Correlation of optical coherence tomography and fundus fluorescein angiography following photodynamic therapy for choroidal neovascular membranes

Accuracy of a Machine-Learning Algorithm for Detecting and Classifying Choroidal Neovascularization on Spectral-Domain Optical Coherence Tomography

Background: To evaluate the performance of a machine-learning (ML) algorithm to detect and classify choroidal neovascularization (CNV), secondary to age-related macular degeneration (AMD) on spectral-domain optical coherence tomography (SD-OCT) images. Methods: Baseline fluorescein angiography (FA) and SD-OCT images from 1037 treatment-naive study eyes and 531 fellow eyes, without advanced AMD from the phase 3 HARBOR trial (NCT00891735), were used to develop, train, and cross-validate an ML pipeline combining deep-learning–based segmentation of SD-OCT B-scans and CNV classification, based on features derived from the segmentations, in a five-fold setting. FA classification of the CNV phenotypes from HARBOR was used for generating the ground truth for model development. SD-OCT scans from the phase 2 AVENUE trial (NCT02484690) were used to externally validate the ML model. Results: The ML algorithm discriminated CNV absence from CNV presence, with a very high accuracy (area under the receiver operating characteristic [AUROC] = 0.99), and classified occult versus predominantly classic CNV types, per FA assessment, with a high accuracy (AUROC = 0.91) on HARBOR SD-OCT images. Minimally classic CNV was discriminated with significantly lower performance. Occult and predominantly classic CNV types could be discriminated with AUROC = 0.88 on baseline SD-OCT images of 165 study eyes, with CNV from AVENUE. Conclusions: Our ML model was able to detect CNV presence and CNV subtypes on SD-OCT images with high accuracy in patients with neovascular AMD.

Relation Between Retinal Vasculature and Retinal Thickness in Macular Edema

This study has investigated the relationship of the retinal vasculature and the retinal thickness for Macular Edema (ME) subjects. Ninety sets of Fluorescein Angiograph (FA) and Optical Coherence Tomography (OCT) of 54 participants were analyzed. Multivariate analysis using the binary logistic regression model was used to study the association between vessel parameters and retinal thickness. The results reveal retinal vessel feature i.e. fractal dimension (FD) as the most sensitive parameter to the changes in retinal thickness associated with ME. Thus, indicating a direct relationship between the retinal vasculature and retinal thickness which is caused due to neovascular causing exudates, leakages and hemorrhages, with applications for alternate modality for detection of ME.

Morphologic Criteria of Lesion Activity in Neovascular Age-Related Macular Degeneration: A Consensus Article

Intravitreal antivascular endothelial growth factor drugs represent the current standard of care for neovascular age-related macular degeneration (nAMD). Individualized treatment regimens aim at obtaining the same visual benefits of monthly injections with a reduced number of injections and follow-up visits, and, consequently, of treatment burden. The target of these strategies is to timely recognize lesion recurrence, even before visual deterioration. Early detection of lesion activity is critical to ensure that clinical outcomes are not compromised by inappropriate delays in treatment, but questions remain on how to effectively monitor the choroidal neovascularization (CNV) activity. To assess the persistence/recurrence of lesion activity in patients undergoing treatment for nAMD, an expert panel developed a decision algorithm based on the morphological features of CNV. After evaluating all current retinal imaging techniques, the panel identified optical coherent tomography as the most reliable tool to ascertain lesion activity when funduscopy is not obvious.

Early detection of age related macular degeneration: current status

Early diagnosis and treatment of choroidal neovascularization (CNV), a main cause of severe vision loss in age related macular degeneration (AMD), is crucial in order to preserve vision and the quality of life of patients. This review summarizes current literature on the subject of early detection of CNV, both in the clinic setting and mainly in the patient’s home. New technologies are evolving to allow for earlier detection and thus vision preservation in AMD patients.

Optical coherence tomography for the diagnosis, monitoring and guiding of treatment for neovascular age-related macular degeneration: a systematic review and economic evaluation

BACKGROUND

Age-related macular degeneration is the most common cause of sight impairment in the UK. In neovascular age-related macular degeneration (nAMD), vision worsens rapidly (over weeks) due to abnormal blood vessels developing that leak fluid and blood at the macula.

OBJECTIVES

To determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected nAMD and monitoring those previously diagnosed with the disease.

