Optical coherence tomographic reflectivity of cystoid spaces is related to recurrent diabetic macular edema after triamcinolone

Optical Coherence Tomography Reflectivity in Foveal Cysts: A Novel Biomarker for Early-Response Prediction of Diabetic Macular Edema Treated with Dexamethasone

This study investigated spectral-domain optical coherence tomography (OCT) biomarkers to predict short-term anatomical improvement for diabetic macular edema (DME) after dexamethasone (DEX) injection in intravitreal anti-vascular endothelial growth factor (anti-VEGF) non-responders. This retrospective comparative study included 31 eyes of 31 patients with DME unresponsive to anti-VEGF, divided into better and lesser responder groups. OCT prior to DEX injection was used to evaluate the morphological features including optical density (ODN) and optical density ratio (ODR) of the outer nuclear layer (ONL) cysts. Correlations between baseline OCT parameters and mean central macular thickness (CMT) changes at 1 month were analyzed. There were no between-group differences in age, sex, number of previous anti-VEGF injections, duration of diabetes, or HbA1c level. However, ODN and ODR values in ONL cysts were lower in the better responder group (p = 0.020 and p < 0.001, respectively). ODN and ODR showed negative correlations with CMT changes (R = −0.546, p = 0.002 and R = −0.436, p = 0.014, respectively). Higher OCT reflectivity in the foveal cystoid space was associated with a lesser decrease in CMT after DEX injection in anti-VEGF non-responders, suggesting the usefulness of this parameter in predicting short-term CMT responses after DEX injection.

Factors predicting the treatment frequency of ranibizumab injections during the second year in diabetic macular edema

PURPOSE

To investigate the predictors of annual treatment frequency in the second year of pro re nata (PRN) intravitreal ranibizumab (IVR) injections for diabetic macular edema (DME).

STUDY DESIGN

A retrospective study.

METHODS

We reviewed 65 eyes of 60 patients with center-involved DME who received PRN IVR injections after 3 monthly loading doses. The central subfield thickness (CST) and qualitative findings were assessed on the spectral domain optical coherence tomography (SD-OCT) images. We then investigated whether the parameters at the baseline or at the 12-month visit were associated with treatment frequency in the second year.

RESULTS

The number of ranibizumab injections decreased from 6 (4-8) during the first year to 2 (0-3) during the second year (P < .001). The injection numbers during the first year (ρ = 0.259, P = .037) but not during the second year (ρ = 0.152, P = .226) were modestly related to the logarithm of the minimum angle of resolution (logMAR) improvement at 24 months. Multivariate analyses revealed that the CST (β = 0.336, P = .005) and hyperreflective walls in the foveal cystoid spaces (β = 0.273, P = .020) at baseline were associated with the number of IVR injections during the second year. The treatment frequency during the second year was also related to the CST (β = 0.266, P = .012), hyperreflective walls (β = 0.394, P = .002), and cumulative doses of ranibizumab injections (β = 0.294, P = .006) at the 12-month visit.

CONCLUSIONS

The cumulative doses of ranibizumab injections, CST, and hyperreflective walls in the foveal cystoid spaces at the 12-month visit are designated predictors of the treatment frequency of ranibizumab injections during the second year in DME.

LONG-TERM EFFECT OF CYSTOTOMY WITH OR WITHOUT THE FIBRINOGEN CLOT REMOVAL FOR REFRACTORY CYSTOID MACULAR EDEMA SECONDARY TO DIABETIC RETINOPATHY

PURPOSE

To show the long-term effect of cystotomy with or without fibrinogen clot removal for refractory cystoid macular edema secondary to diabetic retinopathy.

METHODS

Retrospective analyses of the medical records of 30 eyes of 30 patients with refractory cystoid macular edema secondary to diabetic retinopathy who had followed up for 12 months after the surgery were performed.

RESULTS

There were 15 men and 15 women. The mean ± SD age was 68.4 ± 7.9 years. The best-corrected visual acuity (logarithm of the minimal angle of resolution) at 12 months after the surgery (0.33 ± 0.25, Snellen equivalent, 20/42) was statistically better than the preoperative best-corrected visual acuity (0.45 ± 0.33, Snellen equivalent, 20/56) (P < 0.01). The central sensitivity on microperimetry (dB) was not statistically changed between preoperatively (24.0 ± 4.9) and 12 months after the surgery (24.1 ± 4.0) (P = 0.75). The central retinal thickness on optical coherence tomography (μm) at 12 months after the surgery (300.3 ± 99.0) was statistically improved compared with the preoperative central retinal thickness (565.6 ± 198.7) (P < 0.01). During the follow-up period, cystoid macular edema relapsed in seven of 30 eyes. The preoperative cystoid cavity reflectivity on optical coherence tomography in patients with fibrinogen clot removal (n = 16) was significantly higher than that in patients without fibrinogen clot removal (n = 14) (P < 0.04).

