CHOROIDAL THICKNESS CHANGES IN PROLIFERATIVE DIABETIC RETINOPATHY TREATED WITH PANRETINAL PHOTOCOAGULATION VERSUS PANRETINAL PHOTOCOAGULATION WITH INTRAVITREAL BEVACIZUMAB

Anti-VEGF drugs compared with laser photocoagulation for the treatment of proliferative diabetic retinopathy: a systematic review and individual participant data meta-analysis

Background

Proliferative diabetic retinopathy is a major cause of sight loss in people with diabetes, with a high risk of vitreous haemorrhage, tractional retinal detachment and other complications. Panretinal photocoagulation is the primary established treatment for proliferative diabetic retinopathy. Anti-vascular endothelial growth factor drugs are used to treat various eye conditions and may be beneficial for people with proliferative diabetic retinopathy.

Objective

To investigate the efficacy and safety of anti-vascular endothelial growth factor therapy for the treatment of proliferative diabetic retinopathy when compared to panretinal photocoagulation.

Methods

A systematic review and network meta-analysis of randomised controlled trials comparing anti-vascular endothelial growth factor (alone or in combination) to panretinal photocoagulation in people with proliferative diabetic retinopathy. The database searches were updated in May 2023. Trials where the primary focus was treatment of macular oedema or vitreous haemorrhage were excluded. Key outcomes were best corrected visual acuity, diabetic macular oedema and vitreous haemorrhage. Individual participant data were obtained and analysed for three large, high-quality trials in combination with published data from other trials. Network meta-analyses of best corrected visual acuity and meta-analyses of other outcomes combined individual participant data with published data from other trials; regression analyses against patient covariates used just the individual participant data.

Results

Twelve trials were included: one of aflibercept, five of bevacizumab and six of ranibizumab. Individual participant data were available from 1 aflibercept and 2 ranibizumab trials, representing 624 patients (33% of the total). When considered together, anti-vascular endothelial growth factors produced a modest, but not clinically meaningful, benefit over panretinal photocoagulation in best corrected visual acuity, after 1 year of follow-up (mean difference in logarithm of the minimum angle of resolution -0.116, 95% credible interval -0.183 to -0.038). There was no clear evidence of a difference in effectiveness between the anti-vascular endothelial growth factors. The benefit of anti-vascular endothelial growth factor appears to decline over time. Analysis of the individual participant data trials suggested that anti-vascular endothelial growth factor therapy may be more effective in people with poorer visual acuity, in those who have vitreous haemorrhage and, possibly, in people with poorer vision generally. Anti-vascular endothelial growth factor was superior to panretinal photocoagulation at preventing macular oedema after 1 year (relative risk 0.48, 95% confidence interval 0.28 to 0.83) and possibly at preventing vitreous haemorrhage (relative risk 0.72, 95% confidence interval 0.47 to 1.10). Anti-vascular endothelial growth factor reduced the incidence of retinal detachment when compared to panretinal photocoagulation (relative risk 0.41, 95% confidence interval 0.22 to 0.77). Data on other adverse events were generally too limited to identify any differences between anti-vascular endothelial growth factor and panretinal photocoagulation.

Conclusions

Anti-vascular endothelial growth factor has no clinically meaningful benefit over panretinal photocoagulation for preserving visual acuity. However, anti-vascular endothelial growth factor therapy appears to delay or prevent progression to macular oedema and vitreous haemorrhage. The possibility that anti-vascular endothelial growth factor therapy may be more effective in patients with poorer health and poorer vision merits further clinical investigation. The long-term effectiveness and safety of anti-vascular endothelial growth factor treatment are unclear, particularly as additional panretinal photocoagulation and anti-vascular endothelial growth factor treatment will be required over time.

Funding

This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR132948.

Anti-VEGF Injections vs. Panretinal Photocoagulation Laser Therapy for Proliferative Diabetic Retinopathy: A Systematic Review and Meta-Analysis

TOPIC

To evaluate the efficacy and safety of anti-VEGF and panretinal photocoagulation (PRP) for the treatment of proliferative diabetic retinopathy (PDR). The outcomes examined are changes in best-corrected visual acuity (BCVA), neovascularization (NV), central macular thickness (CMT), and adverse outcomes.

CLINICAL RELEVANCE

Diabetic retinopathy is the leading cause of blindness in working-aged adults globally. At present, no consensus has been reached on the optimal choice for the treatment of PDR.