DATA SOURCES

Databases searched: MEDLINE (1946 to March 2013), MEDLINE In-Process & Other Non-Indexed Citations (March 2013), EMBASE (1988 to March 2013), Biosciences Information Service (1995 to March 2013), Science Citation Index (1995 to March 2013), The Cochrane Library (Issue 2 2013), Database of Abstracts of Reviews of Effects (inception to March 2013), Medion (inception to March 2013), Health Technology Assessment database (inception to March 2013).

REVIEW METHODS

Types of studies: direct/indirect studies reporting diagnostic outcomes.

INDEX TEST

time domain optical coherence tomography (TD-OCT) or spectral domain optical coherence tomography (SD-OCT).

COMPARATORS

clinical evaluation, visual acuity, Amsler grid, colour fundus photographs, infrared reflectance, red-free images/blue reflectance, fundus autofluorescence imaging, indocyanine green angiography, preferential hyperacuity perimetry, microperimetry. Reference standard: fundus fluorescein angiography (FFA). Risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. A Markov model was developed (65-year-old cohort, nAMD prevalence 70%), with nine strategies for diagnosis and/or monitoring, and cost-utility analysis conducted. NHS and Personal Social Services perspective was adopted. Costs (2011/12 prices) and quality-adjusted life-years (QALYs) were discounted (3.5%). Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In pooled estimates of diagnostic studies (all TD-OCT), sensitivity and specificity [95% confidence interval (CI)] was 88% (46% to 98%) and 78% (64% to 88%) respectively. For monitoring, the pooled sensitivity and specificity (95% CI) was 85% (72% to 93%) and 48% (30% to 67%) respectively. The FFA for diagnosis and nurse-technician-led monitoring strategy had the lowest cost (£ 39,769; QALYs 10.473) and dominated all others except FFA for diagnosis and ophthalmologist-led monitoring (£ 44,649; QALYs 10.575; incremental cost-effectiveness ratio £ 47,768). The least costly strategy had a 46.4% probability of being cost-effective at £ 30,000 willingness-to-pay threshold.

LIMITATIONS

Very few studies provided sufficient information for inclusion in meta-analyses. Only a few studies reported other tests; for some tests no studies were identified. The modelling was hampered by a lack of data on the diagnostic accuracy of strategies involving several tests.

CONCLUSIONS

Based on a small body of evidence of variable quality, OCT had high sensitivity and moderate specificity for diagnosis, and relatively high sensitivity but low specificity for monitoring. Strategies involving OCT alone for diagnosis and/or monitoring were unlikely to be cost-effective. Further research is required on (i) the performance of SD-OCT compared with FFA, especially for monitoring but also for diagnosis; (ii) the performance of strategies involving combinations/sequences of tests, for diagnosis and monitoring; (iii) the likelihood of active and inactive nAMD becoming inactive or active respectively; and (iv) assessment of treatment-associated utility weights (e.g. decrements), through a preference-based study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012001930.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Optical coherence tomography for the monitoring of neovascular age-related macular degeneration: a systematic review

TOPIC

To compare the accuracy of optical coherence tomography (OCT) with alternative tests for monitoring neovascular age-related macular degeneration (nAMD) and detecting disease activity among eyes previously treated for this condition.

CLINICAL RELEVANCE

Traditionally, fundus fluorescein angiography (FFA) has been considered the reference standard to detect nAMD activity, but FFA is costly and invasive. Replacement of FFA by OCT can be justified if there is a substantial agreement between tests.

METHODS

Systematic review and meta-analysis. The index test was OCT. The comparator tests were visual acuity, clinical evaluation (slit lamp), Amsler chart, color fundus photographs, infrared reflectance, red-free images and blue reflectance, fundus autofluorescence imaging, indocyanine green angiography (ICGA), preferential hyperacuity perimetry, and microperimetry. We searched the following databases: MEDLINE, MEDLINE In-Process, EMBASE, Biosis, Science Citation Index, the Cochrane Library, Database of Abstracts of Reviews of Effects, MEDION, and the Health Technology Assessment database. The last literature search was conducted in March 2013. We used the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) to assess risk of bias.

