Laser Treatment For Diabetic Retinopathy Research Articles

Vision-Related Quality of Life and Treatment Satisfaction Following Panretinal Photocoagulation in Diabetic Retinopathy-A Panel Study.

Background and Objectives: The aim of the study was to evaluate vision-related quality of life (VR-QOL) and treatment satisfaction (TS) in patients with diabetic retinopathy treated with panretinal photocoagulation (PRP). Material and Methods: The panel study included 95 patients who underwent PRP for diabetic retinopathy. Eligible patients with no history of previous PRP were interviewer-administered the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) and Retinopathy Treatment Satisfaction Questionnaire (RetTSQ) beforehandand one month after the last session of laser application. The study was conducted between June 2017 and June 2019 at tertiary care center in Serbia, Belgrade. We assessed pre- to post-PRP values of the composite score and subscale scores of VFQ-25 and RetTSQ, using a paired samples t-test. Univariate logistic regression was used to analyze the relationship between binary outcomes and potential predictors. Multivariate regression included predictors from univariate analyses that were statistically significant. Results: The mean VFQ-25 composite score was 65.4 ± 17.4 before and 63.3 ± 19.5 after PRP (p = 0.045). Subscale analysis showed that two of the 11 items achieved a significant decrease after laser application (general vision and dependency). The mean RetTSQ score at baseline was 60.0 ± 11.8 and at the exit visit was 60.3 ± 12.3 (p = 0.858). Sub-scale analysis showed significant deterioration for five of the 13 items. Multivariate logistic regression found that significant predictor of VFQ-25 composite score reduction was fewer laser burns (p = 0.002) while significant predictor of RetTSQ total score reduction was presence of hyperlipidaemia (p = 0.021). Conclusion: The use of vision-related quality of life and treatment satisfaction questionnaires in conjunction with clinical examination, appears to provide a more comprehensive overview of an individual's daily well-being following PRP. Laser treatment for diabetic retinopathy leads to deterioration of some of the patients' perceived VR-QOL and TS. Health-care providers should inform patients about their treatment options and together decide which therapeutic method is best for them.

Decision-making support system for the personalization of retinal laser treatment in diabetic retinopathy

In this work, we propose a decision-making support system for automatically mapping an effective photocoagulation pattern for the laser treatment of diabetic retinopathy. The purpose of research to create automated personalization of diabetic macular edema laser treatment. The results are based on analysis of large semi-structured data, methods and algorithms for fundus image processing. The technology improves the quality of retina laser coagulation in the treatment of diabetic macular edema, which is one of the main reasons for pronounced vision decrease. The proposed technology includes original solutions to establish an optimal localization of multitude burns by determining zones exposed to laser. It also includes the recognition of large amount of unstructured data on the anatomical and pathological locations' structures in the area of edema and data optical coherent tomography. As a result, a uniform laser application on the pigment epithelium of the affected retina is ensured. It will increase the treatment safety and its effectiveness, thus avoiding the use of more expensive treatment methods. Assessment of retinal lesions volume and quality will allow predicting the laser photocoagulation results and will contribute to the improvement of laser surgeon's skills. The architecture of a software complex comprises a number of modules, including image processing methods, algorithms for photocoagulation pattern mapping, and intelligent analysis methods.

IDF21-0058 The effect of fenofibrate therapy on laser treatment for diabetic retinopathy: a meta-analysis of randomized trials

Background: Diabetic eye disease remains a leading cause of blindness. While good control of blood pressure and glycaemia modestly reduces the progression of microvascular disease, this is often difficult to achieve and may have undesired side-effects. Fibrates are lipid-modifying agents that lower circulating triglycerides and have modest HDL-cholesterol raising effects. A major cardiovascular study of fenofibrate suggested that it may reduce the need for laser treatment for diabetic eye disease.

