Ultra-Widefield OCT Angiography

Optical Coherence Tomography Angiography (OCTA), a functional extension of OCT, has the potential to replace most invasive fluorescein angiography (FA) exams in ophthalmology. So far, OCTA's field of view is however still lacking behind fluorescence fundus photography techniques. This is problematic, because many retinal diseases manifest at an early stage by changes of the peripheral retinal capillary network. It is therefore desirable to expand OCTA's field of view to match that of ultra-widefield fundus cameras. We present a custom developed clinical high-speed swept-source OCT (SS-OCT) system operating at an acquisition rate 8-16 times faster than today's state-of-the-art commercially available OCTA devices. Its speed allows us to capture ultra-wide fields of view of up to 90 degrees with an unprecedented sampling density and hence extraordinary resolution by merging two single shot scans with 60 degrees in diameter. To further enhance the visual appearance of the angiograms, we developed for the first time a three-dimensional deep learning based algorithm for denoising volumetric OCTA data sets. We showcase its imaging performance and clinical usability by presenting images of patients suffering from diabetic retinopathy.

[Artificial intelligence in the management of anti-VEGF treatment: the Vienna fluid monitor in clinical practice]

Der Vienna Fluid Monitor ist ein künstlicher Intelligenz(KI)-Algorithmus zur präzisen Lokalisation und Quantifizierung von retinaler Flüssigkeit. Der Algorithmus soll Klinikern und Klinikerinnen helfen, objektive und genaue Behandlungsentscheidungen bei der antivaskulären endothelialen Wachstumsfaktor(Anti-VEGF)-Therapie von Patienten mit neovaskulärer altersbedingter Makuladegeneration zu treffen. Ziel der Implementierung ist die Optimierung der Patientensicherheit, die Erhaltung der Sehleistung und gleichzeitig die Behandlungslast für das Gesundheitssystem und die Patienten zu verringern.

Correlation of Retinal Thickness and Swept-Source Optical Coherence Tomography Angiography Derived Vascular Changes in Patients with Neovascular Age-Related Macular Degeneration

Purpose: The aim of this study was to investigate whether structural OCT changes, in specific retinal thickness, is associated with the vascular response within the nAMD CNV lesion. In other words, whether SSOCTA derived parameters may prove suitable to assess CNV activity in future.Methods: During the first 3 months patients were prospectively followed with visits at days 7, and 14 after each anti-VEGF treatment up to day 90. At baseline, day 30 and 60 Aflibercept was administered. OCT-derrived retinal thickness (RT) and OCTA-derived CNV lesion parameters (vessel area [VA]), total vessel length [TVL], total number of junctions [TNJ], junction density [JD]) were determined. Parameters were exported from SSOCT/A (PlexElite, Zeiss) images using the semi-automated AngioTool software. Additionally, the superficial and deep vascular plexus fractal dimension of the para- and perifoveal region were identified. Consequently, all OCTA derived parameters were correlated with RT.Results: 16 consecutive patients presenting with treatment-naïve, SSOCTA-positive CNV lesions were included. A weak to moderate statistically significant correlation was found between the mean RT of the inner as well as the outer ETDRS ring with the SSOCTA-derived vascular markers vessel area (VA; r² = -0.38, p < .001; r² = -0.47, p < .001, respectively), total vessel length, (TVL; r² = -0.38, p < .001; r² = -0.48, p < .001, respectively) and total number of junctions (TNJ; r² = -0.35, p < .001; r² = -0.44, p < .001, respectively). Junctions density (JD), and all variables based on fractal dimension (FD) did not show statistically significant correlations with retinal thickness measurements.Conclusions: In summary, we could confirm a moderate, however, statistically significant correlation between mean para- and perifoveal retinal thickness and the SSOCTA derived vascular parameters VA, TVL, and TNJ. This leads us to the conclusion that an SSOCTA-based activity analysis of the CNV complex is not yet a substitute for retinal thickness or in-depth fluid analysis in patients with nAMD.

Verteporfin Therapy and Triamcinolone Acetonide: Convergent Modes of Action for Treatment of Neovascular Age-Related Macular Degeneration

PURPOSE

Choroidal neovascularization associated with age-related macular degeneration is the primary cause of blindness in the elderly in developed countries, due to a number of pathogenic effects, including angiogenesis, cell-mediated inflammation, leukocyte adhesion and extravasation, and matrix remodeling.

METHODS

By producing photochemical effects at the site of target tissue (lesion), photodynamic therapy (PDT) can induce vascular damage and blood flow stasis, leading to occlusion of vascularization and lesion leakage.

RESULTS

PDT with verteporfin (Visudyne, Novartis) has been shown to be safe and effective in reducing the risk of vision loss in patients with classic containing subfoveal CNV and occult with no classic CNV. However, in predominantly occult CNV, the treatment may be most effective in smaller lesions, and less in larger lesions. Most important, visual acuity rarely is improved.

CONCLUSIONS

Pilot studies and large case series suggest that a combination of PDT and intravitreal triamcinolone acetonide has the potential to improve visual outcomes and reduce the need for additional treatments. Randomized, prospective clinical trials are underway to confirm the efficacy and safety of this novel treatment modality.

eHealth 2015 Special Issue: Impact of Electronic Health Records on the Completeness of Clinical Documentation Generated during Diabetic Retinopathy Consultations

Background: Two years ago, the Diabetic Retinopathy (DRP) and Traumatology clinic of the Department of Ophthalmology and Optometrics at the Medical University of Vienna, Austria switched from paper-based to electronic health records. A customized electronic health record system (EHR-S) was implemented.

Objectives: To assess the completeness of information documented electronically compared with manually during patient visits.

Methods: The Preferred Practice Pattern for Diabetic Retinopathy published by the American Academy of Ophthalmology was distilled into a list of medical features grouped into categories to be assessed and documented during the management of patients with DRP. The last seventy paper-based records and all electronic records generated since the switch were analyzed and graded for the presence of features on the list and the resulting scores compared.