METHODS

Cochrane, Embase, PubMed, Scopus, Web of Science, and CiNAHL were searched for articles from their inception to June 2023 according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis. The review was registered prospectively with PROSPERO (CRD42023437778). Tool data analysis was performed using RevMan software version 5.4 (Review Manager [RevMan] [computer program], The Cochrane Collaboration, 2020). Randomized control trials (RCTs) of PDR patients treated with anti-VEGF, PRP, or a combination were included. Risk of bias was assessed using the Rob2 assessment tool (revised tool for risk of bias in randomized trials), and certainty of evidence was assessed with the Grading Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Nineteen studies were included, with 1361 patients (n = 1788 eyes) treated for PDR with either anti-VEGF (n = 274), PRP (n = 482), or combination (n = 320). Our results show more favorable BCVA outcomes with anti-VEGF compared with PRP at 3 months (mean difference [MD] = 2.35 letters; 95% confidence interval [CI], 1.18-3.52; I2 = 0%) and 12 months follow-up (MD = 3.39 letters; 95% CI, 0.63-6.14; I2 = 26%). Combination treatment showed better BCVA outcomes compared with PRP at 12 months (MD = 4.06 letters; 95% CI, 0.26-7.86; I2 = 0%). Combination showed lower CMT at 3 months (MD = -33.10 μm; 95% CI, -40.12 to -26.08; I2 = 25%) and 6 months (MD = -34.28 μm; 95% CI, -55.59 to -12.97; I2 = 85%) compared with PRP, but CMT results were similar at 12 months. Complete regression of total NV (NVT) was more likely with anti-VEGF compared with PRP (odds ratio = 6.15; 95% CI, 1.39-27.15; I2 = 80%). Posttreatment vitreous hemorrhage, vitrectomy, and increased intraocular pressure events were similar between the anti-VEGF and combination groups compared with PRP; however, macular edema results favored the anti-VEGF over the PRP group. Using the GRADE assessment, BCVA evidence was rated to be of moderate certainty, whereas CMT and NVT evidence certainty was rated as very low.

CONCLUSION

Anti-VEGF and combination treatments could be regarded as alternative approaches to PRP alone in the management of PDR after engaging in a shared decision-making process based on patients' adherence, diabetic macular edema status, and preference. Limitations of this meta-analysis include the heterogeneity in participants' characteristics, treatment regimens, and outcome reporting between studies. Further RCTs should be conducted to compare the effectiveness of these treatments in the long term.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Anti-VEGF drugs compared with laser photocoagulation for the treatment of diabetic retinopathy: a systematic review and meta-analysis

Background

Diabetic retinopathy is a major cause of sight loss in people with diabetes. The most severe form, proliferative diabetic retinopathy, carries a high risk of vision loss, vitreous haemorrhage, macular oedema and other harms. Panretinal photocoagulation is the primary treatment for proliferative diabetic retinopathy. Anti-vascular endothelial growth factor drugs are used to treat various eye conditions and may be beneficial for people with diabetic retinopathy.

Objective

To investigate the efficacy and safety of anti-vascular endothelial growth factor therapy for the treatment of diabetic retinopathy when compared to panretinal photocoagulation.

Methods

A systematic review and network meta-analysis of all published randomised controlled trials comparing anti-vascular endothelial growth factor (alone or in combination with panretinal photocoagulation) to panretinal photocoagulation in people with diabetic retinopathy. The database searches were updated in May 2023. Trials where the primary focus was treatment of macular oedema or vitreous haemorrhage were excluded.

Results

A total of 14 trials were included: 3 of aflibercept, 5 of bevacizumab and 6 of ranibizumab. Two trials were of patients with non-proliferative diabetic retinopathy; all others were in proliferative diabetic retinopathy. Overall, anti-vascular endothelial growth factor was slightly better than panretinal photocoagulation at preventing vision loss, measured as best corrected visual acuity, at up to 2 years follow-up [mean difference in the logarithm of the minimum angle of resolution -0.089 (or 3.6 Early Treatment Diabetic Retinopathy Study letters), 95% confidence interval -0.180 to -0.019]. There was no clear evidence of any difference between the anti-vascular endothelial growth factors, but the potential for bias complicated the comparison. One trial found no benefit of anti-vascular endothelial growth factor over panretinal photocoagulation after 5 years. Anti-vascular endothelial growth factor was superior to panretinal photocoagulation at preventing macular oedema (relative risk 0.29, 95% confidence interval 0.18 to 0.49) and vitreous haemorrhage (relative risk 0.77, 95% confidence interval 0.61 to 0.99). There was no clear evidence that the effectiveness of anti-vascular endothelial growth factor varied over time.

