Bio

Clinical Focus


  • Macular Degeneration, Diabetic Retinopathy, Retinal Vascular Disease, Retinal Detachment Surgery
  • Branch and Central Retinal Vein Occlusion, Macular Pucker
  • Ophthalmology
  • Macular Edema, Macular Hole Surgery, Epiretinal Membrane, Endophthalmitis
  • Lens Dislocation and Subluxation, Complications of Cataract Surgery

Academic Appointments


Administrative Appointments


  • Director, Ophthalmic Diagnostics (2010 - Present)
  • Ophthalmology Department Liaison, Stanford University Hospital Operating Rooms (2013 - Present)

Honors & Awards


  • America's Top Ophthalmologists, Consumer’s Research Council of America (2012, 2013)
  • Heed Fellowship, Heed Ophthalmic Foundation (2010)
  • Mentoring Program in Ophthalmology Scholarship, Annenberg Center for Health Sciences at Eisenhower (2009)
  • Paul Kayser International Travel Scholar, Pan-American Ophthalmological Foundation (2009)
  • Howard Hughes Medical Institute Research Training Fellowship, Howard Hughes Medical Institute (2003)
  • Medical Scientist Research Fellowship, Stanford Medical Scholars Program (2003)
  • Certificate of Recognition, NASA (2003)
  • ARVO Travel Award, National Eye Institute (2003)
  • Kolos Scholar, Stanford Medical Scholars Program (2001)
  • AMA Travel Award, American Medical Association (2001)
  • Baxter Foundation Scholar, Stanford Medical Scholars Program (2001)
  • Award for Excellence in Teaching, Stanford Department of Biological Sciences (2000)
  • Firestone Medal for Excellence in Research, Stanford University (1999)

Boards, Advisory Committees, Professional Organizations


  • Fellow, American Academy of Ophthalmology (2011 - Present)
  • Fellow, American College of Surgeons (2012 - Present)
  • Member, The Retina Society (2014 - Present)
  • Member, American Society of Retina Specialists (2009 - Present)
  • Member, Vit-Buckle Society (2012 - Present)
  • Life Member, Society of Heed Fellows (2012 - Present)
  • Member, Association for Research in Vision and Ophthalmology (2001 - Present)
  • President-Elect, Stanford University Medical Center Alumni Association Board of Governors (2013 - Present)
  • Editorial Board Member, Ophthalmic Surgery, Lasers, and Imaging Retina (2012 - Present)
  • Editorial Board Member, American Society of Retina Specialists Retina Image Bank (2013 - Present)
  • Editorial Board Member, Journal of Ophthalmology (2013 - Present)
  • Editorial Board Member, Austin Journal of Clinical Ophthalmology (2013 - Present)
  • Editorial Board Member, International Journal of Ophthalmology & Eye Science (IJOES) (2013 - Present)
  • Editorial Board Member, Journal of Ophthalmic Research (2013 - Present)
  • Editorial Board Member, JSM Ophthalmology (2013 - Present)
  • Editorial Board Member, Clinical Microbiology: Open Access (CMO) (2013 - Present)
  • Editorial Board Member, Journal of Clinical & Medical Case Reports (2013 - Present)
  • Editorial Board Member, WebMedCentral Plus (2012 - Present)
  • Member, Howard Hughes Medical Institute Bay Area Alumni Network Steering Committee (2012 - Present)
  • Member, Ophthalmology Innovation Network (2012 - Present)
  • Medical and Surgical Retina Section Editor, The Eye Handbook (2012 - Present)
  • Lead Faculty Member, WebMedCentral (2011 - Present)
  • Contributing Editor, OphthalmologyWeb (2008 - Present)

Professional Education


  • Board Certification: Ophthalmology, American Board of Ophthalmology (2010)
  • Fellowship:Stanford University School of Medicine (06/30/2010) CA
  • Residency:Bascom Palmer Eye Institute (06/30/2009) FL
  • Internship:Huntington Memorial Hospital (06/24/2006) CA
  • Medical Education:Stanford School of Medicine (06/12/2005) CA
  • MS, Stanford University, Biological Sciences (2000)
  • AB/BS, Stanford University, Philosophy & Biological Sciences (1999)

Community and International Work


  • Arbor Free Clinic, Menlo Park

    Partnering Organization(s)

    Stanford University School of Medicine

    Populations Served

    Underserved

    Location

    Bay Area

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    Yes

  • Haitian Eye Initiative, Cap Haitian, Milot, Thomonde

    Topic

    Cataract and Glaucoma Surgery

    Partnering Organization(s)

    Surgical Eye Expeditions, Project Medishare

    Populations Served

    Northern and Central Haiti

    Location

    International

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    Yes

Research & Scholarship

Current Research and Scholarly Interests


Imaging Informatics
Retinal Vascular Disease
Retinal Laser Treatments
Hereditary Retinal Degenerations
Macular Degeneration
Ocular Imaging
Diabetic Retinopathy
Retinopathy of Prematurity
Endophthalmitis
Acute Retinal Necrosis
Uveitis

Clinical Trials


  • Endogenous Endophthalmitis in the Inpatient Setting Recruiting

    The purpose of this study is to determine the rate of endogenous endophthalmitis in patients admitted to Stanford Hospital with a systemic infection and positive blood cultures, as this may improve the clinical care of this population of patients.

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  • Study of Bimonthly VEGF Trap-Eye Compared to As-needed Administration or Other Therapy for Exudative Age-Related Macular Degeneration Recruiting

    Over the last several years, the standard of care for wet macular degeneration has become treatment with intravitreal injections of ranibizumab (Lucentis, Genentech), administered as frequently as every 4 weeks. In contrast, clinical trials of a soluble VEGF receptor, Aflibercept/VEGF Trap-Eye (Eylea, Regeneron Pharmaceuticals) have demonstrated maintained anatomic and visual improvement with many fewer injections (typically monthly injections for 3 months, followed by every-other-month injections, and as few as 5 injections a year). The purpose of this study is to determine whether patients who have switched from ranibizumab to VEGF Trap-Eye have comparable results.

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  • Rates of Apnea in Patients Undergoing Vitreoretinal Surgery Recruiting

    The purpose of this study is to determine if apnea (the stopping of breathing) occurs in patients undergoing undergoing monitored anesthesia care (MAC) for vitreoretinal surgery

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  • Study of Human Central Nervous System Stem Cells (HuCNS-SC) in Age-Related Macular Degeneration (AMD) Recruiting

    The purpose of this Phase I/II study is to investigate the safety and preliminary efficacy of unilateral subretinal transplantation of HuCNS-SC cells in subjects with geographic atrophy secondary to age-related macular degeneration.

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  • Outcomes of Diabetic Macula Edema Patients Switched to Aflibercept From Bevacizumab and/or Ranibizumab Recruiting

    Patients with diabetic macular edema who were switched to aflibercept after having been treated with bevacizumab or ranibizumab were retrospectively reviewed to assess for visual acuity and anatomic outcomes.

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Projects


  • Automated Analysis of Retinal OCT Images, Stanford University (2012 - Present)

    Location

    300 Pasteur Drive, Stanford, CA 94305

Teaching

2013-14 Courses


Publications

Journal Articles


  • Automated drusen segmentation and quantification in SD-OCT images. Medical image analysis Chen, Q., Leng, T., Zheng, L., Kutzscher, L., Ma, J., de Sisternes, L., Rubin, D. L. 2013; 17 (8): 1058-1072

    Abstract

    Spectral domain optical coherence tomography (SD-OCT) is a useful tool for the visualization of drusen, a retinal abnormality seen in patients with age-related macular degeneration (AMD); however, objective assessment of drusen is thwarted by the lack of a method to robustly quantify these lesions on serial OCT images. Here, we describe an automatic drusen segmentation method for SD-OCT retinal images, which leverages a priori knowledge of normal retinal morphology and anatomical features. The highly reflective and locally connected pixels located below the retinal nerve fiber layer (RNFL) are used to generate a segmentation of the retinal pigment epithelium (RPE) layer. The observed and expected contours of the RPE layer are obtained by interpolating and fitting the shape of the segmented RPE layer, respectively. The areas located between the interpolated and fitted RPE shapes (which have nonzero area when drusen occurs) are marked as drusen. To enhance drusen quantification, we also developed a novel method of retinal projection to generate an en face retinal image based on the RPE extraction, which improves the quality of drusen visualization over the current approach to producing retinal projections from SD-OCT images based on a summed-voxel projection (SVP), and it provides a means of obtaining quantitative features of drusen in the en face projection. Visualization of the segmented drusen is refined through several post-processing steps, drusen detection to eliminate false positive detections on consecutive slices, drusen refinement on a projection view of drusen, and drusen smoothing. Experimental evaluation results demonstrate that our method is effective for drusen segmentation. In a preliminary analysis of the potential clinical utility of our methods, quantitative drusen measurements, such as area and volume, can be correlated with the drusen progression in non-exudative AMD, suggesting that our approach may produce useful quantitative imaging biomarkers to follow this disease and predict patient outcome.

