Comparison between Widefield En Face Swept-Source OCT and Conventional Multimodal Imaging for the Detection of Reticular Pseudodrusen.

PURPOSE: The ability to detect reticular pseudodrusen (RPD)/subretinal drusenoid deposits (SDDs) using 12×12-mm widefield en face swept-source optical coherence tomography (SS-OCT) imaging was compared with conventional multimodal imaging (color, fundus autofluorescence (FAF), and infrared reflectance [IR] imaging) in eyes with nonexudative age-related macular degeneration (AMD). DESIGN: Cross-sectional study. PARTICIPANTS: Patients with nonexudative AMD were prospectively enrolled in an SS-OCT imaging study at the Bascom Palmer Eye Institute. METHODS: On the same day, all participants underwent color, FAF, and IR fundus imaging, as well as imaging with a prototype Zeiss 100 kHz SS-OCT instrument (Carl Zeiss Meditec Inc, Dublin, CA). Two masked graders assessed the presence, absence, or uncertainty of RPD/SDDs on conventional multimodal images and separately on 4 different SS-OCT en face images derived from the same volumetric dataset. The results from grading the conventional images and the SS-OCT en face images were compared. MAIN OUTCOME MEASURES: Agreement in the detection of RPD/SDDs using different imaging modalities. RESULTS: A total of 307 eyes (209 patients) were graded for the presence or absence of RPD/SDDs. The agreement between SS-OCT and multimodal imaging was 83%. The difference in RPD/SDD detection with either image modality was not statistically significant (P = 0.21). The sensitivity of SS-OCT in RPD/SDD detection was 83%, and when using conventional imaging, the sensitivity was 75%. When using SS-OCT imaging alone, 10% of RPD/SDD cases would be missed, and when using conventional imaging alone, 14% of RPD/SDD cases would be missed. The presence of RPD/SDD was confirmed retrospectively in 48 of 52 cases once the overall grading was unmasked and the graders reevaluated the conventional multimodal images and the widefield SS-OCT en face images. CONCLUSIONS: All 4 imaging modalities used together provided the best strategy for the detection of RPD/SDDs. However, when using widefield en face SS-OCT slab imaging alone, the detection of RPD/SDDs was at least as good as conventional imaging.

IMAGING WITH MULTIMODAL ADAPTIVE-OPTICS OPTICAL COHERENCE TOMOGRAPHY IN MULTIPLE EVANESCENT WHITE DOT SYNDROME: THE STRUCTURE AND FUNCTIONAL RELATIONSHIP.

PURPOSE: To elucidate the location of pathological changes in multiple evanescent white dot syndrome (MEWDS) with the use of multimodal adaptive optics (AO) imaging. METHODS: A 5-year observational case study of a 24-year-old female with recurrent MEWDS. Full examination included history, Snellen chart visual acuity, pupil assessment, intraocular pressures, slit lamp evaluation, dilated fundoscopic exam, imaging with Fourier-domain optical coherence tomography (FD-OCT), blue-light fundus autofluorescence (FAF), fundus photography, fluorescein angiography, and adaptive-optics optical coherence tomography. RESULTS: Three distinct acute episodes of MEWDS occurred during the period of follow-up. Fourier-domain optical coherence tomography and adaptive-optics imaging showed disturbance in the photoreceptor outer segments (PR OS) in the posterior pole with each flare. The degree of disturbance at the photoreceptor level corresponded to size and extent of the visual field changes. All findings were transient with delineation of the photoreceptor recovery from the outer edges of the lesion inward. Hyperautofluorescence was seen during acute flares. Increase in choroidal thickness did occur with each active flare but resolved. CONCLUSION: Although changes in the choroid and RPE can be observed in MEWDS, Fourier-domain optical coherence tomography, and multimodal adaptive optics imaging localized the visually significant changes seen in this disease at the level of the photoreceptors. These transient retinal changes specifically occur at the level of the inner segment ellipsoid and OS/RPE line. En face optical coherence tomography imaging provides a detailed, yet noninvasive method for following the convalescence of MEWDS and provides insight into the structural and functional relationship of this transient inflammatory retinal disease.

SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF NEOVASCULAR MACULAR TELANGIECTASIA TYPE 2.

BACKGROUND/PURPOSE: To image subretinal neovascularization in proliferative macular telangiectasia Type 2 (MacTel2) using swept source optical coherence tomography based microangiography (OMAG). METHODS: Patients with macular telangiectasia Type 2 were enrolled in a prospective, observational study known as the MacTel Project and evaluated using a high-speed 1,050 nm swept-source OCT prototype system. The OMAG algorithm generated en face flow images from three retinal layers, and the region bounded by the outer retina and Bruch membrane, the choriocapillaris, and the remaining choroidal vasculature. The en face OMAG images were compared with images from fluorescein angiography and indocyanine green angiography. RESULTS: Three eyes with neovascular macular telangiectasia Type 2 were imaged. The neovascularization was best identified from the en face OMAG images that included a layer between the outer retinal boundary and Bruch membrane. Optical coherence tomography based microangiography images identified these abnormal vessels better than fluorescein angiography and were comparable to the images obtained using indocyanine green angiography. In all 3 cases, OMAG identified choroidal vessels communicating with the neovascularization, and these choroidal vessels were evident in the 2 cases with indocyanine green angiography imaging. In 1 case, monthly injections of bevacizumab reduced the microvascular complexity of the neovascularization, and the telangiectatic changes within the retinal microvasculature. In another case, less frequent bevacizumab therapy was associated with growth of the subretinal neovascular complex. CONCLUSION: Optical coherence tomography based microangiography imaging provided detailed, depth-resolved information about subretinal neovascularization in macular telangiectasia Type 2 eyes demonstrating superiority to fluorescein angiography imaging, and similarities to indocyanine green angiography imaging for documenting the retinal microvascular changes, the size and extent of the neovascular complex, the communications between the neovascular complex and the choroidal circulation, and the response to monthly bevacizumab therapy.

