by
Baptiste Coudrillier;
Diogo M. Geraldes;
Nghia T. Vo;
Robert Atwood;
Christina Reinhard;
Ian C. Campbell;
Yazdan Raji;
Julie Albon;
Richard L. Abel;
Christopher Ethier
The lamina cribrosa (LC) is a complex mesh-like tissue in the posterior eye. Its biomechanical environment is thought to play a major role in glaucoma, the second most common cause of blindness. Due to its small size and relative inaccessibility, high-resolution measurements of LC deformation, important in characterizing LC biomechanics, are challenging. Here we present a novel noninvasive imaging method, which enables measurement of the three-dimensional deformation of the LC caused by acute elevation of intraocular pressure (IOP). Posterior segments of porcine eyes were imaged using synchrotron radiation phase contrast micro-computed tomography (PC μCT) at IOPs between 6 and 37 mmHg. The complex trabecular architecture of the LC was reconstructed with an isotropic spatial resolution of 3.2 μm. Scans acquired at different IOPs were analyzed with digital volume correlation (DVC) to compute full-field deformation within the LC. IOP elevation caused substantial tensile, shearing and compressive devformation within the LC, with maximum tensile strains at 30 mmHg averaging 5.5%, and compressive strains reaching 20%. We conclude that PC μCT provides a novel high-resolution method for imaging the LC, and when combined with DVC, allows for full-field 3D measurement of ex vivo LC biomechanics at high spatial resolution.
Diffuse correlation spectroscopy (DCS) is an optical modality used to measure an index of blood flow in biological tissue. This blood flow index depends on both the red blood cell flow rate and density (i.e., hematocrit), although the functional form of hematocrit dependence is not well delineated. Herein, we develop and validate a novel tissue-simulating phantom containing hundreds of microchannels to investigate the influence of hematocrit on blood flow index. For a fixed flow rate, we demonstrate a significant inverse relationship between hematocrit and blood flow index that must be accounted for to accurately estimate blood flow under anemic conditions.
by
Justine R Smith;
Alexandra L Farrall;
Janet L Davis;
Joke H de Boer;
Anthony J Hall;
Manabu Mochizuki;
Nida H Sen;
Hiroshi Takase;
Ninette H ten Dam-van Loon;
Valérie Touitou;
Daniel V Vasconcelos-Santos;
David J Wilson;
Steven Yeh;
Mark HB Radford
Introduction Vitreoretinal lymphoma is a rare ocular cancer with high morbidity and mortality despite treatment. Diagnosis by cytopathology is often delayed, and various molecular and image-based investigations have been developed. Diverse treatments are used, but there is a limited medical evidence to differentiate their effectiveness. We designed an international registry that would collect diagnostic, treatment and outcomes data, to establish new evidence for the management of this cancer. Methods and analysis The International Vitreoretinal B-Cell Lymphoma Registry will accrue data retrospectively for individuals aged 18 years or older, diagnosed with new or recurrent vitreoretinal B-cell lymphoma on or after 1 January 2020. A steering committee of subspecialised ophthalmologists identified 20 key clinical data items that describe patient demographics, tissue involvements, diagnostic testing, ocular and systemic treatments and treatment complications, and visual acuity and survival outcomes. Customised software was designed to permit collection of these data across a single baseline and multiple follow-up forms. The platform collects data without identifiers and at 3 month reporting intervals. Outcomes of the project will include: (1) descriptions of clinical presentations, and diagnostic and therapeutic preferences; (2) associations between clinical presentations, and diagnostics and treatments, and between diagnostics and treatments (assessed by ORs with 95% CIs); and (3) estimations of rates of vision loss, and progression-free and overall survival (assessed by Kaplan-Meier estimates). Ethics and dissemination The registry has received Australia-wide approval by a national human research ethics committee. Sites located outside Australia are required to seek local human research ethics review. Results generated through the registry will be disseminated primarily by peer-reviewed publications that are expected to inform clinical practice, as well as educational materials.
by
Delesha M. Carpenter;
Gail E. Tudor;
Robyn Sayner;
Kelly W. Muir;
Alan L. Robin;
Susan J. Blalock;
Mary Elizabeth Hartnett;
Annette Giangiacomo;
Betsy L. Sleath
Objective: We examined whether six patient-provider communication behaviors directly affected the intraocular pressure (IOP) of glaucoma patients or whether patient medication adherence and eye drop technique mediated the relationship between self-efficacy, communication, and IOP.
Methods: During an 8-month, longitudinal study of 279 glaucoma patients and 15 providers, two office visits were videotape-recorded, transcribed, and coded for six patient-provider communication behaviors. Medication adherence was measured electronically and IOP was extracted from medical records. We ran generalized estimating equations to examine the direct effects of communication on IOP and used bootstrapping to test whether medication adherence and eye drop technique mediated the effect of communication on IOP.
Results: Provider education about medication adherence (B = −0.50, p < 0.05) and inclusion of patient input into the treatment plan (B = −0.35, p < 0.05) predicted improved IOP. There was no evidence of significant mediation.
Conclusion: The positive effects of provider education and provider inclusion of patient input in the treatment plan were not mediated by adherence and eye drop technique.
