneration

Objective

This study aimed to determine which colour contrast sensitivity differences exist in early to advanced age-related macular degeneration (AMD) and examine the potential utility of the King-Devick Variable Color Contrast Sensitivity Chart in detecting AMD severity.

Methods and analysis

A total of 85 participants (144 total eyes) were recruited from multiple clinical practices and enrolled in the study. The control group consisted of 57 healthy eyes. The non-exudative AMD (NE-AMD) group consisted of 45 eyes. The exudative AMD (E-AMD) group consisted of 42 eyes. In a single study visit, monocular best-corrected visual acuity (BCVA) at 40 cm with 100% black contrast was determined for each eye. Using the BCVA line, the number of letters correctly identified (out of 10) was recorded for various colour presentations (red, green, blue and yellow) and at decreasing contrast levels (100%, 75%, 50% and 25%).

Results

Our results show worse visual performance under various colour contrast settings in E-AMD patients compared with healthy controls and NE-AMD. Colour contrast performance using blue and yellow differentiated more advanced stages of disease in E-AMD from earlier NE-AMD disease. Blue and black colour contrast performance more accurately identified the E-AMD group from healthy controls and the NE-AMD group.

Conclusion

The findings of this study demonstrate that colour contrast, particularly with black, blue and yellow, is impaired in E-AMD suggesting the potential for colour contrast measures to serve as an adjunctive clinical tool in identifying subtle altered visual function as well as the potential for detecting disease severity.

Optical Quality and Intraocular Scattering in the Diabetic Eye without Diabetic Retinopathy

SIGNIFICANCE

This study suggests that despite having comparable best-corrected visual acuity and normal fundus appearance, objective measurements of optical quality showed that patients with diabetes but without overt retinopathy may have impaired visual function. Screening using the Optical Quality Analysis System might help identify those patients.

PURPOSE

Visual impairments are common in diabetes, but the status of the problem is unclear before the development of diabetic retinopathy. The aim of this pilot study was to investigate the optical quality and intraocular scattering in the diabetic eye without diabetic retinopathy.

METHODS

Twenty-seven patients with diabetes without diabetic retinopathy were enrolled. Twenty-seven age- and sex-matched healthy volunteers served as a control group. Optical quality parameters included modulation transfer function cutoff frequency, Strehl (two-dimensional) ratio, and Optical Quality Analysis System values at 100, 20, and 9 contrast levels. The objective scatter index was assessed using the Optical Quality Analysis System. Correlations were analyzed between the modulation transfer function cutoff, Strehl ratio, objective scatter index, and Optical Quality Analysis System value, and the age of the patient and the duration of diabetes mellitus.

RESULTS

The diabetic group exhibited lower modulation transfer function cutoff, Strehl ratio, and Optical Quality Analysis System values at 100, 20, and 9% contrast levels and higher objective scatter index than did the controls (all, P < .01). There were no associations between the optical quality parameters and age or the duration of diabetes mellitus in the diabetic participants (all, P > .05). Moderate associations were found between all parameters obtained from the Optical Quality Analysis System and age in the control group (all, P < .01).

CONCLUSIONS

This pilot study suggests that optical quality was reduced, and intraocular scattering increased in the diabetic eye without diabetic retinopathy compared with controls.

Association Between the Severity of Diabetic Retinopathy and Falls in an Asian Population With Diabetes: The Singapore Epidemiology of Eye Diseases Study

Importance

The presence and severity of diabetic retinopathy (DR) may contribute to the risk of falling in persons with diabetes, but evidence is currently equivocal.

Objective

To investigate the associations of diabetes and DR severity with the likelihood of falls in a multiethnic Asian population.

Design, Setting, and Participants

Cross-sectional post hoc analysis of the Singapore Epidemiology of Eye Diseases study, a population-based study of participants from 3 ethnic groups (3280 Malay, 3400 Indian, and 3353 Chinese individuals) conducted from 2004 to 2011. Of these participants, 552 had data missing on diabetes, falls history, or other covariates or had ungradable fundus photographs and were excluded, leaving 9481 participants. These 9481 underwent a standardized clinical examination and responded to an interviewer-administered questionnaire that collected clinical and sociodemographic information. Multivariable logistic regression models adjusted for confounding fall risk factors assessed the associations of falls with diabetes, DR, and DR severity. A trend analysis was conducted in participants with diabetes to assess if risk of falling was associated with DR severity. Data were analyzed from January 1 through April 30, 2017.

Exposures

Diabetes was defined as a random glucose level of at least 200 mg/dL, hemoglobin A1c concentration of at least 6.5% of total hemoglobin, self-reported use of diabetic medication, or history of physician-diagnosed diabetes. Severity of DR was graded as none, minimal, mild, moderate, and vision threatening (VT).

