Monotherapy laser photocoagulation for diabetic macular oedema

Efficacy of anti-VEGF monotherapy versus anti-VEGF therapy with subthreshold micropulse laser (SML) in the management of diabetic macular oedema (DMO): a systematic review and meta-analysis

BACKGROUND

Intravitreal injection anti-vascular endothelial growth factor (IVI anti-VEGF) therapy serves as the primary treatment for centre involving diabetic macular oedema (DMO). Conventional laser therapy (CLT) adjunct has proven beneficial; however, it is not widely used due to significant risks of retinal scarring. Subthreshold micropulse laser (SML) therapy has, however, emerged as a comparable alternative to combination therapy, offering a distinct advantage by mitigating the risk of retinal scarring.

METHODS

A search of six databases was conducted. A meta-analysis of mean differences was performed including subgroup analyses where appropriate. Primary outcome was the number of injections at 12-14 months; secondary outcomes were changes in central macular thickness (CMT) and best corrected visual acuity (BCVA) at 6-8 months and 12-14 months.

RESULTS

A total of ten papers including six randomised clinical trials and four retrospective clinical studies were included in our study, capturing 563 eyes of 478 patients. Overall, the risk of bias was moderate for these studies. Significantly fewer anti-VEGF therapy injections were administered in the combination therapy versus anti-VEGF monotherapy patients at 12-14 months who had poor visual acuity (6/18 Snellen or worse) at baseline, mean difference - 2.25 (95% CI; - 3.35, - 1.15; p < 0.05). Combination therapy was not associated with significantly fewer intravitreal injections in patients with a higher visual acuity (6/15 Snellen or better) at baseline. Our analysis also showed significant improvements to both BCVA and CMT were reached at 6 - 8 month post-baseline at the 95% confidence intervals: - 1.13 (- 2.09, - 0.16) and - 4.04 (- 7.59, - 0.50). These improvements remained statistically significant at 12-14 months: - 0.94 (- 1.67, - 0.20) and - 1.92 (- 3.52, - 0.32) respectively with combination therapy.

CONCLUSION

Our findings demonstrate that combination therapy (SML + IVI anti-VEGF) is associated with fewer intravitreal injections. We report a better BCVA and a reduction in CMT at 6 and 12 months from baseline with combination treatment compared to the IVI anti-VEGF monotherapy comparator. SML is a proven non-scarring cost-effective therapy for DMO that should be readily available in the medical retinal therapy as it may reduce the burden of care.

Autonomous screening for laser photocoagulation in fundus images using deep learning

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of blindness in adults worldwide. Artificial intelligence (AI) with autonomous deep learning algorithms has been increasingly used in retinal image analysis, particularly for the screening of referrable DR. An established treatment for proliferative DR is panretinal or focal laser photocoagulation. Training autonomous models to discern laser patterns can be important in disease management and follow-up.

METHODS

A deep learning model was trained for laser treatment detection using the EyePACs dataset. Data was randomly assigned, by participant, into development (n=18 945) and validation (n=2105) sets. Analysis was conducted at the single image, eye, and patient levels. The model was then used to filter input for three independent AI models for retinal indications; changes in model efficacy were measured using area under the receiver operating characteristic curve (AUC) and mean absolute error (MAE).

RESULTS

On the task of laser photocoagulation detection: AUCs of 0.981, 0.95, and 0.979 were achieved at the patient, image, and eye levels, respectively. When analysing independent models, efficacy was shown to improve across the board after filtering. Diabetic macular oedema detection on images with artefacts was AUC 0.932 vs AUC 0.955 on those without. Participant sex detection on images with artefacts was AUC 0.872 vs AUC 0.922 on those without. Participant age detection on images with artefacts was MAE 5.33 vs MAE 3.81 on those without.

CONCLUSION

The proposed model for laser treatment detection achieved high performance on all analysis metrics and has been demonstrated to positively affect the efficacy of different AI models, suggesting that laser detection can generally improve AI-powered applications for fundus images.

Diabetic Retinopathy Leading to Blindness- A Review

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes that damages the retina, leading to blindness. People with type 1 diabetes are at greater risk of developing DR than people with type 2 diabetes. Diabetic retinopathy may be divided into two primary categories: Proliferative diabetic retinopathy (PDR) and non-proliferative diabetic retinopathy (NPDR). There are multiple risk factors for the onset and progression of diabetic retinopathy, such as hypertension, obesity, smoking, duration of diabetes, and genetics. Numerous investigations have evaluated the levels of a wide range of inflammatory chemokines within DR patients' serum, vitreous, and aqueous fluids. In diabetic retinopathy, the vitreous fluid exhibited rises in angiogenic factors like platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) or declines in antiangiogenic factors like pigment epithelium-derived factor (PEDF). For prevention of diabetic retinopathy, more physical activity as well as less sedentary behavior were linked to a reduced likelihood of DR. Supplementing with nutraceuticals containing vitamins (B1, B2, B6, B12, C, D, E, and l-methyl folate) and mineral (zinc) can help decrease or avoid an outbreak of DR. Only laser photocoagulation and Anti-vascular endothelial growth factor (Anti-VEGF) injections are advised as favorable therapies in severe retinopathy. When it comes to treating DR's VEGF levels, inflammation, oxidative stress, apoptosis, and angiogenesis, Traditional Chinese medicine (TCM) has an excellent future.