    View details for DOI 10.1016/j.media.2013.06.003

    View details for PubMedID 23880375

  • Traumatic airbag maculopathy. JAMA ophthalmology Kung, J., Leung, L. B., Leng, T., Liao, Y. J. 2013; 131 (5): 685-687

    View details for DOI 10.1001/jamaophthalmol.2013.883

    View details for PubMedID 23699847

  • Quantitative Evaluation of Drusen on Photographs OPHTHALMOLOGY Rubin, D. L., de Sisternes, L., Kutzscher, L., Chen, Q., Leng, T., Zheng, L. L. 2013; 120 (3): 644-?

    View details for Web of Science ID 000315738200034

    View details for PubMedID 23714606

  • Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP): Four-years of Screening with Telemedicine CURRENT EYE RESEARCH Fijalkowski, N., Zheng, L. L., Henderson, M. T., Wallenstein, M. B., Leng, T., Moshfeghi, D. M. 2013; 38 (2): 283-291

    Abstract

    To report the four-year experience of the Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP) telemedicine initiative, which was developed to reduce the risk of blindness from retinopathy of prematurity (ROP).A retrospective analysis of the SUNDROP archival data between 12/1/2005 and 11/30/2009. A total of 410 consecutively enrolled infants meeting ROP screening criteria had nurse-obtained fundoscopic images evaluated remotely by an ROP specialist. Every infant then received at least one dilated bedside binocular indirect ophthalmoscope (BIO) examination within one week of discharge. All infants were then followed with both telemedicine images and bedside evaluation in clinic according to recommended screening timelines. Primary outcomes were treatment-warranted ROP (TW-ROP), defined as Early Treatment of ROP Type 1, and adverse anatomical outcomes.The SUNDROP telemedicine screening initiative has not missed any TW-ROP in its four-year evaluation period. A total of 410 infants (820 eyes) were imaged, resulting in 1486 examinations and 18,097 unique images. An average of 12.2 images were obtained per patient. Fourteen infants met TW-ROP criteria on telemedicine examination. After bedside evaluation, 13 infants required laser photocoagulation and one was followed until he spontaneously regressed. Infants with TW-ROP had a significantly lower gestational age (24.9 weeks), birth weight (658.7 grams), and were more likely to be male than the no TW-ROP cohort (all p values <0.00001). Telemedicine had a calculated sensitivity of 100%, specificity of 99.8%, positive predicative value of 92.9% and negative predictive value of 100% for the detection of TW-ROP. No patient progressed to retinal detachment or any adverse anatomical outcome.The SUNDROP initiative demonstrated a high degree of diagnostic reliability and was able to capture all infants with TW-ROP. Telemedicine offers a cost-effective, reliable and accurate screening methodology for identifying infants with TW-ROP without sacrificing quality of care.

    View details for DOI 10.3109/02713683.2012.754902

    View details for Web of Science ID 000314900400008

    View details for PubMedID 23330739

  • Abundance of Myelinated Nerve Fibers JAMA OPHTHALMOLOGY Leng, T., Nyong'o, O. L. 2013; 131 (2): 245-245

    View details for Web of Science ID 000316684400024

    View details for PubMedID 23411895

  • Carbon nanotube bucky paper as an artificial support membrane for retinal cell transplantation. Ophthalmic surgery, lasers & imaging retina Leng, T., Fishman, H. A. 2013; 44 (1): 73-76

    Abstract

    Transplantation of epithelial cells on a substrate to rescue diseased retinal cells is an experimental therapy for age-related macular degeneration. Carbon nanotube bucky paper was tested for cell transplantation into the retina.Bucky paper was prepared and human RPE cells cultured on its surface demonstrating its utility as a cell transplantation substrate. Bucky paper was implanted underneath 9 rabbit retinas using a standard 3-port pars plana vitrectomy and subretinal bleb. A 1 mm retinotomy was created through which Bucky paper precut to fit was inserted with the subretinal forceps, into the subretinal bleb. The retina was reattached by airfluid exchange.By light microscopy, RPE cells demonstrated normal morphology and growth patterns on the bucky paper surface. Scanning electron microscopy confirmed a confluent monolayer of cells, and indicated the formation of microvilli on the apical surface. Bucky paper remained flat in the subretinal space after 2 weeks, the retina fully attached without edema or inflammation.Bucky paper possesses the necessary attributes for therapeutic cell transplantation in the eye.

    View details for DOI 10.3928/23258160-20121221-16

    View details for PubMedID 23410811

  • FOVEAL CAVITATION AS AN OPTICAL COHERENCE TOMOGRAPHY FINDING IN CENTRAL CONE DYSFUNCTION RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Leng, T., Marmor, M. F., Kellner, U., Thompson, D. A., Renner, A. B., Moore, W., Sowden, J. C. 2012; 32 (7): 1411-1419

    Abstract

    To describe a distinctive foveal cavitation as seen by spectral-domain optical coherence tomography in certain cone dysfunction syndromes.Observational case series. Patients were evaluated by dilated fundus examination, fundus photography, fundus autofluorescence, full-field electroretinogram, multifocal electroretinogram, spectral-domain optical coherence tomography, color vision testing, fluorescein angiography, Goldmann visual field testing, and molecular genetic analysis.We present eight patients with foveal cavitation in association with presumed cone dysfunction. This was characterized on spectral-domain optical coherence tomography by a gap in the subfoveal outer segment layer without more diffuse retinal thinning. There were 5 patients of age 10 years to 27 years and 3 patients of age 49 years to 52 years, with a 1.5- to 38-year history of bilateral visual loss. A small foveal oval-shaped area of reduced foveal fundus autofluorescence, surrounded by increased fundus autofluorescence, was seen in the younger patients, and a broad circle of increased fundus autofluorescence in the older patients. The multifocal electroretinogram always showed central amplitude reduction, but there were varying degrees of cone dysfunction on full-field electroretinogram. There were mild abnormalities on desaturated color vision testing. The family history was noncontributory in all cases. None of the cases were congenital. ABCA4 gene mutations were identified in three of five patients tested; CNGB3 testing was negative in these patients.Cone dysfunction syndromes typically show retinal thinning on optical coherence tomography imaging, although several case reports have noted focal outer retinal loss. Our case series shows that a distinctive optical coherence tomography finding, foveal cavitation, may be a clue to cone dysfunction syndromes, but is not specific to any one hereditary disorder or age group.

    View details for DOI 10.1097/IAE.0b013e318236e4ea

    View details for Web of Science ID 000305782100025

    View details for PubMedID 22466470

  • Cannula-Based 25-Gauge Vitreous Tap And Injection: A New Surgical Technique RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Chan, A., Leng, T., Moshfeghi, D. M. 2012; 32 (5): 1021-1022

    View details for DOI 10.1097/IAE.0b013e318248e6ba

    View details for Web of Science ID 000303502200022

    View details for PubMedID 22311272

  • Effect of Lidocaine Gel Anesthesia on Endophthalmitis Rates Following Intravitreal Injection OPHTHALMIC SURGERY LASERS & IMAGING Lad, E. M., Maltenfort, M. G., Leng, T. 2012; 43 (2): 115-120

    Abstract

    To determine whether the use of lidocaine gel before application of povidone-iodine affects endophthalmitis rates following intravitreal injections.Retrospective consecutive case series of all intravitreal injections and post-intravitreal injection endophthalmitis cases at one institution from 2000 to 2009. A review of medical records of post-intravitreal injection endophthalmitis cases was performed to determine whether lidocaine gel was applied prior to povidone-iodine antisepsis and to analyze the clinical course and outcomes.A total of 8,802 intravitreal injections were administered during the study period. When no lidocaine gel was used prior to povidone-iodine antisepsis, four cases of endophthalmitis following 4,120 intravitreal injections (0.097%) were recorded. When 2% lidocaine gel was applied before povidone-iodine, four cases of endophthalmitis following 4,682 intravitreal injections (0.085%) were observed (P = 1.00, odds ratio = 1.12).The use of lidocaine gel prior to povidone-iodine antisepsis did not significantly alter post-intravitreal injection endophthalmitis rates.

