Caffeine and the Risk of Diabetic Retinopathy in Type 2 Diabetes Mellitus: Findings from Clinical and Experimental Studies.

The aim of this study was to assess the potential benefits of caffeine intake in protecting against the development of diabetic retinopathy (DR) in subjects with type 2 diabetes (T2D). Furthermore, we tested the effect of topical administration of caffeine on the early stages of DR in an experimental model of DR. In the cross-sectional study, a total of 144 subjects with DR and 147 individuals without DR were assessed. DR was assessed by an experienced ophthalmologist. A validated food frequency questionnaire (FFQ) was administered. In the experimental model, a total of 20 mice were included. One drop (5 µL) of caffeine (5 mg/mL) (n = 10) or vehicle (5 µL PBS, pH 7.4) (n = 10) was randomly administered directly onto the superior corneal surface twice daily for two weeks in each eye. Glial activation and retinal vascular permeability were assessed using standard methods. In the cross-sectional study in humans, the adjusted-multivariable model showed that a moderate and high (Q2 and Q4) caffeine intake had a protective effect of DR (odds ratio (95% confidence interval) = 0.35 (0.16-0.78); p = 0.011 and 0.35 (0.16-0.77); p = 0.010, respectively). In the experimental model, the administration of caffeine did not improve either reactive gliosis or retinal vascular permeability. Our results suggest a dose-dependent protective effect of caffeine in the development of DR, while the potential benefits of antioxidants in coffee and tea should also be considered. Further research is needed to establish the benefits and mechanisms of caffeinated beverages in the development of DR.

Correction to: Type 2 diabetes-associated carotid plaque burden is increased in patients with retinopathy compared to those without retinopathy.

The author found errors in Table 1 after publication of the original article [1].

Increased Burden of Cerebral Small Vessel Disease in Patients With Type 2 Diabetes and Retinopathy.

OBJECTIVE: We sought to examine the presence and severity of brain small vessel disease (SVD) in patients with type 2 diabetes and diabetic retinopathy (DR) compared with those without DR. RESEARCH DESIGN AND METHODS: We evaluated 312 patients with type 2 diabetes without previous cardiovascular disease (men 51%; mean age 57 years; age range 40-75 years); 153 patients (49%) had DR. MRI was performed to evaluate the presence and severity (age-related white matter changes scale) of white matter lesions (WMLs) and lacunes, and transcranial Doppler ultrasound was used to measure the Gosling pulsatility index (PI) of the middle cerebral artery (MCA). RESULTS: The prevalence of lesions of cerebral SVD (WML and/or lacunes) was higher in patients with DR (40.2% vs. 30.1% without DR, P = 0.04). Age (P < 0.01) and systolic blood pressure (P = 0.02) were associated with the presence of SVD. The severity of SVD was associated with age and the presence of DR (P < 0.01 and P = 0.01, respectively). Patients with DR showed a higher MCA PI compared with those without DR (P < 0.01). Age, systolic and diastolic blood pressure, and retinopathy and its severity were associated with an increased MCA PI (P < 0.01 for all variables). A positive correlation was found between MCA PI values and the presence and severity of SVD (P < 0.01 for both variables). CONCLUSIONS: Patients with type 2 diabetes who have DR have an increased burden of cerebral SVD compared with those without DR. Our findings suggest that the brain is a target organ for microangiopathy, similar to other classic target organs, like the retina.

Association of low oleic acid intake with diabetic retinopathy in type 2 diabetic patients: a case-control study.