Complementary Approaches to Retinal Health Focusing on Diabetic Retinopathy

Diabetes mellitus affects carbohydrate homeostasis but also influences fat and protein metabolism. Due to ophthalmic complications, it is a leading cause of blindness worldwide. The molecular pathology reveals that nuclear factor kappa B (NFκB) has a central role in the progression of diabetic retinopathy, sharing this signaling pathway with another major retinal disorder, glaucoma. Therefore, new therapeutic approaches can be elaborated to decelerate the ever-emerging "epidemics" of diabetic retinopathy and glaucoma targeting this critical node. In our review, we emphasize the role of an improvement of lifestyle in its prevention as well as the use of phytomedicals associated with evidence-based protocols. A balanced personalized therapy requires an integrative approach to be more successful for prevention and early treatment.

OCT-angiography based artificial intelligence-inferred fluorescein angiography for leakage detection in retina [Invited]

Optical coherence tomography angiography (OCTA) covers most functions of fluorescein angiography (FA) when imaging the retina but lacks the ability to depict vascular leakage. Based on OCTA, we developed artificial intelligence-inferred-FA (AI-FA) to delineate leakage in eyes with diabetic retinopathy (DR). Training data of 19,648 still FA images were prepared from FA-photo and videos of 43 DR eyes. AI-FA images were generated using a convolutional neural network. AI-FA images achieved a structural similarity index of 0.91 with corresponding real FA images in DR. The AI-FA generated from OCTA correctly depicted vascular occlusion and associated leakage with enough quality, enabling precise DR diagnosis and treatment planning. A combination of OCT, OCTA, and AI-FA yields more information than real FA with reduced acquisition time without risk of allergic reactions.

[Pain after panretinal photocoagulation: 50-millisecond pulse versus conventional pulse]

Background

Diabetic retinopathy is a progressive disfunction of blood vessels of the retina secondary to chronic hyperglycemia. There are several treatments, out of which panretinal photocoagulation (PRP) stands out.

Objective

To compare the level of pain in patients undergoing PRP with different impulse.

Material and methods

Comparative, cross-sectional study that compared the level of pain in patients undergoing PRP with a 50-millisecond pulse (group A) versus conventional 200 milliseconds pulse (group B). Mann-Whitney U test was used.

Results

There were 26 patients, 12 (46.16%) female and 14 (53.84%) males. The median age was 58.73 ± 7.31 (40-75) years. 40 eyes were studied, 18 (45%) right and 22 (55%) left. The mean level of glycated hemoglobin was 8.15 ± 1.08 (6.5-12) %. The mean laser power was 297 ± 53.61 (200-380) and 214.5 ± 41.73 (170-320) milliwatts; the mean fluence was 18.85 ± 5.28 (12-28) J/cm2 and 65.9 ± 12.87 (52-98) J/cm2; the mean level of pain was 3.1 ± 1.33 (1-5) and 7.5 ± 1.23 (6-10) points for group A and B, respectively, and there was statistically significant difference (p ˂ 0.001) in the level of pain. There were no complications in any group.

Conclusion

The application of retinal 50-millisecond pulse PRP causes less pain and side effects than 200-millisecond pulse PRP.

Standard threshold laser versus subthreshold micropulse laser for adults with diabetic macular oedema: the DIAMONDS non-inferiority RCT

BACKGROUND

The National Institute for Health and Care Excellence recommends macular laser to treat diabetic macular oedema with a central retinal subfield thickness of < 400 µm on optical coherence tomography. The DIAMONDS (DIAbetic Macular Oedema aNd Diode Subthreshold micropulse laser) trial compared standard threshold macular laser with subthreshold micropulse laser to treat diabetic macular oedema suitable for macular laser.

OBJECTIVES

Determining the clinical effectiveness, safety and cost-effectiveness of subthreshold micropulse laser compared with standard threshold macular laser to treat diabetic macular oedema with a central retinal subfield thickness of < 400 µm.

DESIGN

A pragmatic, multicentre, allocation-concealed, double-masked, randomised, non-inferiority, clinical trial.

SETTING

Hospital eye services in the UK.

PARTICIPANTS

Adults with diabetes and centre-involving diabetic macular oedema with a central retinal subfield thickness of < 400 µm, and a visual acuity of > 24 Early Treatment Diabetic Retinopathy Study letters (Snellen equivalent > 20/320) in one/both eyes.

INTERVENTIONS

Participants were randomised 1 : 1 to receive 577 nm subthreshold micropulse laser or standard threshold macular laser (e.g. argon laser, frequency-doubled neodymium-doped yttrium aluminium garnet 532 nm laser); laser treatments could be repeated as needed. Rescue therapy with intravitreal anti-vascular endothelial growth factor therapies or steroids was allowed if a loss of ≥ 10 Early Treatment Diabetic Retinopathy Study letters between visits occurred and/or central retinal subfield thickness increased to > 400 µm.

MAIN OUTCOME MEASURES

The primary outcome was the mean change in best-corrected visual acuity in the study eye at 24 months (non-inferiority margin 5 Early Treatment Diabetic Retinopathy Study letters). Secondary outcomes included the mean change from baseline to 24 months in the following: binocular best-corrected visual acuity; central retinal subfield thickness; the mean deviation of the Humphrey 10-2 visual field in the study eye; the percentage of people meeting driving standards; and the EuroQol-5 Dimensions, five-level version, National Eye Institute Visual Function Questionnaire - 25 and Vision and Quality of Life Index scores. Other secondary outcomes were the cost per quality-adjusted life-years gained, adverse effects, number of laser treatments and additional rescue treatments.