    View details for DOI 10.3928/15428877-20120119-01

    View details for Web of Science ID 000305342900004

    View details for PubMedID 22283227

  • REDUCING ORAL FLORA CONTAMINATION OF INTRAVITREAL INJECTIONS WITH FACE MASK OR SILENCE RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Doshi, R. R., Leng, T., Fung, A. E. 2012; 32 (3): 473-476

    Abstract

    To provide experimental evidence to support or refute the proposition that the use of surgical face masks and/or avoidance of talking can decrease the dispersion of respiratory flora during an intravitreal injection.Ten surgeons recited a 30-second standardized script with blood agar plates positioned 30 cm below their mouths. The plates were divided into 4 groups, with 10 plates per group. In Group 1, participants did not wear a face mask. In Group 2, participants wore a standard surgical mask. In Group 3, no mask was worn, but plates were pretreated with 5% povidone-iodine. In Group 4, no mask was worn, and participants remained silent for 30 seconds. The plates were then incubated at 37°C for 24 hours, and the number of colony-forming units (CFUs) was determined.Mean bacterial growth were as follows: Group 1, 8.6 CFUs per subject; Group 2, 1.1 CFUs per subject; Group 3, 0.1 CFUs per subject; and Group 4, 2.4 CFUs per subject. Differences between the groups were statistically significant (P < 0.05), with the exception of Group 2 versus Group 4 (P = 0.115).The use of a face mask and avoidance of talking each significantly decreased the dispersion of bacteria. Even without these interventions, plates pretreated with povidone-iodine demonstrated the least bacterial growth.

    View details for DOI 10.1097/IAE.0B013E31822C2958

    View details for Web of Science ID 000300907200007

    View details for PubMedID 22374155

  • The influence of medical school and residency training program upon choice of an academic career and academic productivity among otolaryngology faculty in the United States of America: Our experience of 1433 academic otolaryngologists CLINICAL OTOLARYNGOLOGY Leng, T., Jaben, K. A., Zheng, L., Yang, J., Paulus, Y. M., Moshfeghi, A. A., Maltenfort, M. G., Campbell, P. G., Ratliff, J. K., Moshfeghi, D. M. 2012; 37 (1): 58-62
  • Two cases of X-linked retinoschisis with different spectral domain optical coherence tomography findings. Clinical ophthalmology (Auckland, N.Z.) Leng, T. 2012; 6: 1563-1565

    Abstract

    Spectral domain optical coherence tomography was used to image the maculae of two brothers who had the diagnosis of X-linked retinoschisis maculopathy. One patient demonstrated a large foveal cyst in one eye and a lamellar macular hole in the fellow eye. The second patient demonstrated small retinal cysts in multiple layers of the retina. Spectral domain optical coherence tomography allowed high-resolution imaging and characterization of the features in X-linked retinoschisis in these patients, and it highlighted the variability of the same genetic disease, even in one family.

    View details for DOI 10.2147/OPTH.S36756

    View details for PubMedID 23055679

  • Intravitreal dexamethasone in the management of delayed-onset bleb-associated endophthalmitis. International journal of inflammation Jacobs, D. J., Pathengay, A., Flynn, H. W., Leng, T., Miller, D., Shi, W. 2012; 2012: 503912-?

    Abstract

    Purpose. To report the visual acuity (VA) outcomes and culture results of delayed-onset bleb-associated endophthalmitis (BAE) with and without intravitreal dexamethasone (IVD). Methods. Retrospective nonrandomized comparative case series of BAE at Bascom Palmer Eye Institute between January 1, 1996 and December 31, 2009. Clinical data were compared using the 2-sided Student's t-test for patients who received IVD and patients who did not receive IVD. Results. 70/83 (84%) received IVD, and 13/83 (16%) did not receive IVD. Mean baseline VA was 20/90 in the IVD group and 20/70 in the group that did not receive IVD (P = 0.57). Mean presenting VA was 0.9/200 in the IVD group and 1.7/200 in the group that did not receive IVD (P = 0.23). Repeat cultures were positive in 2/70 (3%) IVD cases and 1/13 (8%) cases that did not receive IVD (P = 0.57). Mean VA at 1 month was 5/200 in the IVD group and 1.8/200 in the group that did not receive IVD, logMAR? of 0.85 and 1.56, respectively (P = 0.02). Mean VA at 3 months was 7/200 in the IVD group and 3/200 in the group that did not receive IVD, logMAR? of 0.74 and 1.33, respectively (P = 0.14). Conclusion. In the current study of BAE, IVD was associated with improved short-term VA outcomes without an increased rate of persistent infection.

    View details for DOI 10.1155/2012/503912

    View details for PubMedID 22288020

  • Medical School and Residency Influence on Choice of an Academic Career and Academic Productivity Among US Neurology Faculty ARCHIVES OF NEUROLOGY Campbell, P. G., Lee, Y. H., Bell, R. D., Maltenfort, M. G., Moshfeghi, D. M., Leng, T., Moshfeghi, A. A., Ratliff, J. K. 2011; 68 (8): 999-1004

    Abstract

    To evaluate the effectiveness of medical schools and neurology training programs in the United States by determining their contribution to academic neurology in terms of how many graduates choose academic careers and their respective influence on current medical knowledge through bibliometric analysis.Biographical information from current faculty members of neurology training programs in the United States was obtained through an Internet-based search of departmental Web sites. Collected variables included medical school attended, residency program completed, and current academic rank. For each faculty member, ISI Web of Science and Scopus h -indices were also collected.Data from academic neurologists from 120 training programs with 3249 faculty members were collected. All data regarding training program and medical school education were compiled and analyzed by the institution from which each individual graduated. The 20 medical schools and neurology residency training programs producing the greatest number of graduates remaining in academic practice and the mean h -indices are reported. More medical school graduates of the Columbia University College of Physicians and Surgeons chose to enter academic neurology practice than the graduates of any other institution. Analyzed by residency training program attended, New York Presbyterian Hospital (Columbia University), Mayo Clinic (Rochester, Minnesota), and Mount Sinai Medical Center (New York, New York) produced the most graduates remaining in academics.This retrospective, longitudinal cohort study examines through quantitative measures the academic productivity and rank of academic neurologists. The results demonstrate that several training programs excel in producing a significantly higher proportion of academically active neurologists.

    View details for DOI 10.1001/archneurol.2011.67

    View details for Web of Science ID 000293647500005

    View details for PubMedID 21482917

  • Medical school and residency influence on choice of an academic career and academic productivity among neurosurgery faculty in the United States Clinical article JOURNAL OF NEUROSURGERY Campbell, P. G., Awe, O. O., Maltenfort, M. G., Moshfeghi, D. M., Leng, T., Moshfeghi, A. A., Ratliff, J. K. 2011; 115 (2): 380-386

    Abstract

    Factors determining choice of an academic career in neurological surgery are unclear. This study seeks to evaluate the graduates of medical schools and US residency programs to determine those programs that produce a high number of graduates remaining within academic programs and the contribution of these graduates to academic neurosurgery as determined by h-index valuation.Biographical information from current faculty members of all accredited neurosurgery training programs in the US with departmental websites was obtained. Any individual who did not have an American Board of Neurological Surgery certificate (or was not board eligible) was excluded. The variables collected included medical school attended, residency program completed, and current academic rank. For each faculty member, Web of Science and Scopus h-indices were also collected.Ninety-seven academic neurosurgery departments with 986 faculty members were analyzed. All data regarding training program and medical school education were compiled and analyzed by center from which each faculty member graduated. The 20 medical schools and neurosurgical residency training programs producing the greatest number of graduates remaining in academic practice, and the respective individuals' h-indices, are reported. Medical school graduates of the Columbia University College of Physicians and Surgeons chose to enter academics the most frequently. The neurosurgery training program at the University of Pittsburgh produced the highest number of academic neurosurgeons in this sample.The use of quantitative measures to evaluate the academic productivity of medical school and residency graduates may provide objective measurements by which the subjective influence of training experiences on choice of an academic career may be inferred. The top 3 residency training programs were responsible for 10% of all academic neurosurgeons. The influence of medical school and residency experiences on choice of an academic career may be significant.