Results: In all categories, clinical documentation was more complete in the EHR group.

Conclusions: In our setting, the implementation of an EHR-S showed a statistically significant positive impact on documentation completeness.

Citation: Mitsch C, Huber P, Kriechbaum K, Scholda C, Duftschmid G, Wrba T, Schmidt-Erfurth U. Impact of Electronic Health Records on the Completeness of Clinical Documentation Generated during Diabetic Retinopathy Consultations. Appl Clin Inform 2015; 6: 478–487

http://dx.doi.org/10.4338/ACI-2015-03-RA-0028

Artificial scotoma estimation based on population receptive field mapping

Population receptive field (pRF) mapping based on functional magnetic resonance imaging (fMRI) is an ideal method for obtaining detailed retinotopic information. One particularly promising application of pRF mapping is the estimation and quantification of visual field effects, for example scotomata in patients suffering from macular dysfunction or degeneration (MD) or hemianopic defects in patients with intracranial dysfunction. However, pRF mapping performance is influenced by a number of factors including spatial and temporal resolution, distribution of dural venous sinuses and patient performance. This study addresses the ability of current pRF methodology to assess the size of simulated scotomata in healthy individuals. The data demonstrate that central scotomata down to a radius of 2.35° (4.7° diameter) visual angle can be reliably estimated in single subjects using high spatial resolution protocols and multi-channel receive array coils.

Supervised learning and dimension reduction techniques for quantification of retinal fluid in optical coherence tomography images

PurposeThe purpose of the present study is to develop fast automated quantification of retinal fluid in optical coherence tomography (OCT) image sets.MethodsWe developed an image analysis pipeline tailored towards OCT images that consists of five steps for binary retinal fluid segmentation. The method is based on feature extraction, pre-segmention, dimension reduction procedures, and supervised learning tools.ResultsFluid identification using our pipeline was tested on two separate patient groups: one associated to neovascular age-related macular degeneration, the other showing diabetic macular edema. For training and evaluation purposes, retinal fluid was annotated manually in each cross-section by human expert graders of the Vienna Reading Center. Compared with the manual annotations, our pipeline yields good quantification, visually and in numbers.ConclusionsBy demonstrating good automated retinal fluid quantification, our pipeline appears useful to expert graders within their current grading processes. Owing to dimension reduction, the actual learning part is fast and requires only few training samples. Hence, it is well-suited for integration into actual manufacturer's devices, further improving segmentation by its use in daily clinical life.

Eyetracker-based gaze correction for robust mapping of population receptive fields

Functional MRI enables the acquisition of a retinotopic map that relates regions of the visual field to neural populations in the visual cortex. During such a "population receptive field" (PRF) experiment, stable gaze fixation is of utmost importance in order to correctly link the presented stimulus patterns to stimulated retinal regions and the resulting Blood Oxygen Level Dependent (BOLD) response of the appropriate region within the visual cortex. A method is described that compensates for unstable gaze fixation by recording gaze position via an eyetracker and subsequently modifies the input stimulus underlying the PRF analysis according to the eyetracking measures. Here we show that PRF maps greatly improve when the method is applied to data acquired with either saccadic or smooth eye movements. We conclude that the technique presented herein is useful for studies involving subjects with unstable gaze fixation, particularly elderly patient populations.

eHealth 2015 Special Issue: Impact of Electronic Health Records on the Completeness of Clinical Documentation Generated during Diabetic Retinopathy Consultations

BACKGROUND

Two years ago, the Diabetic Retinopathy (DRP) and Traumatology clinic of the Department of Ophthalmology and Optometrics at the Medical University of Vienna, Austria switched from paper-based to electronic health records. A customized electronic health record system (EHR-S) was implemented.

OBJECTIVES

To assess the completeness of information documented electronically compared with manually during patient visits.

METHODS

The Preferred Practice Pattern for Diabetic Retinopathy published by the American Academy of Ophthalmology was distilled into a list of medical features grouped into categories to be assessed and documented during the management of patients with DRP. The last seventy paper-based records and all electronic records generated since the switch were analyzed and graded for the presence of features on the list and the resulting scores compared.

RESULTS

In all categories, clinical documentation was more complete in the EHR group.

CONCLUSIONS

In our setting, the implementation of an EHR-S showed a statistically significant positive impact on documentation completeness.

Intravitreal bevacizumab (Avastin) versus triamcinolone (Volon A) for treatment of diabetic macular edema: one-year results

PURPOSE

The objective was to compare retinal morphology and function following intravitreal injections of bevacizumab (Avastin) or triamcinolone (Volon A) in patients with early diabetic macular edema (DME).

PATIENTS AND METHODS

The study was planned as a randomized, prospective, interventional clinical trial. A total of 30 diabetic patients with treatment-naïve, clinically significant macular edema were included in this study and randomized to two equal groups. One group initially received three injections of 2.5 mg bevacizumab in monthly intervals. The second group received a single injection of 8 mg triamcinolone, followed by two sham interventions. Functional and anatomic results were evaluated monthly using ETDRS vision charts and spectral-domain optical coherence tomography. According to the study protocol, retreatment after 3 months was dependent on functional and anatomic outcome in a PRN regimen.

RESULTS

Baseline best corrected visual acuity (BCVA) was 0.30 logMAR and central retinal subfield thickness (CSRT) was 505 μm in the bevacizumab group and 0.32 logMAR and 490 μm CSRT in the triamcinolone group. After 3 months, BCVA improved to 0.23 logMAR (bevacizumab) and 358 μm CRST and 0.26 logMAR (triamcinolone) and 308 μm CSRT. After 12 months, BCVA further recovered in the bevacizumab group (0.18 logMAR) but slightly decreased in the triamcinolone group (0.36 logMAR).