RESULTS

The DIAMONDS trial recruited fully (n = 266); 87% of participants in the subthreshold micropulse laser group and 86% of participants in the standard threshold macular laser group had primary outcome data. Groups were balanced regarding baseline characteristics. Mean best-corrected visual acuity change in the study eye from baseline to month 24 was -2.43 letters (standard deviation 8.20 letters) in the subthreshold micropulse laser group and -0.45 letters (standard deviation 6.72 letters) in the standard threshold macular laser group. Subthreshold micropulse laser was deemed to be not only non-inferior but also equivalent to standard threshold macular laser as the 95% confidence interval (-3.9 to -0.04 letters) lay wholly within both the upper and lower margins of the permitted maximum difference (5 Early Treatment Diabetic Retinopathy Study letters). There was no statistically significant difference between groups in any of the secondary outcomes investigated with the exception of the number of laser treatments performed, which was slightly higher in the subthreshold micropulse laser group (mean difference 0.48, 95% confidence interval 0.18 to 0.79; p = 0.002). Base-case analysis indicated no significant difference in the cost per quality-adjusted life-years between groups.

FUTURE WORK

A trial in people with ≥ 400 µm diabetic macular oedema comparing anti-vascular endothelial growth factor therapy alone with anti-vascular endothelial growth factor therapy and macular laser applied at the time when central retinal subfield thickness has decreased to < 400 µm following anti-vascular endothelial growth factor injections would be of value because it could reduce the number of injections and, subsequently, costs and risks and inconvenience to patients.

LIMITATIONS

The majority of participants enrolled had poorly controlled diabetes.

CONCLUSIONS

Subthreshold micropulse laser was equivalent to standard threshold macular laser but required a slightly higher number of laser treatments.

TRIAL REGISTRATION

This trial is registered as EudraCT 2015-001940-12, ISRCTN17742985 and NCT03690050.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 50. See the NIHR Journals Library website for further project information.

Laser Treatment Modalities for Diabetic Retinopathy

Diabetes is a chronic progressive metabolic disorder that is caused by the body's inability to regulate blood glucose levels. If uncontrolled, it can lead to various complications. Among its various complications, long-term diabetes leads to diabetic retinopathy (DR). It is a disease involving blood vessels and the destruction of retinal nerves. It is usually classified into two types: proliferative diabetic retinopathy (PDR) and nonproliferative diabetic retinopathy (NPDR). It progresses and causes loss of vision. The leading cause of loss of vision is diabetic macular edema (DME). The argon laser is used as a modality in the management of PDR. There are various types of laser photocoagulation, such as peripheral retinal laser photocoagulation, focal macular laser photocoagulation, and grid photocoagulation. DR results in various adverse consequences such as vitreous hemorrhage, fibrosis, traction, detachment of the retina, and glaucoma. To assess DR, a detailed fundus examination with a slit lamp biomicroscope needs to be done. Seven-standard field stereoscopic-color fundus photography needs to be done for documentation and follow-up. Patients with diabetes mellitus (DM) type 1 have a greater risk of suffering from DR. Another major complication of the condition is DME, which is characterized by an increase in the permeability of vessels and the thickening of the central part of the retina along with the accumulation of hard exudates on the macula. This article discusses various laser therapy modalities for the treatment of DR, their types, mechanisms, and aims. Clinical features of DR include abnormal dilatation of capillaries, and outpouchings in the form of microaneurysm from the capillary wall are one of the earliest and most dangerous changes; later, non-perfusion of the retina occurs, which is associated with cotton wool spots and blot hemorrhages. In patients suffering from PDR and maculopathy, peripheral retinal laser photocoagulation is used as a mode of intervention.

Diabetic Macular Edema Treatment: Laser Photocoagulation Versus anti-VEGF Drugs

Abstract: Objective: The present study was aimed to compare best-corrected vision and central macular thickness for macular edema in diabetes (DME) after utilizing laser, Avastin, and Lucentis. Methods: A retrospective randomized cross-sectional study was conducted at Alfaisal Eye Center, Khartoum. Best-corrected vision and central macular thickness (CMT) were assessed by Snellen's chart and Heidelberg optical coherence tomography OCT, respectively. Results: In this study, a total of 252 records of DME-treated patients with laser applications, Avastin, and Lucentis were enrolled, their mean age was 57 ± 5.22 yrs. A significant enhancement in best-corrected vision and CMT of studied groups with laser applications, Avastin, and Lucentis was obtained (P= 0.000) with no differences between treated groups (p= 0.445 and 0,479), respectively. Non-significant differences in variable measurements related to gender or age (p = 0.117, 0.781), respectively. CMT of females (260 ± 48 μm) was thinner than males (306 ± 74 μm) after treatment (P = 0.000). Conclusion: laser applications, Avastin, and Lucentis improved best-corrected vision and reduced central macular thickness significantly with no clear differences between studied groups. Age or gender have a non-significant impact on dependent variables. Females gained thinner results compared to males after treatment.  

Trends in treatment of retinal disorders in the Brazilian Public Health System over a 10-year period

Objective:

To investigate trends in terms of number and cost of intravitreal injection, photocoagulation and panphotocoagulation procedures performed by the Brazilian Public Health System, from 2010 to 2019.

Methods:

The Brazilian Public Health System Database was used as the primary source of data. Intravitreal injection, photocoagulation and panphotocoagulation procedures performed from 2010 to 2019 were investigated. Procedure prevalence and cost trends were analyzed according to year and region. Annual trends were examined using generalized linear models, with a significance level of 5% (p=0.05).

Results:

There was a significant increase in the prevalence of intravitreal injections (1,088%), panphotocoagulation (51%) and photocoagulation (37%) procedures from 2010 to 2019. Intravitreal injections accounted for the most significant increase. However, costs were not significantly readjusted over the years.

Conclusion:

Over a 10-year period, there was a significant increase in the number of procedures associated with retinal disorders. Procedure costs saw little readjustments over time. In spite of limitations, inaccuracies and lack of details, the Brazilian Public Health System Database is the primary source of data for the Public Health System related research in Brazil, and can contribute with information on ocular health and costs of ophthalmic procedures.

