THREE-DIMENSIONAL ANALYSIS OF RETINAL MICROANEURYSMS WITH ADAPTIVE OPTICS OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To characterize retinal microaneurysms (MAs) in patients with diabetes using adaptive optics optical coherence tomography (AOOCT) and compare details found in AOOCT with those found in commercially available retinal imaging techniques. METHODS: Patients with diabetes and MA in the macular area were included in this pilot study. The area of interest, identified in standard fluorescein angiography, was imaged using an AO fundus camera and AOOCT. Microaneurysms were characterized in AOOCT (visibility, reflectivity, feeding/draining vessels, and intraretinal location) and compared with findings in AO fundus camera, OCT angiography, and fluorescein angiography. RESULTS: Fifty-three MAs were imaged in 15 eyes of 10 patients. Feeding and/or draining vessels from both capillary plexus could be identified in 34 MAs in AOOCT images. Of 45 MAs imaged with OCT angiography, 18 (40%) were visible in the superior plexus, 12 (27%) in the deep capillary plexus, and 15 MAs (33%) could not be identified at all. Intraluminal hyperreflectivity, commonly seen in AO fundus camera, corresponded only in 8 of 27 cases (30%) to intraluminal densities seen in AOOCT. CONCLUSION: Adaptive optics OCT imaging revealed that MAs located in the inner nuclear layer were connected to the intermediate and/or deep capillary plexus. Intraluminal hyperreflectivity seen on AO fundus camera images originated from a strong reflection from the vessel wall and only in a third of the cases from intraluminal clots. Currently, AOOCT is the most expedient in vivo imaging method to capture morphologic details of retinal microvasculature in 3D and in the context of the surrounding retinal anatomy.

Detailed analysis of retinal morphology in patients with diabetic macular edema (DME) randomized to ranibizumab or triamcinolone treatment.

PURPOSE: Our purpose was to compare the impact in diabetic macula edema (DME) of two intravitreal drugs (0.5 mg ranibizumab vs. 8 mg triamcinolone) on changes in retinal morphology in spectral-domain optical coherence tomography (SD OCT) images, color fundus photography (CF) and fluorescein angiography (FA) images during a 1-year follow-up. METHODS: Post hoc analysis was conducted of morphologic characteristics in OCT, FA and CF images of eyes with a center involving DME that were included in a prospective double-masked randomized trial. Eligible patients were divided at random into two groups receiving either pro re nata treatment with 0.5 mg ranibizumab or 8 mg triamcinolone after a fixed loading dose. OCT and CF images were acquired at monthly visits and FA images every three months. RESULTS: Twenty-five eyes of 25 patients (ranibizumab: n = 10; triamcinolone: n = 15) were included in this study. Patients treated with ranibizumab showed better visual acuity results after 12 months than patients receiving triamcinolone (p = 0.015) although edema reduction was similar (p = 0.426) in both groups. The initial effect on macular edema shedding after a single ranibizumab injection could be amplified with the following two injections of the loading dose. After a single injection of triamcinolone the beneficial initial effect on the macula edema faded within 3 months. Subretinal fluid and INL cystoid spaces diminished early in the course of treatment while fluid accumulation in the ONL seemed to be more persistent in both treatment arms. In FA, the area of leakage diminished significantly in both treatment arms. After repeated injections the morphologic OCT and FA characteristics of the treatment arms converged. CONCLUSIONS: Despite the higher dosage of triamcinolone, both therapies were safe and effective for treating diabetic macular edema. Fluid accumulation in the INL and subretinal space was more responsive to therapy than fluid accumulation in the ONL. Clinicaltrials.gov : NCT00682539.

COMPARISON OF GANGLION CELL INNER PLEXIFORM LAYER THICKNESS BY CIRRUS AND SPECTRALIS OPTICAL COHERENCE TOMOGRAPHY IN DIABETIC MACULAR EDEMA.