CONCLUSION

Intravitreal bevacizumab and triamcinolone are both equally effective in reducing CSRT in early DME. After 6 months, rehabilitation of vision was comparable in both treatment arms, whereas at the final follow-up at month 12, BCVA was superior in the bevacizumab than in the triamcinolone sample. This may be related to cataract development following steroid treatment, as well as to substance-specific mechanisms within the angiogenic versus the inflammatory cascade.

New approaches for the treatment of diabetic macular oedema: recommendations by an expert panel

The current standard therapy for patients with diabetic macular oedema (DME)--focal/grid laser photocoagulation--usually does not improve impaired vision, and many patients lose vision despite laser therapy. Recent approval of ranibizumab by the European Medicines Agency to treat visual impairment due to DME fulfils the previously unmet medical need for a treatment that can improve visual acuity (VA) in these patients. We reviewed 1- and 2-year clinical trial findings for ranibizumab used as treatment for DME to formulate evidence-based treatment recommendations in the context of this new therapy. DME with or without visual impairment should be considered for treatment when it fulfils the Early Treatment Diabetic Retinopathy Study (ETDRS) criteria for clinically significant oedema. For DME with centre involvement and associated vision loss due to DME, monthly ranibizumab monotherapy with treatment interruption and re-initiation based on VA stability is recommended. Laser therapy based on ETDRS guidelines is recommended for other forms of clinically significant DME without centre involvement or when no vision loss has occurred, despite centre involvement. Because these recommendations are based on randomised controlled trials of 1-2 years duration, guidance may need updating as long-term ranibizumab data become available and as additional therapeutic agents are assessed in clinical trials.

Use of systemic steroid after successful macular surgery in eyes with epiretinal membrane: a randomized, controlled clinical study

PURPOSE

To evaluate the functional and morphological outcomes of postoperative systemic steroid therapy after successful macular surgery in eyes with macular edema due to idiopathic macular epiretinal membranes (ERMs).

DESIGN

Prospective, randomized, investigator-masked, controlled clinical study.

METHODS

Twenty-eight patients scheduled for 23-gauge vitrectomy combined with ERM and inner limiting membrane (ILM) peeling for macular edema due to ERM were included in this single center trial. Patients were randomized to receive oral steroid therapy (Prednisolone, 100 mg per day for 5 days) or no oral steroid (control group) after surgery. Main outcome measures included best corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study), central retinal thickness (CRT), retinal volume (RV), and macular morphology as determined by spectral domain optical coherence tomography (SD-OCT, Cirrus). Examinations were carried out preoperatively and at week 1, at months 1 and 3, postoperatively.

RESULTS

At month 3, mean BCVA improved to a eight-letter gain in each study group (P<0.01 compared with baseline for both groups), showing no statistically significant difference between both the groups (P=0.19). Morphologically, retinal surface folds resolved within 1 month after surgery in both treatment groups, followed by a progressive recovery of retinal layer integrity and a statistical significant (P<0.01) decrease in CRT and RV without significant differences between both groups (P=0.62, P=0.13, respectively, ANOVA between the groups).

CONCLUSION

The early postoperative use of systemic steroid treatment after successful vitrectomy combined with ERM and ILM peeling does not seem to improve significantly the anatomic and functional outcomes in eyes with ERM.

The influence of cortical, nuclear, subcortical posterior, and mixed cataract on the results of microperimetry

PURPOSE

Microperimetry is a useful instrument for evaluating sensitivity threshold due to retinal pathologies. The aim of the study is to assess the impact of different forms of cataract on microperimetry results.

METHODS

In a prospective design, patients were recruited for cataract surgery at the Department of Ophthalmology, Medical University of Vienna. Exclusion criteria were any other ophthalmic disease except cataract, that is, macular pathology. Using the Lens Opacities Classification System III classification, patients were classified into four groups: nuclear, cortical, subcapsular posterior, and mixed cataract. Then patients underwent microperimetry: results were analyzed for magnitude of retinal sensitivity loss and correlated to the forms and density of the cataract.

RESULTS

Mean density of cataract was LOCS 3.2-3.5 in the four groups. Differences were not statistically significant. The best-corrected visual acuity (BCVA) was LogMAR 0.5 ± 0.13 in nuclear, LogMAR 0.49 ± 0.21 in cortical, and LogMAR 0.58 ± 0.12 in mixed cataract patients, and significantly worse in patients with subcapsular posterior cataract (LogMAR 0.64 ± 0.12). Microperimetry shows a mean sensitivity of 11.4-12.6 dB without significant group differences. The BCVA is correlated with microperimetry in patients with nuclear and cortical cataract. Density of cataract is highly correlated with microperimetry results in all groups.

CONCLUSION

The present study shows a good correlation of microperimetry results with the BCVA of patients with nuclear and cortical cataract. In patients with subcapsular posterior cataract, microperimetry results were better than estimated by BCVA. Density of cataract is highly correlated with macular sensitivity. A reduction of 1 dB in microperimetry per 1 posterior capsule opacification score increase can be estimated for these patients.

Reproducibility of high-resolution optical coherence tomography measurements of the nerve fibre layer with the new Heidelberg Spectralis optical coherence tomography

AIM

Conventional time-domain OCT technology for detection of retinal nerve fibre layer (RNFL) neurodegeneration suffers from technical inaccuracy owing to a lack of exact scan centring around the optic disc as well as a true follow-up possibility. In this study, the authors evaluated a novel high-resolution spectral-domain OCT device (SD-OCT) with an incorporated eye-tracking feature in its ability to objectively measure the RNFL thickness (RNFLT) by testing intraobserver reproducibility in a series of healthy volunteers.

METHODS

Triplicate circumferential RNFL scans of six peripapillary sectors were obtained from both eyes of all 31 participants. The authors compared the measurements of RNFLT during three separate examination days under miotic (Mi) and mydriatic (My) pupil conditions using a high-speed (HS) and high-resolution (HR) scan-acquisition mode. To examine the intersession reproducibility of the SD-OCT measurements, the mean, SD and coefficient of variation (COV) were calculated.