CONCLUSION

The cystotomy with or without fibrinogen clot removal may be a promising treatment option for refractory cystoid macular edema secondary to diabetic retinopathy.

Morphometric analysis of fibrovascular pigment epithelial detachments treated with ranibizumab and aflibercept

PURPOSE

To assess fibrovascular pigment epithelial detachments (PED) and their response to two different anti-VEGF agents using optical coherence tomography (OCT) morphometric analysis.

METHODS

Seventy-three consecutive, treatment-naïve eyes with fibrovascular PED (>125 μm) treated with ranibizumab or aflibercept were retrospectively included. A custom-made software was used to manually segment and calculate PED maximum height, base area, volume and internal reflectivity at baseline, after three injections and 1 year.

RESULTS

Visual acuity (VA) change was 2 ETDRS letters ± 7.6 after three injections and 3.2 ETDRS letters ± 10.3 at 1 year. There was no significant difference between VA changes amongst the two drugs. At 1 year, anti-VEGF treatment resulted in a mean reduction of 125 μm in maximum PED height, of 2.26 mm² in base area and of 0.54 mm³ in volume with a corresponding increase in reflectivity. These changes were more prominent in the aflilbercept group. The observed PED and VA changes at year 1 were strongly correlated with their values at baseline and after three injections.

CONCLUSIONS

Anti-VEGF treatment resulted in a reduction of all PED dimensions and a corresponding increase in optical reflectivity. Higher, larger and more hypo-reflective PEDs demonstrated a better anatomical response, especially with aflibercept, but this was not correlated with VA.

Detection rate of diabetic macular microaneurysms comparing dye-based angiography and optical coherence tomography angiography

Diabetic maculopathy (DM) is a microvascular dysfunction clinically characterized by microaneurysms (MA) leading to edema and central visual deprivation. This prospective explorative study investigated 27 eyes of 17 patients with DM by fluorescein/indocyanine green angiography (FA/ICGA; SPECTRALIS HRA-OCT, Heidelberg Engineering) and by swept source-optical coherence tomography angiography (SS-OCTA; DRI-OCT Triton Plus, Topcon) to identify clinically relevant MAs. The SS-OCTA cubes were split into the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) according to the automated segmentation. The images of all modalities were superimposed for alignment by an Early Treatment Diabetic Retinopathy Study grid overlay and compared to each other. In total, the mean number of MAs in FA was 33.4 ± 22 (standard deviation) (median 27.5 [q1:21.75;q3:38.25]), in ICGA 24.9 ± 16.9 (17.5 [14;35]), in the SCP 6.5 ± 3.7 (5.5 [3.75;9.25]) and in the DCP 18.1 ± 10.5 (18.5 [10.75;23.5]). Mixed effects models between ICGA and the DCP were borderline significant (p = 0.048; 95% confidence interval 0.21 to 13.49), whereas all other imaging methods differed significantly. Quantitative analysis of MAs in DM showed a plausible agreement between ICGA and the DCP in SS-OCTA. These findings contribute to the imaging methodology in DM.

Hyperreflective Walls in Foveal Cystoid Spaces as a Biomarker of Diabetic Macular Edema Refractory to Anti-VEGF Treatment

Diabetic macular edema (DME) refractory to anti-VEGF drugs is a socioeconomic burden. In this retrospective study, we investigated the relationship between DME remission and hyperreflective walls in foveal cystoid spaces, a novel finding on spectral domain optical coherence tomography (SD-OCT) images in DME. In a cross-sectional study, we assessed the relationship between hyperreflective walls in foveal cystoid spaces and other OCT findings in 110 eyes of 110 DME patients. Hyperreflective walls were delineated in 27 of 171 foveal cystoid spaces. Eyes with hyperreflective walls in foveal cystoid spaces had poorer visual acuity and more severe photoreceptor disruption than did those without such findings (P = 0.008 and P < 0.001, respectively). In the other longitudinal study, we evaluated the relationship between this finding and the remission in 54 eyes of 51 DME patients treated with as-needed ranibizumab injections for 24 months. Foveal cystoid spaces with hyperreflective walls were often persistent, and the cumulative rates of DME remission among eyes with and without the hyperreflective walls were 7.7% (1 eye) and 48.8% (20 eyes) at 18 months (hazard ratio, 0.092; P = 0.025). We characterized hyperreflective walls in foveal cystoid spaces and designated them as a predictor of no DME remission under ranibizumab injections.

Rebound Phenomenon after Intravitreal Injection of Triamcinolone Acetonide for Macular Edema

INTRODUCTION

The aim of this article was to report on a rebound phenomenon after intravitreal triamcinolone acetonide (IVTA) injection for macular edema secondary to diabetic retinopathy (DR) and central or branch retinal vein occlusion (CRVO/BRVO).

