Assessment of Corneal Fluorescein Staining in Different Dry Eye Subtypes Using Digital Image Analysis

To describe a new objective technique of digital image analysis for the quantification and the morphological characterization of corneal staining in the setting of dry eye disease (DED), and to apply it to distinguish Sj\uf6gren syndrome (SS) from ocular graft versus-host disease (oGVHD)

Evaluación de la estructura de las glándulas de meibomio mediante tecnología infrarroja

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Óptica y Optometría, Departamento de Optometría y Visión, leída el 26/06/2019Dry eye disease (DED) is a multifactorial disease of the ocular surface considered one of the most frequently encountered ocular conditions seen by eye care practitioners. Nowadays, DED is estimated to affect between 5 − 50% of the worldwide population. Furthermore, the prevalence of DED increases linearly with age which makes DED a growing public health concern as the global population of older people is expected to be more than double its current amount by 2050. According to DED classification, the aqueous deficient dry eye (ADDE) and evaporative dry eye (EDE) are the two major DED types and are considered to exist on a continuum rather than as separate entities. Despite this, according to the current DED understanding, an evaporative component is more common than an ADDE component. Currently, the Meibomian gland dysfunction (MGD) is considered the leading cause of EDE. This condition may result in alteration of the tear film, symptoms of eye irritation, clinically apparent inflammation and ocular surface disease. Therefore, any change that occurs in the morphology of the MG or in its secretion has an important clinical impact...El ojo seco o síndrome de ojo seco (SOS) es una enfermedad multifactorial de la superficie ocular considerada como una de las afecciones oculares más frecuentes observadas por los profesionales de la visión en la práctica clínica. Hoy en día, se estima que el SOS afecta al 5-50% de la población mundial. Además, su prevalencia aumenta linealmente con la edad, lo que hace que el SOS sea un problema de salud pública creciente, ya que se espera un aumento del doble de la población mundial de personas ancianas para 2050. Según la clasificación del SOS, se pueden distinguir principalmente dos tipos: el ojo seco acuodeficiente, caracterizado por un déficit en la capa acuosa de la película lagrimal y el ojo seco evaporativo, el cual se caracteriza por una alteración en la evaporación de esta. A pesar de esta diferenciación, recientemente se ha observado que ambos tipos de SOS pueden coexistir simultáneamente, aunque el componente evaporativo tiende a ser el más común. Actualmente, la disfunción de las glándulas de meibomio (DGM) se considera la causa principal de la SOS evaporativo. Esta condición puede provocar alteración de la película lagrimal, síntomas de irritación ocular, inflamación clínicamente aparente y enfermedad de la superficie ocular. Por lo tanto, cualquier cambio que se produzca en la morfología o en la secreción de las glándulas puede tener un impacto clínico importante...Zespół suchego oka (ZSO) jest wieloczynnikowym schorzeniem powierzchni ocznej i jedną z najczęściej obserwowanych w praktyce klinicznej dolegliwości okulistycznych. Obecnie szacuje się, że ZSO dotyka od 5 do 50% światowej populacji. Ponadto, zachorowalność na ZSO wzrasta liniowo z wiekiem. Szacuje się, iż populacja osób starszych ulegnie do 2050 roku podwojeniu, przez co ZSO może stać się znaczącym problem zdrowia publicznego. Zgodnie z przyjętą ogólnie klasyfikacją, podtyp ZSO związany z niedostatecznym wydzielaniem warstwy wodnej filmu łzowego (ang. aqueous deficient) oraz podtyp związany z nadmiernym jego parowaniem (ang. evaporative) są dwoma najbardziej powszechnymi rodzajami ZSO, które nierzadko są współistniejące. Badania naukowe pokazują, że ZSO spowodowane zwiększonym parowaniem łez występuje częściej niż pozostałe typy. Obecnie uważa się, że za ten podtyp odpowiada w dużej mierze dysfunkcja gruczołów Meiboma (ang. Meibomian gland dysfunction, MGD). Dysfunkcja ta powoduje zaburzenia filmu łzowego, podrażnienie, stan zapalny i chorobę powierzchni oka. Stąd też, każda zmiana zachodząca w morfologii gruczołów Meiboma lub w ich zdolności wydzielniczej ma duże znaczenie kliniczne...Fac. de Óptica y OptometríaTRUEunpu

