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Dive into the research topics where Stephen F. Oster is active.

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Featured researches published by Stephen F. Oster.


American Journal of Ophthalmology | 2010

The association between percent disruption of the photoreceptor inner segment-outer segment junction and visual acuity in diabetic macular edema.

Anjali S. Maheshwary; Stephen F. Oster; Ritchie Yuson; Lingyun Cheng; Francesca Mojana; William R. Freeman

PURPOSE To evaluate the integrity of the photoreceptor inner segment/outer segment (IS/OS) junction using spectral-domain optical coherence tomography (SD OCT) in patients with diabetic macular edema and to correlate the relationship between the integrity of the IS/OS junction and visual acuity. DESIGN Retrospective, comparative, consecutive case series. METHODS Sixty-two eyes from 38 patients with diabetic macular edema underwent SD OCT imaging. For each patient, 2 experienced observers masked to visual acuity measured several SD OCT variables, including central macular thickness, retinal volume, global disruption scale of outer retina, percentage disruption of the outer retina, and history of previous treatments. Visual acuity recorded as number of Early Treatment Diabetic Retinopathy Study letters was used as the outcome variable in univariate and multivariate analysis testing the measured SD OCT variables as predictors. RESULTS A statistically significant correlation between percentage disruption of the IS/OS junction and visual acuity was found (P = .0312). Additionally, there was a strong trend suggesting a relationship between macular volume and visual acuity, although borderline significance was found (P = .07). CONCLUSIONS Disruption of the photoreceptor IS/OS junction is an important predictor of visual acuity among diabetic macular edema patients.


Retina-the Journal of Retinal and Vitreous Diseases | 2010

Disruption of the photoreceptor inner segment/outer segment layer on spectral domain-optical coherence tomography is a predictor of poor visual acuity in patients with epiretinal membranes.

Stephen F. Oster; Francesca Mojana; Manpreet Brar; Ritchie Yuson; Lingyun Cheng; William R. Freeman

Purpose: The purpose of this study was to evaluate the predictive value of spectral domain-optical coherence tomography-determined integrity of the photoreceptor inner segment/outer segment (IS/OS) junction on visual acuity in patients with epiretinal membranes (ERMs). Methods: This is a retrospective consecutive case series of 54 eyes from 48 patients with primary ERMs who underwent spectral domain-optical coherence tomography scans. Regression analysis was used to calculate the relative contribution of several variables, including photoreceptor IS/OS disruption, grade of IS/OS disruption, macular thickness, and ERM grade on fundus imaging to visual acuity. Results: The strongest individual predictor of visual acuity among patients with ERM was central retinal thickness on spectral domain-optical coherence tomography (r2 = 0.16, P = 0.0024), but the most efficient model was the combination of macular thickness and presence or absence of photoreceptor IS/OS disruption (r2 = 0.24, P = 0.0008). Additional measured variables did not significantly contribute to visual acuity prediction. Inner segment/outer segment layer integrity was also an independent predictor of visual acuity, and patients with IS/OS disruption were 6.88 times as likely to have 20/50 or worse vision than patients with intact photoreceptor layers (odds ratio: 6.88, confidence interval: 1.56–30.43, P = 0.01). Conclusion: Disruption of the photoreceptor IS/OS junction is a statistically significant predictor of poor visual acuity among patients with ERM and is most useful when combined with central retinal thickness measurement.


