Anterior-segment spectral domain optical coherence tomography in epidermolysis bullosa

Corneal Epithelial Thickness Mapping: A Major Review

The corneal epithelium (CE) is the outermost layer of the cornea with constant turnover, relative stability, remarkable plasticity, and compensatory properties to mask alterations in the underlying stroma. The advent of quantitative imaging modalities capable of producing epithelial thickness mapping (ETM) has made it possible to characterize better the different patterns of epithelial remodeling. In this comprehensive synthesis, we reviewed all available data on ETM with different methods, including very high-frequency ultrasound (VHF-US) and spectral-domain optical coherence tomography (SD-OCT) in normal individuals, corneal or systemic diseases, and corneal surgical scenarios. We excluded OCT studies that manually measured the corneal epithelial thickness (CET) (e.g., by digital calipers) or the CE (e.g., by confocal scanning or handheld pachymeters). A comparison of different CET measuring technologies and devices capable of producing thickness maps is provided. Normative data on CET and the possible effects of gender, aging, diurnal changes, refraction, and intraocular pressure are discussed. We also reviewed ETM data in several corneal disorders, including keratoconus, corneal dystrophies, recurrent epithelial erosion, herpes keratitis, keratoplasty, bullous keratopathy, carcinoma in situ, pterygium, and limbal stem cell deficiency. The available data on the potential role of ETM in indicating refractive surgeries, planning the procedure, and assessing postoperative changes are reviewed. Alterations in ETM in systemic and ocular conditions such as eyelid abnormalities and dry eye disease and the effects of contact lenses, topical medications, and cataract surgery on the ETM profile are discussed.

Evaluation of Clinical and Oral Findings in Patients with Epidermolysis bullosa

Introduction: Epidermolysis bullosa (EB) is a genetically inherited disease characterized by recurrent bullae and erosions on the skin with numerous signs of dental caries and poor oral hygiene. The aim of this study was to investigate the general clinical and oral findings of patients with EB. Materials and Methods: In this prospective study, the clinical and oral findings and family history of 26 cases with EB were evaluated. The type of EB, gender, age, parental consanguinity, dental caries, oral findings, distribution of lesions and presence of associated anomalies, clinical and oral findings correlated with gender were recorded. Results: All 26 patients with EB had a history of consanguinity and siblings with EB to varying degrees. In our study, malnutrition, anemia and growth retardation, gastrointestinal system complications, hair thinning, hand and nail deformity, ocular problems and renal disease (in one case) were observed with variable frequencies. When the intraoral findings of the patients were investigated, extensive dental caries in all EB types, enamel hypoplasia in junctional EB (JEB) and the presence of tooth-root to be extracted in dystrophic EB (DEB), intraoral bullae and lesions, ankyloglossia, vestibular sulcus insufficiency, microstomia and maxillary atrophy were observed. Three cases had restorative treatment and one case had prosthetic rehabilitation. Conclusions: Oral involvement can be seen with varying frequencies depending on the type of EB and the severity of the disease. It may result from delayed oral and dental rehabilitation due to physical disabilities, limitations and more pressing medical problems. Microstomy, pain from mucosal lesions, and restricted access to the mouth can be caused by poor oral hygiene. Oral complications and caloric needs of individuals with EB should be determined, and individual prophylaxis should be applied to prevent caries formation and protect teeth.

Time-domain full-field optical coherence tomography (TD-FF-OCT) in ophthalmic imaging

Ocular imaging plays an irreplaceable role in the evaluation of eye diseases. Developing cellular-resolution ophthalmic imaging technique for more accurate and effective diagnosis and pathogenesis analysis of ocular diseases is a hot topic in the cross-cutting areas of ophthalmology and imaging. Currently, ocular imaging with traditional optical coherence tomography (OCT) is limited in lateral resolution and thus can hardly resolve cellular structures. Conventional OCT technology obtains ultra-high resolution at the expense of a certain imaging range and cannot achieve full field of view imaging. In the early years, Time-domain full-field OCT (TD-FF-OCT) has been mainly used for ex vivo ophthalmic tissue studies, limited by the low speed and low full-well capacity of existing two-dimensional (2D) cameras. The recent improvements in system design opened new imaging possibilities for in vivo applications thanks to its distinctive optical properties of TD-FF-OCT such as a spatial resolution almost insensitive to aberrations, and the possibility to control the curvature of the optical slice. This review also attempts to look at the future directions of TD-FF-OCT evolution, for example, the potential transfer of the functional-imaging dynamic TD-FF-OCT from the ex vivo into in vivo use and its expected benefit in basic and clinical ophthalmic research. Through non-invasive, wide-field, and cellular-resolution imaging, TD-FF-OCT has great potential to be the next-generation imaging modality to improve our understanding of human eye physiology and pathology.