RESULTS

No significant differences were found in all groups, independent of the mode of image acquisition and examination day (p always >0,05). Under all conditions, low COVs between 0.545% and 3.97% (intrasession COV on baseline) were found. The intersession COV with activated follow-up mode ranged between 0.29% and 1.07%. In both settings, the temporal sector showed the highest COV values.

CONCLUSIONS

True follow-up measurement of identical peripapillary regions may enable clinicians to detect discrete levels of retinal thickness change over time. This constitutes a crucial prerequisite for a reliable monitoring of subtle RNFL changes in neurodegenerative disorders.

Morphological and functional analysis of the loading regimen with intravitreal ranibizumab in neovascular age-related macular degeneration

AIM

To quantify and correlate the morphological and functional effects of the recommended loading regimen with intravitreal ranibizumab in neovascular age-related macular degeneration (AMD).

METHODS

In a prospective, interventional clinical trial, 29 consecutive patients (29 eyes) with choroidal neovascularisation secondary to AMD received three initial monthly intravitreal injections of ranibizumab. During this loading regimen, best corrected visual acuity (BCVA) and microperimetry (MP) testing, as well as optical coherence tomography and fluorescein angiography (FA), were performed using a standardised protocol and the results correlated.

RESULTS

Significant morphological and functional therapeutic effects were observed as early as 1 week following the first treatment. Throughout the loading-dose period, central retinal thickness, including intraretinal cysts and subretinal fluid, decreased fast and significantly (p<0.01); pigment epithelial detachment resolved less rapidly. The mean leakage area by FA decreased (p<0.01) and retinal function (BCVA and MP) increased significantly (both p<0.01). However, the change in morphology and function was only significant between baseline and week 1. There was no significant additional morphological or functional benefit following the second and third injection.

CONCLUSION

The initial administration of intravitreal ranibizumab in neovascular AMD induced a significant effect on intra- and subretinal fluid and visual function; subsequent injections had a less pronounced effect. It remains to be determined whether this loading regimen should be mandatory in all patients or if a single dose regimen would lead to a comparable functional and morphological retinal improvement.

Comparison of retinal thickness measurements and segmentation performance of four different spectral and time domain OCT devices in neovascular age-related macular degeneration

AIMS

To evaluate the reliability of different optical coherence tomography (OCT) devices and scanning patterns in the assessment of retinal thickness and segmentation performance in neovascular age-related macular degeneration (nAMD).

METHODS

28 eyes with nAMD and 10 healthy eyes were imaged using conventional time domain (TD) OCT as well as three spectral-domain (SD) OCT systems. Radial scans of 6 mm in size were compared between Stratus and Topcon OCT, in addition to raster scans of all three SD-OCT devices. Retinal thickness values were analysed.

RESULTS

Spectralis SD-OCT demonstrated the highest values of all OCT devices in central millimetre thickness (CMMT), and Topcon OCT raster scans showed the lowest values. Significant correlations could be found between the CMMT measurements of Cirrus and Spectralis OCT (r = 0.87). Analyses showed best segmentation for Cirrus and Spectralis SD-OCTs. Cirrus 200x200x1024 scans showed 4% and Stratus OCT 38% moderate or severe segmentation errors.

CONCLUSION

Retinal thickness values were generally higher in SD-OCT analysis. Different performances of automatic retinal thickness analysis indicate the potential of different software algorithms to quantify retinal morphology in nAMD. Further development of current algorithms may improve quantification of retinal thickness detection in the future even further.

Ranibizumab (Lucentis) in neovascular age-related macular degeneration: evidence from clinical trials

BACKGROUND

Neovascular age-related macular degeneration (AMD) has a poor prognosis if left untreated, frequently resulting in legal blindness. Ranibizumab is approved for treating neovascular AMD. However, further guidance is needed to assist ophthalmologists in clinical practice to optimise treatment outcomes.

METHODS

An international retina expert panel assessed evidence available from prospective, multicentre studies evaluating different ranibizumab treatment schedules (ANCHOR, MARINA, PIER, SAILOR, SUSTAIN and EXCITE) and a literature search to generate evidence-based and consensus recommendations for treatment indication and assessment, retreatment and monitoring.

RESULTS

Ranibizumab is indicated for choroidal neovascular lesions with active disease, the clinical parameters of which are outlined. Treatment initiation with three consecutive monthly injections, followed by continued monthly injections, has provided the best visual-acuity outcomes in pivotal clinical trials. If continued monthly injections are not feasible after initiation, a flexible strategy appears viable, with monthly monitoring of lesion activity recommended. Initiation regimens of fewer than three injections have not been assessed. Continuous careful monitoring with flexible retreatment may help avoid vision loss recurring. Standardised biomarkers need to be determined.

CONCLUSION

Evidence-based guidelines will help to optimise treatment outcomes with ranibizumab in neovascular AMD.

[Three-dimensional imaging in central serous chorioretinopathy]

BACKGROUND

Conventional optical coherence tomography (OCT) has brought new insights to retinal diagnostics, but it is restricted due to its low scanning speed and limited resolution. In this study, high-resolution raster scanning OCT (HR-OCT) was used to identify typical changes in central serous chorioretinopathy (CSC).

METHODS

Fifteen consecutive patients with acute CSC were imaged using HR-OCT with an axial image resolution of 6 mum. The scanned area measured 6x6 mm2. Three-dimensional (3D) evaluation was performed using various analysing programmes.

RESULTS

Topographic changes in CSC could be visualised with 3D reconstructions in all locations. Retinal thickness was measured with the automatic segmentation mode and quantified precisely. Results were presented in 2D and 3D maps. En-face imaging as a modality to present an integrative overview showed specific alterations in CSC.