American Journal of Ophthalmology | 2009

Correlation between Spectral-Domain Optical Coherence Tomography and Fundus Autofluorescence at the Margins of Geographic Atrophy

Manpreet Brar; Igor Kozak; Lingyun Cheng; Dirk-Uwe Bartsch; Ritchie Yuson; N. Nigam; Stephen F. Oster; Francesca Mojana; William R. Freeman

PURPOSE To study the appearance of margins of geographic atrophy in high-resolution optical coherence tomography (OCT) images and to correlate those changes with fundus autofluorescence (FAF) imaging. DESIGN Retrospective, observational case study. METHODS Patients with geographic atrophy secondary to dry age-related macular degeneration were assessed by means of spectral-domain OCT (Spectralis Heidelberg Retinal Angiograph/OCT; Heidelberg Engineering, Heidelberg, Germany; or OTI Inc, Toronto, Canada) as well as autofluorescence imaging (Heidelberg Retinal Angiograph or Spectralis; Heidelberg Engineering). The outer retinal layer alterations were analyzed in the junctional zone between normal retina and atrophic retina and were correlated with corresponding FAF. RESULTS Twenty-three eyes of 16 patients between 62 and 96 years of age were examined. There was a significant association between OCT findings and the FAF findings (r = 0.67; P < .0001). Severe alterations of the outer retinal layers at margins on spectral-domain OCT correspond significantly to increased autofluorescence; smooth margins on OCT correspond significantly to normal FAF (kappa, 0.7348; P < .0001). CONCLUSIONS Spectral-domain OCT provides in vivo insight into the pathogenesis of geographic atrophy and its progression. Visualization of reactive changes in the retinal pigment epithelial cells at the junctional zone and correlation with increased FAF; secondary to increased lipofuscin, together these methods may serve as determinants of progression of geographic atrophy.


Retina-the Journal of Retinal and Vitreous Diseases | 2010

Correlation between morphologic features on spectral-domain optical coherence tomography and angiographic leakage patterns in macular edema.

Manpreet Brar; Ritchie Yuson; Igor Kozak; Francesca Mojana; Lingyun Cheng; Dirk-Uwe Bartsch; Stephen F. Oster; William R. Freeman

Purpose: The purpose of this study was to determine the morphologic patterns of angiographic macular edema using simultaneous colocalization of fluorescein angiography and spectral-domain optical coherence tomography (SD-OCT) images in diabetes, epiretinal membrane, uveitic and pseudophakic cystoid macular edema, and vein occlusion. Methods: Eighty-seven consecutive patients (107 eyes) with macular edema from 5 different etiologies were imaged by simultaneous scanning laser ophthalmoscopy/OCT to study the morphologic patterns of edema on SD-OCT and then correlated/colocalized with the fluorescein angiographic patterns of leakage. Statistical analysis was done to analyze the differences in the morphologic OCT pattern by different diseases. Results: Spectral-domain OCT characteristics of macular edema showed a significant difference across different diseases (P = 0.037). Cystic fluid pockets were found to be more commonly seen in patients with diabetic macular edema and retinal vein occlusions, whereas those cases with macular edema secondary to epiretinal membrane showed noncystic changes on OCT. Seventy of the 107 eyes had diffuse angiographic leakage, and the remaining 37 eyes had cystoid leakage on angiography. Of the 70 eyes with diffuse leakage, 24.28% showed microcysts on SD-OCT in the area of edema, and 70% eyes had diffuse thickening or distorted architecture without cyst. All 37 eyes with cystoid leakage showed cysts in the area of edema by SD-OCT. A total of 3.73% of eyes with fluorescein angiographic leakage had no abnormalities on SD-OCT. Conclusion: Eyes with diabetic macular edema and retinal vein occlusions have a significantly higher incidence of cyst formation on SD-OCT. There was no correlation between visual acuity and cyst formation. Diffuse noncystoid angiographic macular edema may show microcysts on SD-OCT, but diffuse edema is more commonly associated with thickening or distortion of the retinal layers without cyst formation. Cystoid leakage on fluorescein angiography is always associated with cystic changes on SD-OCT.