RESULTS

We included 8 studies involving more than 400 participants. Seven reported the performance of OCT (3 time-domain [TD] OCT, 3 spectral-domain [SD] OCT, 1 both types) and 1 reported the performance of ICGA in the detection of nAMD activity. We did not find studies directly comparing tests in the same population. The pooled sensitivity and specificity of TD OCT and SD OCT for detecting active nAMD was 85% (95% confidence interval [CI], 72%-93%) and 48% (95% CI, 30%-67%), respectively. One study reported ICGA with sensitivity of 75.9% and specificity of 88.0% for the detection of active nAMD. Half of the studies were considered to have a high risk of bias.

CONCLUSIONS

There is substantial disagreement between OCT and FFA findings in detecting active disease in patients with nAMD who are being monitored. Both methods may be needed to monitor patients comprehensively with nAMD.

Correlation between components of newly diagnosed exudative age-related macular degeneration lesion and focal retinal sensitivity

PURPOSE

To analyse lesion components determining retinal sensitivity in microperimetry in eyes with newly diagnosed exudative age-related macular degeneration (AMD).

METHODS

Visual acuity, contrast sensitivity, microperimetry, optical coherence tomography (OCT), and fluorescein (FA) and indocyanine green (ICGA) angiographies of 23 eyes of 23 patients were analysed. Central microperimetry grids with 28 test stimulus sites were automatically aligned with three-dimensional OCTs and manually aligned with angiographies. Thicknesses of the neuroretina, neuroepithelial detachment (NED), retinal pigment epithelial (RPE) elevation and subretinal tissue were measured under the 644 microperimetry stimulus sites. Areas of classic and occult choroidal neovascularizations (CNVs), subretinal and intraretinal haemorrhage, and late hyperfluorescence in ICGA were identified. The impact of the lesion components on retinal sensitivity was evaluated with correlation analysis and multivariate modelling.

RESULTS

Decreased retinal sensitivity correlated significantly with the presence of CNV, haemorrhage, subretinal tissue and RPE elevation. Out of the OCT parameters, the most important determinant of sensitivity was the thickness of RPE elevation (Spearman's rho, r = -0.202, p < 0.0001). The thicknesses of subretinal tissue (r = -0.168, p < 0.0001) and NED had weaker effects (r = -0.147, p < 0.0001), and the neuroretinal thickness remained nonsignificant. In multivariate modelling, RPE elevation and subretinal tissue in OCT, CNV membranes in angiographies and haemorrhage had the strongest impacts on retinal sensitivity.

CONCLUSION

The most important lesion components affecting retinal function were RPE elevation and subretinal tissue in OCT as well as neovascular membranes and haemorrhage in angiographies. NED and neuroretinal thickening remained less significant.

Early visual impacts of optical coherence tomographic parameters in patients with age-related macular degeneration following the first versus repeated ranibizumab injection

BACKGROUND

The aim of this study is to evaluate the early visual impacts of various optical coherence tomographic (OCT) parameters after the first versus repeated intravitreal ranibizumab injection in patients with exudative age-related macular degeneration (AMD).

METHODS

A retrospective comparative case series study was conducted on 20 eyes of 18 consecutive patients who received intravitreal ranibizumab injection for exudative AMD either for the first time (group 1; n = 8) with no prior anti-vascular endothelial growth factor (anti-VEGF) injection in the same or fellow eye, or for repeated times during the course of monthly injected ranibizumab (group 2; n = 12 eyes). The following baseline and 1 month post-injection data was collected for both groups and compared: best-corrected visual acuity (BCVA), qualitative and quantitative OCT parameters including: foveal thickness, foveal volume (central 1-mm circle), retinal volume at 3- and 5-mm central circles, retinal pigment epithelium (RPE) elevation, type of fluid collections, and type of AMD lesion. The size of the fluid and fibrovascular lesion (FVL) areas were measured using manual delineation and automatic calculation of the device. We made correlations between the post-injection visual acuity (VA) and each of post-injection OCT parameters in both groups and these were the main outcome measures.

RESULTS

In group 1, there was a strong correlation between post-injection logarithm of minimum angle of resolution (logMAR) BCVA and each of the following: FVL size, foveal thickness, retinal volume at 3- and 5-mm central circles, RPE elevation, the size of the fluid area, and age of the patient (r > 0.70, p < 0.05), whereas in group 2; logMAR BCVA was strongly correlated only with foveal volume (r = 0.74, p = 0.01). Multivariate analysis showed that post-injection FVL size (r (2) = 0.69) and foveal volume (r (2) = 0.55) were the most important factors for VA 1 month following the initial and repeated ranibizumab injection, respectively.