Conclusions

Anti-vascular endothelial growth factor injections reduce vision loss when compared to panretinal photocoagulation, but the benefit is small and unlikely to be clinically meaningful. Anti-vascular endothelial growth factor may have greater benefits for preventing complications such as macular oedema. Observational studies extending follow-up beyond the 1-year duration of most trials are needed to investigate the longer-term effects of repeated anti-vascular endothelial growth factor injections.

Funding

This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR132948.

Central serous chorioretinopathy: An evidence-based treatment guideline

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Anti-vascular endothelial growth factor for proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is an advanced complication of diabetic retinopathy that can cause blindness. It consists of the presence of new vessels in the retina and vitreous haemorrhage. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. Anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR.

OBJECTIVES

To assess the effectiveness and safety of anti-VEGFs for PDR and summarise any relevant economic evaluations of their use.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov, and the WHO ICTRP. We did not use any date or language restrictions. We last searched the electronic databases on 1 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment, or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments. We excluded studies that used anti-VEGFs in people undergoing vitrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed the risk of bias (RoB) for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 15 new studies in this update, bringing the total to 23 RCTs with 1755 participants (2334 eyes). Forty-five per cent of participants were women and 55% were men, with a mean age of 56 years (range 48 to 77 years). The mean glycosylated haemoglobin (Hb1Ac) was 8.45% for the PRP group and 8.25% for people receiving anti-VEGFs alone or in combination. Twelve studies included people with PDR, and participants in 11 studies had high-risk PDR (HRPDR). Twelve studies were of bevacizumab, seven of ranibizumab, one of conbercept, two of pegaptanib, and one of aflibercept. The mean number of participants per RCT was 76 (ranging from 15 to 305). Most studies had an unclear or high RoB, mainly in the blinding of interventions and outcome assessors. A few studies had selective reporting and attrition bias. No study reported loss or gain of 3 or more lines of visual acuity (VA) at 12 months. Anti-VEGFs ± PRP probably increase VA compared with PRP alone (mean difference (MD) -0.08 logMAR, 95% CI -0.12 to -0.04; I2 = 28%; 10 RCTS, 1172 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may increase regression of new vessels (MD -4.14 mm2, 95% CI -6.84 to -1.43; I2 = 75%; 4 RCTS, 189 eyes; low-certainty evidence) and probably increase a complete regression of new vessels (RR 1.63, 95% CI 1.19 to 2.24; I2 = 46%; 5 RCTS, 405 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP probably reduce vitreous haemorrhage (RR 0.72, 95% CI 0.57 to 0.90; I2 = 0%; 6 RCTS, 1008 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may reduce the need for vitrectomy compared with eyes that received PRP alone (RR 0.67, 95% CI 0.49 to 0.93; I2 = 43%; 8 RCTs, 1248 eyes; low-certainty evidence). Anti-VEGFs ± PRP may result in little to no difference in the quality of life compared with PRP alone (MD 0.62, 95% CI -3.99 to 5.23; I2 = 0%; 2 RCTs, 382 participants; low-certainty evidence). We do not know if anti-VEGFs ± PRP compared with PRP alone had an impact on adverse events (very low-certainty evidence). We did not find differences in visual acuity in subgroup analyses comparing the type of anti-VEGFs, the severity of the disease (PDR versus HRPDR), time to follow-up (< 12 months versus 12 or more months), and treatment with anti-VEGFs + PRP versus anti-VEGFs alone. The main reasons for downgrading the certainty of evidence included a high RoB, imprecision, and inconsistency of effect estimates.

AUTHORS' CONCLUSIONS

Anti-VEGFs ± PRP compared with PRP alone probably increase visual acuity, but the degree of improvement is not clinically meaningful. Regarding secondary outcomes, anti-VEGFs ± PRP produce a regression of new vessels, reduce vitreous haemorrhage, and may reduce the need for vitrectomy compared with eyes that received PRP alone. We do not know if anti-VEGFs ± PRP have an impact on the incidence of adverse events and they may have little or no effect on patients' quality of life. Carefully designed and conducted clinical trials are required, assessing the optimal schedule of anti-VEGFs alone compared with PRP, and with a longer follow-up.

