Surgical considerations in diabetic vitrectomy

To investigate morphological variations in the macular area with optical coherence tomography (OCT) after vitrectomy for diabetic fibrovascular proliferation. We reviewed 108 cases using OCT 7-15 months after vitrectomy. Of these, 32 received OCT within 3 months postoperatively. Morphological variations were categorized and correlated with visual outcome. Only 24 cases (21.4%) had no obvious abnormalities. The most frequent findings were epiretinal membrane (52.8%), macular thickening (37.0%) and macular cysts (28.7%). Multivariate regression showed that diffuse macular thickening, loss of foveal depression and diffuse retinal thinning were significantly associated with poor visual acuity. Sequential OCT (< 3 and >or= 7 months) revealed that epiretinal membrane and oedema outside of fovea changed significantly between two examinations. OCT may identify diverse morphological changes in the macular area after diabetic vitrectomy for fibrovascular proliferation. Macular appearance may change over time, and certain types of morphological changes may be associated with poor visual function.

Ranibizumab for Retinal Neovascularization

Diabetic macular oedema (DMO) is a complication of diabetic retinopathy and a leading cause of visual impairment in patients with diabetes. ILUVIEN® (Alimera Sciences Inc., Alpharetta, GA, USA) is an intravitreal implant of fluocinolone acetonide (FAc), which is indicated in Europe for the treatment of vision impairment associated with chronic DMO that is considered insufficiently responsive to available therapies. This article reviews the clinical effectiveness and safety of the FAc implant from real-world studies presented at the Association for Research in Vision and Ophthalmology (ARVO) 2018 Annual Meeting. Review findings: Evidence from real-world studies, with the FAc implant in persistent or recurrent DMO, show consistent outcomes at a similar time point with those reported in the pivotal randomised controlled trials (RCTs). Real-world studies have also shown that the FAc implant led to improvements in visual acuity and central retinal thickness, as well as reductions in treatment burden. Increases in intraocular pressure (IOP) observed in these studies were consistent with those reported at a similar time point in the RCTs and with the effect of other corticosteroid treatments. Expert opinion and conclusions: The results suggest that FAc offers a clinical and cost-effective alternative in the treatment of persistent or recurrent DMO. There are low risks of raised IOP and cataract formation, both of which are amenable to treatment.

ObjectiveTo report visual acuity in patients undergoing pars plana vitrectomy (PPV) reoperations for complications of proliferative diabetic retinopathy (PDR).DesignRetrospective case series.SubjectsDiabetic patients undergoing reoperation with PPV between 2015 and 2018 at a university referral center.MethodsPatient charts were reviewed for indication for initial and repeat PPV, baseline clinical characteristics including gender, age, and lens status, and pre- and post-operative best-corrected visual acuity.Main Outcome MeasuresBest-corrected visual acuity at last follow-up.ResultsOf 538 eyes (409 patients) undergoing a PPV for diabetic retinopathy, 153 (28.4%) eyes had reoperation. Among the 130 eyes (119 patients) that met the inclusion criteria, 55 eyes (50 patients) underwent reoperation for complications of PDR, defined as non-clearing vitreous hemorrhage (NCVH) and/or tractional retinal detachment (TRD). Within this subgroup of 55 eyes, 19 (34.5%) eyes had an indication for the first surgery of NCVH. Fourteen (73.7%) of these NCVH eyes achieved a visual acuity of 20/80 or better. When the indication for the first surgery was TRD (33 eyes, 60%), 8 (24.2%) eyes achieved this same outcome (p=0.0011).ConclusionApproximately one of every four eyes treated with PPV for PDR will undergo repeat PPV during follow-up. VA outcomes after the repeat PPV were variable, with NCVH cases achieving better outcomes compared to TRD.

Diabetic retinopathy is a severe complication of diabetes mellitus that often leads to blindness. Because the pathophysiology of diabetic retinopathy is not fully understood and novel therapeutic interventions require testing, there is a need for reliable animal models that mimic all the complications of diabetic retinopathy. Pig eyes share important anatomical and physiological similarities with human eyes. Previous studies have demonstrated that INS C94Y transgenic pigs develop a stable diabetic phenotype and ocular alterations such as cataracts. The aim of this study was to conduct an in-depth analysis of pathological changes in retinas from INS C94Y pigs exposed to hyperglycaemia for more than 2years, representing a chronic diabetic condition. Eyes from six INS C94Ypigs and six age-matched control littermates were analysed via histology and immunohistochemistry. For histological analyses of retinal (layer) thickness, sections were stained with H&E or Mallory's trichrome. For comparison of protein expression patterns and vessel courses, sections were stained with different antibodies in immunohistochemistry. Observed lesions were compared with reported pathologies in human diabetic retinopathy. INS C94Ypigs developed several signs of diabetic retinopathy similar to those seen in humans, such as intraretinal microvascular abnormalities, symptoms of proliferative diabetic retinopathy and central retinal oedema in a region that is cone rich, like the human macula. The INS C94Ypig is an interesting model for studying the pathophysiology of diabetic retinopathy and for testing novel therapeutic strategies.