BACKGROUND: The objective of this study was to describe the intake of macronutrient, especially fatty acids, and explore their possible effect on diabetic retinopathy (DR) in patients with type 2 diabetes mellitus. METHODS: In this case-control study, we included a total of 146 patients with DR and 148 without DR. The intake of macronutrient was evaluated using a validated food frequency questionnaire. We used logistic regression adjusted for sex, age, diabetes duration, energy intake, educational level, physical activity, waist circumference, systolic blood pressure, high-density lipoprotein cholesterol and diabetes treatment, to estimate odds ratio (ORs) of DR. RESULTS: Patients with DR had significantly lower intake of fibre, monounsaturated fatty acids (MUFA), and palmitic and oleic acid. Inverse associations were observed between MUFA and oleic acid intake in DR. Subjects with intermediate and high MUFA intake were less likely to have DR than those with lower MUFA intake, with ORs of 0.46 (95 % CI: 0.22-0.93) and 0.42 (95 % CI: 0.18-0.97), respectively. Similarly, intermediate and high oleic acid intake were associated with reduced DR frequency compared with low oleic acid intake, with OR values of 0.48 (95 % CI: 0.23-0.97) and 0.37 (95 % CI: 0.16-0.85), respectively. These associations were stronger in patients with a longer diabetes duration. CONCLUSION: In type 2 diabetes mellitus, MUFA and oleic acid intake were inversely associated with DR.

Relationship of the adherence to the Mediterranean diet with health-related quality of life and treatment satisfaction in patients with type 2 diabetes mellitus: a post-hoc analysis of a cross-sectional study.

OBJECTIVE: The main aim of this study was to assess the association between adherence to the traditional Mediterranean diet (MedDiet) and health-related quality of life (HRQoL) and treatment satisfaction in patients with type 2 diabetes mellitus (T2DM). METHODS: This cross-sectional study included 294 patients with T2DM (146 with diabetic retinopathy and 148 without retinopathy). HRQoL and treatment satisfaction were assessed with the Audit Diabetes-Dependent Quality of Life and Diabetes Treatment Satisfaction Questionnaires, respectively. Adherence to the MedDiet was evaluated with the relative Mediterranean Diet Score (rMED). The rMED was added to multivariate linear regression models to assess its relative contribution as a quantitative as well as a qualitative variable after recoding to maximize each of the model's coefficients of determination to explain quality of life as well as treatment satisfaction dimensions. RESULTS: The adherence to the Mediterranean diet showed no significant association with the overall quality of life score. However, rMED was associated with some HRQoL dimensions: travels, self-confidence and freedom to eat and drink (p = 0.020, p = 0.015, p = 0.037 and p = 0.015, respectively). Concerning treatment satisfaction, rMED was positively associated with its overall score (p = 0.046), and especially with the understanding of diabetes (p = 0.0004) and treatment recommendation (p = 0.036), as well as with the perceived frequency of hyperglycaemias (p = 0.039). CONCLUSION: Adherence to the Mediterranean diet was associated with greater treatment satisfaction in patients with T2DM. Although we found no association with overall HRQoL, adherence to this dietary pattern was associated with some quality of life dimensions.

Lower Hemoglobin Concentration Is Associated with Retinal Ischemia and the Severity of Diabetic Retinopathy in Type 2 Diabetes.

Aims. To assess the association of blood oxygen-transport capacity variables with the prevalence of diabetic retinopathy (DR), retinal ischemia, and macular oedema in patients with type 2 diabetes mellitus (T2DM). Methods. Cross-sectional, case-control study (N = 312) with T2DM: 153 individuals with DR and 159 individuals with no DR. Participants were classified according to the severity of DR and the presence of retinal ischemia or macular oedema. Hematological variables were collected by standardized methods. Three logistic models were adjusted to ascertain the association between hematologic variables with the severity of DR and the presence of retinal ischemia or macular oedema. Results. Individuals with severe DR showed significantly lower hemoglobin, hematocrit, and erythrocyte levels compared with those with mild disease and in individuals with retinal ischemia and macular oedema compared with those without these disorders. Hemoglobin was the only factor that showed a significant inverse association with the severity of DR [beta-coefficient = -0.52, P value = 0.003] and retinal ischemia [beta-coefficient = -0.49, P value = 0.001]. Lower erythrocyte level showed a marginally significant association with macular oedema [beta-coefficient = -0.86, P value = 0.055]. Conclusions. In patients with DR, low blood oxygen-transport capacity was associated with more severe DR and the presence of retinal ischemia. Low hemoglobin levels may have a key role in the development and progression of DR.

