Publications by authors named "Sadda S"

The aim of this study was to evaluate the functional efficacy of retinal progenitor cell (RPC) containing sheets with BDNF microspheres following subretinal transplantation in a rat model of retinal degeneration. Sheets of E19 RPCs derived from human placental alkaline phosphatase (hPAP) expressing transgenic rats were coated with poly-lactide-co-glycolide (PLGA) microspheres containing brain-derived neurotrophic factor (BDNF) and transplanted into the subretinal space of S334ter line 3 rhodopsin retinal degenerate rats. Controls received transplants without BDNF or BDNF microspheres alone.

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Purpose: To evaluate retinal sheet transplants in S334ter-line-3 retinal degenerate rats by comparing visual responses recorded electrophysiologically with morphology based on light and electron microscopy.

Methods: S334ter-line-3 retinal degenerate rats (n = 7) received retinal sheet transplants between postnatal days 28 and 31. The donor tissue was derived from transgenic embryonic day 19 (E19) rat retinae expressing human placental alkaline phosphatase (hPAP).

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Purpose: To determine the intergrader reproducibility for computer-assisted grading of optical coherence tomography (OCT) images in eyes with neovascular age-related macular degeneration (AMD), by using a standardized grading procedure.

Methods: Sixty OCT image sets (of six radial lines each) were independently analyzed by two graders using validated custom software (OCTOR) to draw boundaries manually on OCT B-scans. Spaces delineated by these boundaries included retina, subretinal fluid, subretinal tissue, and pigment epithelial detachments (PEDs).

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Purpose: To demonstrate the benefit of enhanced quantitative analysis of optical coherence tomography (OCT) images using computer-assisted grading to compare the short-term morphologic effects of pegaptanib and bevacizumab treatment for neovascular age-related macular degeneration (AMD).

Design: Retrospective consecutive case series.

Participants: Fifty-three cases with neovascular AMD undergoing pegaptanib or bevacizumab therapy.

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The purpose of this study is to characterize the co-expression of nestin--a neuroectodermal stem cell and a reactive glial marker-with various mature retinal cell markers in retinal progenitor cells (RPCs) expanded in vitro, followed either by in vitro induction or subretinal transplantation. Rat RPCs derived from embryonic day (E) 17 rat retina were expanded in serum free defined culture, and induced to differentiate by all-trans retinoic acid (RA). Following induction, cells were stained for nestin in combination with retinal neuronal and glial markers.

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Objective: To identify factors associated with variability in retinal nerve fiber layer (RNFL) thickness measurements obtained by optical coherence tomography (OCT).

Design: Retrospective observational case series.

Participants: One hundred fifty consecutive patients with known or suspected glaucomatous optic nerve damage undergoing OCT imaging for RNFL thickness measurement.

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We present a method for the 3-D shape reconstruction of the retinal fundus from stereo paired images. Detection of retinal elevation plays a critical role in the diagnosis and management of many retinal diseases. However, since the shape of ocular fundus is nearly planar, its 3-D depth range is very narrow.

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A visual discrimination apparatus was developed to evaluate the visual sensitivity of normal pigmented rats (n=13) and S334ter-line-3 retinal degenerate (RD) rats (n=15). The apparatus is a modified Y maze consisting of two chambers leading to the rats' home cage. Rats were trained to find a one-way exit door leading into their home cage, based on distinguishing between two different visual alternatives (either a dark background or black and white stripes at varying luminance levels) which were randomly displayed on the back of each chamber.

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Purpose: To demonstrate feature subanalysis and error correction of optical coherence tomography (OCT) data by using computer-assisted grading.

Methods: The raw exported StratusOCT (Carl Zeiss Meditec, Inc., Dublin, CA) scan data from 20 eyes of 20 patients were analyzed using custom software (termed OCTOR) designed to allow the user to define manually the retinal borders on each radial line scan.

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Retinal transplantation is one among the various treatment strategies aimed to prevent and restore visual loss. Sheets of fetal retina with or without retinal pigment epithelium (RPE) are transplanted into the subretinal space. Retinal transplants have been shown to substantially improve visual responses in rat retinal degeneration models following retinal transplantation, based on behavior and electrophysiology.

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Purpose: To compare computerized analysis with traditional grading methods in the analysis of fluorescein angiograms from patients with choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) and to examine the clinical relevance of parameters generated by computerized analysis by testing their relationships with clinical measures of vision.

Methods: Custom quantitative fluorescein analysis (QFA) software was used to analyze 62 angiograms from patients with CNV for whom distance visual acuity (DVA) data were available. On applying QFA, we obtained three mathematical parameters for each lesion component: pixel area (PA), integrated intensity (II), and positive fluorescence (PF).