    View details for DOI 10.3171/2011.3.JNS101176

    View details for Web of Science ID 000293145100037

    View details for PubMedID 21495810

  • SELECTIVE RETINAL THERAPY WITH MICROSECOND EXPOSURES USING A CONTINUOUS LINE SCANNING LASER RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Paulus, Y. M., Jain, A., Nomoto, H., Sramek, C., Gariano, R. F., Andersen, D., Schuele, G., Leung, L., Leng, T., Palanker, D. 2011; 31 (2): 380-388

    Abstract

    To evaluate the safety, selectivity, and healing of retinal lesions created using a continuous line scanning laser.A 532-nm Nd:YAG laser (PASCAL) with retinal beam diameters of 40 ?m and 66 ?m was applied to 60 eyes of 30 Dutch-belted rabbits. Retinal exposure duration varied from 15 ?s to 60 ?s. Lesions were acutely assessed by ophthalmoscopy and fluorescein angiography. Retinal pigment epithelial (RPE) flatmounts were evaluated with live-dead fluorescent assay. Histological analysis was performed at 7 time points from 1 hour to 2 months.The ratios of the threshold of rupture and of ophthalmoscopic visibility to fluorescein angiography visibility (measures of safety and selectivity) increased with decreasing duration and beam diameter. Fluorescein angiography and live-dead fluorescent assay yielded similar thresholds of RPE damage. Above the ophthalmoscopic visibility threshold, histology showed focal RPE damage and photoreceptor loss at 1 day, without inner retinal effects. By 1 week, photoreceptor and RPE continuity was restored. By 1 month, photoreceptors appeared normal.: Retinal therapy with a fast scanning continuous laser achieves selective targeting of the RPE and, at higher power, of the photoreceptors without permanent scarring or inner retinal damage. Continuous scanning laser can treat large retinal areas within standard eye fixation time.

    View details for DOI 10.1097/IAE.0b013e3181e76da6

    View details for Web of Science ID 000286586500024

    View details for PubMedID 20930656

  • DELAYED-ONSET BLEB-ASSOCIATED ENDOPHTHALMITIS (1996-2008) Causative Organisms and Visual Acuity Outcomes RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Leng, T., Miller, D., Flynn, H. W., Jacobs, D. J., Gedde, S. J. 2011; 31 (2): 344-352

    Abstract

    The purpose of this study was to report the clinical features, organisms, and outcomes of patients with delayed-onset bleb-associated endophthalmitis.Retrospective consecutive case series. Patients who were treated for delayed-onset bleb-associated endophthalmitis between January 1, 1996, and July 1, 2008, at a single institution were included. Information on visual acuities, clinical characteristics, causative organisms, and treatment outcomes were collected. Infections within 1 month of glaucoma filtering surgery, inadvertent filtering blebs after cataract surgery, and patients with glaucoma drainage devices were excluded.A total of 71 eyes from 68 patients were identified. An adjunctive antifibrotic agent was used in 48 eyes (68%). The mean time between surgery and endophthalmitis was 4.8 years (range, 0.1-16; standard deviation, 3.6). The average follow-up time after initial treatment was 37 months (range 1-144; standard deviation, 41). At presentation, 17 eyes (24%) had a bleb leak. Fifty-seven eyes (83%) were culture positive. The most common causative organisms were Streptococcus species in 20 eyes (30%), gram-negative organisms in 19 eyes (28%), and coagulase-negative Staphylococcus in 12 eyes (18%). All gram-positive isolates were sensitive to vancomycin. Nine eyes (13%) eventually underwent evisceration or enucleation secondary to pain and/or poor vision. The main outcome measure was best-corrected visual acuity at the last follow-up examination. Final visual acuities in the initial tap/inject group (n = 45) versus the initial vitrectomy group (n = 24) were as follows: ? 20/40 (29% vs. 4.2%), 20/50 to 20/400 (36% vs. 29%), and <5/200 (36% vs. 62%).Streptococcus species and gram-negative organisms were the most common causative isolates identified in this case series of delayed-onset bleb-associated endophthalmitis. Despite treatment of the infection, visual outcomes were generally poor.

    View details for DOI 10.1097/IAE.0b013e3181e09810

    View details for Web of Science ID 000286586500020

    View details for PubMedID 20838358

  • The vitreous trap: a simple, surgeon-controlled technique for obtaining undiluted vitreous and subretinal specimens during pars plana vitrectomy. Retina (Philadelphia, Pa.) Moshfeghi, A. A., Albini, T. A., Kitchens, J. W., Leng, T., Moshfeghi, D. M. 2011; 31 (2): 426-427

    View details for DOI 10.1097/IAE.0b013e318200c125

    View details for PubMedID 21233788

  • Improving the therapeutic window of retinal photocoagulation by spatial and temporal modulation of the laser beam JOURNAL OF BIOMEDICAL OPTICS Sramek, C., Leung, L., Leng, T., Brown, J., Paulus, Y. M., Schuele, G., Palanker, D. 2011; 16 (2)

    Abstract

    Decreasing the pulse duration helps confine damage, shorten treatment time, and minimize pain during retinal photocoagulation. However, the safe therapeutic window (TW), the ratio of threshold powers for thermomechanical rupture of Bruch's membrane and mild coagulation, also decreases with shorter exposures. Two potential approaches toward increasing TW are investigated: (a) decreasing the central irradiance of the laser beam and (b) temporally modulating the pulse. An annular beam with adjustable central irradiance was created by coupling a 532-nm laser into a 200-?m core multimode optical fiber at a 4-7 deg angle to normal incidence. Pulse shapes were optimized using a computational model, and a waveform generator was used to drive a PASCAL photocoagulator (532 nm), producing modulated laser pulses. Acute thresholds for mild coagulation and rupture were measured in Dutch-Belted rabbit in vivo with an annular beam (154-163 ?m retinal diameter) and modulated pulse (132 ?m, uniform irradiance "flat-top" beam) with 2-50 ms pulse durations. Thresholds with conventional constant-power pulse and a flat-top beam were also determined. Both annular beam and modulated pulse provided a 28% increase in TW at 10-ms duration, affording the same TW as 20-ms pulses with conventional parameters.

    View details for DOI 10.1117/1.3542045

    View details for Web of Science ID 000288939200056

    View details for PubMedID 21361711

  • Retinopathy of prematurity in an infant with Aicardi's syndrome EYE Leng, T., Moshfeghi, D. M. 2011; 25 (2): 257-258

    View details for DOI 10.1038/eye.2010.189

    View details for Web of Science ID 000287187300025

    View details for PubMedID 21151036

  • Delayed-onset bleb-associated endophthalmitis: presentation and outcome by culture result. Clinical ophthalmology (Auckland, N.Z.) Jacobs, D. J., Leng, T., Flynn, H. W., Shi, W., Miller, D., Gedde, S. J. 2011; 5: 739-744

