C. K. Brinkmann

Macular Thickness Measurements in Healthy Eyes Using Six Different Optical Coherence Tomography Instruments

PURPOSE To compare central retinal thickness (CRT) measurements in healthy eyes by different commercially available OCT instruments and to compare the intersession reproducibility of such measurements. METHODS Six different OCT instruments (Stratus OCT [Carl Zeiss Meditec, Inc. Dublin, CA], SOCT Copernicus [Reichert/Optopol Technology, Inc., Depew, NY], Spectral OCT/SLO [Opko/OTI, Inc., Miami, FL], RTVue-100 [Optovue Corp., Fremont, CA], Spectralis HRA+OCT [Heidelberg Engineering, Inc., Heidelberg, Germany], and Cirrus HD-OCT [Carl Zeiss Meditec, Inc.]) were used to assess CRT in both eyes of healthy subjects. Measurements were performed in two different sessions on the same day with each of the systems. From these measurements, the mean CRT was calculated. For the assessment of the intersession reproducibility of the instruments, we calculated the coefficient of the variation of test-retest variation. RESULTS Twenty healthy subjects were included in the study. Compared with the Stratus OCT all spectral OCT instruments showed significantly higher CRTs. The Spectralis HRA+OCT and Cirrus HD-OCT showed similar CRT values but significantly higher values than did all other instruments. The coefficients of variation for repeated measurements was 3.33% for the Stratus OCT, 0.46% for the Spectralis HRA+OCT, 3.09% for the Cirrus HD-OCT, 2.23% for the OCT/SLO, 2.77% for the RTVue-100 OCT, and for the SOCT 3.5%, respectively. discussion. The six OCT systems provided different results for CRT. The measurements with the Stratus OCT showed the lowest thicknesses, whereas those with the Cirrus HD-OCT and Spectralis HRA+OCT yielded the highest ones. These discrepancies can be explained by the differences in the retinal segmentation algorithms used by the various OCT systems. Whereas the Spectralis HRA+OCT and Cirrus HD-OCT include the RPE layer in the retinal segmentation, the other instruments do not. The data imply that the different OCT systems cannot be used interchangeably for the measurement of macular thickness.

Morphologic Changes in Patients with Geographic Atrophy Assessed with a Novel Spectral OCT-SLO Combination

PURPOSE To investigate the appearance of geographic atrophy in high-resolution optical coherence tomography (OCT) images, the fundus autofluorescence (FAF) pattern, and infrared images simultaneously recorded with a novel combined OCT-scanning laser ophthalmology (SLO) system. METHODS Patients aged over 50 years with geographic atrophy secondary to dry age-related macular degeneration (ARMD) were assessed in a prospective cross-sectional study by means of simultaneous spectral OCT-SLO (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany). The integrity of the retinal layers was analyzed in the apparently normal areas, the junctional zone between the normal retina and the geographic atrophy, and the atrophic area. The presence and integrity of the external limiting membrane, the photoreceptor inner segments, the outer segments, and the retinal pigment epithelium were assessed. RESULTS Fifty-two eyes of 52 patients (28 women, 24 men) aged 51 to 92 years were examined. Retinal layer alterations were documented, not only in atrophic zones, but also in junctional zones surrounding the geographic atrophy. Disintegration of the retinal layers began in the RPE and adjacent retinal layers, such as the photoreceptor inner and outer segments and external limiting membrane. CONCLUSIONS Novel imaging modalities will provide further valuable insight into ARMD pathogenesis. The key to understanding the morphologic change lies in in vivo depiction of retinal layers by spectral OCT technology in combination with other imaging modalities such as FAF.

Effects of ranibizumab in patients with subfoveal choroidal neovascularization attributable to age-related macular degeneration.

PURPOSE To demonstrate not only prevention of vision loss but also improvement in best-corrected visual acuity (BCVA) after treatment with ranibizumab on a variable-dosing regimen over 24 months in patients with age-related macular degeneration (AMD). DESIGN Interventional case series. METHODS SETTING Institutional. STUDY POPULATION One hundred and thirty-eight eyes of 138 patients treated intravitreally with 0.5 mg ranibizumab (Lucentis; Novartis, Basel, Switzerland). Age above 50 years, BCVA 0.2 to 1.2 logarithm of the minimal angle of resolution (logMAR), primary or recurrent subfoveal choroidal neovascularization (CNV) secondary to AMD. OBSERVATION PROCEDURES After single initial treatment, monthly follow-up examination. Retreatment in case of one of the following: sign of subretinal fluid or intraretinal edema, increase in central retinal thickness (CRT) on optical coherence tomography (OCT), active CNV on fluorescein angiography, increase of metamorphopsia, and loss of BCVA > 5 letters on Early Treatment Diabetic Retinopathy Study (ETDRS) chart. MAIN OUTCOME MEASURES Compared with baseline: proportion of eyes gaining > or = 15 letters, proportion of eyes losing or gaining < 15 letters, change in CRT. RESULTS After 24 months, 30% of eyes gained > or = 15 letters. After 24 months, 55% of eyes lost or gained < 15 letters. Mean CRT of 386 +/- 145 microm at baseline was significantly reduced to 211 +/- 39 microm after 24 months (P = .036). Mean injection number per patient was 5.6 +/- 2.9 and 4.3 +/- 3.8 from baseline to month 12 and month 12 to 24, respectively. CONCLUSION Intravitreal ranibizumab on a variable-dosing regimen was effective in significantly increasing mean BVCA and reducing CRT. This beneficial outcome was achieved with a low-rate of mild ocular adverse effects among our patients.

Multimodal imaging in macular diagnostics: combined OCT-SLO improves therapeutical monitoring

BackgroundDigital imaging methods are a centrepiece for diagnosis and management of macular disease. A recently developed imaging device is composed of simultaneous confocal scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT). By means of clinical samples the benefit of this technique concerning diagnostic and therapeutic follow-up will be assessed.MethodsThe combined OCT-SLO-System (Ophthalmic Technologies Inc., Toronto, Canada) allows for confocal en-face fundus imaging and high resolution OCT scanning at the same time. OCT images are obtained from transversal line scans. One light source and the identical scanning rate yield a pixel-to-pixel correspondence of images. Three-dimensional thickness maps are derived from C-scan stacking.ResultsWe followed-up patients with cystoid macular edema, pigment epithelium detachment, macular hole, venous branch occlusion, and vitreoretinal tractions during their course of therapy. The new imaging method illustrates the reduction of cystoid volume, e.g. after intravitreal injections of either angiostatic drugs or steroids. C-scans are used for appreciation of lesion diameters, visualisation of pathologies involving the vitreoretinal interface, and quantification of retinal thickness change.ConclusionThe combined OCT-SLO system creates both topographic and tomographic images of the retina. New therapeutic options can be followed-up closely by observing changes in lesion thickness and cyst volumes. For clinical use further studies are needed.

Effects of combination therapy with verteporfin photodynamic therapy and ranibizumab in patients with age-related macular degeneration.

Purpose:  This open‐label, prospective, small‐scale study investigated the benefits of same‐day verteporfin and intravitreal ranibizumab in patients with predominantly classic, minimally classic or occult subfoveal choroidal neovascularization (CNV) secondary to age‐related macular degeneration.