Dry Eye Syndrome

Dry eye syndrome is one of the most common types of ocular surface disorders that significantly worsen the quality of life of tens of millions of people worldwide.In the last decades, researchers worldwide investigated the composition and regulatory mechanisms of the preocular tear film to better understand dry eye syndrome. The tear film, in fact, plays a critical role in maintaining corneal and conjunctival integrity, protecting the eyes against infections, and preserving visual acuity. Recent scientific discoveries helped us gain a more and more accurate understanding of the structure and functioning of the tear film and how disorders in the tear film relate to dry eye syndrome. Today, ophthalmologists benefit from sophisticated diagnostic techniques, and they have at their disposal a wide range of effective therapeutic options to manage dry eye syndrome. This book illustrates the most recent research results in the diagnosis and treatment of dry eye syndrome, and it is of interest to the broad audience that comprises ophthalmologists, researchers, and students

Assessment of the repeatability in an automatic methodology for hyperemia grading in the bulbar conjunctiva

When the vessels of the bulbar conjunctiva get congested with blood, a characteristic red hue appears in the area. This symptom is known as hyperemia, and can be an early indicator of certain pathologies. Therefore, a prompt diagnosis is desirable in order to minimize both medical and economic repercussions. A fully automatic methodology for hyperemia grading in the bulbar conjunctiva was developed, by means of image processing and machine learning techniques. As there is a wide range of illumination, contrast, and focus issues in the images that specialists use to perform the grading, a repeatability analysis is necessary. Thus, the validation of each step of the methodology was performed, analyzing how variations in the images are translated to the results, and comparing them to the optometrist's measurements. Our results prove the robustness of our methodology to various conditions. Moreover, the differences in the automatic outputs are similar to the optometrist's ones

Applications of Anterior Segment Optical Coherence Tomography in Cornea and Ocular Surface Diseases

Optical coherence tomography (OCT) is a noncontact technology that produces high-resolution cross-sectional images of ocular tissues. Anterior segment OCT (AS-OCT) enables the precise visualization of anterior segment structure; thus, it can be used in various corneal and ocular surface disorders. In this review, the authors will discuss the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Use of AS-OCT for anterior segment surgery and postoperative management will also be discussed. In addition, application of the device for research using human data and animal models will be introduced

Parallel definition of tear film maps on distributed-memory clusters for the support of dry eye diagnosis

[Abstract] Background and objectives The analysis of the interference patterns on the tear film lipid layer is a useful clinical test to diagnose dry eye syndrome. This task can be automated with a high degree of accuracy by means of the use of tear film maps. However, the time required by the existing applications to generate them prevents a wider acceptance of this method by medical experts. Multithreading has been previously successfully employed by the authors to accelerate the tear film map definition on multicore single-node machines. In this work, we propose a hybrid message-passing and multithreading parallel approach that further accelerates the generation of tear film maps by exploiting the computational capabilities of distributed-memory systems such as multicore clusters and supercomputers. Methods The algorithm for drawing tear film maps is parallelized using Message Passing Interface (MPI) for inter-node communications and the multithreading support available in the C++11 standard for intra-node parallelization. The original algorithm is modified to reduce the communications and increase the scalability. Results The hybrid method has been tested on 32 nodes of an Intel cluster (with two 12-core Haswell 2680v3 processors per node) using 50 representative images. Results show that maximum runtime is reduced from almost two minutes using the previous only-multithreaded approach to less than ten seconds using the hybrid method. Conclusions The hybrid MPI/multithreaded implementation can be used by medical experts to obtain tear film maps in only a few seconds, which will significantly accelerate and facilitate the diagnosis of the dry eye syndrome.Ministerio de Economía y Competitividad; TIN2013-42148-PPortugal. Fundação para a Ciência e a Tecnologia; POCI-01-0145-FEDER-006961Portugal. Fundação para a Ciência e a Tecnologia; UID/EEA/50014/2013Portugal. Fundação para a Ciência e a Tecnologia; SFRH/BPD/111177/2015

Open Source Software for Automatic Detection of Cone Photoreceptors in Adaptive Optics Ophthalmoscopy Using Convolutional Neural Networks

Imaging with an adaptive optics scanning light ophthalmoscope (AOSLO) enables direct visualization of the cone photoreceptor mosaic in the living human retina. Quantitative analysis of AOSLO images typically requires manual grading, which is time consuming, and subjective; thus, automated algorithms are highly desirable. Previously developed automated methods are often reliant on ad hoc rules that may not be transferable between different imaging modalities or retinal locations. In this work, we present a convolutional neural network (CNN) based method for cone detection that learns features of interest directly from training data. This cone-identifying algorithm was trained and validated on separate data sets of confocal and split detector AOSLO images with results showing performance that closely mimics the gold standard manual process. Further, without any need for algorithmic modifications for a specific AOSLO imaging system, our fully-automated multi-modality CNN-based cone detection method resulted in comparable results to previous automatic cone segmentation methods which utilized ad hoc rules for different applications. We have made free open-source software for the proposed method and the corresponding training and testing datasets available online