The Effectiveness of Laser Treatment for Diabetic Retinopathy in Patients with Chronic Kidney Disease

Background: Panretinal photocoagulation (PRP) remains one of the effective methods of treatment in pre- and proliferative forms of retinopathy with high efficiency. The aim of this study was to investigate the efficacy of PRP depending on the somatic status, laboratory parameters, and the severity of chronic kidney disease (CKD) in patients with type 2 diabetes (T2D) and a history of diabetic retinopathy (DR). Methods and Results: The study included 76 patients (50 women and 26 men) with T2D who underwent PRP for DR (152 eyes) using a VISULAS® 532s solid-state laser (ZEISS). The patients were divided into two groups depending on the severity of CKD. Group 1 (n=32, 64 eyes) included patients with CKD Stage 1, Group 2 (n=44, 88 eyes) included patients with CKD Stage 2. All patients underwent standard ophthalmological examination: visometry, tonometry, perimetry, biomicroscopy of the anterior segment of the eye and vitreous body, and fundus ophthalmoscopy. Thickness map of the retina was obtained using the RTVue-100 OCT (Optovue, Fremont, CA) EMM5 scan protocol and the Stratus OCT (Carl Zeiss Meditec, USA) radial scan protocol. Laboratory methods included a general blood test, PPG, FG, HbA1c, general urine analysis, and the assessment of blood levels of creatinine, ALT, and AST. PRP was carried out according to the standard method, gradually, in three stages; the interval between the stages of laser treatment was 1 month. After laser treatment, all patients, regardless of the treatment stage, were prescribed topical Broxinac® (Bromfenac ophthalmic solution 0.09%). The dynamics of corrected visual acuity (CVA) parameters and the retinal thickness of the macular region were assessed before PRP and 3 months after the complex treatment. Multivariate analysis revealed a linear and nonlinear effect of lipid spectrum indicators (TC and LDL) on the formation of CL (crystalline lens) pathology. After treatment, a significant increase in CVA was noted in both study groups. The effectiveness of PRP coagulation depended on the severity of the CKD stage in T2D patients with DR. Normalization of morphometric parameters of the macular region of the retina was noted in 93.8% of cases in Group 1 and in 86.4% of cases in Group 2. The decrease in the effectiveness of treatment was associated with the presence of macroangiopathy (CAD), concomitant diseases (CHF, AH and dyslipidemia), and CKD stage. Conclusion: Prolonged administration of the non-steroidal, anti-inflammatory drug Bromfenacum® for a month after each stage of PRP is effective.

A clinical study of contrast sensitivity and visual acuity in patients following retinal photocoagulation for diabetic retinopathy

This study is aimed to assess the effect of retinal photocoagulation on contrast sensitivity and visual acuity.In this prospective observational study,patients with diabetic retinopathy in either one or both eyes requiring retinal photocoagulation were included in the study. Eyes which were subjected to treatment for diabetic retinopathy were divided into 3 groups. Group 1 included eye which were subjected to pan retinal photocoagulation (PRP) alone, Group 2 included eyes which were subjected to PRP and macular laser (ML) and Group 3 included eyes which were subjected to ML alone. Assessment of visual acuity and contrast sensitivity were done before and three months post retinal photocoagulation.Descriptive statistics were used and where required. paired t test, One- way, ANOVA, Post HOC tests, Tukey HSD tests were used. The sample size was calculated to be 64 eyes. Total of 64 eyes of 37 patients, underwent retinal photocoagulation for diabetic retinopathy. Out of the 37 patients, only 16 patients (29 eyes) came for follow up at the end of 3 months of laser photocoagulation. Number of eyes requiring PRP was more when compared to PRP with ML and ML alone. Pre-laser and post-laser visual acuity following PRP, remained unchanged. Improvement in visual acuity was seen in eyes that underwent ML alone. There was worsening of visual acuity in eyes that underwent combination of PRP and ML. However, p value was not significant. Pre-laser and post-laser contrast sensitivity, improved in eyes that underwent only PRP and macular laser alone. There was a reduction in CS when both forms of treatment were combined, though p value was not significant Eyes which underwent PRP alone, showed improvement in contrast sensitivity without any change in visual acuity. While reduction in visual acuity and contrast sensitivity was observed in eyes which underwent combination treatment (PRP and ML), there was improvement in visual acuity and contrast sensitivity in eyes which underwent macular laser alone. Contrast sensitivity is necessary component of visual function. Abnormal contrast sensitivity can affect day to day activities. Hence it is important to counsel patients about the possibility of contrast sensitivity being affected to some extent following laser treatment for diabetic retinopathy.