Vitamin D Deficiency Is Associated with the Presence and Severity of Diabetic Retinopathy in Type 2 Diabetes Mellitus.

There is very few evidences on the role of vitamin D in the development of diabetic retinopathy. The aim of the current study was to explore whether there is an association of vitamin D status and diabetic retinopathy in type 2 diabetes. Two groups of patients were selected: 139 and 144 patients with and without retinopathy, respectively, as assessed by an experienced ophthalmologist. Subjects with advanced late diabetic complications were excluded to avoid confounding biases. 25-Hydroxy-vitamin D3 (25(OH)D) concentrations and vitamin D deficiency were associated with the presence of diabetic retinopathy. Additionally, patients with more advanced stages of retinopathy (grades 2-4) had lower concentrations of 25(OH)D and were more frequently vitamin D deficient as compared with patients not carrying this eye complication. In conclusion, our study confirms the association of vitamin D deficiency with the presence and severity of diabetic retinopathy in type 2 diabetes. Further experimental and prospective studies on this issue are clearly warranted.

Microangiopathy of common carotid vasa vasorum in type 1 diabetes mellitus.

OBJECTIVE: We hypothesize that in type 1 diabetes vasa vasorum (VV) are affected by microangiopathic changes. For this purpose, we assessed the status of the VV signal in patients with type 1 diabetes. METHODS: The VV signal at the arterial adventitia of the common carotid artery was evaluated by contrast-enhanced ultrasound imaging. The VV contrast agent signal was quantified in an plaque-free arterial segment as the ratio of the adventitial signal and that of the lumen of the artery. We studied 113 type 1 diabetic patients, 60 with and 53 without retinopathy and without known cardiovascular disease, and a group of 78 non-diabetic subjects free of cardiovascular risk factors. All study subjects underwent a clinical evaluation. RESULTS: The mean ± standard deviation VV signal of healthy subjects was 0.562 ± 0.135. Type 1 diabetic patients showed a higher adventitial VV signal (0.723 ± 0.128) than non-diabetic subjects (P < 0.0001). After adjustment for cardiovascular risk confounders, this difference remained significant. No differences in VV signal, or common carotid intima-media thickness, between subjects with and without retinopathy were found. CONCLUSIONS: Type 1 diabetic patients, independently of their retinopathy status, show an increased angiogenesis of the VV of the common carotid artery compared with non-diabetic subjects. Diabetic microangiopathy, that according to our results would also affect the wall of the large arteries, could be a factor contributing to atherosclerosis in type 1 diabetes mellitus.

Type 2 diabetes-associated carotid plaque burden is increased in patients with retinopathy compared to those without retinopathy.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality among subjects with type 2 diabetes (T2D), and diabetic retinopathy (DR) has been associated with an increased risk for CVD. The present study was designed to test the concept that T2D patients with DR, but without previous cardiovascular (CV) events and with normal renal function, have an increased atherosclerotic burden compared with patients without DR. METHODS: A cross-sectional study was performed using patients with normal renal function (estimated glomerular filtration rate (eGFR) >60 ml/min) and without previous CV events. A total of 312 patients (men, 51%; mean age, 57 yrs; age range 40-75 yrs) were included in the study; 153 (49%) of the patients had DR. B-mode carotid ultrasound imaging was performed for all of the study subjects to measure the carotid intima-media thickness (cIMT) and carotid plaques in the common carotid artery (CCA), bifurcation and internal carotid artery (ICA). RESULTS: The percentage of carotid plaques in T2D patients with DR was higher than in T2D patients without DR (68% vs. 52.2%, p = 0.0045), and patients with DR had a higher prevalence of ≥2 carotid plaques (44.4% vs. 21.4%; p < 0.0001). No differences were observed in the cIMT measured at different carotid regions between the patients with or without DR. Using multivariate logistic regression (adjustment for major risk factors for atherosclerosis), DR was independently associated with mean-internal cIMT (p = 0.0176), with the presence of carotid plaques (p = 0.0366) and with carotid plaque burden (≥2 plaques; p < 0.0001). CONCLUSIONS: The present study shows that DR in T2D patients without CVD and with normal renal function is associated with a higher atherosclerotic burden (presence and number of plaques) in the carotid arteries. These patients may be at a higher risk for future CV events; therefore, an ultrasound examination of the carotid arteries should be considered in patients with DR for more careful and individualised CV assessment and follow-up.