    Abstract

    To determine how culture results are associated with clinical presentations and outcomes in delayed-onset bleb-associated endophthalmitis (BAE).Retrospective consecutive case series of BAE at Bascom Palmer Eye Institute between January 1, 1996 and December 31, 2009. All patients had prior glaucoma filtering surgery. BAE was defined as intraocular infection with vitreous involvement receiving treatment with intravitreal antibiotics. Visual acuity (VA) outcomes and other clinical data were grouped by culture result and compared using the 2-sided Student's t-test.Mean logMAR change at 3 months after treatment (3-month logMAR?).Eighty-six eyes of 85 patients were identified. Two eyes were primarily eviscerated. Fifty-three (63%) eyes were culture-positive with the following organisms: Streptococcus, 21 (25%); coagulase-negative Staphylococcus, 9 (11%); Enterococcus, 6 (7%); Gram-negative, 15 (18%); Moraxella, 8 (10%); Pseudomonas, 3 (4%); and Serratia, 3 (4%). Presenting logMAR VA: culture-positive worse than culture-negative cases (2.45 vs 2.19, P = 0.05). Presenting intraocular pressure (IOP): culture-positive higher than culture-negative cases (24 mmHg vs 14 mmHg, P = 0.002). Poor presenting view of the fundus: Streptococcus worse than coagulase-negative Staphylococcus cases (90% vs 44%, P = 0.006), Pseudomonas and Serratia worse than Moraxella cases (100% vs 50%, P = 0.04). Three month logMAR?: culture-positive worse than culture-negative cases (1.03 vs 0.43, P = 0.02), Streptococcus worse than coagulase-negative Staphylococcus cases (1.44 vs 0.31, P = 0.004), Pseudomonas and Serratia worse than coagulase-negative Staphylococcus cases (2.41 vs 0.31, P = 0.001), Pseudomonas and Serratia worse than Moraxella cases (2.41 vs 0.04, P = 0.001). A culture result of Streptococcus or Serratia was present in 6 of 7 eyes that received an additional treatment of enucleation or evisceration (P = 0.01).Culture-positive cases were associated with worse presenting VA, higher presenting IOP, and worse VA outcomes than culture-negative cases. Streptococcus, Pseudomonas, and Serratia cases were associated with poor presenting view of the fundus and worse VA outcomes than coagulase-negative Staphylococcus and Moraxella cases.

    View details for DOI 10.2147/OPTH.S17975

    View details for PubMedID 21691583

  • Endogenous Candida albicans endophthalmitis following spontaneous abortion and IUD removal. Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye Doshi, R. R., Wender, J. D., Jumper, J. M., Sanislo, S. R., Leng, T. 2011; 42 Online: e132-4

    Abstract

    The authors report a rare case of a 32-year-old woman who developed endogenous Candida albicans endophthalmitis following spontaneous abortion and removal of a contraceptive intrauterine device. Considerations regarding diagnosis and management are presented based on a review of the literature.

    View details for DOI 10.3928/15428877-20111208-02

    View details for PubMedID 22165949

  • Neovascularization in Purtscher's retinopathy. Clinical ophthalmology (Auckland, N.Z.) Chan, A., Fredrick, D. R., Leng, T. 2011; 5: 1585-1587

    Abstract

    We report a case of neovascularization secondary to Purtscher's retinopathy that showed minimal improvement with photocoagulation treatment. A 14-year-old boy with a history of cerebellar medulloblastoma presented with blurry vision and floaters after being struck by a motor vehicle while riding his bike. At presentation, visual acuity was 20/400 in his right eye and counting fingers in his left eye. Fundus examination showed disk edema, retinal whitening, and retinal hemorrhages in both eyes. Optical coherence tomography demonstrated thinning of the temporal retina and disruption of the inner segment-outer segment junction of the photoreceptor layer in the right eye and thickening and edema of the nasal macula, as well as a central foveal hyper-reflectivity, in the left eye. At the initial visit, there was no ischemia or neovascularization (NV). One month later, the patient developed NV of the disk and ischemia in the mid-periphery of the left eye. The patient underwent treatment with pan-retinal photocoagulation. The NV regressed, but visual outcome remained poor at his 5-month follow-up visit.

    View details for DOI 10.2147/OPTH.S26076

    View details for PubMedID 22125405

  • Photodynamic therapy rescue for subretinal fluid exacerbation after focal laser treatment in idiopathic central serous chorioretinopathy. The open ophthalmology journal Leng, T., Sanislo, S. R., Jack, R. L. 2011; 5: 6-9

    Abstract

    To report a case of subretinal leakage after focal laser treatment for idiopathic central serous chorioretinopathy (ICSC). This rare complication was successfully treated with photodynamic therapy (PDT).Interventional case report.A 36-year-old male presented with ICSC in his right eye. After a period of observation without resolution, he was treated with focal laser. That treatment resulted in a massive exacerbation of his subretinal fluid. PDT was successfully used to treat the severe exacerbation with rapid resolution of the subretinal fluid, improvement in visual acuity, decreased leakage on fluorescein angiography, and reduction of subretinal fluid on ophthalmoscopic exam and by optical coherence tomography.Ophthalmologists should consider the use of PDT in cases where focal laser causes an exacerbation of subretinal fluid in ICSC.

    View details for DOI 10.2174/1874364101105010006

    View details for PubMedID 21399767

  • Kinetics of central macular thickness reduction in patients with macular edema after intravitreal drug therapy. Clinical ophthalmology (Auckland, N.Z.) He, L., Chan, A., Leng, T., Blumenkranz, M. S. 2011; 5: 1751-1758

    Abstract

    The purpose of this study was to characterize central macular thickness and retinal volume following intravitreal injections using time domain and spectral domain optical coherence tomography (TD-OCT and SD-OCT, respectively).Nine patients with macular edema secondary to diabetes or retinal vein occlusion treated with intravitreal triamcinolone 4.0 mg and/or bevacizumab 1.25 mg were enrolled. Central macular thickness and volume was measured by SD-OCT and TD-OCT scan at baseline, and 1, 3, 6, 24, 48 hours, and 1 week postinjection.Equations were derived to describe central macular thickness and volume reduction in the hours following intravitreal injection. Measurements of central macular thickness by SD-OCT were significantly reduced by 3 hours (P = 0.03) and retinal volume by 6 hours (P = 0.03). Central macular thickness measured 40.9 (28.6-53.2) ?m thicker on the SD-OCT instrument while volume measured 3.47 (3.27-3.66) mm(3) higher.Significant central macular thickness and volume reductions occur in the first hours after injection with triamcinolone and/or bevacizumab.

    View details for DOI 10.2147/OPTH.S26631

    View details for PubMedID 22205836

  • Focal periocular carboplatin chemotherapy avoids systemic chemotherapy for unilateral, progressive retinoblastoma. Retina (Philadelphia, Pa.) Leng, T., Cebulla, C. M., Schefler, A. C., Murray, T. G. 2010; 30 (4): S66-8

    Abstract

    The purpose of this study was to report a case of a boy with unilateral, multifocal retinoblastoma who was successfully treated with periocular carboplatin injections for a tumor that progressed despite focal laser ablation.This is an interventional case report. A boy with a paternal history of retinoblastoma and in utero identification of an RB1 mutation was monitored beginning at 2 weeks of age. When the patient was 6 months old, the first tumor was detected and treatment with a direct, ablative, large spot-size diode laser was initiated. During a 38-month period of follow-up, the patient received 23 laser treatments and 3 periocular carboplatin injections (20 mg in 2 mL) to treat 3 tumors in 1 eye.Initially, diode laser ablation of the tumors produced a favorable involutional response of the tumors, associated with a decrease in size and vascularity. Despite aggressive treatment with 12 consecutive laser treatments for 9.7 months, progressive tumor growth was observed in the superonasal tumor, whereas the other 2 tumors remained quiescent. At that time, a series of three focal periocular injections of carboplatin were administered in combination with continued laser ablation. The tumor regressed with type 4 chorioretinal scarring. No systemic chemotherapy or radiation was required.This case of unilateral, multifocal retinoblastoma was successfully treated solely with diode laser ablation and rescue periocular injections of carboplatin after the failure of laser alone. A trial of periocular carboplatin with laser may be considered in cases of unilateral retinoblastoma that are resistant to laser ablation therapy alone.

    View details for PubMedID 20419851

  • Intraoperative Use of Three-Dimensional Spectral-Domain Optical Coherence Tomography OPHTHALMIC SURGERY LASERS & IMAGING Ide, T., Wang, J., Tao, A., Leng, T., Kymionis, G. D., O'Brien, T. P., Yoo, S. H. 2010; 41 (2): 250-254

    Abstract

    To develop a prototype three-dimensional anterior segment spectral-domain optical coherence tomography (SD-OCT) device and demonstrate the feasibility of its use in the operating room.Single-institution interventional case series including six consecutive patients undergoing Descemet's stripping automated endothelial keratoplasty (DSAEK). The prototype anterior segment SD-OCT was used intraoperatively to search for the presence of interface fluid between the host cornea and the DSAEK graft.Anterior segment SD-OCT was successfully used intraoperatively during DSAEK. After the initial placement of the graft, no fluid was clinically apparent; however, interface fluid was identified by anterior segment SD-OCT in two of the six cases. After additional aspiration, all patients were fluid-free on follow-up anterior segment SD-OCT scanning.Intraoperative anterior segment SD-OCT was used successfully to find interface fluid that was clinically undetectable under the microscope. As such, all patients were able to leave the operating room with a fully attached graft.