Information Technology for Decision-making Support for Personalized Parameter Selection in Retinal Laser Treatment and Photocoagulation Outcome Prognostication

We propose a new information technology for mapping macular photocoagulation patterns in the laser treatment of diabetic retinopathy and evaluating the treatment strategy efficacy. The technology relies on processing optical coherence tomography (OCT) data, fundus image segmentation, mapping photocoagulation plans, and development of prognostic indicators of the laser photocoagulation treatment outcome. Analysis of the OCT data enables a pathological area to be extracted and then refined based on retinal image segmentation results, allowing a photocoagulation treatment region to be outlined. A photocoagulation plan mapped for the region of interest (ROI) is then analyzed to identify the treatment success probability based on prognostic indicators. The technology developed will offer the retina specialist a preliminary photocoagulation plan, as well as allowing the assessment of the diabetic retinopathy treatment efficacy to be carried out.

Diabetic retinopathy knowledge and management approaches of primary care physicians

Aim: We evaluated the level of knowledge on diabetic retinopathy (DR) and management approaches of primary care physicians with important roles in preventive health services.Material and Methods: Using a Google form, a 14-item questionnaire was prepared to the family physicians’ knowledge about DR and the examination tools they use and their management approach. This questionnaire was sent to 92 family physicians in Turkey via the What’s App Messenger.Results: According to the questionnaire responses, 90 (97.8%) of the family physician centers had a Snellen chart and 91 (98.9%) a direct ophthalmoscope. Among the physicians, 79 (85.9%) did not perform visual acuity examinations for diabetic patients, and 39 (42.4%) did not use an ophthalmoscope. While 34 (37.0%) of the surveyed physicians did not refer diabetic patients to an ophthalmologist for DR examinations at all, only 22 (23.9%) referred patients to an ophthalmologist at the time of initial diagnosis and 19 (20.7%) referred patients at 1 year after the initial diagnosis. 10 (10.8%) of the surveyed physicians referred patients to an ophthalmologist at 2-year intervals, 4 (4.3%) at 6-month intervals, and three (3.3%) at over 2-year intervals. Among the physicians, 64 (69.6%), 57 (62.0%), and 63 (68.5%) were not familiar with the stages of DR, fundus fluorescein angiography, and laser treatment for DR, and 60 (65.2%) did not know how to perform intraocular injection treatment methods. A total of 87 (94.6%) physicians stated a need for training programs in DR.Conclusion: DR, an eye complication of diabetes mellitus, is not well understood by family physicians, and more than half of physicians referred their patients to an ophthalmologist either late after diagnosis or not at all. It is therefore important for family physicians to undergo training programs on DR to increase their effectiveness in primary health care services.

Do patients receiving laser treatment for sight threatening diabetic retinopathy and those under the care of a consultant led multidisciplinary diabetes specialist team have better HbA1c value than those that are not under a diabetes specialist?

AbstractPurposeTo evaluate if patients with sight threatening diabetic retinopathy who undergo laser photocoagulation treatment and are under the care of a consultant‐led specialist diabetes team have a better HbA1c value than those that are not under a specialist diabetes team.MethodsRetrospective review of all patients who underwent pan laser photocoagulation (PRP) treatment or macular laser therapy between 1st January 2018 and 31st December 2018 were included in the study.ResultsWe identified 64 patients who underwent laser treatment for diabetic retinopathy in the 12‐month period, 21 female and 43 male. Of these, 36 patients (56%) had type‐2 diabetes, 12 patients (18%) had type‐1 diabetes and in 16 patients (25%), this was undocumented. In terms of type of laser therapy, 50 (78%) underwent PRP and 14 (22%) underwent macular laser. 33 patients (51%) who underwent laser treatment were under the care of a specialist diabetes team within 1 year of receiving treatment. The average HbA1c value of patients who were under a diabetes specialist was 80.9 mmol/mol (9.6%), versus those who were not under a diabetes specialist was 72.7 mmol/mol (8.8%).ConclusionOur study showed that amongst patients who underwent laser treatment for sight threatening diabetic retinopathy, majority underwent pan retinal photocoagulation for proliferative disease rather than macular laser for maculopathy. This observation is expected, as macular laser is less commonly practiced since the advent of anti‐VEGF therapy for diabetic maculopathy. Surprisingly, the HbA1c values on average were better in those who were not under a specialist diabetes team compared to those who were under the care of a specialist. Although this is unexpected, it may be explained by the fact that those under a diabetes team have poorer control of their blood sugars, and/or more advanced diabetes to begin with.

Incremental cost-effectiveness of screening and laser treatment for diabetic retinopathy and macular edema in Malawi.