Main Outcomes and Measures

A self-reported fall occurring in the previous 12 months, when the participant fell and landed on the ground.

Results

Of the 9481 participants with a mean (SD) age of 58.7 (10.3) years (4781 women [50.4%]), 6612 (69.7%) had no diabetes and 2869 (30.3%) had diabetes, of whom 857 (29.9%) had DR in at least 1 eye. A history of falls was reported in 872 (13.2%) without diabetes, 328 (16.3%) with no DR, 44 (14.2%) with minimal DR, 54 (26.2%) with mild DR, 34 (27.2%) with moderate DR, and 43 (19.9%) with VTDR (P for trend < .001). In multivariable models, those with DR were more likely to have fallen (odds ratio [OR], 1.31; 95% CI, 1.07-1.60; P = .008) compared with those with no diabetes; no associations were found for participants without DR compared with those with no diabetes. In addition, compared with participants with diabetes but without DR, those with mild (OR, 1.81; 95% CI, 1.23-2.67; P = .003) and moderate (OR, 1.89; 95% CI, 1.16-3.07; P = .01) nonproliferative DR were more likely to have fallen. Having VTDR was not independently associated with a higher likelihood of falling.

Conclusions and Relevance

The presence of mild to moderate nonproliferative DR was independently associated with an increased likelihood of falling in persons with diabetes compared with persons with diabetes but without DR. Management strategies for diabetes should incorporate fall education and prevention information, particularly in patients with early-stage DR. Longitudinal studies exploring the association between mild to moderate nonproliferative DR and falling will be required to confirm these findings.

The efficacy and safety of aflibercept and conbercept in diabetic macular edema

Diabetic macular edema (DME) has shown an increasing prevalence during the past years and is the leading cause of diabetic retinopathy blindness. Traditional treatment modalities include laser and corticosteroid therapy, which, however, either act through unclear mechanisms or cause cataracts and elevated intraocular pressure. In recent years, as the pathogenic role of VEGF in DME has been well-recognized, the intravitreal injection of anti-VEGF drugs has become the first-line treatment of DME due to their great efficacy in improving visual acuity and mitigating macular edema. Advantages have been shown for aflibercept and conbercept, the two recombinant decoy receptors that can bind VEGF with high specificity and affinity, in DME treatment in clinical trials conducted both worldwide and in People’s Republic of China. This review introduces the structural characteristics and molecular mechanisms of action of these two anti-VEGF drugs, and summarizes the clinical trials evaluating their efficacy and safety, with the hope to provide clues for designing optimal and personalized therapeutic regimens for DME patients.

The clinical relevance of visualising the peripheral retina

Recent developments in imaging technologies now allow the documentation, qualitative and quantitative evaluation of peripheral retinal lesions. As wide field retinal imaging, capturing both the central and peripheral retina up to 200° eccentricity, is becoming readily available the question is: what is it that we gain by imaging the periphery? Based on accumulating evidence it is clear that findings in the periphery do not always associate to those observed in the posterior pole. However, the newly acquired information may provide useful clues to previously unrecognised disease features and may facilitate more accurate disease prognostication. In this review, we explore the anatomy and physiology of the peripheral retina, focusing on how it differs from the posterior pole, recount the history of peripheral retinal imaging, describe various peripheral retinal lesions and evaluate the overall relevance of peripheral retinal findings to different diseases.

Impact of Incidence and Progression of Diabetic Retinopathy on Vision-Specific Functioning

PURPOSE

To investigate the independent impact of the incidence and progression of diabetic retinopathy (DR) on visual functioning (VF).

DESIGN

Population-based cohort study.

PARTICIPANTS

A total of 518 participants aged 40 to 80 years (baseline visit 2007-2009 and second visit 6 years later, 2013-2015), with diabetes, clinical data, and VF information at both visits.

MAIN OUTCOME MEASURES

VF-7 scores, converted to interval-level person measures (in logits) using Rasch analysis.

METHODS

Incident DR was defined using the Modified Airlie House classification as "none or minimal" DR at baseline and at least mild nonproliferative DR at follow-up; incident vision-threatening DR (VTDR; severe nonproliferative DR, proliferative DR, and/or clinically significant macular edema) as no VTDR at baseline, and present at follow-up; and DR progression as at least a 1-step worsening in DR at follow-up from mild or worse status at baseline. The longitudinal associations between incident DR, VTDR, and DR progression, as well as change in composite and individual item scores of VF, were assessed using multivariable linear regression models.