Does conventional laser photocoagulation still have a place in the treatment of diabetic macular edema?

Objective: The study aimed to investigate the long-term efficacy of conventional laser photocoagulation in the treatment of diabetic macular edema. Methods: In this retrospective study, the records of patients presented with diabetic macular edema (DME) and non-proliferative diabetic retinopathy were reviewed. DME defined as clinically significant macular edema was treated by using argon green or yellow dye laser with focal, grid, and modified grid techniques according to Early Treatment Diabetic Retinopathy Study parameters. Best-corrected visual acuity (BCVA) was measured. BCVA change after the treatment and its relationship with other factors were evaluated. Results: The study included 133 eyes of 81 patients. The mean follow-up was 28.26 months. BCVA demonstrated the increase of 2 lines or more in 20.7% of the eyes, stabilization within 2 lines in 60.7% of the eyes, and loss of 2 lines or more in 18.3% of the eyes. The eyes with baseline BCVA lower than or equal to 0.50 showed a statistically significant increase (p=0.001) whereas the eyes with baseline BCVA of more than 0.50 did not show a statistically significant change (p=0.070) after laser photocoagulation treatment. Conclusions: Conventional laser photocoagulation is an effective treatment in diabetic macular edema including center-involved type and stabilizes visual acuity in the majority of the patients. Improvement in BCVA is significant in the group with lower baseline BCVA. Abbreviations: DM = diabetes mellitus, DME = diabetic macular edema, ETDRS = early treatment diabetic retinopathy study, CSME = clinically significant macular edema, CLP = conventional laser photocoagulation, VEGF = vascular endothelial growth factor, BCVA = best-corrected visual acuity, ANOVA = analysis of variance, VA = visual acuity.

Effectiveness of interventions to increase uptake and completion of treatment for diabetic retinopathy in low- and middle-income countries: a rapid review protocol

BACKGROUND

Vision loss due to diabetic retinopathy can largely be prevented or delayed through treatment. Patients with vision-threatening diabetic retinopathy are typically offered laser or intravitreal injections which often require more than one treatment cycle. However, treatment is not always initiated, or it is not completed, resulting in poor visual outcomes. Interventions aimed at improving the uptake or completion of treatment for diabetic retinopathy can potentially help prevent or delay visual loss in people with diabetes.

METHODS

We will search MEDLINE, Embase, Global Health and Cochrane Register of Studies for studies reporting interventions to improve the uptake of treatment for diabetic retinopathy (DR) and/or diabetic macular oedema (DMO), compared with usual care, in adults with diabetes. The review will include studies published in the last 20 years in the English language. We will include any study design that measured any of the following outcomes in relation to treatment uptake and completion for DR and/or DMO: (1) proportion of patients initiating treatment for DR and/or DMO among those to whom it is recommended, (2) proportion of patients completing treatment for DR and/or DMO among those to whom it is recommended, (3) proportion of patients completing treatment for DR and/or DMO among those initiating treatment and (4) number and proportion of DR and/or DMO rounds of treatment completed per patient, as dictated by the treatment protocol. For included studies, we will also report any measures of cost-effectiveness when available. Two reviewers will screen search results independently. Risk of bias assessment will be done by two reviewers, and data extraction will be done by one reviewer with verification of 10% of the papers by a second reviewer. The results will be synthesised narratively.

DISCUSSION

This rapid review aims to identify and synthesise the peer-reviewed literature on the effectiveness of interventions to increase uptake and completion of treatment for DR and/or DMO in LMICs. The rapid review methodology was chosen in order to rapidly synthesise the available evidence to support programme implementers and policy-makers in designing evidence-based health programmes and public health policy and inform the allocation of resources.

SYSTEMATIC REVIEW REGISTRATION

OSF osf.io/h5wgr.

Intravitreal steroids for macular edema in diabetes

BACKGROUND

Diabetic macular edema (DME) is secondary to leakage from diseased retinal capillaries with thickening of central retina, and is an important cause of poor central visual acuity in people with diabetic retinopathy. Intravitreal steroids have been used to reduce retinal thickness and improve vision in people with DME.

OBJECTIVES

To assess the effectiveness and safety of intravitreal steroid therapy compared with other treatments for DME.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase on 15 May, 2019. We also searched reference lists, Science Citation Index, conference proceedings, and relevant trial registers. We conducted a top up search on 21 October, 2020.

SELECTION CRITERIA

We included randomized controlled trials that evaluated any type of intravitreal steroids as monotherapy against any other intervention (e.g. observation, laser photocoagulation, anti-vascular endothelial growth factor (antiVEGF) for DME.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and risk of bias and extracted data. Where appropriate, we performed meta-analyses.