    View details for DOI 10.3928/15428877-20100303-15

    View details for Web of Science ID 000275606400015

    View details for PubMedID 20307045

  • Retinal capillary hemangioma in von Hippel-Lindau disease Arch Ophthalmol Leng T, Murray TG 2010; 128 (4): 425
  • Branch retinal artery occlusion after septoplasty. Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye Leng, T., Moshfeghi, D. M. 2010; 41 Online: e1-2

    Abstract

    Loss of vision after uncomplicated rhinosurgery is a rare and uncommon complication. The authors describe a case of branch retinal artery occlusion after septoplasty in a 40-year-old otherwise healthy man. The likely etiology was injection of local anesthetics into the nasal mucosa during surgery. Vision loss could potentially have been prevented through the application of topical vasoconstrictive agents prior to anesthetic injection. Furthermore, slow injection and aspiration prior to injection could also help prevent inadvertent intraarterial injection.

    View details for DOI 10.3928/15428877-20101124-13

    View details for PubMedID 22785539

  • Descemet Stripping Automated Endothelial Keratoplasty Tissue Preparation With Femtosecond Laser and Contact Lens CORNEA Ide, T., Yoo, S. H., Kymionis, G. D., Leng, T., Marini, C., Stanciu, N. A., O'Brien, T. P. 2010; 29 (1): 93-98

    Abstract

    To report a novel method of preparing planar Descemet stripping automated endothelial keratoplasty (DSAEK) tissue using a femtosecond laser with a hyperopic soft contact lens (Hyp-SCL).DSAEK tissue was prepared from 11 cadaveric porcine eyes. A femtosecond laser was used to create 400-microm flaps, with or without a Hyp-SCL, after which the eyes were imaged with anterior segment optical coherence tomography. The ratio of the mean central thickness (C) to the mean peripheral thickness (P) was calculated using the flap tool.Eleven eyes were cut (5 without, 5 with, and 1 without and with a Hyp-SCL). In all corneas, the cut interfaces were visualized by anterior segment optical coherence tomography. The mean C:P ratio of the flap made without a Hyp-SCL was 0.998 (range 0.968-1.03, SD = 0.254) compared with 0.904 (range 0.851-0.985, SD = 0.509) with a Hyp-SCL (P = 0.001), demonstrating that a cut made with a Hyp-SCL created a flap that was significantly more concave than that created without a Hyp-SCL, resulting in a more planar DSAEK graft. However, the C:P ratios calculated for DSAEK tissue made without (mean 0.998, range 0.965-1.02, SD = 0.0195) and with (mean 1.02, range 0.986-1.05, SD = 0.0250) a Hyp-SCL did not show significance (P = 0.07).Combining a femtosecond laser and a Hyp-SCL may aid in the creation of planar donor tissue for DSAEK. Clinically, this could reduce the amount of postoperative hyperopic shift, although further human corneal studies are warranted.

    View details for Web of Science ID 000273211500016

    View details for PubMedID 19907309

  • Branch retinal artery occlusion after septoplasty. Ophthalmic surgery, lasers & imaging : the official journal of the International Society for Imaging in the Eye Leng, T., Moshfeghi, D. M. 2010; 41 Online: e1-2

    Abstract

    Loss of vision after uncomplicated rhinosurgery is a rare and uncommon complication. The authors describe a case of branch retinal artery occlusion after septoplasty in a 40-year-old otherwise healthy man. The likely etiology was injection of local anesthetics into the nasal mucosa during surgery. Vision loss could potentially have been prevented through the application of topical vasoconstrictive agents prior to anesthetic injection. Furthermore, slow injection and aspiration prior to injection could also help prevent inadvertent intraarterial injection.

    View details for DOI 10.3928/15428877-20101124-13

    View details for PubMedID 21117572

  • ENDOPHTHALMITIS CAUSED BY PROTEUS SPECIES Antibiotic Sensitivities and Visual Acuity Outcomes RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Leng, T., Flynn, H. W., Miller, D., Murray, T. G., Smiddy, W. E. 2009; 29 (7): 1019-1024

    Abstract

    The purpose of this study was to report the clinical presentation, causative organisms, antibiotic sensitivities, management, and visual acuity outcomes in patients with endophthalmitis caused by Proteus species at a university teaching hospital over a 24-year period.This was a retrospective consecutive case series. The Bascom Palmer Eye Institute Microbiology Laboratory database was reviewed to identify all patients with intraocular cultures positive for Proteus species between 1983 and 2007. Clinical records were reviewed to ascertain the clinical presentation, management, and visual acuity outcomes.In the 13 patients identified, all cases followed intraocular surgery, and 1 was associated with a recurrent corneal ulcer. Of the 1,751 organisms isolated from intraocular culture during the study period, 244 were Gram negative. Proteus species represented 5.3% of gram-negative organisms and <1% of the total isolates identified. Endophthalmitis developed 2 days to 14 days postoperatively (median, 3.5 days), and patients were observed 1 month to 61 months after presentation (median, 17 months). Presenting vision ranged from light perception to 20/200. Ten patients had positive cultures for Proteus mirabilis, and three patients had a growth of Proteus morganii. Four patients (31%) were infected with >1 organism. All Proteus isolates were sensitive to the antibiotics clinically administered, including cefazolin, ceftazidime, gentamicin, and the fluoroquinolones. Five patients (38%) initially received intravitreal injections of antibiotics alone, 1 received an anterior chamber washout in combination with intravitreal injections, and 7 patients (54%) received pars plana vitrectomy in combination with intravitreal injections. Two of the patients (15%) who received vitrectomies had either an intraocular lens or retained nuclear fragments removed. Six patients (46%) received additional antibiotic injections during the clinical course, and 6 patients (46%) underwent additional surgical procedures. Final visual acuity was better than light perception in 5 patients (38%) and was light perception or no light perception in 8 patients (62%). Only 4 patients (31%) had a final vision acuity > or =5/200.Despite prompt treatment with appropriate antibiotics, the clinical outcome for Proteus species endophthalmitis is often poor.

    View details for Web of Science ID 000267955400017

    View details for PubMedID 19584659

  • SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY CHARACTERISTICS OF CUTICULAR DRUSEN RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Leng, T., Rosenfeld, P. J., Gregori, G., Puliafito, C. A., Punjabi, O. S. 2009; 29 (7): 988-993

    Abstract

    To evaluate the appearance of cuticular drusen with spectral domain optical coherence tomography.Eyes of patients with cuticular drusen were imaged using a prototype spectral domain optical coherence tomography instrument with 5-microm axial resolution. Thickness maps were obtained after automated segmentation of the internal limiting membrane and retinal pigment epithelium layers using a proprietary algorithm. The volume of subretinal fluid (SRF) was calculated using a manual segmentation technique that involved drawing boundaries around the SRF. The repeatability of these measurements was tested by comparing the volume measurements from multiple scans performed on the same day in four eyes of three patients.Sixteen eyes from eight patients with cuticular drusen were scanned. Areas of decreased retinal thickness overlying drusen were best visualized using the three-dimensional retinal thickness map. The distribution and sawtooth pattern of cuticular drusen were best visualized using three-dimensional retinal pigment epithelium segmentation. Of the 16 eyes, 13 had SRF within the macula. In the eyes with macular SRF, characteristic excrescences were present along the outer retina and attenuation of the photoreceptor inner and outer segment boundary were observed in many areas. In areas where the retina was detached, the retinal pigment epithelium-Bruch's membrane complex appeared nodular or attenuated. The volumetric measurements of the SRF were performed using a manual segmentation with a 1.11% mean difference between repeated measurements on the same day (range, 0.47-1.68%; standard deviation, 0.55%).The sawtooth pattern of drusen and the presence of excrescences along the detached outer retina are characteristic features of cuticular drusen that should be helpful in confirming the diagnosis of this condition. The volumetric analysis of the SRF is repeatable and may be useful in following the clinical course of these patients.