ObjectiveTo investigate the economic impact of introducing targeted screening and laser photocoagulation treatment for sight-threatening diabetic retinopathy and macular edema in a setting with no previous screening or laser treatment for diabetic retinopathy in sub-Saharan Africa.Materials and methodsA cohort Markov model was built to compare combined targeted screening and laser treatment for patients with sight-threatening diabetic retinopathy and macular edema against no intervention. Primary outcomes were incremental cost per quality-adjusted life year (QALY) gained and per disability-adjusted life year (DALY) averted. Primary data were collected on 357 participants from the Malawi Diabetic Retinopathy Study, a prospective, observational cohort study. Multiple scenarios were explored and a probabilistic sensitivity analysis was performed.ResultsIn the base case (age: 50 years, service utilization rate: 80%), the cost of the intervention and the years of severe visual impairment averted per patient screened were $209 and 2.2 years respectively. Applying the World Health Organization threshold of cost-effectiveness for Malawi ($679), the base case was cost-effective when QALYs were used ($400 per QALY gained) but not when DALYs were used ($766 per DALY averted). The intervention was more cost-effective when it targeted younger patients (age: 30 years) and less cost-effective when the utilization rate was lowered to 50%.ConclusionsAnnual photographic screening of diabetic patients attending medical diabetes clinics in Malawi, with the provision of laser treatment for those with sight-threatening diabetic retinopathy and macular edema, appears to be cost-effective in terms of QALYs gained, in our base case scenario. Cost-effectiveness improves if services are utilized more intensively and extended to younger patients.

Highlights over Laser Treatment for Diabetic Retinopathy

Highlights over Laser Treatment for Diabetic Retinopathy

Analysis of vision and the situation macular edema lesions after laser treatment of diabetic retinopathy

Objective To investigate the changes in visual acuity and macular edema lesions after laser treatment of diabetic retinopathy. Methods 92 patients with diabetic retinopathy were chosen for this study, they were treated with laser treatment,proliferative diabetic retinopathy(NPDR group)to take the whole retinal photocoagulation treatment of patients with non-proliferative diabetic retinopathy(PDR group) patients to take time full retinal photocoagulation treatment.Before and after treatment,visual acuity and macular edema changes were observed. Results Compared to pre-treatment,visual acuity after treatment in both two groups were significantly improved(0.49±0.08)°vs(0.43±0.09)°;(0.48±0.09)°vs(0.44±0.07)°],the difference was statistically significant(t= 3.728,2.104,all P 0.05);compared with before treatment,foveal retinal thickness were significantly lower after treatment[(253.41±66.73)μm vs(393.36±92.18)μm;(287.25±61.57)μm vs(388.02±89.83)μm],the difference was statistically significant(t= 6.233,3.541,all P< 0.05);the thickness of the retinal foveal in NPDR group was significantly lower than PDR group,the difference was statistically significant(t= 2.445,P< 0.05 ). Conclusion Laser in the treatment of diabetic retinopathy can significantly improve visual acuity and macular edema,and it is better in non-proliferative diabetic retinopathy,which worthy of further promotion in clinical practice. Key words: Diabetes mellitus/complication,retinopathy; Laser coagulation; Vision; Macula

Recent developments in laser treatment of diabetic retinopathy.

Laser photocoagulation has been the mainstay of diabetic retinopathy treatment since its development in mid-20th century. With the advent of antivascular endothelial growth factor therapy, the role of laser therapy appeared to be diminished, however many advances in laser technology have been developed since. This review will describe recent advances in laser treatment of diabetic retinopathy including pattern scan laser, short-pulse duration and a reduced fluence laser, and navigated laser system for proliferative diabetic retinopathy and macular edema.

New Laser Technologies for Diabetic Retinopathy

Diabetic retinopathy is a leading cause of severe visual impairment for adults worldwide. Vision loss from systemic diabetes usually occurs secondary to macular edema or from de novo proliferation from the retinal vasculature. The Diabetic Retinopathy Study (DRS) established that panretinal photocoagulation (PRP) reduces the risk of severe vision loss from proliferative disease by >50 % and, thus, PRP has become the gold standard in the treatment of proliferative disease. The Early Treatment of DRS expanded the use of laser photocoagulation to clinically significant macular edema. Advances in laser technology have led to the development of semi-automated lasers, including pattern scanning laser (PASCAL®, Topcon) and fully automated lasers, such as the navigating lasers (NAVILAS®, OD/OS), that aim to deliver faster, safer, more accurate, and less painful treatment of diabetic eye disease and other retinal conditions. Sublethal phototherapy with subthreshold diode micropulsed laser treatment for macular edema has led to a paradigm shift in our understanding of retinal photocoagulation by demonstrating similar efficacy with less collateral damage. Here, we review the current data on laser treatment of diabetic retinopathy with an emphasis on understanding the new laser photocoagulation technologies for treatment of proliferative diabetic retinopathy and clinically significant diabetic macular edema.