PURPOSE: Reduced thickness of the ganglion cell inner plexiform layer indicates diabetic neurodegeneration and can be assessed by spectral domain optical coherence tomography. The authors investigated the comparability of ganglion cell inner plexiform layer measurements from two spectral domain optical coherence tomography devices in patients with diabetic macular edema (DME). METHODS: Analysis of optical coherence tomography data sets of eyes with and fellow eyes without DME. Macular cube scans of sufficient signal strength on Cirrus (Carl Zeiss Meditec) were compared with correlating scans on Spectralis (Heidelberg Engineering, Germany) being acquired within 1 hour. RESULTS: Eighty-one equivalent data sets for 20 eyes with DME (20 patients; 6 female) and 33 for 9 fellow eyes without DME (9 patients; 2 female) were included from each device. In DME eyes, mean ganglion cell inner plexiform layer thicknesses were 62.5 ± 20.4 µm on Cirrus and 91.2 ± 9.3 µm on Spectralis. Ganglion cell inner plexiform layer was significantly thicker on Spectralis analyzing eyes with and without signs of DME (P < 0.001). The ganglion cell inner plexiform layer variance (54.2%) related to device differences decreased to 34.8% in eyes without DME. CONCLUSION: Ganglion cell inner plexiform layer data from different devices vary considerably and cannot be used interchangeably. As spectral domain optical coherence tomography is indispensable for identifying ganglion cell loss associated with diabetic neurodegeneration, clinicians should be aware of the difference when monitoring patients.

RETINAL MORPHOMETRY CHANGES MEASURED WITH SPECTRAL DOMAIN-OPTICAL COHERENCE TOMOGRAPHY AFTER PAN-RETINAL PHOTOCOAGULATION IN PATIENTS WITH PROLIFERATIVE DIABETIC RETINOPATHY.

PURPOSE: To identify the effects of pan-retinal laser treatment on the integrity of neurosensory retinal layers. METHODS: Patients were examined with fluorescence angiography after a standardized examination for diabetic retinopathy and a peripapillary ring scan with spectral domain optical coherence tomography. A single-session pan-retinal photocoagulation was performed using the PASCAL pattern scanning argon laser applying a minimum of 1,500 spots. Optical coherence tomography was evaluated more than 6 months. RESULTS: Eighteen eyes of 12 consecutive patients with new onset, treatment-naive proliferative diabetic retinopathy secondary to diabetes Type 2 were treated and retinal optical coherence tomography morphology evaluated. Retinal nerve fiber layer thickness increased statistically significantly from baseline to week 1, when it reached its peak. The combined thickness of the outer plexiform and the inner nuclear layers and the combined thickness of the inner plexiform and the ganglion cell layers showed no relevant changes. The combined thickness of the retinal pigment epithelium and the photoreceptor cell layers decreased at month 1 followed by a steady increase in thickness, which remained below baseline values over time. CONCLUSION: Pan-retinal photocoagulation in proliferative diabetic retinopathy leads to a slowly reversible, marked biological response with statistically significant morphometric changes detected by spectral domain optical coherence tomography. Swelling of the retinal nerve fiber and outer nuclear layers induce an increase in peripapillary total retinal thickness. Simultaneously, the photoreceptor and retinal pigment epithelium layers decrease in thickness. These changes indicate diffuse retinal inflammation after pan-retinal laser therapy.

Distribution of intraretinal exudates in diabetic macular edema during anti-vascular endothelial growth factor therapy observed by spectral domain optical coherence tomography and fundus photography.