AimsTo evaluate diabetic retinopathy (DR) data from across the SUSTAIN clinical trial programme.Materials and methodsThe SUSTAIN clinical trial programme evaluated the efficacy and safety of semaglutide, a glucagon‐like peptide‐1 analogue, for the treatment of type 2 diabetes (T2D). In SUSTAIN 6, a 2‐year, pre‐approval cardiovascular outcomes trial, semaglutide was associated with a significant increase in the risk of DR complications (DRC) vs placebo. DR data from across the SUSTAIN trials were evaluated, and post hoc analyses of the SUSTAIN 6 data were conducted. These included subgroup analyses to identify at‐risk patients and a mediation analysis with initial change in glycated haemoglobin (HbA1c; percentage‐points at week 16) as a covariate, to examine the role of the magnitude of reduction in HbA1c as an intermediate factor affecting risk of DRC.ResultsThere was no imbalance in DR adverse events across the SUSTAIN 1 to 5 and Japanese trials. The majority of the effect with semaglutide vs placebo in SUSTAIN 6 may be attributed to the magnitude and rapidity of HbA1c reduction during the first 16 weeks of treatment in patients who had pre‐existing DR and poor glycaemic control at baseline, and who were treated with insulin.ConclusionsEarly worsening of DR is a known phenomenon associated with the rapidity and magnitude of improvement in glycaemic control with insulin; the DRC findings in SUSTAIN 6 are consistent with this. Guidance regarding the early worsening of DR is recommended with insulin. Similar recommendations may be appropriate for semaglutide.

Diabetic Macular Edema is a complication of diabetic retinopathy which is a cause of vision loss. It is assessed by detecting the hard exudates present in the color fundus images. The proposed method has two stages, there are detection of hard exudates and classification of diabetic macular edema severity from color fundus images. A feature extraction technique is used to capture the global features like intensity, color and texture of the fundus images and discriminate the normal from abnormal images. In this, the detection of hard exudates are done by using extreme learning machine classifier. This can be used to improve the detection accuracy. Disease severity classification is assessed by using regional property of the hard exudates in the retinal image. The detection performance has a sensitivity of 99% with specificity between 85% and 98%. The severity classification accuracy is 98% for the abnormal images.

A small number of eyes with proliferative diabetic retinopathy develop massive central fibrovascular membranes characterized by vitreoretinal tractions along the arcades and optic disk and retinal traction lines extending through the macula. The aim of our study was first to present the results of vitrectomy for removal of these central membranes and second to determine the correlation between preoperative parameters and postoperative visual outcome. We treated 28 eyes with severe central fibrovascular diabetic membranes by a modified bi-manual en bloc excision technique during vitrectomy. Preoperative examination included general status, visual acuity, slit-lamp investigation, binocular funduscopy, ultrasound investigation and visual evoked potentials (VEP). Further, we analyzed intraoperative complications and postoperative anatomic and functional outcomes. The retinas of 27 eyes with central traction retinal detachments were reattached by surgery. With a minimum of 6 months' follow-up, the macula remained attached in 24 eyes, while the retinas were completely attached in 22 eyes. Preoperative visual acuity was defective light perception to 0.1; an increase in visual acuity to maximal 0.1 was seen in 50% of the patients postoperatively. Preoperative visual acuity of light perception was associated with no functional improvement. Preoperative ultrasound investigation gave information about the real anatomic situation of the retina, especially if funduscopy was not possible. The other preoperative parameters could not predict correctly the functional outcome of vitrectomy in diabetics with severe central fibrovascular membranes because of the damage of the optic nerve and the retina. The high rate of anatomical reattachment after vitrectomy in diabetic eyes with severe central fibrovascular membranes is associated with a slight improvement of function; only preoperative visual acuity of hand motions or better was associated with an improvement of function.

