Reversal of diabetic retinopathy by continuous subcutaneous insulin infusion: a case report

Screening for retinopathy in children with type 1 diabetes in Denmark

BACKGROUND/OBJECTIVE

Children with type 1 diabetes (T1D) are screened regularly for retinopathy with fundus photography to prevent visual impairment. According to Danish national guidelines, screening should take place at age 12, 15, and 18 years after minimum 3 years of diabetes. As glycemic control has improved, prevalence of retinopathy is expected to be decreased. The aim of this study is to investigate the prevalence, degree, and progression of retinopathy in children with T1D and to explore if screening at 12 years is currently indicated in Denmark.

METHODS

Data on all Danish children with onset of T1D from 2003 to 2013 (n = 2943) were collected from the "DanDiabKids" registry. For children with registered screenings (n = 2382), prevalence of retinopathy at 12, 15, and 18 years was determined. In children with retinopathy, subsequent screenings were studied to reveal if retinopathy was persistent or temporary.

RESULTS

Prevalence of retinopathy at 12, 15, and 18 years was 0.9%, 2.3%, and 3.1%, respectively. Minimal background retinopathy was seen in over 90% and 100% at 12 years. In available re-screenings, retinopathy resolved spontaneously in 87.5% of all cases and 100% of cases at 12 years.

CONCLUSIONS

The prevalence of retinopathy in Danish children with T1D was low. At 12 years, prevalence was 0.9% and exclusively minimal background retinopathy with 100% remission in re-screenings. Thus, screening at this age does not seem to have significant clinical relevance. We propose more individualized screening selection before the age of 15.

Widefield Optical Coherence Tomography Angiography in Diabetic Retinopathy

PURPOSE

To summarize the role of widefield optical coherence tomography angiography (WF-OCTA) in diabetic retinopathy (DR), extending from the acquisition strategies to the main clinical findings.

METHODS

A PubMed-based search was carried out using the terms "Diabetic retinopathy", "optical coherence tomography angiography", "widefield imaging", and "ultra-widefield imaging". All studies published in English up to August 2020 were reviewed.

RESULTS

WF-OCTA can be obtained with different approaches, offering advantages over traditional imaging in the study of nonperfusion areas (NPAs) and neovascularization (NV). Quantitative estimates and topographic distribution of NPA and NV are useful for treatment monitoring and artificial intelligence-based approaches. Curvature, segmentation, and motion artifacts should be assessed when using WF-OCTA.

CONCLUSIONS

WF-OCTA harbors interesting potential in DR because of its noninvasiveness and capability of objective metrics of retinal vasculature. Further studies will facilitate the migration from traditional imaging to WF-OCTA in both the research and clinical practice fields.

A five-year prospective study of diabetic retinopathy progression in chinese type 2 diabetes patients with "well-controlled" blood glucose

Purpose

To determine the progression rate and risk factors for diabetic retinopathy (DR) in Chinese type 2 diabetic patients who have reached the target hemoglobin A1c (HbA1c) level recommended by the American Diabetes Association.

Methods

This was a 5-year community-based prospective study. The study population consisted of patients with type 2 diabetes with HbA1c less than 7.0%. Demographic information, systemic examination results and ophthalmological test results for each participant were collected. The outcome of this study was the progression of DR, which was defined as an increase in DR grade in one or both eyes at the final visit in comparison to the baseline status. The association between each potential risk factor and DR progression was studied.

Results

A total of 453 patients with HbA1c less than 7.0% were included in the study group. In 146 patients (32.22%), DR developed or progressed during the five-year follow-up. Baseline HbA1c level was the only independent risk factor for DR progression (p<0.01, OR = 2.84, 95%CI: 2.11~3.82). The logistic regression function suggested that the possibility of DR progression increased fastest when baseline HbA1c increased from 5.2% to 6.4%. The 5-year DR progression rate in patients with baseline HbA1c less than 5.2%, between 5.2% and 6.4%, and over 6.4% were 19.62%, 24.41%, and 76.83%, respectively.

Conclusions

To slow the progression of DR in Chinese patients with type 2 diabetes, more intensive glucose control is recommended.

The 5-year onset and regression of diabetic retinopathy in Chinese type 2 diabetes patients

PURPOSE

To determine the rate and risk factors of diabetic retinopathy (DR) onset and regression in Chinese type 2 diabetes mellitus patients.