CONCLUSIONS

The size of FVL and foveal volume showed a significant correlation with VA in AMD patients shortly after the first and repeated ranibizumab injection, respectively. Further studies with larger sample sizes are needed in order to support these results.

Association of fluorescein angiographic features with visual acuity and with optical coherence tomographic and stereoscopic color fundus photographic features of diabetic macular edema in a randomized clinical trial

BACKGROUND

Fluorescein angiography (FA) has been performed as part of the management of diabetic macular edema for many years. Its current role relative to the role of optical coherence tomography (OCT) is not well defined.

PURPOSE

To evaluate the associations of FA features with visual acuity (VA) and with OCT and fundus photographic characteristics in eyes with diabetic macular edema.

METHODS

In a clinical trial, conducted by the Diabetic Retinopathy Clinical Research Network to compare two methods of laser photocoagulation to treat diabetic macular edema, FA (film and digital), color photographs, OCT, and VA measurements were obtained at baseline and at 1 year. Grading of morphologic features was performed at a reading center. Reproducibility of FAs was assessed, and the correlations of FA features with VA, OCT, and color photograph features were computed.

RESULTS

From 79 clinical sites, data of 323 study eyes and 203 fellow nonstudy eyes were analyzed. Fluorescein leakage area at baseline was associated with reduced VA, increased OCT measures of retinal thickness and volume, and color photographic measurements of retinal thickening (r = 0.33-0.58). No important associations were found with changes from baseline to 12 months in these parameters or with any of the other variables analyzed.

CONCLUSION

Fluorescein leakage is associated with VA and some OCT and color photographic variables. We did not identify any unique FA variables that had a stronger association with VA than OCT measures of retinal thickness. These data may be useful to investigators planning future diabetic macular edema clinical trials.

Confocal scanning laser tomography analysis of choroidal neovascularization and correlation with quantitative fluorescein angiography

PURPOSE

To investigate the agreement between confocal scanning laser tomography and quantitative fluorescein angiography in the analysis of retinal-thickness changes in patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

MATERIALS AND METHODS

The edema index of a cSLT was measured in 18 eyes of 16 patients with CNV secondary to AMD that underwent photodynamic therapy (PDT) with Visudyne. Measurements were taken 1 hour before as well as 1 hour, 1 month, and 3 months after therapy. Moreover, a custom-written algorithm was used to analyze the integrated contrast amplitude (ICA) of fluorescein angiograms acquired before as well as 1 month and 3 months after PDT. Confocal scanning laser analysis of the edema index (EI) before and after PDT and correlation of the results with quantitative fluorescein angiography was performed.

RESULTS

A statistical significant increase of the EI was observed 1 hour after PDT. Nonetheless, no other statistical significant change over time was observed either on the EI or the ICA. Significant correlation was observed between the EI and the ICA as well as their changes over time, yet better results were observed when non-parametric correlation was calculated.

CONCLUSIONS

The axial intensity profile of the cSLT and the edema index provide important information with respect to the neovascular membranes and correlate well with quantitative fluorescein angiography. The application of cSLT and the EI provide an important tool that could complement the investigation of new treatments of neovascular membranes.

Intravitreal bevacizumab (Avastin) for neovascular age-related macular degeneration using a variable frequency regimen in eyes with no previous treatment

PURPOSE

To evaluate a variable frequency regimen with intravitreal bevacizumab for treatment of neovascular age-related macular degeneration (AMD) in eyes that have not received any previous treatment.

METHODS

Retrospective review of patients with neovascular AMD who were treated with three consecutive monthly intravitreal injections of bevacizumab (1.25 mg) and retreated based on the PrONTO study criteria. Outcome measures included visual acuity (VA) and central retinal thickness. Subgroup analysis was conducted to identify pretreatment characteristics that could determine visual outcome with treatment.

RESULTS

A total of 109 eyes of 109 patients were treated. The mean age was 82 years, and the mean follow-up period was 9.4 months (range 6-12 months). At baseline, the mean VA was 45.6 letters (6/37.5) and mean central retinal thickness 343 microm. This improved to 51 letters (6/30) (P < 0.001)) and 231 microm (P < 0.001) at 6 months. At 6 months, VA was improved by at least five letters in 50%, remained stable in 30% and worsened by at least five letters in 20% of patients. Patients with large intraretinal cysts on optical coherence tomography before treatment had an increased risk of worse vision (odds ratio 10.5, 95% confidence interval 1.69-64.99; P = 0.018).