Validation and Repeatability of the Epidermolysis Bullosa Eye Disease Index in Dystrophic Epidermolysis Bullosa

PURPOSE

Dystrophic epidermolysis bullosa (DEB) is a devastating condition that causes painful corneal abrasions and vision loss. Epidermolysis Bullosa Eye Disease Index (EB-EDI) for the first time captures and quantifies EB-specific assessment of ocular symptoms and activities of daily living scales. This survey will become critical in developing new interventions on patients' quality of life.

METHODS

Three-part set of the EB-EDI baseline, EB-EDI interval, and Ocular Surface Disease Index (OSDI) survey was distributed to 92 patients with DEB who previously reported eye symptoms on previous surveys. It was then posted online through several EB patient organizations. We compared the EB-EDI with the gold standard OSDI and examined the repeatability of the EB-EDI over a 7- to 15-day interval.

RESULTS

Of the 45 individuals who initially responded, 30 of 45 (67%) completed the surveys sent 7 to 15 days later. The age of participants ranged from 6 to 51 years (mean 21 ± 15 years), and 60% (18 of 30) of participants were younger than 18 years. The overall Cronbach alpha values for the subscales of EB-EDI baseline and interval tools presented a good internal consistency (≥0.7). From 2 visits, the domain scores of EB-EDI baseline (0.94) and interval tools (0.83) were shown to have excellent test-retest reliability (intraclass correlation coefficient >0.8). By comparison, OSDI had the intraclass correlation coefficient score of 0.72 ± 0.11. The convergent validation analysis showed that correlations between the domain scores of EB-EDI baseline and interval tools and the subscales of the OSDI reached the hypothesized strength.

CONCLUSIONS

Based on a 30-person repeated-measures study, we found that the EB-EDI has excellent reliability and validity specifically in patients with DEB.

Recent advances in optical coherence tomography for anterior segment imaging in small animals and their clinical implications

Anterior segment optical coherence tomography (AS-OCT) is a rapidly evolving area of OCT imaging, providing high-resolution and non-invasive volumetric imaging of the anterior segment. This review focuses on recent advances in AS-OCT imaging in small animals, which we categorize into ultrahigh-resolution, spectroscopic, magnetomotive, polarization-sensitive, and angiographic AS-OCTs. We summarize their technical foundations, review their applications to small animal imaging, and briefly discuss their current and future clinical applications.

Genetic Disorders of the Extracellular Matrix: From Cell and Gene Therapy to Future Applications in Regenerative Medicine

Metazoans have evolved to produce various types of extracellular matrix (ECM) that provide structural support, cell adhesion, cell-cell communication, and regulated exposure to external cues. Epithelial cells produce and adhere to a specialized sheet-like ECM, the basement membrane, that is critical for cellular homeostasis and tissue integrity. Mesenchymal cells, such as chondrocytes in cartilaginous tissues and keratocytes in the corneal stroma, produce a pericellular matrix that presents optimal levels of growth factors, cytokines, chemokines, and nutrients to the cell and regulates mechanosensory signals through specific cytoskeletal and cell surface receptor interactions. Here, we discuss laminins, collagen types IV and VII, and perlecan, which are major components of these two types of ECM. We examine genetic defects in these components that cause basement membrane pathologies such as epidermolysis bullosa, Alport syndrome, rare pericellular matrix-related chondrodysplasias, and corneal keratoconus and discuss recent advances in cell and gene therapies being developed for some of these disorders. Expected final online publication date for the Annual Review of Genomics and Human Genetics, Volume 23 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.