METHODS

This is a 5-year community-based prospective study. The demographic information, systemic examination results and ophthalmological test results of each participant were collected. The study outcomes were DR incidence, defined as the onset of DR in at least one eye, and DR regression, defined as full regression from existing DR to no retinopathy without invasive treatments. The associations between each potential risk factor and the outcomes were studied.

RESULTS

In total, 778 participants were enrolled. There were 322 patients without DR at baseline, of which 151 participants developed DR during follow-up (DR incidence rate = 46.89%). Baseline hyperglycemia and high blood pressure were two independent risk factors associated with DR incidence. Among the 456 participants with existing DR at entry, 110 fully recovered after 5 years (DR regression rate = 24.12%). Low baseline glucose and low serum triglyceride were two independent factors associated with DR regression.

CONCLUSIONS

DR incidence occurred more frequently in patients with hyperglycemia and high blood pressure. DR regression occurred mostly in patients with lower glucose and lower serum triglyceride levels among Chinese type 2 diabetes patients.

A controlled study of the influence of continuous subcutaneous insulin infusion treatment on diabetic retinopathy during pregnancy

Forty consecutive pregnant patients with insulin-dependent (Type I) diabetes mellitus were randomized at the end of the first trimester for treatment with conventional insulin therapy (CIT) or continuous subcutaneous insulin infusion therapy (CSII). Nine patients randomized into the CSII group declined the pump treatment. The mean glycosylated haemoglobin (Hb AIc) decreased (p less than 0.001) both in the CIT and the CSII groups with no difference between the groups. Some deterioration in retinopathy was found in 2/18 patients in the CIT group, in 5/13 in the CSII group, and in 3/9 of those who declined the pump treatment. The proportion of patients whose retinopathy progressed did not differ significantly between the groups, and in the majority the deterioration was mild. However, two patients in the CSII group developed acute ischaemic retinopathy, which progressed to proliferative stage in spite of laser treatment. In these two cases the decrease in the Hb AIc level was among the greatest and fastest in the study. These data suggest that a rapid near normalization of glycaemic control by CSII during pregnancy can accelerate the progress of retinopathy in poorly controlled diabetic patients.

Existence of islet regenerating factors within the pancreas

Reduction in the functional mass of beta-cells is a common denominator in most forms of diabetes. Since the replicative potential of beta-cells is limited, the search for factors that trigger islet neogenesis becomes imperative. Here we tested the hypothesis that regenerating factors for the pancreas are either secreted by or present within the pancreatic milieu itself. For this purpose, we intraperitoneally injected pancreatic cell culture supernatant (PCCS), from normal pancreas, into streptozotocin (STZ)-induced diabetic mice for 15 consecutive days. The PCCS-treated mice showed sustained reversal in 77.77% of experimental diabetic mice as evidenced by restoration of normoglycemia, increase in serum insulin levels and occurrence of neo islets in histopathological studies during a two month follow up, as opposed to the control diabetic mice which remained hyperglycemic throughout. In order to examine the potential of PCCS to bring about the regeneration of islets, we treated intra-islet precursor cells with PCCS in vitro, which led to the neogenesis of islets as evidenced by dithiozone and insulin immunostaining. These findings substantiate our hypothesis and make the search for regenerative factors converge towards the pancreas and its immediate surroundings. Such regenerative approaches, in combination with other therapeutic strategies to promote islet neogenesis may, in future, provide a cure and/or better means for the control and management of diabetes.

Reperfusion of occluded capillary beds in diabetic retinopathy

PURPOSE

To demonstrate the reperfusion of nonperfused capillary beds in diabetic retinopathy.

METHODS

In a retrospective study, we reviewed 292 fluorescein angiograms of 94 eyes of 74 patients (mean age, 52 years; range, 20 to 68 years) with diabetic retinopathy. Fluorescein angiography was performed repeatedly (mean, three times; range, two to eight times) during a mean follow-up period of 2 years (range, 3 months to 12 years). None of the 94 eyes received laser photocoagulation.