CONCLUSION

HR-OCT was able to provide essential additional information about CSC when combined with appropriate analysing programmes, allowing the identification of typical differences. Aside from precise volumetric measurements, exact localisation of pathological deviations could be achieved.

Three-dimensional high resolution OCT imaging of macular pathology

Raster scanning spectral domain optical coherence tomography (SD-OCT) enables realistic three-dimensional (3D) imaging of macular disease. This approach allows the clinician to investigate the diagnostic situation in detail before and during pharmacological or surgical intervention. This study demonstrates the clinical potential of SD-OCT in chorioretinal disease. Selected datasets are presented to visualize typical morphologic findings, which are identified in more than 2700 patients. Scans are presented as online assessable 3D-models. Clinically relevant structures are visualized in macular disease and highlight the importance of precise imaging, which clearly is a clinical necessity to plan and indicate modern therapeutic strategies for our patients.

Intravitreal bevacizumab (Avastin) for macular oedema secondary to retinal vein occlusion: 12-month results of a prospective clinical trial

AIMS

The aim of the study was to evaluate functional and anatomical changes after intravitreal bevacizumab (Avastin) in eyes with persistent macular oedema secondary to branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO).

METHODS

Twenty-nine consecutive eyes with macular oedema secondary to BRVO (21 eyes) or CRVO (eight eyes) were included in a prospective clinical trial. Eyes were treated with three initial intravitreal bevacizumab injections of 1 mg at a monthly interval. Retreatment was based on central retinal thickness (CRT) based on optical coherence tomography. If continuous injections were indicated up to month 6, the dose was increased to 2.5 mg.

RESULTS

After 12 months of follow-up, mean visual acuity increased from 50 letters (20/100) at baseline to 66 letters (20/50(+1); +16 letters; p<0.001) at month 12 and CRT decreased from 558 mum at baseline to 309 mum at month 12 (-249 mum; p<0.001). Patients received a mean of eight out of 13 possible injections. No drug-related systemic or ocular side effects following intravitreal bevacizumab treatment were observed. Fluorescein angiography revealed no progression of avascular areas.

CONCLUSIONS

Intravitreal therapy using bevacizumab appears to be a safe and effective treatment in patients with macular oedema secondary to retinal vein occlusion. However, the main limitations of this treatment modality are its short-term effectiveness and high recurrence rate.

Characteristics of severe intraocular inflammation following intravitreal injection of bevacizumab (Avastin)

BACKGROUND/AIMS

To report a series of severe intraocular inflammatory events following intravitreal injections of bevacizumab (Avastin). This procedure is performed on a rapidly increasing number worldwide, and rare complications such as intraocular inflammation, endophthalmitis or intraocular haemorrhage are gaining in importance in clinical routine.

METHODS

This is a single-centre retrospective interventional case series of eight patients with severe intraocular inflammation after intravitreal injection of bevacizumab at one referral centre consecutively seen out of approximately a total of 2500 injections performed in that time period. Patients who developed severe intraocular inflammation after intravitreal injection were evaluated clinically, including slit-lamp examination, best-corrected Snellen visual acuity (VA), slit-lamp photography, optical coherence tomography and fluorescein angiography prior to the event and during follow-up.

RESULTS

Patients noticed a painless drop in VA up to 2 days following the injection. All patients had a marked anterior chamber reaction with increased flare and cells, but no hypopyon. Typical posterior segment findings included vitreous cellular infiltrates of pseudogranulomatous aspect. Due to their initial clinical aspect suspicious of an endophthalmitis, three cases were treated with systemic antibiotics, but the final diagnosis was uveitis. Five cases showed a characteristic pseudogranulomatous vitreous infiltration as seen in vitritis and were treated only topically.

CONCLUSIONS

Characteristic features of an inflammation induced by bevacizumab injection include an early onset with painless loss in VA mostly without conjunctival or ciliary injection. Patients respond to systemic or topical cortisone treatment with slow recovery but without permanent damage. Vitreous haemorrhage and infectious endophthalmitis might be differentiated by time course and symptoms.

[Three-dimensional optical coherence tomography for evaluating the retinal architecture before and after surgery for vitreomacular traction.]

PURPOSE: To investigate the morphology of the vitreoretinal interface before and after delamination of epiretinal membranes using three-dimensional volumetric high-resolution optical coherence tomography (HROCT). METHODS: Extension and intensity of vitreomacular traction due to epiretinal membranes (ERM) and the architecture of retinal layers in 14 eyes of 14 patients were evaluated preoperatively using high-resolution raster scanning OCT (Cirrus prototype, resulting in a 6x6-mm field, 2 mm in depth). Additionally, stratus OCT, visual acuity testing, and fundus photography were performed. Standardized prospective follow-up was done continuously at 1, 4, and 7 days and 1 and 3 months postoperatively. RESULTS: The ERM appeared tightly adherent to the retinal surface in 85% of cases, but nevertheless could be differentiated from the retinal surface in 100%. Vertical traction forces from the ERM to the intraretinal layers were found in 93% of cases. Structural alteration of the retina was seen neither immediately following surgery nor during follow-up. After a mean of 4 weeks, the retinal structural integrity had recovered with resolution of the traction-induced deviations seen preoperatively. Mean preoperative visual acuity increased from 0.4+/-0.2 Snellen preoperatively to 0.5+/-0.2 Snellen after 3 months. Mean retinal thickness decreased from 482+/-84 mum to 328+/-80 mum after 3 months (HROCT). CONCLUSIONS: Three-dimensional HROCT imaging enables unprecedented in vivo identification of the extension and dynamics of epiretinal traction. Epiretinal membranes are clearly delineated in the en face view, and the distribution of traction forces throughout the intraretinal layers is identified down to the level of the retinal pigment epithelium. During follow-up, quantification of substantial release in retinal traction was possible and correlated to conventional OCT findings.