Progression of retinopathy with glucagon-like peptide-1 receptor agonists with cardiovascular benefits in type 2 diabetes – A systematic review and meta-analysis

Background: Diabetic Retinopathy (DR) imposes a profound multidimensional burden on patients, extending beyond physiological visual loss to compromise daily functioning and psychosocial well-being. While the clinical progression of DR is well-documented, empirical evidence regarding its specific impact on quality of life (QoL) domains in developing regions remains limited Objective: This study aimed to describe the quality of life and identify specific functional deficits among patients with diabetes mellitus complicated by diabetic retinopathy in West Sumatra, Indonesia. Method: A quantitative descriptive cross-sectional study was conducted at the Eye Clinic of Ibnu Sina Yarsi Islamic Hospital, Bukittinggi. A total of 70 patients with confirmed diabetic retinopathy were recruited using purposive sampling. Data were collected using the validated Indonesian version of the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Descriptive statistical analysis was performed to determine demographic characteristics and domain-specific QoL scores. Results: The study cohort was primarily female (61.4%) and elderly, with 64.3% of the participants being 60 years or older. Most participants had been living with diabetes for more than 10 years (68.6%). Overall, half of the participants (50.0%) reported a moderate quality of life, while 28.6% rated their quality of life as poor. Analysis of specific domains showed that "near activities" and "mental health" were the most significantly affected areas. In contrast, scores for "color vision" and "peripheral vision" were relatively well-preserved. Conclusion: diabetic retinopathy severely impacts patients' quality of life, particularly affecting their independence in near-vision tasks and their psychological well-being. These findings underscore the pressing need for comprehensive nursing interventions that encompass routine psychosocial assessments and education on adaptive self-management, in conjunction with clinical management of glycemic levels, to enhance the overall well-being of this vulnerable population

Hypertension and Diabetic Retinopathy

Diabetic macular ischemia (DMI) is a troublesome complication of diabetes mellitus. The pathogenesis, progression, consequences, and treatment options for this disease are still poorly understood. However, it is believed that this complication is associated with several risk factors like poor glycemic control and high blood pressure. Two factors have been identified in the pathogenesis of the disease that play pivotal roles in disease development and progression. One of these factors includes extensive damage to the microvasculature of the retina. This includes narrowing of the vascular lumen and extensive damage to the endothelial cells, pericytes and the extracellular matrix. The second factor includes extensive damage to the neurosensory layer of the retina. DMI is always associated with other complications of diabetic retinopathy like retinal edema, so it is very difficult to find an isolated case of DMI. Moreover, the condition is also very rare making it very difficult to study and diagnose. However, a number of diagnostic tests like optical coherence tomography (OCT), fluorescence angiography (FA), and perimetry can be used as tools for the early detection of DMI. Since this disease damages the retina, loss of vision is an inevitable consequence that can progressively worsen over time. Also, DMI has been implicated as a risk factor for retinal edema and progressive diabetic retinopathy. Until now, no defined treatment protocol has been devised. The only available treatments focus on the management of risk factors (hyperglycemia and hypertension). Still, many aspects of DMI remain poorly studied and understood. This review paper aims to add to our current understanding of diabetic macular ischemia (DMI).