Ophthalmology | 2011

Clinical Evaluation and Treatment Accuracy in Diabetic Macular Edema Using Navigated Laser Photocoagulator NAVILAS

Igor Kozak; Stephen F. Oster; Marco A. Cortes; Dennis Dowell; Kathrin Hartmann; Jae Suk Kim; William R. Freeman

PURPOSE To evaluate the clinical use and accuracy of a new retinal navigating laser technology that integrates a scanning slit fundus camera system with fluorescein angiography (FA), color, red-free, and infrared imaging capabilities with a computer steerable therapeutic 532-nm laser. DESIGN Interventional case series. PARTICIPANTS Eighty-six eyes of 61 patients with diabetic retinopathy and macular edema treated by NAVILAS. METHODS The imaging included digital color fundus photographs and FA. The planning included graphically marking future treatment sites (microaneurysms for single-spot focal treatment and areas of diffuse leakage for grid pattern photocoagulation) on the acquired images. The preplanned treatment was visible and overlaid on the live fundus image during the actual photocoagulation. The NAVILAS automatically advances the aiming beam location from one planned treatment site to the next after each photocoagulation spot until all sites are treated. Aiming beam stabilization compensated for patients eye movements. The pretreatment FA with the treatment plan was overlaid on top of the posttreatment color fundus images with the actual laser burns. This allowed treatment accuracy to be calculated. Independent observers evaluated the images to determine if the retinal opacification after treatment overlapped the targeted microaneurysm. MAIN OUTCOME MEASURES Safety and accuracy of laser photocoagulation. RESULTS The images were of very good quality compared with standard fundus cameras, allowing careful delineation of target areas on FA. Toggling from infrared, to monochromatic, to color view allowed evaluation and adjustment of burn intensity during treatment. There were no complications during or after photocoagulation treatment. An analysis of accuracy of 400 random focal targeted spots found that the NAVILAS achieved a microaneurysm hit rate of 92% when the placement of the treatment circle was centered by the operating surgeon on the microaneurysm. The accuracy for the control group analyzing 100 focal spots was significantly lower at 72% (P<0.01). CONCLUSIONS Laser photocoagulation using the NAVILAS system is safe and achieves a higher rate of accuracy in photocoagulation treatments of diabetic retinopathy lesions than standard manual-technique laser treatment. Precise manual preplanning and positioning of the treatment sites by the surgeon is possible, allowing accurate and predictable photocoagulation of these lesions. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.


American Journal of Ophthalmology | 2010

Observations by spectral-domain optical coherence tomography combined with simultaneous scanning laser ophthalmoscopy: imaging of the vitreous.

Francesca Mojana; Igor Kozak; Stephen F. Oster; Lingyun Cheng; Dirk-Uwe Bartsch; Manpreet Brar; Ritchie Yuson; William R. Freeman

PURPOSE To determine the ability to detect normal vitreous structure, evolving posterior vitreous detachment (PVD), and related vitreoretinal changes with combined spectral-domain optical coherence tomography (SD-OCT) and scanning laser ophthalmoscopy (SLO). DESIGN Observational cross-sectional study. METHODS Simultaneous SD-OCT and SLO imaging instruments (SD-OCT/SLO) were used to image both eyes of patients with symptoms of PVD. The vitreous cortex, preretinal lacunae, hyaloid, and its relations to the retinal surface were analyzed. In addition, ultrasound was performed in a subset of patients to determine the stage of PVD. RESULTS Two-hundred two eyes of 113 subjects were scanned. There was a high correlation between diagnosis of complete PVD by clinical examination and OCT (95 vs 93 eyes, respectively; kappa, 0.82). A partial PVD was detected more frequently by SD-OCT/SLO than by biomicroscopy examination (45 vs 7 eyes; P < .0001). Ultrasound was performed in a subset of 30 eyes. A high agreement was found between ultrasound and SD-OCT/SLO results for both complete PVD (kappa, 0.933) and incomplete PVD (kappa, 0.91). Vitreous cortex was detected in 181 eyes, and posterior precortical vitreous pocket was detected in 85 eyes. The effects of PVD, including vitreoretinal traction, paravascular lamellar holes, and fine changes at the fovea, could be visualized reliably in detail only with SD-OCT/SLO. In all these eyes, SD-OCT/SLO allowed improved visualization of the vitreoretinal relationship. CONCLUSIONS SD-OCT/SLO provides unprecedented in vivo information about the physiologic and pathologic vitreous structure; it allows an extremely detailed analysis of the vitreoretinal interface, and it is particularly useful for defining focal changes and PVD.