    View details for Web of Science ID 000267955400013

    View details for PubMedID 19584657

  • Retinal Vascular Tumor and Peripheral Retinal Vasculitis in the Setting of Systemic Tuberculosis OPHTHALMIC SURGERY LASERS & IMAGING Leng, T., Schefler, A. C., Murray, T. G. 2009; 40 (4): 409-412

    Abstract

    Tuberculosis commonly affects the eye by causing neovascularization, peripheral vasculitis, and choroidal tubercles. The authors describe a 28-year-old man with systemic tuberculosis who presented with a retinal vascular tumor, peripheral retinal vasculitis, retinal neovascularization, and vitreous hemorrhage causing acute vision loss. He was successfully treated with systemic anti-tuberculosis medications, retinal photocoagulation, and focal ablative diode laser to the tumor. Ophthalmologists should consider performing a purified protein derivative test and a chest x-ray for any patient with a history suspicious for tuberculosis who presents with a vascular tumor.

    View details for DOI 10.3928/15428877-20096030-11

    View details for Web of Science ID 000268127800011

    View details for PubMedID 19634748

  • Eyelid and orbital implant injury after enucleation OphthalmologyWeb Leng T 2009
  • Subconjunctival Air Leakage After Descemet's Stripping Automated Endothelial Keratoplasty(DSAEK) in a Post-Trabeculectomy Eye. The open ophthalmology journal Ide, T., Yoo, S. H., Leng, T., O'Brien, T. P. 2009; 3: 1-2

    Abstract

    To report a case of subconjunctival air leakage from the anterior chamber (AC) into a trabeculectomy bleb after Descemet's stripping automated endothelial keratoplasty (DSAEK).An 89 year-old woman with a previous history of primary open angle glaucoma in her left eye and previous trabeculectomy with mitomycin C had DSAEK on the patient's left eye in order to treat her endothelial disease. During the DSAEK procedure, air was injected into the AC to aid in graft adherence.The day after the surgery, subconjunctival air leakage from the AC into a trabeculectomy bleb was observed.Although our patient did not have any complications from this leak, there exists the potential for hypotony, bleb-related infections, and dislocations of the DSAEK graft. Given the potential consequences, these patients should be monitored closely.

    View details for DOI 10.2174/1874364100903010001

    View details for PubMedID 19554220

  • Three-dimensional spectral domain optical coherence tomography of a clear corneal cataract incision OPHTHALMIC SURGERY LASERS & IMAGING Leng, T., Lujan, B. J., Yoo, S. H., Wang, J. 2008; 39 (4): S132-S134

    Abstract

    A prototype 1,310-nm wavelength spectral domain optical coherence tomography (SD-OCT) instrument was constructed and mounted onto a conventional slit lamp for imaging of the anterior segment. The device had an axial resolution of 8 microm and was able to acquire real-time two-dimensional images at 14 frames/second and full three-dimensional datasets in approximately 7 seconds. An SD-OCT dataset of 100 B-scans, each consisting of 512 A-scans, was acquired from the left eye ofa patient who had undergone phacoemulsification with a clear corneal incision. The resulting dataset could be manipulated in three-dimensional space to analyze the geometry of the wound. Additionally, stromal edema and iris features were clearly imaged with the device. SD-OCT can be used to analyze clear corneal incisions to determine optimal wound construction technique and geometry as they relate to the prevention of complications such as postoperative wound leak, infection, and epithelial ingrowth.

    View details for Web of Science ID 000258283000025

    View details for PubMedID 18777882

  • Glaucoma valves and shunts OphthalmologyWeb Leng T 2008
  • A model retinal interface based on directed neuronal growth for single cell stimulation BIOMEDICAL MICRODEVICES Mehenti, N. Z., Tsien, G. S., Leng, T., Fishman, H. A., Bent, S. F. 2006; 8 (2): 141-150

    Abstract

    In this work, we use cell micropatterning technologies to direct neuronal growth to individual electrodes, and demonstrate that such an approach can achieve selective stimulation and lower stimulation thresholds than current field-effect based retinal prostheses. Rat retinal ganglion cells (RGCs) were purified through immunopanning techniques, and microcontact printing (microCP) was applied to align and pattern laminin on a microelectrode array, on which the RGCs were seeded and extended neurites along the pattern to individual electrodes. The stimulation threshold currents of RGCs micropatterned to electrodes were found to be significantly less than those of non-patterned RGCs over a wide range of electrode-soma distances, as determined with calcium imaging techniques. Moreover, the stimulation threshold for micropatterned cells was found to be independent of electrode-soma distance, and there was no significant effect of microCP on cell excitability. The effects of additional stimulation parameters, such as electrode size and pulse duration, on threshold currents were determined. The stimulation results quantitatively demonstrate the potential benefits of a retinal prosthetic interface based on directed neuronal growth.

    View details for DOI 10.1007/s10544-006-7709-3

    View details for Web of Science ID 000237486500006

    View details for PubMedID 16688573

  • Directed retinal nerve cell growth for use in a retinal prosthesis interface INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE Leng, T., Wu, P., Mehenti, N. Z., Bent, S. F., Marmor, M. F., Blumenkranz, M. S., Fishman, H. A. 2004; 45 (11): 4132-4137

    Abstract

    Retinal prosthetic devices that use microelectrode arrays to stimulate retinal nerve cells may provide a viable treatment for degenerative retinal diseases. Current devices are based on electrical field-effect stimulation of remaining functional neural elements. However, the distance between target neurons and electrodes limits the potential density of electrodes and the ability to stimulate specific types of retinal neurons that contribute to visual perceptions. This study was conducted to investigate the use of microcontact printing (muCP) to direct cultured or explant retinal ganglion cell (RGC) neurites to precise and close stimulation positions and to evaluate the cell types that grow from a retinal explant.RGCs and whole retinal explants were isolated from postnatal day-7 Sprague-Dawley rats using immunopanning purification and microdissection, respectively. Aligned muCP was used to direct the growth of RGC neurites from pure cultures (n=105) and retinal explants (n=64) along laminin patterns and to individual microelectrodes. Immunofluorescence stains (n=39) were used to determine the cell types that grew out from the retinal explants.RGC neurite growth was directed reproducibly along aligned laminin micropatterns to individual microelectrodes in pure RGC cultures and from full-thickness explanted rat retinas in 92% of experiments, neurites from pure RGC cultures extended along the laminin lines with an average length of 263 +/- 118 microm (SD; n=27) after 24 hours. Neurites from retinal explants extended in more than 80% of experiments and were observed to grow to an average length of 279 +/- 78 microm (n=64) after 2 days in culture. These neurites grew up to 3 mm after 1 month of culture on the laminin micropatterns. Immunohistochemical stains demonstrated that extended processes from both RGCs and glial cells grew out of retinal explants onto stamped laminin lines.Using muCP to pattern surfaces with growth factors, individual neuronal processes from pure RGC culture and whole retinal explants can be directed to discrete sites on a microelectronic chip surface. By directing RGC neurite processes to specific sites, single cell stimulation becomes possible. This may allow discrete populations of retinal neurons to be addressed so that physiologic retinal processing of visual information can be achieved.

    View details for DOI 10.1167/iovs.03-1335

    View details for Web of Science ID 000224678200039

    View details for PubMedID 15505066

  • The chick chorioallantoic membrane as a model tissue for surgical retinal research and simulation RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES Leng, T., MILLER, J. M., Bilbao, K. V., Palanker, D. V., Huie, P., Blumenkranz, M. S. 2004; 24 (3): 427-434

    Abstract

    We describe the use of chick chorioallantoic membrane (CAM) as a model system for the study of the precision and safety of vitreoretinal microsurgical instruments and techniques.The CAM was prepared for experimentation with and without its inner shell membrane (ISM) attached for in vivo and in vitro experiments that simulated medical and surgical interventions on the retina.The CAM's ease of use, low cost, and anatomic structure make it a convenient model for surgical retinal and retinal vascular modeling.While CAM has been used extensively in the past for ocular angiogenesis studies, we describe the tissue as a useful tool for a variety of other applications, including (1) testing of novel surgical tools and techniques for cutting and coagulating retina and its vasculature, (2) testing vessel cannulation and injection techniques, (3) angiographic studies, and (4) endoscopic surgery.