METHODS

The data were analyzed retrospectively. Complete ophthalmic examinations, including spectral domain optical coherence tomography, were performed before and 2 months after IVTA injection. The incidence of a rebound phenomenon was defined as an increase in central retinal thickness of >10% from baseline at 2 months after IVTA injection.

RESULTS

This retrospective study included 211 consecutive patients (268 eyes). One hundred ninety (71.2%), 39 (14.6%), and 39 (14.6%) eyes had macular edema (ME) due to DR, CRVO, and BRVO. In total, 9.7% of the eyes showed a rebound phenomenon (DR: 9.5%, CRVO: 5.2%, BRVO: 15.4%). The mean number of prior injections of vascular endothelial growth factor inhibitor or corticosteroid agent was statistically significantly higher in the rebound group (6.8 vs. 5.3) than in the nonrebound group (p = 0.01).

CONCLUSION

Our study shows that 9.7% of the eyes with ME secondary to DR and RVO developed a rebound phenomenon following IVTA injection, limiting its therapeutic effect. We found an increased number of prior intravitreal pharmacotherapy to be a risk factor for a rebound phenomenon.

Hyperreflective Foci in the Outer Retinal Layers as a Predictor of the Functional Efficacy of Ranibizumab for Diabetic Macular Edema

Anti-VEGF drugs are as the first-line therapies for diabetic macular edema (DME). In this study, we investigated the association between hyperreflective foci in the outer retinal layers and functional efficacy in DME patients who received intravitreal ranibizumab (IVR) injections. We retrospectively reviewed 77 eyes of 71 patients with DME treated with pro re nata IVR injections for at least 12 months. We evaluated how baseline hyperreflective foci in the outer retinal layers on spectral domain optical coherence tomography images were associated with an improvement in logarithm of the minimum angle of resolution visual acuity (logMAR VA) at 12 months. Forty-three eyes with hyperreflective foci in the outer retinal layers had greater VA improvement than 34 eyes without such foci at 12 months. Multivariate analyses demonstrated that both logMAR VA and hyperreflective foci in the outer retinal layers at baseline were associated with VA improvement. Structural analyses revealed that the central subfield thickness was decreased and that the ellipsoid zone of photoreceptors was improved more significantly in eyes with hyperreflective foci in the outer layers than eyes without such lesions. Baseline hyperreflective foci in the outer retinal layers predict the functional efficacy of IVR injections for DME.

Reflectance and Thickness Analysis of Retinal Layers in Patients with Epiretinal Membranes Using Spectral-Domain OCT before and after Vitrectomy with Membrane Peeling

PURPOSE

To compare thickness and reflectance of retinal layer findings in patients with idiopathic epiretinal membranes (ERMs) before and after surgery with those of normal controls.

DESIGN

Retrospective study.

PARTICIPANTS

Patients with ERMs before and after surgery and healthy controls.

METHODS

Spectral-domain (SD) OCT imaging of eyes with ERMs before and after surgery and of healthy eyes were analyzed for morphologic appearance and using a customized algorithm to measure retinal layer reflectance and thickness. Findings were correlated with visual acuity outcomes.

MAIN OUTCOME MEASURES

Retinal layer thickness and reflectance.

RESULTS

Thirty-four ERM and 12 healthy eyes were identified. Mean preoperative best-corrected visual acuity (BCVA) improved from 0.53±0.31 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/68) to 0.41±0.25 logMAR (Snellen equivalent, 20/51) after surgery (P = 0.030). Differences in reflectance and thickness of retinal layers were identified among the preoperative ERM, postoperative ERM, and healthy eyes. High preoperative reflectance of the internal limiting membrane (ILM) to outer plexiform layer (OPL) was correlated with better postoperative BCVA (r = -0.451; P = 0.007). A larger improvement in BCVA was correlated with preoperative thick measurements of the outer nuclear layer (r = 0.514; P = 0.002), high reflectance of the group of layers from the ILM to the OPL (r = 0.426; P = 0.012), and low reflectance of the photoreceptor layer (r = -0.453; P = 0.007). Using linear regression analysis, better postoperative BCVA was associated with better preoperative vision (standardized regression coefficient, 0.553; P = 0.001) and high reflectance of the group of layers from the ILM to OPL (standardized regression coefficient, -0.526; P = 0.001). A larger improvement in BCVA was associated with worse preoperative BCVA (standardized regression coefficient, -0.539; P < 0.001) and high reflectance of the group of layers from the ILM to OPL (standardized regression coefficient, -0.428; P = 0.001).