CONCLUSIONS

The majority of patients had improvement or stability of VA regardless of the angiographic type of choroidal neovascularization. Intravitreal bevacizumab with this tailored regimen is beneficial in the treatment of neovascular AMD in the short term. The presence of large intraretinal cysts on optical coherence tomography is a poor prognostic factor for visual improvement with this treatment.

Photodynamic therapy with verteporfin in age-related macular degeneration: a systematic review of efficacy, safety, treatment modifications and pharmacoeconomic properties

Photodynamic therapy (PDT) with verteporfin has been used less comprehensively in the treatment of exudative age-related macular degeneration (AMD), and specifically of choroidal neovascularization (CNV), since the advent of antiangiogenic therapies. Recently, there has been a renewed interest in PDT as an adjunct to these and other agents in the treatment of neovascular AMD. In light of this new development and the European Medicines Evaluation Agency's (EMEA) recent labelling decision to rescind approval for the use of PDT in occult CNV lesions, the present systematic review was undertaken to revisit the evidence supporting its clinical application. Photodynamic therapy provided the first pharmacological treatment for patients suffering from subfoveal CNV, the major cause of severe vision loss in AMD. Key clinical trials evaluating efficacy and safety have examined patients with all lesion subtypes, with the primary labelled indication (i.e. lesions containing a classic component of > or = 50% ) deriving from the results of the Treatment of Age-related Macular Degeneration with Photodynamic Therapy (TAP) Study. The subsequent TAP Study Group post hoc categorization of lesions as predominantly classic is open to question, however, as it appears that the overall efficacy in this group only may have reflected the especially strong response in 100% classic lesions. Based on a subgroup analysis of the Verteporfin in Photodynamic Therapy Study, the indication for PDT subsequently was expanded in some jurisdictions, including that of the EMEA, to include occult lesions with no classic component. However, the subsequent Visudyne in Occult Study found no benefit in 100% occult lesions, resulting in the EMEA rescinding its approval for this indication.

Comparison of spectral-domain versus time-domain optical coherence tomography in management of age-related macular degeneration with ranibizumab

PURPOSE

To compare the ability to delineate and detect patterns of choroidal neovascularization (CNV) activity in patients with exudative age-related macular degeneration (AMD) after ranibizumab treatment between time-domain optical coherence tomography (TD-OCT) and 4 different spectral-domain optical coherence tomography (SD-OCT) devices.

DESIGN

Prospective, consecutive case series.

PARTICIPANTS

Sixty-one eyes of 58 patients with exudative AMD after ranibizumab treatment were included in this study.

METHODS

All patients were imaged with TD-OCT and at least 1 of 4 different SD-OCT devices at the same visit after ranibizumab treatment. The OCT images were analyzed in a masked fashion by 2 independent graders (KS, TY) to delineate and detect the presence of CNV activity defined as the presence of subretinal fluid, intraretinal cysts, intraretinal fluid, sub-retinal pigment epithelium (sub-RPE) fluid, or a combination thereof. The automated evaluation of retinal thickness also was analyzed between devices.

MAIN OUTCOME MEASURES

Evidence of CNV activity on linear B-scans and 3-dimensional so-called cube scans on SD-OCT and linear B-scan on TD-OCT.

RESULTS

In linear B-scan mode, all 4 SD-OCT devices were superior in their ability to delineate sub-RPE fluid compared with TD-OCT (P<0.05). Three of 4 SD-OCT devices were superior in delineating intraretinal fluid, and 2 of 4 SD-OCT devices were superior in delineating subretinal fluid and intraretinal cysts (P<0.05). In the 3-dimensional so-called cube mode, all 4 SD-OCT devices were superior in detecting subretinal fluid and 2 of 4 SD-OCT devices were superior in detecting sub-RPE and intraretinal fluid (P<0.05). There were significant correlations in center point thickness between all SD-OCT devices and TD-OCT (P<0.01), and 3 of 4 and 1 of 3 SD-OCT devices showed significant differences from TD-OCT in center point thickness (P<0.01) and center subfield thickness (P<0.001), respectively.