MAIN RESULTS

We included 10 trials (4348 participants, 4505 eyes). These trials compared intravitreal steroid therapies versus other treatments, including intravitreal antiVEGF therapy, laser photocoagulation, and sham injection. Most trials had an overall unclear or high risk of bias. One trial (701 eyes ) compared intravitreal dexamethasone implant 0.7mg with sham. We found moderate-certainty evidence that dexamethasone leads to slightly more improvement of visual acuity than sham at 12 months (mean difference [MD] -0.08 logMAR, 95% confidence interval [CI] -0.12 to -0.05 logMAR). Regarding improvement of three or more lines of visual acuity, there was moderate-certainty evidence in favor of dexamethasone at 12 months, but the CI covered the null value (risk ratio (RR) 1.39, 95% CI 0.91 to 2.12). Regarding adverse events, dexamethasone increased by about four times the risk of cataract progression and the risk of using intraocular pressure (IOP)-lowering medications compared to sham (RR 3.89, 95% CI 2.75 to 5.50 and RR 4.54, 95% CI 3.19 to 6.46, respectively; moderate-certainty evidence); about 4 in 10 participants treated with dexamethasone needed IOP-lowering medications. Two trials (451 eyes) compared intravitreal dexamethasone implant 0.7mg with intravitreal antiVEGF (bevacizumab and ranibizumab). There was moderate-certainty evidence that visual acuity improved slightly less with dexamethasone compared with antiVEGF at 12 months (MD 0.07 logMAR, 95% CI 0.04 to 0.09 logMAR; 2 trials; 451 participants/eyes; I² = 0%). The RR of gain of three or more lines of visual acuity was inconsistent between trials, with one trial finding no evidence of a difference between dexamethasone and bevacizumab at 12 months (RR 0.99, 95% CI 0.70 to 1.40; 1 trial; 88 eyes), and the other, larger trial finding the chances of vision gain were half with dexamethasone compared with ranibizumab (RR 0.50, 95% CI 0.32 to 0.79; 1 trial; 432 participants). The certainty of evidence was low. Cataract progression and the need for IOP-lowering medications increased more than 4 times with dexamethasone implant compared to antiVEGF (moderate-certainty evidence). One trial (560 eyes) compared intravitreal fluocinolone implant 0.19mg with sham. There was moderate-certainty evidence that visual acuity improved slightly more with fluocinolone at 12 months (MD -0.04 logMAR, 95% CI -0.06 to -0.01 logMAR). There was moderate-certainty evidence that an improvement in visual acuity of three or more lines was more common with fluocinolone than with sham at 12 months (RR 1.79, 95% CI 1.16 to 2.78). Fluocinolone also increased the risk of cataract progression (RR 1.63, 95% CI 1.35 to 1.97; participants = 335; moderate-certainty evidence), which occurred in about 8 in 10 participants, and the use of IOP-lowering medications (RR 2.72, 95% CI 1.87 to 3.98; participants = 558; moderate-certainty evidence), which were needed in 2 to 3 out of 10 participants. One small trial with 43 participants (69 eyes) compared intravitreal triamcinolone acetonide injection 4 mg with sham. There may be a benefit in visual acuity at 24 months (MD -0.11 logMAR, 95% CI -0.20 to -0.03 logMAR), but the certainty of evidence is low. Differences in adverse effects were poorly reported in this trial. Two trials (615 eyes) compared intravitreal triamcinolone acetonide injection 4mg with laser photocoagulation and reached discordant results. The smaller trial (31 eyes followed up to 9 months) found more visual acuity improvement with triamcinolone (MD -0.18 logMAR, 95% CI -0.29 to -0.07 logMAR), but a larger, multicenter trial (584 eyes, 12-month follow-up) found no evidence of a difference regarding change in visual acuity (MD 0.02 logMAR, 95% CI -0.03 to 0.07 logMAR) or gain of three or more lines of visual acuity (RR 0.85, 95% CI 0.55 to 1.30) (overall low-certainty evidence). Cataract progression was about three times more likely (RR 2.68, 95% CI 2.21 to 3.24; moderate-certainty evidence) and the use of IOP-lowering medications was about four times more likely (RR 3.92, 95% CI 2.59 to 5.96; participants = 627; studies = 2; I² = 0%; moderate-certainty evidence) with triamcinolone. About 1 in 3 participants needed IOP-lowering medication. One small trial (30 eyes) compared intravitreal triamcinolone acetonide injection 4mg with intravitreal antiVEGF (bevacizumab or ranibizumab). Visual acuity may be worse with triamcinolone at 12 months (MD 0.18 logMAR, 95% CI 0.10 to 0.26 logMAR); the certainty of evidence is low. Adverse effects were poorly reported in this trial. Four trials reported data on pseudophakic participants, for whom cataract is not a concern. These trials found no decrease in visual acuity in the second treatment year due to cataract progression.

AUTHORS' CONCLUSIONS

Intravitreal steroids may improve vision in people with DME compared to sham or control. Effects were small, about one line of vision or less in most comparisons. More evidence is available for dexamethasone or fluocinolone implants when compared to sham, and the evidence is limited and inconsistent for the comparison of dexamethasone with antiVEGF treatment. Any benefits should be weighed against IOP elevation, the use of IOP-lowering medication and, in phakic patients, the progression of cataract. The need for glaucoma surgery is also increased, but remains rare.

Subthreshold Micropulse Laser in Diabetic Macular Edema: 1-Year Improvement in OCT/OCT-Angiography Biomarkers

Purpose

The aim of this study was to evaluate 1-year quantitative changes in specific inflammatory parameters on optical coherence tomography (OCT) / optical coherence tomography angiography (OCTA) in diabetic macular edema (DME) treated with subthreshold micropulse laser (SMPL).

Methods

Thirty-seven patients / eyes with previously treatment-naïve DME treated with SMPL were prospectively evaluated at 3, 6, and 12 months. Fifteen fellow eyes with only microaneurysms (MAS) not eligible for treatment were controls. Evaluated OCT / OCTA parameters included: central macular thickness (CMT); hyper-reflective retinal spots (HRS); disorganization of inner retinal layers (DRILs); MA in the superficial / deep capillary plexuses (SCP/DCP); cysts in the area at the SCP / DCP; and macular perfusion parameters (MATLAB, version 2017b).