Diabetic retinopathy in sub-Saharan Africa: meeting the challenges of an emerging epidemic

BackgroundSub-Saharan Africa faces an epidemic of diabetes. Diabetes causes significant morbidity including visual loss from diabetic retinopathy, which is largely preventable. In this resource-poor setting, health systems are poorly organized to deliver chronic care with multiple system involvement. The specific skills and resources needed to manage diabetic retinopathy are scarce. The costs of inaction for individuals, communities and countries are likely to be high.DiscussionScreening for and treatment of diabetic retinopathy have been shown to be effective, and cost-effective, in resource-rich settings. In sub-Saharan Africa, clinical services for diabetes need to be expanded with the provision of effective, integrated care, including case-finding and management of diabetic retinopathy. This should be underpinned by a high quality evidence base accounting for differences in diabetes types, resources, patients and society in Africa. Research must address the epidemiology of diabetic retinopathy in Africa, strategies for disease detection and management with laser treatment, and include health economic analyses. Models of care tailored to the local geographic and social context are most likely to be cost effective, and should draw on experience and expertise from other continents. Research into diabetic retinopathy in Africa can drive the political agenda for service development and enable informed prioritization of available health funding at a national level. Effective interventions need to be implemented in the near future to avert a large burden of visual loss from diabetic retinopathy in the continent.SummaryAn increase in visual loss from diabetic retinopathy is inevitable as the diabetes epidemic emerges in sub-Saharan Africa. This could be minimized by the provision of case-finding and laser treatment, but how to do this most effectively in the regional context is not known. Research into the epidemiology, case-finding and laser treatment of diabetic retinopathy in sub-Saharan Africa will highlight a poorly met need, as well as guide the development of services for that need as it expands.

Evidence Based Medicine: Why should we be practicing it all the time?

Evidence Based Medicine: Why should we be practicing it all the time?

Stable refraction and visual acuity in diabetic patients with variable glucose levels under routine care

To investigate how refraction and visual acuity may vary in patients with diabetes under routine care. Fifty-three eyes of 53 patients with various degrees of diabetic retinopathy were examined prospectively on four different occasions within a month. Refraction, best-corrected visual acuity (expressed as logMAR score) and blood glucose were measured on each occasion. Intraindividual variability was calculated as the range between the highest and lowest measurements. Associations between blood glucose levels and each of the other variables were tested by linear regression analysis for each patient. Refraction was completely stable in 43 patients and changed only slightly in 10, in whom the mean intraindividual variability of the spherical equivalent was 0.4 dioptres. Visual acuity test results were also highly reproducible. Mean intraindividual variability in visual acuity was 0.08 logMAR. Mean haemoglobin A1c (HbA1c) was 7.3 ± 1.5% but individual blood glucose levels ranged from 2.8 to > 22.2 mmol/l. Intraindividual variability ranged from 0.5 to 18.1 mmol/l, with a median of 6.0 mmol/l for the entire group. There were no associations between refraction or visual acuity and blood glucose levels or inter- or intraindividual glucose variations. Refraction and visual acuity test results were highly reproducible and stable in patients with reasonably well controlled diabetes but variable blood glucose levels under routine care.

Focal and panretinal photocoagulation with a navigated laser (NAVILAS®)