LONGITUDINAL ANALYSIS OF DIABETIC CHOROIDOPATHY IN PROLIFERATIVE DIABETIC RETINOPATHY TREATED WITH PANRETINAL PHOTOCOAGULATION USING WIDEFIELD SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

PURPOSE

Widefield swept-source optical coherence tomography (OCT) imaging was used to characterize choroidal thickness and vascularity at baseline in proliferative diabetic retinopathy (PDR) and longitudinally after panretinal photocoagulation (PRP).

METHODS

Patients with treatment-naive PDR were imaged at baseline and at 1 week, 1 month, and 3 months after PRP. Previously validated algorithms were used to calculate the mean choroidal thickness (MCT) and choroidal vascularity index (CVI) in 5 regions of 12 mm × 12 mm scans.

RESULTS

Fourteen PDR eyes were included. Baseline MCT in PDR eyes did not differ significantly from normal eyes, but CVI measurements in PDR eyes were lower in all regions (P < 0.001-0.008). After PRP, MCT measurements in PDR eyes were significantly lower at 1 month and 3 months in all regions (P < 0.001-0.005) except the fovea (P = 0.074). However, CVI measurements did not change over time in any region after PRP.

CONCLUSION

The choroid in PDR eyes has a smaller CVI than that in normal eyes. After PRP, the choroidal thickness decreases outside the fovea, but the CVI remains constant, which suggests that a relative decrease in choroidal vascularity persists. These widefield swept-source OCT results are consistent with choroidal alterations found in histopathological reports of diabetic choroidopathy.

Alterations in choroidal vascular parameters following panretinal photocoagulation using enhanced-depth imaging optical coherence tomography in diabetic retinopathy

PURPOSE

To investigate the alteration of choroid in patients with very severe non-proliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP).

METHODS

Thirty-nine eyes of 21 patients with very severe non-proliferative diabetic retinopathy (NPDR) (19 eyes) and early proliferative diabetic retinopathy (PDR) (20 eyes) were recruited. Enhanced-depth imaging optical coherence tomography at baseline, 1, and 6 months after PRP was employed to measure choroidal parameters including total choroidal area (TCA) and choroidal vascular index (CVI).

RESULTS

In eyes with very severe NPDR, subfoveal TCA decreased non-significantly at month 1, which increased significantly at month 6 (539 ± 131µm², 502 ± 134µm², and 598 ± 168µm² at baseline and months 1 and 6, respectively; P = 0.003). Subfoveal CVI increased at month 1 and then decreased at month 6 (68.25 ± 3.05, 69.74 ± 3.62, and 67.84 ± 1.77 at baseline and months 1 and 6, respectively; P < 0.001). A reverse pattern occurred in eyes with early PDR, a non-significant increase in TCA at month 1 followed by a decrease at month 6 (497 ± 95µm², 514 ± 133µm², and 425 ± 95µm² at baseline and months 1 and 6, respectively; P = 0.011). CVI decreased at month 1 and remained relatively stable at month 6 (69.34 ± 3.11, 68.33 ± 3.41, and 68.50 ± 5.04 at baseline, and months 1 and 6, respectively; P = 0.023). Alteration of choroidal thickness was not statistically significant in both groups.

CONCLUSION

Eyes with very severe NPDR and early PDR exhibit a reverse pattern regarding choroidal indices after PRP.

Intravitreal anti-vascular endothelial growth factors, panretinal photocoagulation and combined treatment for proliferative diabetic retinopathy: a systematic review and network meta-analysis

PURPOSE

To conduct a systematic review with network meta-analysis (NMA) of randomized clinical trials (RCTs) comparing panretinal photocoagulation (PRP) versus anti-vascular endothelial growth factor (VEGF) treatment alone or in combination with PRP, for proliferative diabetic retinopathy (PDR).

METHODS

PubMed, Medline and Embase databases were searched for RCTs comparing PRP versus intravitreal anti-VEGF therapy and/or combined PRP and intravitreal anti-VEGF for PDR. The primary outcome measures were the mean best corrected visual acuity (BCVA) change and the regression of neovascularization. Mean change of central macular thickness (CMT), the subgroup analyses of patients without diabetic macular oedema (DME) and the rate of vitreous haemorrhage and vitrectomy were secondary outcomes. Frequentist NMAs were performed.