Results

In the treated group, mean best corrected visual acuity (BCVA) progressively increased from 69.4 ± 12.0 to 76.0 ± 9.1 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (P < 0.001) at 12 months; HRS decreased from baseline (80.75 ± 20.41) at 3 (73.81 ± 17.1, P = 0.002), 6 (69.16 ± 16.48, P < 0.0001), and 12 months (66.29 ± 18.53, P < 0.0001). MA decreased at 3 months in the DCP (P = 0.015), at 6 and 12 months in both plexuses (P ≤ 0.0007). BCVA, HRS, and MA remained stable in the controls during all follow-ups. DRIL was present in 18 of 37 patients at baseline and progressively decreased from 557.0 ± 238.7 to 387.1 ± 282.1 μm (P = 0.01). The area of cyst decreased both in the SCP (P = 0.03) and the DCP (P = 0.02). CMT and perfusion parameters did not change.

Conclusions

SMPL reduced the number of HRS (sign of activated microglia cells in the retina), MA, DRIL extension, and the area of cysts. Further studies are needed to confirm these preliminary data on the anti-inflammatory effect of SMPL, and to explore the mechanism of action.

Translational Relevance

The follow-up of OCT/OCTA noninvasive biomarkers offers a unique insight in the mechanism of laser action, suggesting an anti-inflammatory effect of SMPL.

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

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

Optical coherence tomography angiography assessment of 577 nm laser effect on severe non-proliferative diabetic retinopathy with diabetic macular edema

AIM

To quantitatively evaluate the effect of the combined use of 577-nm subthreshold micropulse macular laser (SML) and multi-point mode pan retinal laser photocoagulation (PRP) on severe non-proliferative diabetic retinopathy (NPDR) with central-involved diabetic macular edema (CIDME) using optical coherence tomography angiography (OCTA).

METHODS

In this observational clinical study, 86 eyes of 86 NPDR patients with CIDME who underwent SML and PRP treatment were included. Images were obtained 1d before laser and post-laser (1d, 1wk, 1, 3, and 6mo) using AngioVue software 2.0. Best corrected visual acuity (BCVA, LogMAR), foveal avascular zone area (FAZ), choriocapillary flow area (ChF), parafoveal vessel density (PVD), capillary density inside disc (CDD), peripapillary capillary density (PCD), macular ganglion cell complex thickness (mGCCT), central macular thickness (CMT), and subfoveal choroidal thickness (ChT) were compared between pre- and post-laser treatment.

RESULTS

BCVA remained stable during 6mo post-laser therapy (pre-laser vs 6mo post-laser: 0.53±0.21 vs 0.5±0.15, P>0.05). PVD, ChF, ChT, CMT, and mGCCT significantly increased 1d post-laser therapy [pre-laser vs 1d post-laser: superficial PVD (%), 40.51±3.42 vs 42.43±4.68; deep PVD (%), 42.66±3.67 vs 44.78±4.52; ChF, 1.72±0.21 vs 1.9±0.12 mm²; ChT, 302.45±69.74 vs 319.38±70.93 µm; CMT, 301.65±110.78 vs 320.86±105.62 µm; mGCCT, 105.71±10.72 vs 115.46±9.64 µm; P<0.05]. However, PVD, ChF and ChT decreased to less than baseline level at 6mo post-laser therapy (pre-laser vs 6mo post-laser: superficial PVD (%), 40.51±3.42 vs 36.32±4.19; deep PVD (%), 42.66±3.67 vs 38.76±3.74; ChF, 1.72±0.21 vs 1.62±0.09 mm²; ChT, 302.45±69.74 vs 289.61±67.55 µm; P<0.05), whereas CMT and mGCCT decreased to baseline level at 6mo post-laser therapy (CMT, 301.65±110.78 vs 297.77±90.23 µm; mGCCT, 105.71±10.72 vs 107.05±11.81 µm; P>0.05). Moreover, FAZ continuously increased while CDD and PCD continuously decreased in 6mo after laser therapy. CMT and ChT had a significant positive correlation with ChF and PVD in most post-laser stages.

CONCLUSION

During a 6-month follow-up period after combined use of SML and PRP therapy, BCVA remained stable and there was a decreased trend in macular edema. Blood flow increased at 1d post-laser therapy and reduced at 6mo post-laser therapy.

Macular laser photocoagulation in the management of diabetic macular edema: Still relevant in 2020?

Macular laser photocoagulation (MLP) is inferior to intravitreal vascular endothelial growth factor (VEGF) inhibitors in the treatment of center-involved diabetic macular edema (DME). Ultra-widefield fluorescein angiography-guided laser photocoagulation to presumed ischemic areas of the peripheral retina or MLP do not reduce the treatment burden nor improve the visual outcomes of eyes treated with anti-VEGF drugs. Destruction of retinal tissue is not necessary to induce a therapeutic response in DME. Modern lasers are capable of producing invisible laser "burns" that do not destroy the targeted tissue using micropulse subthreshold (ST) mode where the laser's duty cycle is modified or alternatively selective retinal therapy (SRT) where ultrashort pulses of continuous wave laser selectively target the RPE. The best results with micropulse ST laser are obtained in eyes with a central macular thickness ≤400 μm. Eyes need to be treated in a continuous manner with no spaces between burns in the edematous area. Micropulse ST-MLP downregulates inflammatory biomarkers produced by activated microglial cells and Müller cells. Micropulse ST-MLP may reduce the anti-VEGF injection burden in DME. In SRT, the diseased RPE is targeted and heated with the laser with the hope that the adjacent RPE migrates and proliferates into these areas to heal the diseased RPE. There is much less experience with SRT, but the results are promising and deserve further study.