American Journal of Ophthalmology | 2010

Viral Retinitis After Intravitreal Triamcinolone Injection in Patients With Predisposing Medical Comorbidities

Ankur M. Shah; Stephen F. Oster; William R. Freeman

PURPOSE To review the cases of viral retinitis after intravitreal steroid administration at a single center, to estimate the incidence, and to propose risk factors for its occurrence. DESIGN Retrospective, observational case series. METHODS Seven hundred thirty-six intravitreal triamcinolone (IVTA) injections were administered in the clinic and operating room by 3 retina specialists at a single academic medical center between September 2002 and November 2008. Inclusion criteria were simply a history of 1 or more IVTA injections during the period. The overall incidence of viral retinitis after IVTA injection was calculated. Subsequently, a chart audit was performed to estimate the number of patients with immune-altering conditions who had received IVTA during the period, and the incidence within this subgroup was calculated. RESULTS Viral retinitis developed after IVTA injection in 3 patients, yielding an overall incidence of 3 in 736 or 0.41%. An estimated 334 injections were administered to patients with an immune-altering condition, including diabetes. All 3 of the patients in whom viral retinitis developed after IVTA injection possessed abnormal immune systems, yielding an incidence rate of 3 in 334 or 0.90% within this subgroup. CONCLUSIONS Our high reported incidence for this potentially devastating complication can be attributed to multiple factors, including coexisting medical immunocompromising comorbidities, a higher dose with a longer duration of local immunosuppression in the vitreous, multiple injections, as well as previous viral retinitis. Caution with a high index of clinical suspicion and frequent follow-up is advised in patients receiving IVTA injection with potentially immune-altering conditions, even after apparent immune recovery.


Retina-the Journal of Retinal and Vitreous Diseases | 2012

Focal navigated laser photocoagulation in retinovascular disease: clinical results in initial case series.

Igor Kozak; Jae Suk Kim; Stephen F. Oster; Jay Chhablani; William R. Freeman

Purpose: To evaluate clinical results after the use of a novel integrated imaging and laser device to perform focal retinal navigated laser photocoagulation in perifoveal abnormalities and retinovascular disease. Methods: Interventional case series of 25 consecutive eyes with perifoveal and retinovascular diseases treated with a navigated laser photocoagulator Navilas (OD-OS, Berlin, Germany). We treated eyes with perifoveal telangiectasia (n = 3), central serous chorioretinopathy (n = 2), and diabetic macular edema with focal leakage (n = 20). Results: The treatments were performed without a contact lens and without topical anesthesia. There was no inadvertent photocoagulation of the fovea, and all laser applications accurately hit the preplanned points. Mean and median (± standard deviation) foveal thickness at baseline was 535 ± 171 &mgr;m and 402 ± 152 &mgr;m, respectively. Mean and median (± standard deviation) foveal thickness at 6 months was 318 ± 112 &mgr;m and 221 ± 127 &mgr;m, respectively. This represents a statistically significant decrease in foveal thickness (P = 0.003). Mean and median visual acuity at baseline was 20/80 and 20/50, respectively. Mean and median visual acuity at 6 months was 20/50 and 20/40, respectively, which represents a significant improvement (P = 0.011). Conclusion: Precise retinal targeting with a navigated laser photocoagulator resulted in highly accurate perifoveal laser application and no foveal damage. At 6 months after the treatment, significant decreases in central foveal thickness and significant improvements in visual acuity were identified.