RESULTS

Of the 518 participants (mean age ± standard deviation [SD] 59.8±9.0 years; 47.7% female), 42 (9.8%), 14 (2.8%), and 32 (42.7%) had incident DR, incident VTDR, and DR progression, respectively, at follow-up. In models adjusting for traditional confounders, persons with incident DR and VTDR had a 13.7% (β = -0.60; 95% confidence interval [CI], -0.96 to -0.24; P = 0.001) and 23% (β = -1.00; 95% CI, -1.61 to -0.38; P = 0.001) reduction in mean VF scores at follow-up. Furthermore, individuals with incident DR had similar independent reductions in scores for 7 individual items of the VF-7, whereas those with incident VTDR had the largest reductions for activities like cooking (31%; P = 0.003), reading the newspaper (29.6%; P < 0.001), and seeing street signs (28%, P = 0.001) at follow-up. Progression of DR was not independently associated with change in overall VF (β = -0.18; 95% CI, -1.00, 0.64; P = 0.660).

CONCLUSIONS

Incident DR, particularly vision-threatening stages, has a substantial negative impact on people's overall vision-dependent functioning and specific activities such as cooking, seeing street signs, and reading the newspaper. Our findings reinforce the need for strategies to prevent or delay the development of DR.

Considerations for management of patients with diabetic macular edema: Optimizing treatment outcomes and minimizing safety concerns through interdisciplinary collaboration

Diabetes is a growing worldwide epidemic and a leading cause of blindness in working-age people around the world. Diabetic retinopathy (DR) and diabetic macular edema (DME) are common causes of visual impairment in people with diabetes and often indicate the presence of diabetes-associated preclinical micro- and macrovascular complications. As such, patients with DR and DME often display complex, highly comorbid profiles. Several treatments are currently available for the treatment of DME, including anti-vascular endothelial growth factor (VEGF) agents, which are administered via intravitreal injection. While the safety profiles of approved ocular anti-VEGF therapies have been reassuring, the high-risk nature of the DME patient population means that treatment must be carefully considered and a holistic approach to disease management should be taken. This requires multidisciplinary, collaborative care involving all relevant specialties to ensure that patients not only receive prompt treatment for DME but also appropriate consideration is taken of any systemic comorbidities to evaluate and minimize potentially serious safety issues.

A STUDY ON VISUAL LIMITATION OF AGE, NUMERICAL SIZE, AND EXPOSURE TIME WHILE USERS OPERATE MOBILE DEVICES

Technological advances have driven the development of information technology (IT) products and communication using mobile devices has become a part of daily life. When using mobile devices, reading time and font size are important communication elements that significantly affect reading performance. However, studies of reading performance in older samples have mainly used printed material or computer monitors; this study examined the performance of users when reading text messages on the interfaces of mobile devices and described their visual limitations. Sixty-two participants took part in the experiment, which involved displaying different font sizes and exposure times. The younger group read 10-point font accurately, while the older group had much worse accuracy, even at 14 points. The younger group correctly read text messages displayed for 0.4 sec. above 80% of the time, while the older group's accuracy was severely impaired even when text was displayed for 1 sec.

The Diabetes Visual Function Supplement Study (DiVFuSS)

BACKGROUND

Diabetes is known to affect visual function before onset of retinopathy (diabetic retinopathy (DR)). Protection of visual function may signal disruption of mechanisms underlying DR.

METHODS

This was a 6-month randomised, controlled clinical trial of patients with type 1 and type 2 diabetes with no retinopathy or mild to moderate non-proliferative retinopathy assigned to twice daily consumption of placebo or a novel, multi-component formula containing xanthophyll pigments, antioxidants and selected botanical extracts. Measurement of contrast sensitivity, macular pigment optical density, colour discrimination, 5-2 macular threshold perimetry, Diabetic Peripheral Neuropathy Symptoms, foveal and retinal nerve fibre layer thickness, glycohaemoglobin (HbA1c), serum lipids, 25-OH-vitamin D, tumour necrosis factor α (TNF-a) and high-sensitivity C reactive protein (hsCRP) were taken at baseline and 6 months. Outcomes were assessed by differences between and within groups at baseline and at study conclusion using meand ± SDs and t tests (p<0.05) for continuous variables.

RESULTS

There were no significant intergroup differences at baseline. At 6 months, subjects on active supplement compared with placebo had significantly better visual function on all measures (p values ranging from 0.008 to <0.0001), significant improvements in most serum lipids (p values ranging from 0.01 to 0.0004), hsCRP (p=0.01) and diabetic peripheral neuropathy (Fisher's exact test, p=0.0024) No significant changes in retinal thickness, HbA1c, total cholesterol or TNF-α were found between the groups.

CONCLUSIONS

This study provides strong evidence of clinically meaningful improvements in visual function, hsCRP and peripheral neuropathy in patients with diabetes, both with and without retinopathy, and without affecting glycaemic control.

TRIAL REGISTRATION NUMBER

www.ClinicalTrials.gov Identifier: NCT01646047.