Intravitreal bevacizumab (Avastin) therapy versus photodynamic therapy plus intravitreal triamcinolone for neovascular age-related macular degeneration: 6-month results of a prospective, randomised, controlled clinical study

AIMS

To compare functional and anatomical outcomes of intravitreal bevacizumab (Avastin) and verteporfin (photodynamic) therapy (PDT) combined with intravitreal triamcinolone (IVTA) in patients with neovascular age-related macular degeneration (AMD).

METHODS

Twenty-eight patients with neovascular AMD were enrolled in a prospective, randomised, controlled clinical trial. All patients randomly assigned to 1 mg intravitreal bevacizumab (0.04 ml) received three initial treatments at 4-week intervals. In further follow-up retreatment was based on optical coherence tomography (OCT). Patients randomly assigned to standard PDT received a same-day intravitreal injection of 4 mg triamcinolone (Kenalog). Retreatment was based on fluorescein angiography at 3-month intervals. Functional and anatomical results were evaluated using the Early Treatment Diabetic Retinopathy Study protocol vision charts, fluorescein angiography and OCT.

RESULTS

In the bevacizumab-treated group mean visual acuity (VA) improved to a 2.2 line gain at 6 months follow-up. Eyes treated in the PDT plus IVTA group had a stable mean VA at month 6 compared with baseline. There was a statistically significant difference (p = 0.03, analysis of variance (ANOVA)) between both groups as early as one day after initial treatment. The reduction in central retinal thickness (CRT) showed no significant difference between both groups (p = 0.3, ANOVA). Mean CRT was reduced from 357 microm at baseline to 239 microm at month 6 in bevacizumab-treated patients and from 326 microm to 222 microm, respectively, in PDT plus IVTA-treated patients. No significant local or systemic safety concerns were detected up to month 6.

CONCLUSION

Intravitreal bevacizumab showed promising 6-month results in patients with neovascular AMD. Functional outcomes appear not only to be dependent on a reduction in CRT but also on the treatment modality used.

Value of polarisation-sensitive optical coherence tomography in diseases affecting the retinal pigment epithelium

OBJECTIVES

To evaluate pathological changes of retinal pigment epithelium (RPE) by polarisation-sensitive optical coherence tomography (PS-OCT).

METHODS

Forty-four eyes (22 patients) with significant pathologies of the RPE were evaluated using PS-OCT. A transversal scanning time domain OCT system was used for two-dimensional cross-sectional imaging of retinal polarisation properties.

RESULTS

The RPE scrambles the polarisation state of backscattered light (ie, acts as a depolarising layer), while the polarisation state of transmitted light is maintained. In patients with RPE pathologies irregularity, elevation, thickening or absence of the RPE is readily visualised by exploiting the depolarisation information. Polarisation scrambling in the sensory retina can be found in cases with advanced dry age-related macular degeneration. Sclera and fibrosis show characteristic birefringence in PS-OCT.

CONCLUSION

PS-OCT allows tissue identification based on polarisation scrambling and birefringence, providing additional information on RPE pathologies. It is a promising new tool for diagnosis, disease follow-up and evaluation of new treatment strategies.

Intravitreal Avastin for macular oedema secondary to retinal vein occlusion: a prospective study

OBJECTIVE

To evaluate efficacy and safety of intravitreal bevacizumab (Avastin) in eyes with macular oedema secondary to central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO).

METHODS

Twenty-eight consecutive patients (28 patients, 29 eyes, 8 CRVO, 21 BRVO) were enrolled in the study. Three intravitreal injections of 1 mg bevacizumab (0.04 ml) were administered at 4-week intervals; further retreatment was based on optical coherence tomography (OCT) findings. Follow-up examinations were done at days 1, 7 and 28 and at monthly intervals thereafter.

RESULTS

Mean baseline central retinal thickness (CRT) in OCT was 558 microm (range 353-928 microm) and mean BCVA was 20/100. One day after the first injection, CRT significantly decreased to 401 microm (p<0.01). Three injections reduced macular oedema to 328 microm CRT (p<0.01) and improved BCVA to 20/50 (p<0.01). At 6 months, CRT was 382 microm (p<0.01), and BCVA was stable at 20/50(-2) (p<0.01), FA showed no evidence of increased avascular zones.

CONCLUSION

Intravitreal injections of bevacizumab appear to be a safe and effective therapy in the treatment of macular oedema secondary to retinal vein occlusion.

Automatic segmentation in three-dimensional analysis of fibrovascular pigmentepithelial detachment using high-definition optical coherence tomography

BACKGROUND/AIMS

A limited number of scans compromise conventional optical coherence tomography (OCT) to track chorioretinal disease in its full extension. Failures in edge-detection algorithms falsify the results of retinal mapping even further. High-definition-OCT (HD-OCT) is based on raster scanning and was used to visualise the localisation and volume of intra- and sub-pigment-epithelial (RPE) changes in fibrovascular pigment epithelial detachments (fPED). Two different scanning patterns were evaluated.

METHODS

22 eyes with fPED were imaged using a frequency-domain, high-speed prototype of the Cirrus HD-OCT. The axial resolution was 6 mum, and the scanning speed was 25 kA scans/s. Two different scanning patterns covering an area of 6 x 6 mm in the macular retina were compared. Three-dimensional topographic reconstructions and volume calculations were performed using MATLAB-based automatic segmentation software.

RESULTS

Detailed information about layer-specific distribution of fluid accumulation and volumetric measurements can be obtained for retinal- and sub-RPE volumes. Both raster scans show a high correlation (p<0.01; R2>0.89) of measured values, that is PED volume/area, retinal volume and mean retinal thickness. Quality control of the automatic segmentation revealed reasonable results in over 90% of the examinations.