RESULTS

Twelve RCTs were included. For the 12-month mean BCVA change, NMA showed a better visual outcome in both the anti-VEGF group and combined group compared to PRP [anti-VEGF vs PRP, mean difference (MD) = 3.42; standard error (SE) = 1.5; combined vs PRP, MD = 3.92; SE = 1.65], with no difference between combined group and anti-VEGF (MD = -0.50; SE = 1.87). No difference in neovascularization regression was found between PRP and anti-VEGF alone or in combination with PRP, but there was significant inconsistency (p = 0.016). Subgroup analyses in patients without DME yielded no difference for the 12-month visual outcome between the three interventions, but with significant inconsistency (p = 0.005).

CONCLUSION

This NMA showed limited evidence of comparable efficacy in terms of neovascularization regression between PRP and anti-VEGF therapy alone or in combination with PRP, but better visual outcomes were associated with anti-VEGF use. Intravitreal anti-VEGF therapy could be a valid therapeutic option in association with PRP.

DETERMINING THE EFFECT OF DIABETES DURATION ON RETINAL AND CHOROIDAL THICKNESSES IN CHILDREN WITH TYPE 1 DIABETES MELLITUS

PURPOSE

Determining the effect of diabetes mellitus duration on retinal and choroidal thicknesses in children with Type 1 diabetes mellitus (T1DM).

METHODS

Children (aged 6-18 years) with Type 1 diabetes and no diabetic retinopathy and age-matched controls were examined using Topcon spectral domain optical coherence tomography. Choroidal thickness and retinal thickness in macula area were measured. The study group was divided into 3 subgroups depending on diabetes mellitus duration-Group 1: <5 years (n = 52), Group 2: 5 to 10 years (n = 39), and Group 3: >10 years (n = 30).

RESULTS

One hundred and twenty-one diabetic children and 32 controls were included. The central choroidal thickness increased from 305.5 μm (SD: 61.7 μm) in the control group to 309.2 μm (SD: 70.1 μm) in Group 1, 315.2 μm (SD: 64.3 μm) in Group 2, and 367.4 μm (SD: 66.0 μm) in Group 3. Group 3 differed significantly from Group 1 (P = 0.0002), Group 2 (P = 0.0014), and the control group (P = 0.0003). The choroid-to-retina thickness ratio was lowest in controls, 1.01 (SD: 0.17), and highest in Group 3, 1.21 (SD: 0.2). Group 3 differed significantly from Group 1, Group 2, and the control group with P = 0.0002, P = 0.0014, and P = 0.0001, respectively. No retina thickening was found.

CONCLUSION

Changes in the choroid may occur before the development of diabetic retinopathy and seem to progress with increasing diabetes mellitus duration despite the absence of diabetic retinopathy and without associated retina thickening. Choroidal thickness could be valuable for screening in diabetic children.

Central serous chorioretinopathy: Towards an evidence-based treatment guideline

Central serous chorioretinopathy (CSC) is a common cause of central vision loss, primarily affecting men 20-60 years of age. To date, no consensus has been reached regarding the classification of CSC, and a wide variety of interventions have been proposed, reflecting the controversy associated with treating this disease. The recent publication of appropriately powered randomised controlled trials such as the PLACE trial, as well as large retrospective, non-randomised treatment studies regarding the treatment of CSC suggest the feasibility of a more evidence-based approach when considering treatment options. The aim of this review is to provide a comprehensive overview of the current rationale and evidence with respect to the variety of interventions available for treating CSC, including pharmacology, laser treatment, and photodynamic therapy. In addition, we describe the complexity of CSC, the challenges associated with treating CSC, and currently ongoing studies. Many treatment strategies such as photodynamic therapy using verteporfin, oral mineralocorticoid antagonists, and micropulse laser treatment have been reported as being effective. Currently, however, the available evidence suggests that half-dose (or half-fluence) photodynamic therapy should be the treatment of choice in chronic CSC, whereas observation may be the preferred approach in acute CSC. Nevertheless, exceptions can be considered based upon patient-specific characteristics.

Alteration of choroidal vascular structure in diabetic retinopathy

PURPOSE

The aim of this study was to analyse choroidal structures in normal patients and patients with diabetes with various severities of diabetic retinopathy (DR).

METHODS

This is a retrospective observation case control study. Three hundred and forty-two diabetic eyes, and age-matched 112 eyes without diabetes mellitus (DM) were enrolled in this study. Patients with DM were classified into no DR, mild/moderate non-proliferative DR (mNPDR), severe NPDR and proliferative DR (PDR). Patients with DM were further divided into two groups based on information regarding systemic DM treatment situation: DM-treated and untreated groups. Central choroidal thickness (CCT), and total choroidal area (TCA), luminal area (LA) and stromal area (SA) were determined using enhanced depth imaging optical coherence tomography and a binarisation method, respectively. The ratio of LA in the TCA was defined as L/C ratio.