PURPOSE: To evaluate changes in the distribution and morphology of intraretinal microexudates and hard exudates (HEs) during intravitreal anti-vascular endothelial growth factor therapy in patients with persistent diabetic macular edema. METHODS: Twenty-four patients with persistent diabetic macular edema after photocoagulation were investigated in this prospective cohort study. Each eye was assigned to a loading dose of three anti-vascular endothelial growth factor treatments at monthly intervals. Additional single treatments were performed if diabetic macular edema persisted or recurred. Intraretinal exudates were analyzed over 6 months using spectral domain optical coherence tomography (SD-OCT) and fundus photography. RESULTS: Before treatment, microexudates were detected by SD-OCT as hyperreflective foci in 24 eyes, whereas HEs were seen in 22 eyes. During therapy, HE increased significantly in number and size. This was accompanied by accumulation of microexudates in the outer retina. Enlargement of hyperreflective structures in SD-OCT was accompanied by enlargement of HE at corresponding fundus locations. A rapid reduction in diabetic macular edema was seen in all patients, but to varying degrees. Patients with hemoglobin A1c levels <7% and serum cholesterol <200 mg/dL formed fewer HEs and featured more edema reduction and visual acuity gain. CONCLUSION: Diabetic macular edema reduction during intravitreal anti-vascular endothelial growth factor therapy was accompanied by dynamic rearrangement of intraretinal exudates at corresponding locations in fundus photography and SD-OCT. Intraretinal aggregates of microexudates detectable as hyperreflective foci by SD-OCT may compose and precede HE before they become clinically visible.

Retinal architecture recovery after grid photocoagulation in diabetic macular edema observed in vivo by spectral domain optical coherence tomography.

PURPOSE: To identify the morphologic changes secondary to macular grid photocoagulation in diabetic macular edema in vivo using spectral domain optical coherence tomography. METHODS: In this prospective cohort study, 13 consecutive patients with vision loss because of clinically significant macular edema associated with diabetes mellitus Type 2 underwent grid laser treatment (PASCAL). Best-corrected visual acuity, Spectralis optical coherence tomography, infrared fundus imaging, and biomicroscopy were performed at baseline, Day 1, Week 1, and Months 1, 2, and 3 after treatment. Fluorescein angiography was performed at baseline and at 3 months. RESULTS: Mean central 1-mm thickness decreased significantly from 438 ± 123 µm (mean ± SD) at baseline to 391 ± 111 µm (P < 0.05) at 3 months with a nonsignificant trend of best-corrected visual acuity improvement. A wipeout of the photoreceptor layer and the inner segment/outer segment line together with an alteration of the overlaying outer nuclear layer and external limiting membrane was seen at Day 1. The lesion was reduced to a focal hyperreflective deposit on the retinal pigment epithelium boundary. In 55% of lesions, the external limiting membrane as well as the previously interrupted inner segment/outer segment line revealed intact continuity at Month 3. In some areas, repair was incomplete indicated by a focal condensation interrupting the inner segment/outer segment line in the lesion center. CONCLUSION: In vivo imaging of morphologic lesion repair in human eyes after PASCAL grid laser of diabetic macular edema demonstrates progressive restoration of the external limiting membrane and inner segment/outer segment integrity as previously described in animal models.

[Diagnosis, treatment and monitoring of diabetic eye disease (Update 2023)]. / Diagnostik, Therapie und Verlaufskontrolle der diabetischen Augenerkrankung (Update 2023).

Diabetes mellitus can cause diabetic retinopathy, diabetic macular edema, optic neuropathy, cataract or dysfunction of the eye muscles. The incidence of these disorders correlates with disease duration and quality of metabolic control. Regular ophthalmological examinations are needed to prevent sight-threatening advanced stages of diabetic eye diseases.

Effect of Changes in Surgical Strategies for the Treatment of Primary Rhegmatogenous Retinal Detachment on Functional and Anatomical Outcomes: A Retrospective Analysis of 812 Cases from the Years 2004 to 2012.