Corneal biomechanical properties in floppy eyelid syndrome.

PURPOSE: To determine corneal biomechanical properties in patients with floppy eyelid syndrome (FES) and to compare them with eyes of controls. METHODS: This case-control study included 208 eyes (72 eyes with FES and 136 without FES) of 107 patients (37 patients with FES and 70 without FES). Patients underwent a complete clinical eye examination that included corneal biomechanical evaluation carried out with the Reichert Ocular Response Analyzer. RESULTS: Corneal hysteresis (CH), corneal resistance factor (CRF), central corneal thickness (CCT), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) were evaluated. Mean CH was significantly lower in patients with FES than in those without FES (9.51 ± 1.56 vs. 11.66 ± 9.11; P < 0.001). These results remained statistically significant after adjusting for age and apnea-hypoapnea index (AHI) (P = 0.028). Mean CRF was 10.02 ± 2.08 in the group of patients with FES and 11.21 ± 5.36 in the group of patients without FES (P = 0.001). Mean IOPcc was 17.7 ± 4.8 in patients with FES and 16.3 ± 4.4 in those without FES (P = 0.036). After adjusting for age and AHI, these differences in CRF and IOPcc were not statistically significant (P = 0.26 and P = 0.87, respectively). No statistically significant difference was found between patients with and without FES for Goldmann-correlated intraocular pressure or CCT. CONCLUSIONS: Patients with FES had statistically lower CH values. Our findings suggest that corneal biomechanical properties could be changed in patients with FES, reflecting additional structural changes in FES.

A prospective cross-sectional study on quality of life and treatment satisfaction in type 2 diabetic patients with retinopathy without other major late diabetic complications.

BACKGROUND: To assess quality of life and treatment satisfaction in patients with type 2 diabetes mellitus with diabetic retinopathy (DR) using validated instruments, with comparison to patients without DR. METHODS: A prospective cross-sectional study was designed to assess the influence of retinopathy on quality of life and treatment satisfaction in patients with type 2 diabetes mellitus who do not have any other advanced late complications that could interfere with these outcomes. We included 148 patients with DR and 149 without DR, all without other advanced diabetic complications. Quality of life was assessed using the Audit of Diabetes Dependent Quality of Life (ADDQoL) questionnaire, and treatment satisfaction was assessed using the Diabetes Treatment Satisfaction Questionnaire (DTSQ). Clinical and treatment variables related to diabetes were also collected. The degree of DR was classified according to the International Clinical Classification System. Multivariate linear regression models were used to model the ADDQoL and DTSQ scores according to sociodemographical and clinical characteristics, and to model the adjusted relationship of DTSQ with ADDQoL. In DR patients, a subanalysis assessed the relationship of these scores with the degree of retinopathy, severity of macular edema, and previous photocoagulation treatment. RESULTS: DR was associated with significantly lower quality of life (p < 0.001), when examining the two general quality of life items and most of the specific domains. Concerning DTSQ, no difference was found in the total score, and only two domains that assess the perception of glycemic control (hyper- and hypoglycemia) showed a worse score in DR (p < 0.001 and p = 0.008, respectively). Quality of life was significantly affected by the severity of DR, and treatment satisfaction was significantly affected by the severity of macular edema. In the multivariate analysis, a significant effect of the interaction between diabetes duration, insulin therapy, and the presence of DR was found for both, ADDQoL and DTSQ. CONCLUSION: In the absence of other major complications, DR has a negative impact on quality of life in patients with type 2 diabetes. Further, treatment satisfaction was not affected by the presence of DR.