CONCLUSIONS

Quantitative differences in reflectance and thickness among preoperative, postoperative, and normal SD OCT imaging allow assessment of retina layer changes secondary to ERMs. High reflectance of the ILM to OPL correlated with and was associated with better postoperative BCVA and improvement in BCVA.

Optical coherence tomography: A guide to interpretation of common macular diseases

Optical coherence tomography is a quick, non invasive and reproducible imaging tool for macular lesions and has become an essential part of retina practice. This review address the common protocols for imaging the macula, basics of image interpretation, features of common macular disorders with clues to differentiate mimickers and an introduction to choroidal imaging. It includes case examples and also a practical algorithm for interpretation.

Optical coherence tomography angiography: A comprehensive review of current methods and clinical applications

OCT has revolutionized the practice of ophthalmology over the past 10-20 years. Advances in OCT technology have allowed for the creation of novel OCT-based methods. OCT-Angiography (OCTA) is one such method that has rapidly gained clinical acceptance since it was approved by the FDA in late 2016. OCTA images are based on the variable backscattering of light from the vascular and neurosensory tissue in the retina. Since the intensity and phase of backscattered light from retinal tissue varies based on the intrinsic movement of the tissue (e.g. red blood cells are moving, but neurosensory tissue is static), OCTA images are essentially motion-contrast images. This motion-contrast imaging provides reliable, high resolution, and non-invasive images of the retinal vasculature in an efficient manner. In many cases, these images are approaching histology level resolution. This unprecedented resolution coupled with the simple, fast and non-invasive imaging platform have allowed a host of basic and clinical research applications. OCTA demonstrates many important clinical findings including areas of macular telangiectasia, impaired perfusion, microaneurysms, capillary remodeling, some types of intraretinal fluid, and neovascularization among many others. More importantly, OCTA provides depth-resolved information that has never before been available. Correspondingly, OCTA has been used to evaluate a spectrum of retinal vascular diseases including diabetic retinopathy (DR), retinal venous occlusion (RVO), uveitis, retinal arterial occlusion, and age-related macular degeneration among others. In this review, we will discuss the methods used to create OCTA images, the practical applications of OCTA in light of invasive dye-imaging studies (e.g. fluorescein angiography) and review clinical studies demonstrating the utility of OCTA for research and clinical practice.

Multimodal retinal imaging of diabetic macular edema: toward new paradigms of pathophysiology

The pathophysiology of diabetic macular edema (DME) is multifactorial and partly still unknown. An increasing body of evidence suggests that neurodegeneration and retinal glial cells activation occur even before the earliest clinical manifestation of diabetic retinal vasculopathy. Nowadays, new non-invasive techniques are available to assess and characterize DME, not only in a quantitative perspective, but also making it possible to understand and quantify the pathogenic processes sustaining fluid accumulation. Optical coherence tomography (OCT) allows documenting not only parameters such as macular volume, central and sectorial retinal thickness, fluid localization, and integrity of retinal layers, but also new still poorly investigated reflectivity aspects. Hyperreflective intraretinal spots (HRS) have been detected on OCT scans through the retinal layers, with a presumptive migration pattern towards the external layers during the occurrence of diabetic retinopathy and DME. These HRS have been hypothesised to represent an in-vivo marker of microglial activation. Autofluorescence of the fundus (FAF) also offers a non-invasive imaging technique of DME. The area of increased FAF correlates with the presence of intraretinal fluid and probably retinal glial activation. Microperimetry allows the measurement of retinal sensitivity by testing specific selected retinal areas. Some studies have shown that increased macular FAF in DME correlates better with visual function assessed with microperimetry than with visual acuity, showing that new imaging and functional techniques may help to elucidate DME pathogenesis and to target therapeutical strategies.

The Vitreomacular Interface in Diabetic Retinopathy

Diabetic retinopathy (DR) is a leading health concern and a major cause of blindness. DR can be complicated by scar tissue formation, macular edema, and tractional retinal detachment. Optical coherence tomography has found that patients with DR often have diffuse retinal thickening, cystoid macular edema, posterior hyaloid traction, and tractional retinal detachment. Newer imaging techniques can even detect fine tangential folds and serous macular detachment. The interplay of the vitreous and the retina in the progression of DR involves multiple chemokine and other regulatory factors including VEGF. Understanding the cells infiltrating pathologic membranes at the vitreomacular interface has opened up the possibility of new targets for pharmacotherapy. Vitrectomies for DR remain a vital tool to help relieve tension on the macula by removing membranes, improving edema absorption, and eliminating the scaffold for new membrane formation. Newer treatments such as triamcinolone acetonide and VEGF inhibitors have become essential as a rapid way to control DR at the vitreomacular interface, improve macular edema, and reduce retinal neovascularization. These treatments alone, and in conjunction with PRP, help to prevent worsening of the VMI in patients with DR.