Practice Implications: Providers should educate glaucoma patients about the importance of medication adherence and include patient input into their treatment plan.
by
Nathaniel R. Moxon;
Anju Goyal;
JoAnn A. Giaconi;
Jamie B. Rosenberg;
Emily Graubart;
Evan L. Waxman;
Daniel Knoch;
Susan H. Forster;
Privthi S. Sankar;
Rukhsana G. Mirza
Eye disease and vision loss impact quality of life, independence, mental health, social function, and mortality.1, 2, 3 Visual impairment affects 7.5% of the United States population and requires frontline providers to diagnose and manage eye conditions.4 , 5 However, the time dedicated to teaching medical students about these conditions has been on the decline for half a century.6, 7, 8 After the 1910 Flexner report, ophthalmology preserved a small but regular role in United States medical school curricula.9 Unfortunately, as undergraduate medical curricula expanded, ophthalmology saw a decline in curricular time, which may be related to the fact that the Liaison Committee on Medical Education does not provide specific guidelines on ophthalmology training.
To adapt to the changing field of ophthalmology, graduate medical education (GME) must teach trainees to harness the power of information technology. The Accreditation Council for Graduate Medical Education (ACGME) Ophthalmology Milestones 2.0 includes the use of information technology, such as the integration of multimodal data into clinical diagnosis for patient-centered care, effective communication and documentation utilizing the electronic health records (EHR), and analysis of EHR data for quality improvement.
Purpose: To use manganese-enhanced magnetic resonance imaging (MEMRI) at 25 × 25 × 800 μm3 to image different retinal and vascular layers in the rat retinas.
Materials and Methods: Manganese-chloride was injected intraocularly in normal (n = 5) and Royal College of Surgeons (RCS, an model of photoreceptor degeneration) (n = 5) rats at postnatal day 90. MEMRI at 4.7 T was performed 24 hours later. MRI was repeated following intravenous Gd-DTPA in the same animals to highlight the vasculatures. Layer assignment and thickness were compared to histology.
Results: MEMRI 24 hours after intravitreal manganese-chloride injection revealed seven bands of alternating hyper- and hypointensities, corresponding histologically to the ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, photoreceptor-segment layer, and choroidal vascular layer. Intravenous Gd-DTPA-which does not cross the blood-retinal barrier and the retinal pigment epithelium-further enhanced the two layers bounding the retina, corresponding to the retinal and choroidal vascular layers, but not the avascular outer nuclear layer and the photoreceptor-segment layer. MEMRI of the RCS retinas revealed the loss of the outer plexiform layer, outer nuclear layer, and photoreceptor-segment layer. Histological analysis corroborated the MRI laminar assignments and thicknesses.
Conclusion: Lamina-specific retinal structures neurodegenerative changes to structure in retinal diseases can be detected using MEMRI.
The performance of hyperspectral imaging (HSI) for tumor detection is investigated in ex-vivo specimens from the thyroid (N = 200) and salivary glands (N = 16) from 82 patients. Tissues were imaged with HSI in broadband reflectance and autofluorescence modes. For comparison, the tissues were imaged with two fluorescent dyes. Additionally, HSI was used to synthesize three-band RGB multiplex images to represent the human-eye response and Gaussian RGBs, which are referred to as HSI-synthesized RGB images. Using histological ground truths, deep learning algorithms were developed for tumor detection. For the classification of thyroid tumors, HSI-synthesized RGB images achieved the best performance with an AUC score of 0.90. In salivary glands, HSI had the best performance with 0.92 AUC score. This study demonstrates that HSI could aid surgeons and pathologists in detecting tumors of the thyroid and salivary glands.
Increasingly, academic health centers are recognizing that residents and fellows are interested in gaining knowledge and skills in health care-related areas outside their normal residency program curriculum. Annually, Emory University School of Medicine's graduate medical education (GME) office educates more than 1300 trainees in 110 programs. While large specialty programs such as internal medicine can develop complementary pathways/tracks for their residents' education, smaller programs typically have limited resources. We anticipated that residency tracks developed and administered at the GME level and open to all residents and fellows could support complementary education in health care–related areas and help promote intraprofessional learning among trainees.1
Purpose: To evaluate outcomes of choroidal melanoma patients treated with 125 I or 103 Pd plaque brachytherapy.
Methods and Materials: From 1993 to 2012, our institution treated 160 patients with 103 Pd (56.1%) and 125 patients with 125 I (43.9%) plaque brachytherapy. Tumor outcomes, visual acuity (VA), and toxicity were compared. Multivariate analyses (MVAs) and propensity score analysis were used to help address differences in baseline characteristics.
Results: Median followup was longer for 125 I patients, 52.7 vs. 43.5 months (p < 0.01). At baseline, 103 Pd patients had lower rates of VA worse than 20/200 (4.4% vs. 16%, p = 0.002), T3–T4 tumors (17.5% vs. 32.8%, p = 0.03), and transpupillary thermotherapy use (3.1% vs. 9.6%, p = 0.001). Both 103 Pd and 125 I provided > 90% 3-year overall survival and > 93% 5-year secondary enucleation-free survival. On MVA, radionuclide was not predictive for tumor outcomes. A higher percentage maintained vision better than 20/40 with 103 Pd (63% vs. 35%, p = 0.007) at 3 years. MVA demonstrated 103 Pd radionuclide (odds ratio [OR]: 2.12, p = 0.028) and tumor height ≤5 mm (OR: 2.78, p = 0.017) were associated with VA better than 20/40. Propensity score analysis matched 23 125 I with 107 103 Pd patients. 103 Pd continued to predict better VA at 3 years (OR: 8.10, p = 0.014). On MVA for the development of VA worse than 20/200 or degree of vision loss, radionuclide was not significant. Lower rates of radiation retinopathy were seen with 103 Pd than 125 I (3 years: 47.3% vs. 63.9%, p = 0.016), with radionuclide significant in MVA.
Conclusions: Both 125 I and 103 Pd achieve excellent tumor control. An increased probability of long-term VA better than 20/40 and reduced risk of radiation retinopathy is associated with 103 Pd.