Widefield En Face Optical Coherence Tomography Imaging of Subretinal Drusenoid Deposits.

BACKGROUND AND OBJECTIVE: To determine whether subretinal drusenoid deposits (SDD) can be detected on widefield en face slab images derived from spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT) volume scans. PATIENTS AND METHODS: Retrospective study of patients with dry age-related macular degeneration (AMD) enrolled prospectively in an OCT imaging study using SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA) with a central wavelength of 840 nm, and a prototype 100-kHz SS-OCT instrument (Carl Zeiss Meditec) with a central wavelength of 1,050 nm. Seven en face slabs were evaluated with thicknesses from 20 to 55 µm and positioned at distances up to 55 µm above the retinal pigment epithelium (RPE). A montage of 6 × 6 mm SD-OCT en face images of the posterior pole from each patient was compared with a 9 × 12 mm SS-OCT single en face slab image and with color, autofluorescence, and infrared reflectance images. RESULTS: A total of 160 patients (256 eyes) underwent scanning with both OCT instruments; 57 patients (95 eyes) also underwent multimodal fundus imaging. Of 95 eyes, 32 (34%) were diagnosed with reticular pseudodrusen (RPD) using multimodal imaging. All eyes with RPD demonstrated a pattern of SDD on widefield en face OCT similar to that observed for RPD. The en face slab image that consistently identified SDD was the 20-µm thick slab with boundaries from 35 to 55 µm above the RPE. CONCLUSION: Widefield en face slab imaging with SD-OCT and SS-OCT can detect SDD and could replace multimodal imaging for the diagnosis of RPD in the future.

Acanthamoeba keratitis associated with tap water use during contact lens cleaning: manufacturer guidelines need to change.

Contact lens-associated Acanthamoeba keratitis continues to be a significant cause of visual morbidity in the United States. Although exposure to water sources while wearing lenses has been a known risk factor for infection for decades, this behavior in several contact lens hygiene protocols continues to prevail. In this review, we surveyed the currently available contact lens cleaning solutions for both soft and rigid gas-permeable contact lenses and reviewed the cleaning instructions of the available solutions. Discrepancies between clinician recommendations and written instructions on a solution packages continues to persist, and we advocate a revision in current manufacturer guidelines to include explicit warnings against use of tap or distilled water sources for cleaning contact lenses or their storage cases.

Macular thickness measurements in normal eyes using spectral domain optical coherence tomography.

BACKGROUND AND OBJECTIVE: Knowledge of the macular thickness in a normal population is important for the evaluation of pathological macular change. The purpose of this study was to define and measure macular thickness in normal eyes using spectral domain optical coherence tomography (OCT). PATIENTS AND METHODS: Fifty eyes from 50 normal subjects (29 men and 21 women, aged 22 to 68 years) were scanned with a prototype Cirrus HD-OCT system (5 microm axial resolution) (Carl Zeiss Meditec, Inc.). The proprietary Cirrus segmentation algorithm was used to produce retinal thickness maps, which were then averaged over 9 regions defined by a circular target centered at the true fovea location. The macular thickness of 13 subjects scanned with both HD-OCT and StratusOCT were compared. RESULTS: After centering the fovea, the mean and standard deviation values for retinal thickness measurements were calculated point wise and averaged on standard regions. For patients scanned with both systems, the thickness measurements from HD-OCT were approximately 50 microm larger than those from StratusOCT. The difference between the two measurements decreased somewhat with eccentricity. CONCLUSION: Using HD-OCT, it is possible to acquire retinal data sets containing an unprecedented number of data points. Furthermore, it is possible to use OCT fundus images to evaluate the scan quality and to center the measurement at the fovea. These advantages, together with good automated segmentation, can produce more accurate retinal thickness measurements. Incorporation of the photoreceptor layer in the measurements is anatomically meaningful and may be significant in evaluating various retinal pathologies and visual acuity outcomes.

Three-dimensional spectral-domain optical coherence tomography images of the retina in the presence of epiretinal membranes.

PURPOSE: To study the inner surface of the retina in the presence of epiretinal membranes (ERMs) using a prototype spectral-domain optical coherence tomography (SD-OCT) device. DESIGN: Small case series, performed in the Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, from August 2005 through December 2006. METHOD: An 8-microm axial-resolution SD-OCT instrument was used to scan the eyes of patients diagnosed with ERM. The ERM and the internal limiting membrane (ILM) were segmented separately to evaluate the traction caused by the ERM on the retina. It was then possible to reconstruct the ILM and ERM surfaces in 3-dimensional space and to obtain corresponding retinal thickness maps. RESULTS: SD-OCT B scans showed the points of attachment of the ERM to the ILM. Segmented surface maps of the ERM produced very smooth sheets, whereas those of the ILM presented wrinkles under and around the ERM. CONCLUSIONS: SD-OCT revealed the geometry of retinal traction in eyes with ERM and may be useful in understanding further the pathologic features of these lesions.

Documentation by spectral domain OCT of spontaneous closure of idiopathic macular holes.

An observational case series using an 8-microm axial resolution prototype spectral domain optical coherence tomography (OCT) system was performed in two patients with idiopathic macular holes. Spontaneous closure and visual acuity improvement occurred in both patients. Useful information about morphology and vitreoretinal relationship of the holes was provided by spectral domain OCT.