BACKGROUND: At the Department of Ophthalmology and Optometry at the MUV surgical method (scleral buckling, vitrectomy, combined vitrectomy/scleral buckling) and timing (daytime, nighttime) for the treatment of primary rhegmatogenous retinal detachment (RRD) changed continuously in the years 2004 to 2012. This study aims to evaluate changes in surgical strategies over time including their impact on functional and anatomical outcomes. METHODS: Retrospective evaluation of patients operated on primary RRD between the years 2004 and 2012. Baseline demographic data, month 3 best-corrected visual acuity (BCVA), surgical method, single success surgery, surgical timing, and intraoperative complications were analyzed. RESULTS: Overall, 812 eyes of 812 patients with a mean (±SD) age of 58.1 ± 13.3 years were included. A total of 413 (51%) patients presented with macula-on and 359 (44%) with macula-off RRD. Month 3 BCVA increased over time, both in macula-on or macula-off groups (p < 0.001). The rate of complete retinal reattachment 3 months postoperatively increased significantly from 65% in 2004 to 83% in 2012 in both groups. Scleral buckling surgeries decreased continuously from 95% to 16% with an appropriate increase in vitrectomies as well as a decrease in surgeries during nighttime (68% in 2004, 6% in 2012) with equal or better visual and functional outcomes. CONCLUSION: Our data showed that improving functional and single-success surgery outcomes in patients operated on for primary RRD. In the years 2004 to 2012, surgical techniques shifted from scleral buckling to primary vitrectomy and were increasingly scheduled during the daytime.

Retinal thickness and volume measurements in diabetic macular edema: a comparison of four optical coherence tomography systems.

PURPOSE: To compare different spectral domain optical coherence tomography devices regarding retinal thickness values in patients with diabetic macular edema and to correlate the results with conventional time domain Stratus OCT data. METHODS: Thirty eyes of 30 consecutive patients with diabetic macular edema were included into a prospective study. The macula was examined by Spectralis HRA+OCT, Cirrus HD-OCT, 3D OCT-1000, and Stratus OCT. The procedures' sequence was performed by a single experienced technician in a randomized fashion according to a computer-generated list. In each eye, foveal thickness, foveal volume, and total macular volume were measured automatically. Intraclass correlation, coefficients of variance, and coefficients of repeatability were calculated. RESULTS: Foveal thickness differed between the particular devices with a mean ± SD ranging from 359.97 ± 105.84 µm to 437.70 ± 115.84 µm. Correlation between the different OCT devices resulted in r > 0.7 (Pearson), and intraclass correlation was >0.9. Agreement of measurements was assessed showing a mean difference of foveal thickness values ranging from 19.2 µm to 77.7 µm (P < 0.05) and coefficients of repeatability ranging from 37.7 µm to 87.4 µm. CONCLUSION: While intradevice reproducibility is satisfactory, retinal thickness and volume measurements should not be used interchangeably because measurements differed significantly between systems. The lack of interdevice agreement seems to be related to the different segmentation algorithm of thickness measurement and should be considered because it may strongly influence treatment decisions and conclusions.

Comparison of safety and effectiveness between 23-gauge and 25-gauge vitrectomy surgery in common vitreoretinal diseases.

PURPOSE: To assess and compare safety and effectiveness between 23-gauge and 25-gauge vitrectomy systems for the treatment of common vitreoretinal diseases in non-vitrectomized eyes. METHODS: Retrospective evaluation of patients who underwent pars plana vitrectomy from April 2018 to December 2019 at the Department of Ophthalmology and Optometry at the Medical University of Vienna (MUV) for the following indications: macular epiretinal membrane, macular hole, macular lamellar hole, vitreous hemorrhage, vitreous opacities, vitreomacular traction syndrome and macular edema. RESULTS: 201 eyes of 195 patients that underwent 23-gauge (n = 105 eyes) or 25-gauge (n = 96 eyes) vitrectomy were included in this study. The mean best-corrected visual acuity (BCVA) improved at 1-3 months postoperatively and beyond 3 months in both gauge groups. Risk of any complication within 1 month postoperatively was lower in the 25-gauge group, but the difference was statistically not significant (HR [95% CI]: 0.95 [0.53; 1.70], p = 0.85). Intraocular pressure less than 5 mmHg was observed in 2 eyes (2%) in the 23-gauge group at the first postoperative day. Intraocular pressure elevation over 25 mmHg occurred in 5 eyes (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group) at postoperative day 1, between 7 and 28 days in 5 cases (2 eyes, 2%, in 23-gauge and 3 eyes, 3%, in 25-gauge group), and in 2 eyes (2%) of the 23-gauge group at postoperative day 145 and 61, respectively. Retinal detachment occurred in 1 eye (1%) in the 23-gauge and in 3 eyes (3%) in the 25-gauge group. We did not observe any cases of endophthalmitis. CONCLUSION: Results in terms of safety, surgical success and visual outcomes for the treatment of common vitreoretinal surgery indications seem to be comparable between 23-gauge and 25-gauge vitrectomy systems, indicating that the two gauge systems can be used equally in the clinical routine.