RESULTS

Reperfusion of occluded capillary beds was observed in 65 (69%) of 94 eyes. Reperfusion was characterized by recanalization in 22 (34%) of the 65 eyes or by intraretinal neovascularization in 54 (83%) of the 65 eyes. The former took place in small nonperfused areas and the latter in larger nonperfused areas. Reperfusion occurred throughout the entire fundus in six of 94 eyes, resulting in resolution of diabetic retinopathy. Reperfused capillary beds with intraretinal neovascularization left vascular remodeling, which was seen as twisted or kinked abnormal vessels.

CONCLUSIONS

In diabetic retinopathy, occluded capillary beds may be reperfused. Twisted abnormal vessels may represent the reperfusion process through intraretinal neovascularization.

Transient proliferative diabetic retinopathy during intensified insulin treatment

Two women aged 22 and 19 years who had had diabetes for 11 and four years, respectively, developed proliferative retinopathy after five to seven months of significantly improved metabolic control. They were participants in two separate prospective studies including 97 insulin-dependent patients. At inclusion, one patient showed minimal background retinopathy and the other showed no retinopathy. Their level of glycosylated hemoglobin was initially high (14.3% and 17.5%) but within five to six months had fallen by 5.7% and 7.5%. The improved metabolic control was obtained by home blood glucose monitoring and insulin pump in the older patient and by home blood glucose monitoring only in the other. By maintaining near normoglycemia, regression of the proliferative retinopathy was achieved. Photocoagulation was not performed. After five and two years of follow-up, respectively, only mild background retinopathy has been noted in both patients. We concluded that a significant lowering of blood glucose may provoke proliferative retinopathy and that sustained good metabolic control may reverse this retinopathy without photocoagulation.

Progression of diabetic retinopathy after pancreas transplantation for insulin-dependent diabetes mellitus

We studied the effect of successful pancreas transplantation and consequent normoglycemia (mean total hemoglobin A1, 7.0 percent; range, 5.8 to 8.3) on visual function and diabetic retinopathy in 22 patients with Type I diabetes mellitus (study group). Sixteen similar patients in whom pancreas transplantation had been unsuccessful (mean total hemoglobin A1, 12.0 percent; range, 8.0 to 18.0) served as a control group. The majority of patients in both groups had advanced proliferative retinopathy. At a mean follow-up of 24 months we found no significant difference between the groups in the rate of progression of retinopathy, expressed as a score. Success of the transplantation did not prevent progression of retinopathy across the range of retinopathy studied. Progressive retinopathy was observed more commonly in patients with low retinopathy scores (nonproliferative or mild proliferative retinopathy) at base line in both the study group (13 of 17 eyes, or 76 percent) and the control group (7 of 12 eyes, or 58 percent). Further analysis suggested the possibility that after three years of euglycemia, the study group had less deterioration than the control group, particularly in eyes with advanced retinopathy. We observed no difference in the rate of loss of vision between the two groups. This study provides evidence that pancreas transplantation and subsequent normoglycemia neither reverse nor prevent the progression of diabetic retinopathy.

Beneficial effect of glycaemic improvement in non-ischaemic forms of diabetic retinopathy: a 3-year follow-up

Recent studies have suggested that optimal glucose control fails to arrest or even worsens background retinopathy possibly by aggravating retinal ischaemia. Fourteen insulin-dependent diabetic patients, aged 34 +/- 11 years (mean +/- SD) treated by long-term intraperitoneal insulin infusion using portable pumps, were followed for 3 years. Preproliferative or proliferative lesions on ophthalmoscopy and large non-perfused areas on fluorescein angiography were exclusion criteria. Six patients were found to have minimal and 8 mild background retinopathy. The patients were retrospectively assigned to two comparable groups except for their glycaemic equilibrium under insulin infusion: average control (n = 6) and excellent control (n = 8), although glycaemic control was significantly improved in all cases when compared to previous conventional therapy. Fluorescein changes were scored blindly and independently by 3 ophthalmologists according to modifications of fluorescein diffusion and capillary abnormalities. The two types of retinal lesions improved gradually in 10 patients and deteriorated in only 1 patient, although not progressing to proliferative retinopathy. Structural improvements were significantly more frequent in the excellently controlled group. We conclude that non-ischaemic lesions may still be arrested and even improved by tight metabolic control.