The relationship between floppy eyelid syndrome and obstructive sleep apnoea.

PURPOSE: To determine the prevalence of eyelid hyperlaxity and floppy eyelid syndrome (FES) in obstructive sleep apnoea (OSA), and the presence of OSA in FES. PARTICIPANTS: One-hundred and fourteen patients who had been consecutively admitted for OSA evaluation and 45 patients with FES in which sleep studies were recorded. METHODS: Subjects underwent eyelid laxity measurement, slit-lamp examination and polysomnography. RESULTS: Eighty-nine patients were diagnosed of OSA. Fourteen patients with OSA had FES (16%) and 54/89 (60.67%) had eyelid hyperlaxity. Two of the 25 non-OSA patients had FES (8%) and 8 of 25 (32%) had eyelid hyperlaxity. There was a significantly higher incidence of eyelid hyperlaxity in OSA than in non-OSA patients (p=0.004). Thirty-eight of the 45 patients with FES were diagnosed of OSA (85%) and 65% had severe OSA. CONCLUSIONS: OSA might be an independent risk factor for eyelid hyperlaxity and severe OSA is common in patients with FES.

Rituximab for peripheral ulcerative keratitis with wegener granulomatosis.

PURPOSE: To demonstrate the effectiveness of Rituximab in the management of peripheral ulcerative keratitis (PUK) associated with Wegener granulomatosis (WG). METHODS: A 50-year-old female with WG, confirmed by skin biopsy and positive anti-neutrophil cytoplasmic antibodies 3 years prior, was presented with a corneoscleral granulomatous mass that affected the superior limbus and with vasculitic PUK in the right eye. The mass was treated daily with oral prednisone (1 mg.kg-1.d-1) in conjunction with weekly maintenance treatment of 10 mg of methotrexate. After 2 months of treatment, the volume of the nodular granulomatous lesion decreased. However, the PUK and corneal thinning persisted, which presented a risk for corneal perforation. Subsequently, two 1000-mg infusions of rituximab were administered at weekly intervals. RESULTS: One week after the first administration of rituximab, we observed persistence of corneal thinning, flattening of the nodular lesion, and disappearance of the necrotic foci. After the second rituximab treatment, the patient exhibited no signs of corneal perforation and we further observed total epithelialization of the PUK. No systemic side effects were seen. After 2 months, no nodular lesion was observed, although conjunctival epithelialization from the previous PUK remained. Weekly methotrexate and 10 mg of prednisone per day were maintained. CONCLUSIONS: Rituximab seems to offer therapeutic promise in the treatment of refractory PUK associated with WG. Rituximab may be the elective treatment for severe anterior ocular inflammation associated with risk for corneal perforation, as a result of WG.

Short-term mitomycin C followed by long-term interferon alpha2beta for conjunctiva-cornea intraepithelial neoplasia.

PURPOSE: To report a case of extensive conjunctiva-cornea intraepithelial neoplasia (CIN) treated topically with mitomycin C (MMC) and interferon (INF)-alpha2beta without surgical resection. METHODS: Case report. RESULTS: : An 82-year-old woman showed an extensive gelatinous red mass in the bulbar conjunctiva with invasion into the caruncle, inferior fornix, and tarsal conjunctiva and extending for 270 degrees of the corneal surface. A diagnosis of CIN was made by surgical biopsy. Surgical excision with safety margins carried the risk of limbal stem cell depletion. A conservative treatment strategy was used with 2 cycles of topical MMC (0.02%), followed by INF-alpha2beta eye drops at a dose of 1 million IU/mL, 4 times a day until tumor disappearance. Total resolution was noted after 75 days of treatment with INF, with no clinical evidence of limbal stem cell deficiency. After 1 year of monitoring, no signs of CIN recurrences were observed. CONCLUSION: MMC (0.02%), followed by INF-alpha2beta (1 million IU/mL) 4 times a day, is an effective treatment against highly extensive CIN, in cases where surgical resection with safety margins is unfeasible.