High-resolution imaging of the human retina in vivo after scatter photocoagulation treatment using a semiautomated laser system.

PURPOSE: To image the ultrastructural morphology of retinal laser effects and their healing response in vivo using spectral domain optical coherence tomography (SD-OCT). DESIGN: Prospective, interventional study. PARTICIPANTS: Ten patients undergoing panretinal photocoagulation for proliferative diabetic retinopathy. METHODS: Panretinal photocoagulation (PRP) was performed using a semiautomated patterned scanning laser system providing a raster of effects with homogenous intensity. Retinal morphology and localization of effects owing to laser-tissue interaction were imaged at 1 day, 1 week, and at monthly intervals for 6 months. The characteristic, specific structural changes during the healing process were followed over time using an SD-OCT device (Spectralis OCT) allowing for high-resolution raster scanning of the entire lesion pattern with identification of identical retinal sites (tracking modality). MAIN OUTCOME MEASURES: Retinal morphology and localization of effects of photocoagulation on SD-OCT images. RESULTS: At day 1 after PRP, the photocoagulation effects were sharply delineated from the surrounding unaffected retina and all spots seemed to be identical in size and location. The area of tissue destruction was confined to the outer retinal layers, extending from the outer nuclear layer (ONL) to the retinal pigment epithelium (RPE). At 1 week, images showed a progressive loss of the affected outer retinal layers, namely, the ONL and the outer plexiform layer. Concomitant distortion of the inner nuclear and plexiform layers generated a pattern of "archways" between adjacent laser spots. The photoreceptor layers (PRL) seemed to be eliminated in the photocoagulated area, particularly at the borders of each lesion. The lesion center contained a condensed RPE and PRL segment. The ONL recovered partially, but the PRL inner and outer segments remained absent. During the long-term follow-up, RPE cells migrated to the center of the lesion, forming a hyperplastic scar. CONCLUSIONS: The characteristic morphology of retinal photocoagulation effects in vivo and over time was identified for the first time in human eyes using SD-OCT. The OCT imaging demonstrated a well-defined reproducible area of destruction confined to the outer retinal layers. Healing proceeded as the condensation of the RPE and PRL in the lesion center.

In vivo retinal morphology after grid laser treatment in diabetic macular edema.