CONCLUSION

Automatic segmentation allows for detailed quantitative and topographic analysis of the RPE and the overlying retina. In fPED, the 128 x 512 scanning-pattern shows mild advantages when compared with the 256 x 256 scan. Together with the ability for automatic segmentation, HD-OCT clearly improves the clinical monitoring of chorioretinal disease by adding relevant new parameters. HD-OCT is likely capable of enhancing the understanding of pathophysiology and benefits of treatment for current anti-CNV strategies in future.

Neue Perspektiven in der Diagnostik

BACKGROUND

Recent advances in optical coherence tomography (OCT) have made it possible to increase resolution and scan velocities so that even greater central areas of the retina can be scanned. The aim of this study is to describe the possibilities offered by this new technology for age-related macular degeneration.

MATERIAL AND METHODS

The study included 20 patients with confirmed active choroidal neovascularization (CNV) as well as pigment epithelial detachment (PED). Three-dimensional imaging was performed with a high-definition raster scanning OCT system (HD-OCT) with an axial resolution of 6 microm and a scan velocity of up to 20,000 A-scans/s. The scanned area measured 6 x 6 mm with a depth of 2 mm. Two-dimensional imaging was carried out with a StratusOCT (Carl Zeiss Meditec).

RESULTS

Comparison of the individual slices showed improved identification of intra- and subretinal structures with the HD-OCT. Demarcation of pathological changes in individual retinal layers is possible with the HD-OCT. Summation images permit accurate localization of a scan. Topographic and volumetric evaluations enable analysis of individual compartments in the entire scanned area and are suitable for monitoring treatment of CNV with anti-VEGF therapy. The raster method decreases the dependence on exploratory methods that have been necessary until now to generate retinal thickness maps.

CONCLUSIONS

This report presents initial experience in using a raster scanning HD-OCT system in patients with neovascular age-related macular degeneration and describes new evaluation functions that aid in obtaining more precise assessment of treatment effect and its impact on the retinal ultrastructure. The results of this study clearly show that development of high-resolution OCT systems in conjunction with development of novel treatment options for exudative diseases offers promising perspectives.

Intravitreales Bevacizumab vs. Verteporfin und intravitreales Triamcinolon Acetonid bei Patienten mit neovaskulärer AMD

AIM

The aim of this study was to compare intravitreal bevacizumab (IVB) and verteporfin therapy in combination with 4 mg intravitreal triamcinolone (PDT-IVTA) in patients with neovascular age-related macular degeneration (AMD).

PATIENTS AND METHODS

A total of 30 eyes of 30 patients with neovascular AMD were included in a prospective, randomized study. Ten eyes received PDT-IVTA with a standard light fluence of 50 J/cm(2) (SPDT-IVTA), ten were treated with PDT-IVTA with a reduced light fluence of 25 J/cm(2) (RPDT-IVTA) and ten received IVB. The main outcome was evaluated using early treatment diabetic retinopathy study (ETDRS) visual acuity, fluorescein angiography and optical coherence tomography (OCT) at baseline as well as at day 1, week 1, 1 month and 3 months after therapy.

RESULTS

At the beginning of therapy, the distribution of the groups was balanced. After 3 months, the SPDT-IVTA group showed a non-significant vision loss of seven letters (p<0.3) while a vision loss of 0.5 letters (p<0.9) was found in the RPDT-IVTA group. At the same time, the IVB group had a vision improvement of 11.8 letters (p<0.001). This vision improvement was statistically significant compared to the results of both PDT-IVTA groups (p<0.005). Central retinal thickness (CRT) decreased up to month 3 in the SPDT-IVTA group by 132 microm, in the RPDT-IVTA group by 78 mum and in the IVB group by 138 microm, (p<0.05 in the three groups). No significant difference in the decrease of CRT was found between the treatment groups after 3 months.

CONCLUSION

IVB shows significantly better results in vision improvement in the short-term compared to the two PDT-IVTA groups. Within 3 months, all groups showed a comparable decrease in CRT. Long-term follow-up is required to evaluate the safety and treatment efficacy of all treatment modalities.

Central visual field impairment during and following cystoid macular oedema

AIM

To determine differential light threshold values obtained with the Micro Perimeter 1 (MP1) in uveitis patients suffering from cystoid macular oedema (CMO) and to compare these measures to retinal thickness.

METHODS

Static threshold perimetry was performed with the MP1 Microperimeter in 27 eyes of 21 patients with a history of chronically recurring CMO. Active CMO was confirmed in 19 eyes. Eight eyes with a history of recurrent CMO were found to have normal foveal contours in optical coherence tomography (OCT). Differential light threshold values (MP1) were compared with the corresponding retinal thickness measures (OCT).

RESULTS

Mean differential threshold values within the central two degrees of the stimulation pattern were reduced compared with normal values and ranged from 5.8 to 9.5 dB in CMO eyes and from 9.3 to 12.9 dB in eyes with a normal foveal contour but a history of previous CMO. The corresponding mean retinal thickness ranged from 390 (SD 90) to 389 (88) microm (at 0 degrees and 1 degree, respectively) for active CMO and from 199 (36) to 211 (33) microm in eyes with normal fovea following CMO resolution. Statistical correlations between mean differential sensitivity threshold and retinal thickness were only weak and showed no association.

CONCLUSIONS

Active CMO causes a marked reduction in central retinal sensitivity. In addition, following the resolution of the CMO, a substantial impairment of central retinal sensitivity remains. Morphology in terms of retinal thickness in OCT does not correlate with visual function in terms of retinal sensitivity in these patients.

Frühe Effekte nach systemischer und intravitrealer Bevacizumab (Avastin®)-Therapie bei neovaskulärer altersbedingter Makuladegeneration

PURPOSE

The purpose of this study was to evaluate the early treatment response following systemic and intravitreal bevacizumab therapy in patients with neovascular age-related macular degeneration (AMD).