CONCLUSIONS

SD-OCT is superior to TD-OCT in evaluating for CNV activity in patients with wet AMD after ranibizumab injection. Retinal thickness measurements between SD-OCT and TD-OCT also were significantly different.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

OCT-guided photodynamic therapy for angiographic occult CNV in pathologic myopia

PURPOSE

Pathologic myopia (PM) is frequently complicated by choroidal neovascularization (CNV). Diagnosis is mainly clinical and angiographic but in recent years optical coherence tomography (OCT) has been noted to add important information. The authors report on the successfully OCT-guided photodynamic therapy (PDT) of an angiographic occult CNV complicating PM.

METHODS

Observational case report. Fluorescein angiography with a confocal SLO (HRA, Heidelberg Engineering, Germany) and OCT Stratus (Carl Zeiss Meditec, Inc.) imaging were used for diagnosis and monitoring of the CNV. Standard PDT was performed.

RESULTS

A highly myopic 17-year-old girl complained of a drop in visual acuity (VA) in left eye (LE), dating back a few weeks. Her best-corrected (BC) VA was 20/40 in the LE, with some metamorphopsia. No hemorrhage or evident signs of CNV were visible either at fundus or at dynamic fluorescein angiography. OCT scans indicated a slight elevation of the RPE-choriocapillary complex with rarefaction of neuroretinal tissue that has been interpreted as CNV. PDT was then performed. LE BCVA had improved to 20/25, metamorphopsias disappeared, and at OCT examination no retinal morphologic modification was evident. Nine months later, BCVA and ophthalmoscopy are still stable.

CONCLUSIONS

In this case, OCT was the fundamental tool for the correct diagnosis and posttherapymonitoring of CNV-complicated PM. The CNV, not clearly detectable using angiographic imaging, was treated with PDT, and results in terms of VA and anatomic resolution were good.

Discrepancy between fluorescein angiography and optical coherence tomography in detection of macular disease

PURPOSE

To compare high-resolution optical coherence tomography (OCT) and fluorescein angiography (FA) in detection of macular edema (ME) of various etiologies.

METHODS

In a retrospective study over a 12-month period at one retina center, data for consecutive eyes that had undergone simultaneous conventional FA (HRA; Heidelberg Engineering, Vista, CA) and StratusOCT (Carl Zeiss Meditec, Dublin, CA) to rule out ME were reviewed. A subset of patients underwent additional examination with extremely high-resolution (6-microm)/ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy (OTI, Inc., Toronto, Ontario, Canada).

RESULTS

Of 1,272 eyes, 1,208 (94.97%) had the finding of ME or subretinal fluid confirmed by both techniques. There were 49 eyes (3.86%) for which FA showed dye leakage in the macular area and OCT showed normal foveal contour. Of 10 eyes in this group that underwent imaging with ultrahigh-speed spectral OCT/scanning laser ophthalmoscopy, 8 had subtle diffuse lucencies in the retina. For 15 eyes (1.17%), OCT showed intraretinal and subretinal fluid, which was missed by FA.

CONCLUSIONS

Both FA and high-resolution OCT are highly sensitive techniques and correlate well in detection of ME. However, there is a small chance that when performed alone they might miss existing subtle ME.

Clinical applications and new developments of optical coherence tomography: an evidence-based review

Optical coherence tomography (OCT) is a new imaging modality that has increasingly become an indispensable tool in clinical practice for the diagnosis and management of ocular diseases involving the macula, optic nerve and anterior segment. The instrument is an advanced imaging technique that provides unprecedented high resolution and cross-sectional tomographic images of the ocular microstructure in situ, and in real time. Since its introduction about four years ago, a multitude of advantages has made OCT an essential instrument in ophthalmic imaging. The technique has fast image acquisition speed and non-contact, non-invasive applicability, allowing a non-excisional 'optical biopsy' to be performed. The purpose of this paper is to provide an evidence-based review of the increasing role of OCT in the diagnosis and management of ocular disorders, particularly in age-related macular degeneration, diabetic macular oedema, macular hole, epiretinal membrane and glaucoma. Being one of the first users of OCT in Australia, our clinical experiences will be highlighted and clinical examples of various conditions will be presented to provide an overview of the immense implications of OCT in practice. The latest developments of the OCT revolution, in relation to combining OCT with fundus photography and scanning laser ophthalmoscopy, will also be described. New developments of three-dimensional visualisation of tissue morphology with future models of ultra-high speed, ultra-high resolution OCT may further enhance the early diagnosis, monitoring of disease progression and assessment of treatment efficacy, facilitated by this powerful technology.