Statins and/or fibrates for diabetic retinopathy: a systematic review and meta-analysis

Evidence from observational studies have found a relationship between serum cholesterol and diabetic retinopathy (DR). Apart of the assumption that cholesterolemic control has benefits for patients with diabetes with or without retinopathy, the effects of lipid-lowering drugs have not been properly mapped and critically assessed so far. The objective of this study was to evaluate the effects of statins and/or fibrates on prevention and progression of DR. We conducted a Systematic review of randomized controlled trials (RCTs) following the Cochrane Handbook for Systematic Reviews of Interventions and reported in accordance to PRISMA Statement. GRADE approach was used to summarize the certainty of the evidence. Eight RCTs that fulfilled our eligibility criteria were included, assessing the effects of fibrates (n = 4), statins (n = 3) and fibrate plus statins (n = 1) for therapy (n = 8) or prevention (n = 4) of DR. Overall, the main concern regarding risk of bias assessment was due to incomplete outcome data because high rate of losses in five RCTs. Furthermore, the risk of reporting bias was rated unclear due the lack of previously published protocol in seven RCTs. Fibrates seemed to be associated with a 45% risk reduction of macular edema incidence (Relative Risk 0.55, 95% confidence interval of 0.38 to 0.81, 1309 participants, 2 RCTs, I² = 0%, low certainty of the evidence). The certainty of evidence for other outcomes was also very low or low, and we are uncertain regarding the effects of fibrates for DR. Overall, adverse events seemed to be similar between fibrate and placebo, but again based on the width of the confidence intervals, an important increase of adverse events cannot be rule out. The combination statin/fibrate did not seem to have benefit for visual acuity but is likely that further studies can modify this estimate since the current evidence is limited. Adverse events and quality of life were not measured or reported. Concluding, this study found eight RCTs, with limited methodological quality, that assessed the effects of fibrates and/or statins for DR. Based on these findings, we are uncertain about the effects of statins for DR. Fibrates seemed to reduce the incidence of macular edema (low certainty evidence) without increase adverse events (low to very low certainty evidence). Number of Protocol registration PROSPERO CRD42016029746.

Monotherapy laser photocoagulation for diabetic macular oedema

BACKGROUND

Diabetic macular oedema (DMO) is a complication of diabetic retinopathy and one of the most common causes of visual impairment in people with diabetes. Clinically significant macular oedema (CSMO) is the most severe form of DMO. Intravitreal antiangiogenic therapy is now the standard treatment for DMO involving the centre of the macula, but laser photocoagulation is still used in milder or non-central DMO.

OBJECTIVES

To access the efficacy and safety of laser photocoagulation as monotherapy in the treatment of diabetic macular oedema.

SEARCH METHODS

We searched CENTRAL, which contains the Cochrane Eyes and Vision Trials Register; MEDLINE; Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 24 July 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any type of focal/grid macular laser photocoagulation versus another type or technique of laser treatment and no intervention. We did not compare laser versus other interventions as these are covered by other Cochrane Reviews.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were gain or loss of 3 lines (0.3 logMAR or 15 ETDRS letters) of best-corrected visual acuity (BCVA) at one year of follow-up (plus or minus six months) after treatment initiation. Secondary outcomes included final or mean change in BCVA, resolution of macular oedema, central retinal thickness, quality of life and adverse events, all at one year. We graded the certainty of the evidence for each outcome using the GRADE approach.

MAIN RESULTS

We identified 24 studies (4422 eyes). The trials were conducted in Europe (nine studies), USA (seven), Asia (four) and, Africa (one), Latin America (one), Europe-Asian (one) and Oceania (one). The methodological quality of the studies was difficult to assess as they were poorly reported, so the predominant classification of bias was unclear.At one year, people with DMO receiving laser were less likely to lose BCVA compared with no intervention (risk ratio (RR) 0.42, 95% confidence interval (CI) 0.20 to 0.90; 3703 eyes; 4 studies; I² = 71%; moderate-certainty evidence). There were also favourable effects observed at two and three years. One study (350 eyes) reported on partial or complete resolution of clinically significant DMO and found moderate-certainty evidence of a benefit at three years with photocoagulation (RR 1.55, 95% CI 1.30 to 1.86). Data on visual improvement, final BCVA, central macular thickness and quality of life were not available. One study related minor adverse effects on the central visual field and another reported one case of iatrogenic premacular fibrosis.Nine studies compared subthreshold versus standard macular photocoagulation (517 eyes). Subthreshold treatment was achieved with different methods of photocoagulation: non-visible conventional (two studies), micropulse (four) or nanopulse (one).Only one small study (29 eyes) reported on improvement or worsening of BCVA and estimates were very imprecise (improvement: RR 0.31, 95% CI 0.01 to 7.09; worsening: RR 0.93, 95% CI 0.15 to 5.76; very low-certainty evidence). All studies reported on continuous BCVA at one year; there was low-certainty evidence of no important difference between subthreshold and standard photocoagulation (mean difference (MD) in logMAR BCVA -0.02, 95% CI -0.07 to 0.03; 385 eyes; 7 studies; I² = 42%), and were possibly different for different techniques (P = 0.07 and I² = 61.5% for subgroup heterogeneity), with better results achieved with micropulse photocoagulation (MD -0.08 logMAR, 95% CI -0.16 to 0.0) as compared to the results achieved with nanopulse (MD 0.0 logMAR, 95% CI -0.06 to 0.06) and non-visible conventional (MD 0.04 logMAR, 95% CI -0.03 to 0.11), all of them compared to the standard lasers. One study reported partial to complete resolution of macular oedema at one year. There was low-certainty evidence of some benefit with standard photocoagulation, but estimates of effect were imprecise (RR 0.47, 95% CI 0.21 to 1.03; 29 eyes; 1 study). Studies also reported on the change in central macular thickness at one year and found moderate-certainty evidence of no important difference between subthreshold and standard photocoagulation (MD -9.1 μm, 95% CI -26.2 to 8.0; 385 eyes; 7 studies; I² = 0%). There were no important adverse effects recorded in the studies.Nine studies compared argon laser versus another type of laser (997 eyes). There was moderate-certainty evidence of a small reduction or no difference between the interventions, with respect to improvement (RR 0.87, 95% CI 0.62 to 1.22; 773 eyes; 6 studies) and worsening of BCVA (RR 0.83, 95% CI 0.57 to 1.21; 773 eyes; 6 studies). Three studies reported few cases of subretinal fibrosis and neovascularization with argon laser and one study found subretinal fibrosis in the krypton group.One study (323 eyes) compared the modified ETDRS (mETDRS) grid technique with the mild macular grid (MMG), which uses mild, widely spaced burns throughout the macula. There was low-certainty evidence of an increased chance of visual improvement with MMG, but the estimate was imprecisely measured and the CIs include an increased risk or decreased risk of visual improvement at one year (RR 1.43, 95% CI 0.56 to 3.65; visual worsening: RR 1.40, 95% CI 0.64 to 3.05; change of logMAR visual acuity: MD -0.04 logMAR, 95% CI -0.01 to 0.09). There was a more significant reduction of central macular thickness with the mETDRS compared to the MMG technique (MD -34.0 µm, -59.8 to -8.3) in the MMG group. The study did not record important adverse effects.