RESULTS

The haemoglobin A1c (HbA1c) value was significantly higher in the DM-untreated than in the DM-treated subjects. L/C ratio was significantly lower in all the diabetic eyes than control eyes (p<0.05). TCA, LA, L/C ratio and CCT were significantly greater in the DM-untreated than treated group (each p<0.05). In the DM-untreated group, TCA and LAs (p<0.05) and L/C ratio (p<0.01) were significantly lower in mNPDR subjects than normal controls (p<0.05). PDR in the DM-untreated group showed significantly larger SA and LA, and greater CCT than normal controls (each p<0.05).

CONCLUSIONS

These results suggest that choroidal vasculature was initially involved at an early DR, whereas thickened LA and SA were noted in advanced DR.

Early Retinal and Choroidal Coat Thickness Changes after Intravitreal Dexamethasone Implant Injection for Diabetic Macular Edema

Background:

Intravitreal steroid injection is one of the treatment options for diabetic macular edema. Dexamethasone implant is the most novel form of intravitreal steroid therapy. Improvement in macular thickness is a well-known effect of Dexamethasone implant however, subfoveal choroidal coat thickness changes require investigation.

Aims:

To evaluate the early central macular thickness and subfoveal choroidal thickness alterations after single-dose dexamethasone implant injection in diabetic macular edema.

Study Design:

Cross-sectional study.

Methods:

We identified 29 patients with diabetic macular edema (29 eyes) who underwent optical coherence tomography and fundus fluorescein angiography. All patients received a single-dose intravitreal Dexamethasone implant and were followed up for central macular thickness and subfoveal choroidal thickness alterations for 1 hour, 1 week, 1 month, and 3 months post-injection.

Results:

The preoperative mean central macular thickness and subfoveal choroidal thickness measurements were 592.3±122.3 (412–879) μm and 264.8±53.7 (165–397) μm, respectively. Central macular thickness measurements decreased significantly in the first hour (p<0.050) and continued to decrease until the third month (p<0.001), whereas the subfoveal choroidal thickness decrement was only significant on the first day (p<0.05). Decreases in subfoveal choroidal thickness and central macular thickness of 1.5% and 5% were observed at 1 hour; however, the difference was not significant (p>0.050). The decrease in central macular thickness was significantly greater than that in subfoveal choroidal thickness at 1 day, 1 week, 1 month, and 3 months (p<0.001).

Conclusion:

Intravitreal Dexamethasone implant has a meaningful effect on central macular thickness in patients with diabetic macular edema, while subfoveal choroidal thickness decreases significantly at first day.

The effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on the OCT-measured macular choroidal thickness of eyes with proliferative diabetic retinopathy

OBJECTIVES:

To investigate the effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on macular choroidal thickness parameters in eyes with high-risk proliferative diabetic retinopathy.

METHODS:

High-risk proliferative diabetic retinopathy patients undergoing laser treatment were prospectively enrolled in this study. One eye was randomly selected for laser treatment combined with bevacizumab injections, study group, whereas the corresponding eye was subjected to laser treatment alone, control group. Spectral-domain optical coherence tomography with enhanced depth imaging was used to measure the macular choroidal thickness prior to and 1 month after treatment. Measurements in both groups were compared. Clinicaltrials.gov: NCT01389505.

RESULTS:

Nineteen patients (38 eyes) with a mean±standard deviation age of 53.4±9.3 years were evaluated, and choroidal thickness measurements for 15 patients were used for comparison. The greatest measurement before treatment was the subfoveal choroidal thickness (341.68±67.66 μm and 345.79±83.66 μm for the study and control groups, respectively). No significant difference between groups was found in terms of macular choroidal thickness measurements at baseline or after treatment. However, within-group comparisons revealed a significant increase in choroidal thickness parameters in 10 measurements in the study group and in only 5 temporal measurements in the control group when 1-month follow-up measurements were compared to baseline values.

CONCLUSIONS:

The macular choroidal thickness does not appear to be significantly influenced by laser treatment alone but increases significantly when associated with bevacizumab injections in patients with proliferative diabetic retinopathy and macular edema. Because bevacizumab injections reduce short-term laser pan-retinal photocoagulation-induced macular edema, our findings suggest that the choroid participates in its pathogenesis.