The effect of long-term near normal glycemic control on mild diabetic retinopathy

Thirty-three type l diabetics who used continuous subcutaneous infusion of insulin (CSll) and 24 diabetics on conventional treatment (maximum of two injections per day) were studied prospectively with ophthalmologic examinations, fundus photography, fluorescein angiography, and glycosylated hemoglobin (HbA1) determinations. Both groups were similar with respect to age, duration of diabetes, and length of follow-up. At entry almost all patients had only mild forms of diabetic retinopathy although three CSll patients had early proliferative retinopathy. The CSll groups achieved superior glycemic control throughout the study (mean HbA1 = 7.4% vs. 10.2%). After an average follow-up of more than 30 months, the CSll group showed significantly less progression of diabetic retinopathy as measured by macular aneurysm counts and by modified ETDRS grading. Careful control of glycemia may delay the progression of diabetic retinopathy.

The management of diabetic eye disease

Many diabetics go through life without ocular examination until complications begin. Ophthalmological consultation should be annual, and ocular complications are best prevented by tight control of blood sugar, best achieved at present with the insulin pump. This article describes diagnosis and management of diabetic retinopathy according to type of diabetes. It also describes indications for pars plana vitrectomy, cataract removal and lens implant. Close cooperation between family physician and ophthalmologist ensures prompt intervention to preserve vision.

Blood glucose control and the evolution of diabetic retinopathy and albuminuria. A preliminary multicenter trial

We conducted a prospective multicenter randomized trial to determine both the feasibility of maintaining blood glucose control at differing levels and the effect of improved control on diabetic microangiopathy and albuminuria. Seventy patients with diabetes (low C-peptide level) with nonproliferative retinopathy were randomly assigned to continuous subcutaneous insulin infusion or unchanged conventional injection treatment. At entry, both groups had similar demographic, clinical, and glycemic characteristics. Over the succeeding eight months, mean 24-hour glucose concentrations (175 +/- 9 mg per deciliter) and glycosylated hemoglobin levels (10.0 +/- 0.3 per cent) remained elevated during conventional treatment but fell to nearly normal levels (117 +/- 6 mg per deciliter and 8.1 +/- 0.2 per cent, respectively) with continuous insulin infusion. The frequency of biochemical hypoglycemia (less than 40 mg of blood glucose per deciliter) was similar in both groups, but ketoacidosis occurred only during continuous infusion. The level of retinopathy, assessed from photographs, progressed in both groups. Continuous infusion was associated with slightly more deterioration, mainly because of the appearance of soft exudates and intraretinal microvascular abnormalities. In contrast, elevated albumin-excretion rates fell during continuous infusion but not during conventional treatment. We conclude that maintenance of differing levels of blood glucose is feasible in a multicenter trial and that a nearly normal blood glucose level for eight months does not retard progression of, and may initially worsen, established retinopathy. These preliminary observations indicate the need for longer trials (particularly of primary prevention).

Continuous subcutaneous insulin infusion (CSII) does not prevent progression of proliferative and preproliferative retinopathy

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Influence of long-term insulin infusion pump treatment of type I diabetes on diabetic retinopathy

Isolated case reports have suggested short-term beneficial effects of subcutaneous insulin infusion pump treatment on background and proliferative diabetic retinopathy. To evaluate this question further, 30 eyes of 15 Type I diabetic patients were evaluated prospectively before and after 11--23 months (mean 18.1 months) of pump treatment. In each patient plasma glucose and total glycosylated hemoglobin fell to normal or near normal levels. The ten eyes without diabetic retinopathy at entry remained without. Four of 20 eyes with diabetic retinopathy at entry advanced by modified Early Treatment Diabetic Retinopathy Study (ETDRS) classification, including one eye that progressed from background to proliferative diabetic retinopathy. No eyes with diabetic retinopathy improved their modified ETDRS classification. One eye progressed to blindness; no other eye lost vision. Six eyes had laser treatment prior to insulin pump treatment; four of these and two more required laser during pump treatment. Two eyes had vitreous hemorrhages prior to pump treatment; one of these and four others hemorrhaged during pump treatment. No eyes with diabetic retinopathy showed regression of microvascular changes. The data suggest prolonged restoration of near normal glucose metabolism with the insulin pump does not reverse established diabetic retinopathy. Whether pump treatment slows the progression, or prevents the development, of diabetic retinopathy remains to be established.