PURPOSE: To analyze immediate in vivo intraretinal morphologic changes secondary to standardized grid photocoagulation using spectral domain optical coherence tomography (SD OCT). DESIGN: Prospective clinical trial. PARTICIPANTS: Thirteen consecutive patients with treatment-naïve clinically significant diabetic macular edema (DME). METHODS: Before and 1 day after standardized grid photocoagulation using the PASCAL system (Pattern Scan Laser, OptiMedica Corporation, Santa Clara, CA), Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) examinations based on an eye-tracking system, infrared fundus imaging, color fundus photography, and biomicroscopy were performed. A standardized visual acuity assessment (Early Treatment Diabetic Retinopathy Study protocol) and fluorescein angiography were performed at baseline. MAIN OUTCOME MEASURES: Morphologic changes secondary to grid laser treatment. RESULTS: One day after laser therapy, immediate morphologic alterations of only the outer retinal layers, that is, the retinal pigment epithelium (RPE), the photoreceptor layer (PRL), and the outer nuclear layer (ONL), were observed. The shape of the laser-induced lesions did not show a sagittal alteration pattern throughout all 3 of the layers, however, but rather seemed to follow an oblique pathway throughout the ONL, changing direction at the level of the external limiting membrane and proceeding sagittally through the PRL and RPE. These morphologic changes also induced biometric changes, such as a decrease in central retinal thickness combined with local thickening at the lesion site, especially in the PRL. CONCLUSIONS: Spectral domain optical coherence tomography provides new insight into the immediate morphologic changes after laser treatment using the PASCAL laser system. Standardized grid photocoagulation induces characteristic homogenous alteration in the neurosensoric retinal layers. Biometric changes, indicating an immediate effect, were observed within 1 day after treatment.

Effect of retinal photocoagulation on intraretinal lipid exudates in diabetic macular edema documented by optical coherence tomography.

PURPOSE: To study the changes in the distribution and morphologic features of intraretinal microexudates after macular photocoagulation. DESIGN: Prospective cohort study. PARTICIPANTS: Thirteen treatment-naïve patients with clinically significant macular edema in type 2 diabetes. METHODS: Patients were treated with focal macular photocoagulation. Changes in the localization of hyperreflective foci were analyzed by spectral domain (SD) optical coherence tomography (OCT) during follow-up at day 1, week 1, and months 1, 2, 3, and 4 in defined areas. Further, fundus photography and infrared imaging were performed at all visits and findings were correlated to OCT results. MAIN OUTCOME MEASURES: Changes in retinal morphologic features detected in OCT. RESULTS: A dynamic change in the distribution pattern of hyperreflective foci was observed over 4 months after the photocoagulation. With the decrease of retinal thickness, the dots either resolved completely or became confluent at the apical border of the outer nuclear layer, and finally formed ophthalmoscopically detectable hard exudates during extended follow-up. In the event of retinal thickening despite laser treatment, the hyperreflective dots maintained their previous distribution throughout all retinal layers. As a fourth response, dissemination of plaques of hard exudates into multiple, separate, hyperreflective foci were detected. CONCLUSIONS: Hyperreflective foci in the retina seem to represent precursors or components of hard exudates. Their specific localization depends greatly on the presence of microvascular extravasation and intraretinal fluid accumulation. Retinal photocoagulation has a major impact on retinal edema and subsequently on the distribution of intraretinal lipid deposits. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Systematic ultrastructural comparison of swept-source and full-depth spectral domain optical coherence tomography imaging of diabetic macular oedema.

BACKGROUND/AIMS: Optical coherence tomography (OCT) is commonly used to diagnose and assess diabetic macular oedema (DME). Swept-source OCT (SS-OCT) promises improved imaging depth and more independence from media opacities. Heidelberg Spectralis full-depth imaging (FDI) combines details at different depths to one representation. The aim of this study was to determine the comparability of the imaging methods concerning DME ultrastructure. METHODS: Two graders assessed the presence of typical DME phenomena in eyes with centre-involving DME on Topcon Atlantis SS-OCT and Heidelberg Spectralis FDI spectral-domain OCT (SD-OCT) B-scans. Retinal layer segmentation was corrected and choroidal layers were manually segmented. Graders measured cyst and subretinal fluid (SRF) diameters and counted hyper-reflective foci (HRF). Findings were recorded and statistically analysed. RESULTS: Statistically significant systematic biases (Spectralis-Atlantis) were found for the HRF count (outside the central mm, -6.39, p=0.0338), chorioretinal thickness (central mm: -35.45 µm, p=0.00034), choroidal thickness (central mm: -60.97 µm, p=0.00004) and Sattler's layer thickness (-42.69 µm, p=0.0001). Intergrader agreement was excellent or very good for posterior vitreous detachment, vitreomacular attachment (central mm) and SRF presence in both devices. Manually delineated Sattler's layer thickness showed an intraclass correlation of 0.85 with FDI SD-OCT but 0.26 with SS-OCT (p=0.003). CONCLUSION: Prominent aspects such as cysts in the outer nuclear layer and SRF can be identified with comparable confidence, while a significant systematic bias underlies chorioretinal, choroidal and Sattler's layer thickness and HRF count. Specialists should use the same device at every examination during longitudinal clinical consideration or cross-sectional evaluation of these ultrastructural biomarkers.