Sir, Cystoid macular oedema occurs as a frequent complication in diabetic retinopathy, retinal vein occlusions, uveitis and postoperatively in cataract surgery. In general, macular oedema is most prevalent in age-related macular degeneration (AMD) Ischaemia and/or inflammation may pathologically explain the development of macular oedema associated with these disorders. No effective, specific treatment by laser, systemic or topical steroids, haemodilution or surgery is available. Hyperbaric oxygen (HBO) treatment has been used in extraocular ischaemic disorders. The hypothesis of hypoxia as a predominant cause of cystoid macular oedema prompted us to start HBO therapy in two patients with chronic macular cystoid oedema refractory to other treatment modalities. Therefore, we present here these two patients, each of whom experienced longlasting visual improvement after HBO. The first patient was a 57-year-old man with type 2 diabetes, with diabetic onset in 1998. He had suffered the complication of preproliferative retinopathy and severe cystoid maculopathy for 6 months prior to presentation. His visual acuity (VA) was 0.5 and he had pronounced metamorphopsia and reading disability. He had a stabilized glycaemic metabolism and normal blood pressure. The second patient was a 56-year-old man with cystoid maculopathy complicated with idiopathic juxtafoveal retinal telangiectasis (group 1 A) on the right eye, with VA 0.2 excentric, paracentral scotoma and reading blindness. The patient had a well treated arterial hypertension. Both patients were given a series of five HBO treatments of pure oxygen for 90 min at a pressure of 2.4 bars absolute in a pressure chamber. Before and after the daily HBO treatment, each patient was tested for visual function by Amsler chart, reading ability and VA (Snellen chart). They also underwent an ophthalmological examination which included testing of the central visual field, biomicroscopy of the anterior eye segment, assessing intraocular pressure, direct and indirect ophthalmoscopy, fundus colour photography, fluorescein angiography (FA) and ocular coherence tomography (OCT). The diabetes patient improved increasingly during the treatment sessions, both subjectively and objectively, as shown in Fig. 1. Visual acuity in the right eye improved from 0.5 to 1.0, he achieved normal reading vision and metamorphopsia disappeared. Follow-up at 8 months showed the improvements to be unchanged. Late phase fluorescein angiography (FA)of the right eye of the diabetes patient at day 0 (A)and day 5 (B)after HBO treatment.The cystoid oedema has nearly disappeared.Optical coherence tomography (OCT)of the same eye at day 0 (C)and day 3 (D)after HBO treatment.The cystoid oedema is reduced. The second patient experienced visual improvement after 3 days, with VA improving from 0.2 to > 0.9, normal reading vision and no metamorphopsia. Fluorescein angiography and OCT demonstrate the results (Fig. 2). No recurrence of symptoms or macular oedema was seen at the 7-month follow-up. The patient still performs auto control by Amsler chart and his reading ability and improvements are unchanged. Late phase FAof the right eye of the non-diabetes patient at day 0 (A)and day 5 (B)after HBO treatment.The cystoid oedema is clearly reduced.Optical coherence tomography of the same eye at day 0 (C)shows a pronounced reduction of cystoid oedema as early as 2 days (D)after beginning HBO treatment. Hyperbaric oxygen therapy provided an outstanding and very rapid improvement in visual function and macular oedema despite the long duration of the disorder. This report seems to be the first in the literature to include a day-by-day objective documentation by OCT showing the absorption of the macular oedema associated with improved visual function. Surprisingly, the improvement in vision occurred shortly after the first treatment with HBO and the patients obtained normal vision after the very short series of HBO treatments. More surprisingly, the improvements have been shown to be longlasting. The therapeutic effect of HBO is caused by a 17-fold increase in the arterial oxygen tension. Several studies have shown a precapillary arterial contraction in cerebral and retinal tissue. This may reduce the oedema of the tissue. The high oxygen diffusion from the choroidal vasculature may further reduce the relative ischaemia of the tissue, improving the oxidative phosporylation and thereby improving retinal function and reducing oedema. Hyperbaric oxygen has been used in the short-term treatment of acute brain oedema. Further studies are needed to establish whether the improvement in vision is due solely to the treatment of the oedema or whether retinal function is also improved during HBO treatment. A previous study by Krott et al. (2002) found HBO adjunctive in the treatment of macular oedema. The authors gave an average of 15 HBO treatments and found no alteration in the oedemas of their diabetes patients, while the macular oedemas in patients with retinal vein occlusions were reduced. One might assume that the treatment should be commenced as soon as possible before fibrotic and thereby irreversible degeneration occurs. However, the present cases demonstrate that normal reading vision can be obtained for patients after a short series of HBO treatments. This finding deserves further research.

Timing of Vitrectomy for Active Proliferative Diabetic Retinopathy

Microvascular dysfunction is one of the most serious complications of diabetic retinopathy (DR). As a novel treatment drug for type 2 diabetes, exenatide possesses protective properties against retinal neurodegeneration. Sphingosine-1-phosphate receptor 2 (S1PR2) could regulate blood glucose in diabetes, and inhibition of S1PR2 is involved in the treatment of diabetes. However, the mechanism of exenatide in human retinal vascular endothelial cells (hRVECs) has not been fully defined. We tested the hypothesis that S1PR2 plays a vital role in high glucose (HG)-induced hRVECs, and that exenatide could ameliorate HG-induced hRVEC injury by regulating S1PR2 production. The hRVECs underwent HG-stimulation. Quantitative real-time polymerase chain reaction (RT-qPCR) and western blot were performed to examine the expression of S1PR2. Oxidative stress levels, inflammatory markers and cell apoptosis were detected using reactive oxygen species (ROS) staining, enzyme-linked immunosorbent assay (ELISA) kits and TUNEL staining. High glucose increased the level of S1PR2 in hRVECs and reduced the expression of glucagon-like peptide-1 receptor (GLP1R) compared to the control group. Exenatide decreased the level of S1PR2 induced by HG. Sphingosine-1 blocked the effects of exenatide, alleviating the ROS and cell apoptosis induced by HG. JTE-013 treatment protected hRVECs from injury by HG. The inhibitory effects of exenatide on S1PR2 expression lessened HG-induced hRVEC injury. The results demonstrate a possible mechanism of exenatide mediated inhibition of S1PR2 synthesis, and support S1PR2 as a novel target for treating DR.