Retina-the Journal of Retinal and Vitreous Diseases | 2010

Vitreoretinal interface abnormalities in healed cytomegalovirus retinitis.

Manpreet Brar; Igor Kozak; William R. Freeman; Stephen F. Oster; Francesca Mojana; Ritchie Yuson

Purpose: The purpose of this study was to use spectral domain-optical coherence tomography in imaging retina and vitreoretinal relationship in healed cytomegalovirus (CMV) retinitis. Methods: Patients with a history of confirmed CMV retinitis and a healed CMV scar on clinical examination underwent spectral domain-optical coherence tomography examinations using a Spectralis Heidelberg retinal angiograph/optical coherence tomography instrument (Heidelberg Engineering, Heidelberg, Germany). Horizontal and vertical cross-sectional B-scans 6 mm × 6 mm passing through the center and margins of healed CMV scars and adjacent retina were obtained. We analyzed the integrity of retinal layers in the area of the CMV scar, integrity of retinal layers at the margins of the CMV scar, margins of the scar and adjacent nonaffected retina, and any structural alterations in the retina or vitreous. Results: Eleven eyes (50%) had vitreous detached, and 11 eyes attached over the area of healed retinitis. Nineteen eyes (86%) had an epiretinal membrane, and 12 eyes (54%) had vitreoretinal gliosis present over the healed retinitis or in its vicinity. The epiretinal membrane and vitreoretinal gliosis occurred concomitantly in 10 eyes and could be well differentiated on scans. None of these were found in control eyes. Conclusion: This first in vivo study of vitreoretinal interface in inactive CMV retinitis shows that the vitreoretinal interface in healed CMV is pathologically changed. The presence of epiretinal membranes, vitreoretinal gliosis, and traction may help explain the higher incidence of retinal elevation, retinal breaks, and retinal detachment in these eyes.


Retina-the Journal of Retinal and Vitreous Diseases | 2010

Dynamics of the Macular Hole-Silicone Oil Tamponade Interface with Patient Positioning as Imaged by Spectral Domain Optical Coherence Tomography

Stephen F. Oster; Francesca Mojana; Dirk-Uwe Bartsch; Michael H. Goldbaum; William R. Freeman

Purpose:The purposes of this study were to evaluate with spectral domain-optical coherence tomography the relationship between the retina and overlying silicone oil tamponade after macular hole surgery and to evaluate how this relationship changes with patient positioning. Methods:We studied a retrospective consecutive case series of 10 eyes from 9 patients who underwent macular hole surgery with silicone oil tamponade and subsequent spectral domain-optical coherence tomography scans. Four of the included eyes were also imaged with patients in face-down posture to determine whether the silicone-retina apposition changes with prone positioning. Finally, a single patient was also scanned in the lateral and supine positions. Results:The posterior surface of the silicone oil bubble was well visualized in all 10 eyes. In the majority of eyes (7 of 10), the oil tamponade bridged the macular hole, creating a prefoveal fluid space, but in 3 eyes the silicone oil filled the macular hole and was seen in touch with the underlying foveal depression or retinal pigment epithelium. In 75% of eyes (3 of 4), the silicone oil-retinal approximation did not vary with face-down position. Supine positioning clearly floated the silicone tamponade anteriorly and off the retinal surface. Conclusion:Silicone oil tamponade can either bridge macular holes or, in a novel finding, fill the underlying foveal depression or macular hole space. Generally, the oil position is stable between face-forward and prone spectral-domain optical coherence tomography images, suggesting that either of these patient positions allows waterproofing of the underlying macular hole. Finally, our images confirm that supine positioning should be avoided postoperatively because it leads to loss of oil-retinal tamponade.

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Igor Kozak

University of California

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Ritchie Yuson

University of California

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Manpreet Brar

University of California

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Lingyun Cheng

University of California

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W. R. Freeman

University of California

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Jae Suk Kim

University of California

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