Editor, L aser photocoagulation is a well evidence-based standard therapy for both proliferative diabetic retinopathy (PDR) and diabetic macular oedema (DME), recently supplemented by e.g. anti-VEGF treatment (Elman et al. 2010). Over the last decades, numerous technical advances have been introduced to laser therapy including subthreshold techniques (Nakamura et al. 2010) and pattern laser generation (Bolz et al. 2010). However, the advantages of computerized precision well known from refractive surgery (‘eye tracking’) have not become widely available despite several technical approaches towards that goal (Naess et al. 2002). Navilas is a novel fundus imaging and laser treatment device (ODOS GmbH, Teltow, Germany) that allows imaging (infrared, colour, fluorescein angiography) and integrated laser treatment of the retina, including pattern laser generation. Besides documentation, safety and patient comfort, the main theoretical advantages lie in retina navigation. The device offers retina navigation by computerized image and target assistance systems, resulting in high precision and reproducibility of theoretically <60–110 lm (Neubauer et al. 2009). It fundamentally differs from other laser devices by applying not a slitlamp, but a scanning slit-based instrument. The instrument takes approximately 25 images per seconds in imaging or treatment mode. For focal laser treatment, the field of view is 50 , and the optical resolution with the instrument used in this study was 1280 · 1024 pixels, for that angle, resulting in approximately 20– 26 pixels ⁄degree. For panretinal laser treatment, a specific widefield lens, resulting in 85 field of view, is used. Because of the slit imaging principle, images of high contrast and sharpness can be obtained (Neubauer et al. 2010). Another difference to slitlampbased laser devices is the touch-screen monitor used for imaging, planning and treating fundus changes (Fig. 1). This allows the retina surgeon to plan laser spots on the screen and then apply automated patterns and single spots as appropriate. A prepositioning mode may be used to automatically advance the targeting aiming beam from targeted retinal position to position after the aiming beam, and the preplanned target can be stabilized on the living fundus. For treatment, the surgeon actuates the laser manually after the target lock has been verified by the surgeon. Exemplarily, we report on two cases of in vivo-navigated laser treatment applying the Navilas device for focal and peripheral laser treatment in diabetic retinopathy. A 52-year-old man suffering from type 2 diabetes for 8 years and mild to moderate nonproliferative diabetic retinopathy (NPDR) on both eyes attended our clinic for routine control. Visual acuity of the right eye had decreased from 20 ⁄ 20 to 25 ⁄ 30 over the last year, the left eye was 20 ⁄ 20. Funduscopy revealed moderate NPDR and retinal thickening originating from the upper vessel arcade extending into the macular region. On fluorescein angiograpy, significant exudation was present in this area. Therefore, focal macular laser photocoagulation for clinically significant macular oedema was performed on the right eye utilizing Navilas. Treatment was preplanned on the software system based on colour fundus imaging (Fig. 2A). Navigated, semi-automatic pattern laser application was conducted without complications (laser settings: spot size: 100 lm, time 100 ms, energy 80–100 mW). One week after treatment, Navilas fundus imaging and spectral-domain optical coherence tomography of the treated areas were conducted, and confirmed laser application to the preplanned area (Fig. 2B and C). A 69-year-old man with a longstanding history of type 2 diabetes and NPDR presented with a decrease of vision of his right eye. Visual acuity had decreased from 20 ⁄30 to 10 ⁄ 100 during the last month; visual acuity on the left eye was 25 ⁄30. Clinical examination revealed PDR with multiple areas of peripheral retinal neovascularisation and a mild vitreous haemorrhage on the right and moderate NPDR on the left eye. Panretinal full scatter photocoagulation (usually applied over 3–4 sessions at our institution) was suggested as a treatment for the right eye. However, the first treatment session using a conventional 532 -nm slitlamp-based laser and a standard contact lens (‘TransEquator’ by Volk, USA) had to be aborted after 50 laser spots. The patient did not agree to continue treatment, as he could not tolerate the contact lens and felt significant pain from retinal laser application. One week later, panretinal pattern photocoagulation using the Navilas laser device was conducted. Because of the optical design of the device, laser treatment can be applied either with or without the use of a contact lens. Although currently not recommended by the manufacturer in selected cases, such as in patients with corneal irritations or blepharospasm, it might be advantageous to not apply Fig. 1. Navilas fundus imaging and laser treatment device applying a slit-based camera and touch-screen monitor for imaging, planning and treating fundus changes.

Retrospective study of outcome of diabetic laser treatment in Singapore National Eye Centre