PATIENTS AND METHODS

In a prospective cohort study 12 eyes with neovascular AMD were treated with 5 mg/kg systemic bevacizumab, and 13 eyes with 1 mg intravitreal bevacizumab. Systemic therapy was given three times at 2-week intervals, intravitreal therapy up to three times at 4-week intervals. Patients were evaluated according to best corrected visual acuity (VA) and optical coherence tomography (OCT) at baseline as well as at week 1, week 4 and week 12 after therapy. Fluorescein angiography (FA) was performed at baseline and week 12.

RESULTS

Systemic and intravitreal bevacizumab therapy showed a treatment response within one week. Visual acuity improved at week 1 by 4.9 letters from baseline in the systemic and by 6.9 letters in the intravitreal treatment group. Central retinal thickness (CRT), as measured by OCT decreased by 51.9 microm and 176.4 microm, respectively. At month 3 a persistent treatment effect was detectable. Mean gain in visual acuity was 11 letters in the systemic and 8.3 letters in the intravitreal group, CRT had decreased by 100 microm and 153.8 microm, respectively. Leakage as evaluated by FA was significantly reduced or absent in all patients.

CONCLUSION

The early treatment responses following systemic and intravitreal bevacizumab appear to be similar. Both groups show improvement in VA and decrease in CRT within 1 week and up to 3 months. Long-term follow-up is required to evaluate the safety and treatment durability of both treatment modalities using bevacizumab.

Increased expression of vascular endothelial growth factor associated with accumulation of lipids in Bruch's membrane of LDL receptor knockout mice

AIM

To investigate the pathogenesis of age related macular degeneration (ARM) with respect to lipid accumulation within Bruch's membrane (BrM) in a knockout model with low density lipoprotein (LDL) receptor deficiency.

METHODS

LDL receptor deficient mice and C57BL/6 controls were fed a standard diet or a high fat (HF) diet. Plasma total cholesterol (pTC) was determined. Eyes were examined by transmission electron microscopy. Immunohistochemical staining for VEGF was performed.

RESULTS

pTC were highest in LDL receptor deficient mice after HF diet and elevated after standard diet compared to controls with and without HF diet. While BrM of controls did not exhibit any visible changes, membrane bound translucent particles were seen in all BrM of knockout mice. The amount of these particles was substantially increased and membranes were thickened after HF diet. VEGF staining was positive in knockout mice only and was located in retinal pigment epithelial cells, the outer plexiform layer, and photoreceptor inner segments. Most intensive VEGF expression was documented after HF diet.

CONCLUSION

LDL receptor deficient mice exhibit an accumulation of lipid particles in BrM which is further increased after fat intake. VEGF expression is found in the outer retinal layers of LDL receptor deficient mice and appears to correlate with the amount of lipid particles present in BrM.

Topographic angiography and optical coherence tomography: a correlation of imaging characteristics

PURPOSE

Topographic angiography (TAG) using confocal scanning laser angiography and optical coherence tomography (OCT) are new imaging modalities that have been introduced during recent years. OCT and TAG imaging were compared to specify the characteristics of each imaging modality.

METHODS

TAG using fluorescein angiography (FA) provides a three-dimensional profile of the vascular structures based on the analysis of a set of 32 confocal images over a depth of 4 mm. OCT provides cross-sectional images of the neurosensory retina and the retinal pigment epithelium-choriocapillary complex (RPE-CC). The authors compared and evaluated both modalities in 10 patients with predominantly classic choroidal neovascularization (CNV), 10 patients with serous pigment epithelial detachment (PED), and 10 patients with geographic RPE atrophy, all secondary to age-related macular degeneration (ARMD).

RESULTS

In patients with classic CNV, TAG detected neovascular structures and delineated their configuration. In PEDs pooling of extravascular fluid is demonstrated, and in geographic RPE atrophy TAG showed reduced choroidal perfusion. Classic CNV was demonstrated by OCT as a hyperreflective band at the level of the RPE-CC, and PED showed a dome-shaped RPE detachment. In geographic RPE atrophy, OCT imaged loss of the RPE band and had an increased depth resolution.

CONCLUSIONS

TAG and OCT are useful imaging modalities in the evaluation of ARMD cases. TAG visualizes the vascular configuration and dynamic perfusion and leakage changes. OCT is able to document intra-, subretinal, and sub-RPE fluid accumulation secondary to CNV. Both modalities may provide further valuable insight into ARMD pathogenesis, enhance diagnostic quality, and improve the assessment of therapeutic effects.

Anecortave acetate for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration

PURPOSE

Anecortave acetate is a novel angiostatic cortisene being evaluated clinically for treatment of exudative age-related macular degeneration (ARMD). A randomized, placebo-controlled, efficacy and safety dose duration study of anecortave acetate for depot suspension (3 mg, 15 mg, 30 mg) in this patient population was completed in June 2003. As part of this trial, 128 patients with subfoveal choroidal neovascularization (CNV) secondary to ARMD were enrolled and treated for up to 2 years by 18 clinical sites in the United States and European Union.

METHODS

Study patients were evaluated clinically with detailed ophthalmic examinations, general physical examinations, assessments of best-corrected logMAR visual acuity, and angiographic evaluations. The Digital Angiography Reading Center (New York City, NY) assessed lesion eligibility while the clinical investigators assessed overall patient eligibility prior to treatment. As part of this study, study medication was delivered as a posterior juxtascleral depot using a specially designed curved cannula at 6-month intervals if in the masked investigator's opinion the patient's lesion could benefit from additional treatment.

RESULTS

The 2-year efficacy results of this placebo-controlled study demonstrated that RETAANE 15 mg (anecortave acetate for depot suspension) was statistically superior to placebo for stabilization of vision (<3 logMAR line change from baseline) and for inhibition of neovascular lesion growth. There were no serious treatment-related safety issues associated with either the study medication or the procedure for administration.

CONCLUSIONS

Anecortave acetate 15 mg for depot suspension is clinically efficacious compared to placebo for treatment of subfoveal exudative ARMD lesions when administered at 6-month intervals as a posterior juxtascleral depot.