Short-time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age-related macular degeneration.

PURPOSE: To investigate the short-time effect of intravitreal injections (IVI) of the vascular endothelial growth factor inhibitors ranibizumab and aflibercept on retinal arterial and venous oxygen saturation (SO2a and SO2v), arteriovenous oxygen saturation difference (AVD) and vessel diameter (VDa and VDv) in patients with diabetic macular oedema (DME) and patients with choroidal neovascularization (CNV) due to age-related macular degeneration. METHODS: Uncontrolled prospective observational study in 100 eyes. Retinal vessel oxygen saturation and diameters were assessed using a retinal oximeter before and minutes after IVI of ranibizumab or aflibercept. RESULTS: 40 eyes with CNV and 34 eyes with DME were included in the analysis. At baseline, SO2a and SO2v were significantly higher in DME (p = 0.043 and p = 0.009, respectively). After IVI, SO2a significantly decreased in CNV and DME eyes by 2.6% (p = 0.016) and 4.6% (p = 0.002) and SO2v decreased by 14.0% (p = 0.004) and 12.4% (p = 0.017), respectively. However, a significant increase in AVD was only found in CNV (15.7%, p = 0.001). VDa decreased significantly only in DME by 5.7% (p = 0.010). No medication-specific disease effect was found and vice versa. CONCLUSIONS: The observed changes can be interpreted as signs of increased metabolic demand during the physiological stress after an IVI. The abnormal arterial constriction and the abolished increase in AVD seen only in eyes with DME indicate an impairment of vascular autoregulation and oxygen distribution and a reduced neuroretinal metabolism in the diabetic retina with a significant impact on inner retinal oxygen consumption shortly after IVI.

Response of Retinal Sensitivity to Intravitreal Anti-angiogenic Bevacizumab and Triamcinolone Acetonide for Patients with Diabetic Macular Edema over One Year.

AIM: The aim of this study was to evaluate and compare microperimetry changes in patients with clinically significant diabetic macular edema secondary to diabetes mellitus, following intravitreal injections of bevacizumab or triamcinolone during a follow-up of 1 year after treatment. MATERIALS AND METHODS: 30 patients with clinically significant macular edema were randomized into two groups of 15 patients each. One group initially received three intravitreal injections of 2.5 mg bevacizumab at monthly intervals. The other received a single injection of 8 mg of triamcinolone followed by two sham interventions at monthly intervals. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were measured. Macular function was documented by microperimetry at baseline, 3, 6, 9 months and at the last visit of each patient. RESULTS: In the bevacizumab group, the mean differential light threshold (±standard deviation) under therapy improved significantly from 8.40 (± 3.8) dB to 12.8 (±4.3) dB at the 12-month follow-up visit (p ≤ .05), whereas in the triamcinolone group it increased from 8.0 (± 2.4) dB at baseline to 9.3 (±3.6) dB at the last visit without reaching statistical significance (p > .05). The mean differential light thresholds between the two groups were not statistically significant at baseline or the last visit (p > .05). In the bevacizumab group, the improvement (slope) in mean differential light threshold was significantly superior to the Triamcinolone group (Estimate = 0.588, p ≤ .05). CONCLUSION: Central macular function as measured by microperimetry in patients with acute DME improved in addition to anatomical restoration after intravitreal bevacizumab and triamcinolone injection. In our clinical study, the measures of the variables in patients receiving bevacizumab were superior to those receiving triamcinolone throughout the one-year observation period.