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Retinal degenerative conditions increase susceptibility to light damage, but rapid retinal degeneration (RD) models show less susceptibility to cyclic dim light. We investigated whether constant blue light (BL) exposure can eliminate the residual visual responses in a comparatively rapid RD rat model. Pigmented rhodopsin mutant S334ter line-3 rat pups (21 days old) were exposed for 5-6 consecutive days to constant BL.

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Introduction: To evaluate whether eyes with longer axial lengths are associated more often with clinically significant cataracts than eyes with shorter axial lengths.

Material And Methods: Charts of consecutive patients who underwent cataract surgery by 4 resident surgeons at Los Angeles County Hospital from July 2001 through May 2002 were retrospectively reviewed. Those patients whose axial lengths were significantly different between the 2 eyes (>or=0.

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Stimulus threshold and response latencies were measured for electrically elicited retinal ganglion cell responses in retina isolated from the eyes of normal and retinal degenerate (rd1) mice. Stimulation of the ganglion cell-side in normal retina yielded a significantly lower mean threshold and shorter latency when compared with stimulation of the photoreceptor side in normal retina. The latency of the ganglion cell-side stimulation in normal retina also proved to be significantly shorter than the latency for stimulation of the ganglion cell side in rd1 retina.

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Objective: To compare the detection of clinically significant diabetic macular edema (DME) by an optical coherence tomography (OCT) grid scanning protocol and biomicroscopic examination.

Design: Retrospective case series.

Participants: Outpatients at the Doheny Eye Institute.

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Existing animal models of choroidal neovascularization (CNV) present several problems: they are hard to reproduce, they are inefficient, and the CNV created is not sustainable. The purpose of this study is to develop a highly efficient, reliable, sustainable rabbit model of CNV to facilitate the study of anti-angiogenic and anti-proliferative therapies for ocular diseases. Twenty-two pigmented rabbits were used in this study.

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Purpose: To evaluate the safety and evidence of efficacy for oral 13-cis retinoic acid as a treatment for patients with subfoveal occult choroidal neovascularization (CNV) due to age-related macular degeneration (ARMD).

Methods: Patients with active, subfoveal occult CNV with no prior treatment of the subfoveal component were eligible for inclusion. Patients received 40 mg of 13-cis retinoic acid twice daily for 5 months, stopped treatment for 2 months, and then resumed treatment for 5 months.

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Objective: To report the frequency and severity of optical coherence tomography (OCT) retinal thickness measurement errors and to describe parameters that predict these errors.

Design: Observational case series.

Participants: Two hundred consecutive patients undergoing OCT imaging.

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Optical coherence tomography (OCT), a non-invasive method, was used for qualitative assessment of fetal retinal sheet transplants by non-invasive imaging. Rhodopsin-mutant S334ter-line-3 rats with fast retinal degeneration (28-37-day old) were transplanted with fetal retinal sheets from embryonic day (E) 18-19 pigmented normal rats. Retinal thickness measurements from transplanted (n = 51), no surgery control (n = 8), and normal pigmented rat eyes (n = 6) were obtained using a Zeiss stratus OCT-3 scanning instrument.

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Objective: To report the recurrence of geographic atrophy (GA) in a patient with nonexudative age-related macular degeneration (AMD) after full macular translocation.

Design: Observational case report.

Methods: Review of the clinical, photographic, and angiographic records of a patient with GA who underwent full macular translocation.

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Multi-unit visual responses to light intensities ranging from -6.46 to 0.81 logcd/m2 were recorded from the surface of the superior colliculus of dark-adapted normal pigmented and normal albino rats.

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Previous studies evaluating neural stem cells transplanted into the mature retina have demonstrated limited levels of graft-host integration and photoreceptor differentiation. The purpose of this investigation is to enhance photoreceptor cell differentiation and integration of retinal progenitor cells (RPC) following subretinal transplantation into retinal degenerate rats by optimization of isolation, expansion, and transplantation procedures. RPCs were isolated from human placental alkaline phosphatase (hPAP)-positive embryonic day 17 (E17) rat retina and expanded in serum-free defined media.

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Purpose: To compare the size of subfoveal lesions based on photographic documentation before and after submacular surgery of choroidal neovascularization (CNV) lesions.

Methods: Subfoveal lesion sizes at baseline and month 3 follow-up visits for patients assigned to surgery in the Submacular Surgery Trials (SST) Pilot Study were assessed categorically using Macular Photocoagulation Study (MPS) disc area (DA) circles. The Submacular Surgery Trials Pilot Study groups reviewed were as follows: Group N (age-related macular degeneration [AMD]; lesion <50% blood; classic CNV present; size < or =9 MPS DAs); Group R (AMD; prior nonfoveal laser; classic CNV present; size < or =9 MPS DAs); Group B (AMD; lesion > or =50% blood); and Group H (ocular histoplasmosis syndrome or idiopathic; classic CNV present; size < or =9 MPS DAs).

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