Optical coherence tomography analysis of a randomized study combining photodynamic therapy with intravitreal triamcinolone

BACKGROUND

The objective of the study was to analyze optical coherence tomography (OCT) scan differences between patients with predominantly classic subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) treated with only photodynamic therapy (PDT) and patients treated with PDT combined with intravitreal triamcinolone acetonide (IVTA).

METHODS

In this prospective study, 61 patients were randomized to receive PDT (n = 30) or PDT combined with IVTA (n = 31). They were evaluated every 3 months with a refraction protocol for best-corrected visual acuity (VA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) charts, fluorescein angiography (FA), and OCT. When measuring foveal thickness on OCT scans, neuroretinal foveal thickness (NFT) was differentiated from outer high reflectivity band thickness (OHRBT). The main outcome measures were mean change in OCT measurements and correlation of VA and angiographic area of the lesion with OCT measurements.

RESULTS

At the 12-month follow-up, the mean change in NFT was not significantly reduced (P = 0.9), but the mean change in OHRBT was significantly lower (P = 0.004) in the group of patients who received combined therapy. There was no correlation between final VA and NFT in either patient group (P = 0.2). The final VA was significantly worse in eyes with a thicker OHRBT (P = 0.04) in the group of patients treated with only PDT. There was no correlation between angiographic area and NFT and OHRBT in either patient group (P > 0.3). There was a statistically significant difference between the pre-treatment angiographic area of the lesion and VA at the 12-month follow-up in the combined therapy group (P = 0.01), and more eyes treated with only PDT presented with intraretinal fluid at the last follow-up (P = 0.01).

CONCLUSION

Combined PDT+IVTA therapy was more effective than PDT alone at reducing OHRBT. This OCT measurement seems to be have a greater effect on VA than NFT.

Measurement of greatest linear diameter for choroidal neovascular membrane using optical coherence tomography

PURPOSE

Correlation of greatest linear diameter (GLD) of choroidal neovascularization (CNV) measured by fundus fluorescein angiography (FA) with optical coherence tomography (OCT).

DESIGN

Retrospective noninterventional observational case series.

METHODS

Patients who underwent verteporfin therapy for subfoveal classic CNV were assessed. GLD of CNV was calculated manually from mean of 6 line scans. GLD measured on OCT and FA was correlated by assessing the agreement of the two techniques by interclass correlation and Bland and Altman technique.

RESULTS

Twenty-seven eyes of 27 patients with subfoveal classic CNV were included. The mean age was 49.3 +/- 18.6 years. The mean GLD calculated on FA was 1973.3 microm and OCT was 2024.2 microm. Substantial agreement was observed between GLD measured on FA and OCT (Inter-Class Correlation [ICC] = 0.77%; 95% confidence interval, 0.56 to 0.89).

CONCLUSIONS

GLD measured on OCT correlates to FA measurement. This method could be beneficial where FA is contraindicated while contemplating photodynamic therapy (PDT).

Injections intra-vitréennes d’anti-VEGF pour la dégénérescence maculaire liée à l’âge exsudative : place des examens complémentaires dans les décisions de retraitement

AIM

Anti-VEGF drugs are the most recent treatments for choroidal neovascularization, the most severe complication of the age-related macular degeneration (AMD). These drugs are administered by intravitreal injections. Several clinical studies have demonstrated their advantages. However, these same studies have not established the modalities for monitoring their efficacy. The aim of this paper is to provide an in-depth look at the existing practices in monitoring anti-VEGF therapy among different French specialists.

METHODS

Several meetings were held with specialists coming from both the hospital setting and private practice to share their practices in monitoring anti-VEGF therapy and to propose more rational monitoring to standardize practices.

RESULTS

The physicians attached an increasing importance to optical coherence tomography (OCT) in monitoring anti-VEGF drugs after intravitreal injection. They acknowledged the value of fluorescein angiography when initiating the treatment and 3 months after beginning anti-VEGF therapy. They advise using fluorescein angiography every time that functional results are not at the level expected by the physician or the patient. The authors provide a flow chart that should help in deciding on retreatment.

CONCLUSION

The authors suggest the use of a flow chart aimed to define indications of retreatment according to clinical response and OCT results.