Association of macular perfusion status with microvascular parameters up to the far periphery in diabetic retinopathy using multimodal imaging.

BACKGROUND: The aim of our study was to investigate a possible association between macular perfusion status and retinal ischemia and leakage up to far peripheral retinal areas in eyes with early to advanced stages of diabetic retinopathy (DR). METHODS: In a retrospective, cross sectional analysis ultrawide field (UWF) color fundus photos (Optos, Optomap California) were graded for DR severity. Foveal avascular zone (FAZ) and vessel density from the superficial (SCP) and deep capillary plexus (DCP) were assessed on optical coherence tomography angiography (OCTA) scans (Topcon, DRI-OCT Triton). UWF angiography images were used to quantify leakage/ischemic index and number of microaneurysms (MA). Age, gender, disease duration, type of diabetes, HbA1C, hypertension, complications of diabetes and ocular history were recorded. Univariate mixed models and Spearman correlation analysis were used for statistical testing. RESULTS: 24 eyes of 17 laser-naive diabetic patients with different stages of DR were analyzed. The mean age was 59.56 ± 8.46 years and the mean disease duration 19.65 ± 12.25 years. No statistically significant associations between FAZ size, macular vessel density of SCP/DCP and peripheral retinal ischemia, leakage and MA number were demonstrated. Higher stages of DR were associated with ischemic index (estimate [95% CI]: 13.04 [1.5; 24.5], p = 0.033) and MA count (estimate [95% CI]: 43.7 [15.6; 71.8], p = 0.01), but no association with leakage index was observed. Only weak correlations between DR severity and anamnestic data were found. CONCLUSION: Retinal ischemic index and the amount of MAs assessed on UWFA up to peripheral areas are indicators of DR severity but not related to microvascular perfusion status in the macular region. Significance and timely sequence of macular vessel density in DR progression may need to be re-evaluated in future studies.

Optical coherence tomographic hyperreflective foci: a morphologic sign of lipid extravasation in diabetic macular edema.

PURPOSE: To analyze hyperreflective foci typically seen in diabetic macular edema (DME) in optical coherence tomography (OCT). DESIGN: Prospective clinical trial. PARTICIPANTS: Twelve consecutive patients with treatment-naïve, clinically significant DME. METHODS: During a same-day examination, a standardized visual acuity assessment (Early Treatment of Diabetic Retinopathy Study protocol), infrared fundus imaging, color fundus photography, and biomicroscopy were performed. Additionally, all patients were scanned using Stratus, Cirrus, and Spectralis OCT and results correlated. MAIN OUTCOME MEASURES: Morphologic changes secondary to DME. RESULTS: In all eyes with DME, distinct hyperreflective foci distributed throughout all retinal layers were found in the OCT scans of all 3 OCT devices. These deposits could not be identified by infrared imaging, fundus photography, or biomicroscopy as long as they were not confluent. Accumulations of such foci at the border of the outer nuclear and in the outer plexiform layer were recognizable clinically as hard exudates showing the same hyperreflective features in OCT. The hyperreflectivity of these foci did not correspond with intraretinal hemorrhage, nor did the lesions cause the characteristic OCT laser beam scattering phenomena typically seen secondary to intraretinal bleedings or microaneurysms. Further, they were detected within the walls of intraretinal microaneurysms. CONCLUSIONS: Well-demarcated, hyperreflective foci were identified in the retina of patients with DME. The deposits were located within walls of intraretinal microaneurysms and scattered throughout all retinal layers, forming confluent plaques in the outer plexiform layer. It is suggested that the foci represent extravasated lipoproteins and/or proteins being a very early subclinical barrier breakdown sign in DME.