    View details for Web of Science ID 000222156800014

    View details for PubMedID 15187666

  • Retinal light processing using carbon nanotubes Official Gazette of the USPTO Patents Loftus D, Leng T, Fishman HA 2004; 1283 (5)
  • The artificial synapse chip: A flexible retinal interface based on directed retinal cell growth and neurotransmitter stimulation ARTIFICIAL ORGANS Peterman, M. C., Mehenti, N. Z., Bilbao, K. V., Lee, C. J., Leng, T., Noolandi, J., Bent, S. F., Blumenkranz, M. S., Fishman, H. A. 2003; 27 (11): 975-985

    Abstract

    The Artificial Synapse Chip is an evolving design for a flexible retinal interface that aims to improve visual resolution of an electronic retinal prosthesis by addressing cells individually and mimicking the physiological stimulation achieved in synaptic transmission. We describe three novel approaches employed in the development of the Artificial Synapse Chip: (i) micropatterned substrates to direct retinal cell neurite growth to individual stimulation sites; (ii) a prototype retinal interface based on localized neurotransmitter delivery; and (iii) the use of soft materials to fabricate these devices. By patterning the growth of cells to individual stimulation sites, we can improve the selectivity of stimulation and decrease the associated power requirements. Moreover, we have microfabricated a neurotransmitter delivery system based on a 5- micro m aperture in a 500-nm-thick silicon nitride membrane overlying a microfluidic channel. This device can release neurotransmitter volumes as small as 2 pL, demonstrating the possibility of chemical-based prostheses. Finally, we have fabricated and implanted an equivalent device using soft flexible materials that conform to the retinal tissue more effectively. As many of the current retinal prosthesis devices use hard materials and electrical excitation at a lower resolution, our approach may provide more physiologic retinal stimulation.

    View details for Web of Science ID 000186491900003

    View details for PubMedID 14616516

  • Wiggling subcutaneous lumps - Furuncular myiasis due to Dermatobia hominis larvae CLINICAL INFECTIOUS DISEASES Leng, T., Smith, D. S. 2003; 37 (4): 542-?
  • Microcontact printing on human tissue for retinal cell transplantation ARCHIVES OF OPHTHALMOLOGY Lee, C. J., Huie, P., Leng, T., Peterman, M. C., Marmor, M. F., Blumenkranz, M. S., Bent, S. F., Fishman, H. A. 2002; 120 (12): 1714-1718

    Abstract

    To demonstrate that microcontact printing, a modern materials fabrication technique, can be used to engineer the surface of human tissue and to show that inhibitory molecules can be used to pattern the growth of retinal pigment epithelial cells or iris pigment epithelial cells on human lens capsule for transplantation.Photolithographic techniques were used to fabricate photoresist-coated silicon substrates into molds. Poly(dimethylsiloxane)stamps for microcontact printing were made from these molds. The poly(dimethylsiloxane) stamps were then used to "wet-transfer" growth inhibitory molecules to the surface of prepared human lens capsules that were obtained during cataract surgery. Human retinal pigment epithelial and rabbit iris pigment epithelial cells were grown on a lens capsule substrate in the presence and absence of a patterned array of inhibitory factors.We found that human lens capsule could be microprinted with a precision similar to that obtained on glass or synthetic polymers. Retinal pigment epithelial cells and iris pigment epithelial cells cultured onto an untreated lens capsule showed spreading and formed into fusiform-appearing cells. In contrast, cells cultured on a lens capsule with a hexagonal micropattern of growth inhibitory molecules retained an epithelioid form within the inhibitory hexagons.Inhibitory growth molecules can be micropatterned onto human lens capsule, and these micropatterns can control the organization of retinal pigment epithelial cells or iris pigment epithelial cells cultured onto the lens capsule surface.Microprinting on autologous human tissue may facilitate efforts to effectively organize cell cultures and transplantations for the replacement of vital ocular tissues such as the retinal pigment epithelium in age-related macular degeneration.

    View details for Web of Science ID 000179737900014

    View details for PubMedID 12470147

  • Novel interface to biological systems for retinal prosthetics BIOMEMS AND BIONANOTECHNOLOGY Peterman, M. C., Lee, C., Leng, T., Huie, P., Fishman, H. A. 2002; 729: 149-154
  • A real world lesson The Bulletin of the Santa Clara County Medical Association Leng T 2001; 7 (6): 6-7
  • Capillary electrophoresis coupled with RBL-2H3 cells as a single-cell biosensor Stanford University Department of Biological Sciences Honors Thesis Leng T, Zare RN 1999

Conference Proceedings


  • Povidone-Iodine Before Lidocaine Gel Anesthesia Achieves Surface Antisepsis Doshi, R. R., Leng, T., Fung, A. E. SLACK INC. 2011: 346-349

    Abstract

    Viscous lidocaine interferes with ocular surface antisepsis. The current study was designed to evaluate the impact on surface antisepsis of different application sequences with lidocaine gel and povidone-iodine solution.Blood agar plates inoculated with Staphylococcus epidermidis were treated with varying sequences of 2% lidocaine gel and 5% povidone-iodine solution. The plates were then incubated at 37°C for 24 hours and bacterial growth was determined.Plates on which povidone-iodine was applied alone or prior to lidocaine gel demonstrated no bacterial growth regardless of whether the antiseptic was retained on the plate for 5 seconds or for 30 seconds. There was no statistically significant difference between bacterial growth on plates not treated with povidone-iodine and on plates treated with lidocaine gel alone or prior to povidone-iodine (P = .553 and P = .485, respectively).Povidone-iodine effectively reduces bacterial counts when applied alone or prior to lidocaine gel. Lidocaine gel was confirmed to be a barrier to antisepsis when administered prior to povidone-iodine.

    View details for DOI 10.3928/15428877-20110210-02

    View details for Web of Science ID 000305342000012

    View details for PubMedID 21366185

  • Full thickness retinal pigment epithelium explants proliferate into epithelial monolayers on synthetic Bruch's membrane substitutes Lombardi, L., Leng, T., Yeh, E., Molnar, F., Noolandi, J., Marmor, M. F., Fishman, H. A., Blumenkranz, M. S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2005
  • Synthetic Bruch's membrane substitutes: Comparisons after subretinal transplantation with cultured iris pigment epithelium Molnar, F. E., Lombardi, L., Berker, N., Yeh, E., Yellachich, D., Leng, T., Dalal, R., Marmor, M. F., Fishman, H. A., Blumenkranz, M. S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2005
  • Cell demographics from full thickness retinal explant growth on micropatterned surfaces Wu, P., Mehenti, N. Z., Leng, T., Marmor, M. F., Blumenkranz, M. S., Fishman, H. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2003: U692-U692
  • A retinal interface based on neurite micropatterning for single cell stimulation Mehenti, N. Z., Peterman, M. C., Leng, T., Marmor, M. F., Blumenkranz, M. S., Bent, S. F. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2003: U704-U704
  • A biodegradable matrix facilitates the use of lens capsule as a substrate for subretinal cell transplantation Bilbao, K. V., Leng, T., Fung, A. E., Huie, P., Sanislo, S. R., Marmor, M. F., Blumenkranz, M. S., Fishman, H. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2002: U972-U972
  • Directed ganglion cell growth and stimulation with microcontact printing as a prototype visual prosthesis interface Leng, T., Huie, P., Mehenti, N. Z., Peterman, M. C., Lee, C. J., Marmor, M. F., Sanislo, S. R., Beni, S. F., Blumenkranz, M. S., Fishman, H. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2002: U1279-U1279
  • The artificial synapse chip: A novel interface for a retinal prosthesis based on neurotransmitter stimulation and nerve regeneration Fishman, H. A., Peterman, M. C., Leng, T., Huie, P., Lee, C. J., Bloom, D. M., Sanislo, S. R., Marmor, M. F., Bent, S. F., Blumenkranz, M. S. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2002: U803-U803
  • Tissue engineered lens capsule as a substrate for IPE and RPE transplantation Fung, A. E., Lee, C. J., Leng, T., Bilbao, L. V., Peterman, M. C., Blumenkranz, M. S., Bent, S. F., Fishman, H. A. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2002: U973-U973

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