Abstract Purpose To describe 2 year clinical outcomes for a retrospective study group of patients undergoing photocoagulation and focal laser treatment for diabetic retinopathy (DR)or maculopathy at an eye institution in Singapore. Methods Retrospective study Results 150 consecutive eyes were recruited.The mean age was 59.3 years old with 46% males and 54% females.Majority were type 2 diabetics (146 out of 150) with mean HBA1c of 8.4 %. Indication for pan retinal laser photocoagulation (PRP) was severe non proliferative DR and indication for macula laser was clinically significant macular edema(CSME). For patients with only PRP performed, the mean change in log mar visual acuity (VA) at 2 yrs was +0.121 +/‐0.46. DR status at 2 yrs was stable in 90.6% of the patients and the macula was unremarkable in 86.8% of the patients. In patients requiring only macula laser, there was improvement in log mar VA at 2 years, with a mean change of ‐0.085 +/‐ 0.18. Diabetic status was stable in 91.3% of the patients and the macula was dry in 95.7% of the patients. In patients undergoing both PRP and macula laser , there was improvement in VA with a mean log mar VA change of ‐0.095 +/‐0.45. DR status at 2 years was stable in 92% of the patients and the macula was dry in 88% of the patients.Complications of laser treatment include epiretinal membrane (5.3%), cystoid macular edema(0.7%)and scar creep(0.7%).0.9% of the patients developed CSME after commencing PRP. Conclusion There is an overall improvement in visual acuity in DR patients undergoing laser treatment. Most patients had stable DR at 2 yrs and there were few complications of the laser.

Fenofibrate suppresses microvascular inflammation and apoptosis through adenosine monophosphate–activated protein kinase activation

The Fenofibrate Intervention and Event Lowering in Diabetes study demonstrated that treatment with fenofibrate in individuals with type 2 diabetes mellitus not only reduced nonfatal coronary events but also diminished the need for laser treatment of diabetic retinopathy and delayed the progression of diabetic nephropathy. However, the mechanism by which fenofibrate may have altered the microvasculature remains unclear. We thus investigated the effect of fenofibrate on human glomerular microvascular endothelial cells (HGMEC). Treatment of HGMEC with fenofibrate resulted in transient activation of adenosine monophosphate–activated protein kinase (AMPK), thereby inducing the phosphorylation of Akt and endothelial nitric oxide synthase, leading to nitric oxide production. We compared AMPK activation induced by bezafibrate and WY14643 with that induced by fenofibrate in HGMEC as well as HepG2 cells. Only fenofibrate activated AMPK in HGMEC. Fenofibrate also inhibited nuclear factor– κB activation by advanced glycation end-products, thereby suppressing the expression of various adhesion molecule genes in HGMEC. Suppression of fenofibrate-induced inhibition of nuclear factor– κB activation was observed in cells treated with AMPK small interfering RNA or compound C. Furthermore, fenofibrate was observed to significantly suppress apoptosis of HGMEC in hyperglycemic culture medium. Treatment with compound C or Nw-nitro-L-arginine methyl ester (L-NAME) abolished the suppressive effect of fenofibrate on HGMEC apoptosis. Our findings suggest that fenofibrate might exert a protective effect on the microvasculature by suppressing inflammation and apoptosis through AMPK activation beyond its lipid-lowering actions.

Early histological alteration of the retina following photocoagulation treatment in diabetic retinopathy as measured by spectral domain optical coherence tomography

To investigate the earliest histological changes of the retina after laser treatment of diabetic retinopathy by using Spectral domain optical coherence tomography (SD-OCT, Heidelberg Engineering, Heidelberg, Germany). This study examined 320 laser burns from 16 eyes of 12 patients with early severe non-proliferative diabetic retinopathy (NPDR) that underwent laser photocoagulation according to the protocol which the Early Treatment Diabetic Retinopathy Study (ETDRS) recommended. SD-OCT scan was performed before the laser treatment, then 1 hour, 24 hours, 48 hours, 72 hours and 1 week after treatment. The main outcome measure was thickness change in outer retina (OR) in the region localized to the laser treatment. The alterations of retinal thickness at the location of the laser burns mainly occurred within the retinal layers that expand from the outer plexiform layer (OPL) to the outer highly reflective layer (HRL) (IS/OS). From 1 hour to 48 hours after laser treatment, the thickness of retina, from OPL to the HRL, increased with time. At 48 hours post- treatment, the increase of retinal thickness from OPL to the HRL reached a peak. At 72 hours, the thickness of retina from the OPL to the HRL began to decrease as a result of the outward migration of OPL towards the retinal pigment epithelial (RPE). At 1 week post- treatment, hyporeflectivity at the level of IS/OS and RPE atrophy was observed in the areas corresponding with the laser burns; the thickness of retina from the OPL to the HRL was essentially within normal thickness. This study demonstrates the subtle in vivo imaging changes of laser lesion and the trend of earliest changes in the thickness of the retina in the level of OPL-HRL, first increasing then subsequently decreasing as shown by SD-OCT in DR post laser treatment.