AUTHORS' CONCLUSIONS

Laser photocoagulation reduces the chances of visual loss and increases those of partial to complete resolution of DMO compared to no intervention at one to three years. Subthreshold photocoagulation, particularly the micropulse technique, may be as effective as standard photocoagulation and RCTs are ongoing to assess whether this minimally invasive technique is preferable to treat milder or non-central cases of DMO.

Laser photocoagulation for proliferative diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a complication of diabetes in which high blood sugar levels damage the blood vessels in the retina. Sometimes new blood vessels grow in the retina, and these can have harmful effects; this is known as proliferative diabetic retinopathy. Laser photocoagulation is an intervention that is commonly used to treat diabetic retinopathy, in which light energy is applied to the retina with the aim of stopping the growth and development of new blood vessels, and thereby preserving vision.

OBJECTIVES

To assess the effects of laser photocoagulation for diabetic retinopathy compared to no treatment or deferred treatment.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 June 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) where people (or eyes) with diabetic retinopathy were randomly allocated to laser photocoagulation or no treatment or deferred treatment. We excluded trials of lasers that are no longer in routine use. Our primary outcome was the proportion of people who lost 15 or more letters (3 lines) of best-corrected visual acuity (BCVA) as measured on a logMAR chart at 12 months. We also looked at longer-term follow-up of the primary outcome at two to five years. Secondary outcomes included mean best corrected distance visual acuity, severe visual loss, mean near visual acuity, progression of diabetic retinopathy, quality of life, pain, loss of driving licence, vitreous haemorrhage and retinal detachment.

DATA COLLECTION AND ANALYSIS

We used standard methods as expected by the Cochrane Collaboration. Two review authors selected studies and extracted data.

MAIN RESULTS

We identified a large number of trials of laser photocoagulation of diabetic retinopathy (n = 83) but only five of these studies were eligible for inclusion in the review, i.e. they compared laser photocoagulation with currently available lasers to no (or deferred) treatment. Three studies were conducted in the USA, one study in the UK and one study in Japan. A total of 4786 people (9503 eyes) were included in these studies. The majority of participants in four of these trials were people with proliferative diabetic retinopathy; one trial recruited mainly people with non-proliferative retinopathy. Four of the studies evaluated panretinal photocoagulation with argon laser and one study investigated selective photocoagulation of non-perfusion areas. Three studies compared laser treatment to no treatment and two studies compared laser treatment to deferred laser treatment. All studies were at risk of performance bias because the treatment and control were different and no study attempted to produce a sham treatment. Three studies were considered to be at risk of attrition bias.At 12 months there was little difference between eyes that received laser photocoagulation and those allocated to no treatment (or deferred treatment), in terms of loss of 15 or more letters of visual acuity (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.89 to 1.11; 8926 eyes; 2 RCTs, low quality evidence). Longer term follow-up did not show a consistent pattern, but one study found a 20% reduction in risk of loss of 15 or more letters of visual acuity at five years with laser treatment. Treatment with laser reduced the risk of severe visual loss by over 50% at 12 months (RR 0.46, 95% CI 0.24 to 0.86; 9276 eyes; 4 RCTs, moderate quality evidence). There was a beneficial effect on progression of diabetic retinopathy with treated eyes experiencing a 50% reduction in risk of progression of diabetic retinopathy (RR 0.49, 95% CI 0.37 to 0.64; 8331 eyes; 4 RCTs, low quality evidence) and a similar reduction in risk of vitreous haemorrhage (RR 0.56, 95% CI 0.37 to 0.85; 224 eyes; 2 RCTs, low quality evidence).None of the studies reported near visual acuity or patient-relevant outcomes such as quality of life, pain, loss of driving licence or adverse effects such as retinal detachment.We did not plan any subgroup analyses, but there was a difference in baseline risk in participants with non-proliferative retinopathy compared to those with proliferative retinopathy. With the small number of included studies we could not do a formal subgroup analysis comparing effect in proliferative and non-proliferative retinopathy.

AUTHORS' CONCLUSIONS

This review provides evidence that laser photocoagulation is beneficial in treating proliferative diabetic retinopathy. We judged the evidence to be moderate or low, depending on the outcome. This is partly related to reporting of trials conducted many years ago, after which panretinal photocoagulation has become the mainstay of treatment of proliferative diabetic retinopathy.Future Cochrane Reviews on variations in the laser treatment protocol are planned. Future research on laser photocoagulation should investigate the combination of laser photocoagulation with newer treatments such as anti-vascular endothelial growth factors (anti-VEGFs).