Embryonic Development of the Orbit.

The embryonic and fetal development of the orbit comprises a series of sequential events, starting with the fertilization of the ovum and extending until birth. Most of the publications dealing with orbital morphogenesis describe the sequential development of each germinal layer, the ectoderm with its neuroectoderm derivative and the mesoderm. This approach provides a clear understanding of the mode of development of each layer but does not give the reader a general picture of the structure of the orbit within any specified time frame. In order to enhance our understanding of the developmental anatomy of the orbit, the authors have summarized the recent developments in orbital morphogenesis, a temporally precise and morphogenetically intricate process. Understanding this multidimensional process of development in prenatal life, identifying and linking signaling cascades, as well as the regulatory genes linked to existing diseases, may pave the way for advanced molecular diagnostic testing, developing minimally invasive interventions, and the use of progenitor/stem cell and even regenerative therapy.

Fetal Development of the Orbit.

Human prenatal development is divided into an embryonic period and a fetal period. Intense organogenetic activity occurs in the embryonic period of prenatal life, while the fetal period is marked by less intense changes. Knowledge of the embryology of the orbit not only allows insights into how normal variations in the orbital structure arise but also provides an understanding of how congenital deformities occur when normal orbital development goes awry. In order to explore our understanding of the developmental anatomy of the orbit during the fetal period of prenatal life, the authors have summarized the major milestones in orbital morphogenesis, a temporally precise and morphogenetically intricate process. This process can be considered as an anatomic series of complex, well-orchestrated changes in morphology as well as a series of complex biochemical and molecular events that coordinate and control the anatomic development. Identifying and linking signaling pathways and regulatory genes linked with normal orbital morphogenesis is a crucial step to offer patients with chronic or incurable orbital diseases effective treatment options in the future.

Embryologic and Fetal Development of the Eyelid and the Lacrimal Drainage System.

The embryological and fetal morphogenesis of the eyelids and lacrimal drainage system is multifactorial and complex. This protracted process begins in the 5th week of prenatal life and involves a successive series of subtle and tightly regulated morphogenetic events. Major milestones of the embryological and fetal development of the eyelids include the beginning of eyelid formation during the 6th week, eyelid fusion by the 8th week, and the development of eyelid structures beginning in the 9th week (immediately following eyelid fusion), with progression until eyelid separation by the 24th week. After eyelid separation, the eyelids begin to assume their newly developed shape. Around the 32nd week, eyelids are almost fully developed and fully separated but still visibly closed. Key development steps of the lacrimal drainage system include formation of the lacrimal lamina (the primordium of the future lacrimal system) and the lacrimal cord (the primordium of the lacrimal canaliculi) in the 7th week, with canalization starting from the 10th week. During the 10th week, the excretory lacrimal system displays a lumen with a true lacrimal duct that can be distinguished. The epithelium of the lacrimal canaliculi is in contact with the palpebral conjunctival epithelium. The two epithelia form a continuous epithelial lamina. The caudal extreme of the lacrimal duct and the inferior meatal lamina join and the latter begins to cavitate. Understanding this multidimensional process of development in prenatal life, as well as identifying and linking signaling cascades and regulatory genes to existing diseases, may pave the way for developing minimally invasive interventions and scar reducing surgical methods, controlling the spread of malignancies, and the use of progenitor/stem cell and even regenerative therapy.

Fungal Infection in an Exenterated Orbit.

A 48-year-old man presented with an Aspergillus fumigatus complex infection of an exenterated orbit. The OS had been exenterated 7 months ago, together with total parotidectomy and neck dissection followed by irradiation due to a massive squamous cell carcinoma with orbital invasion and lymphatic metastasis. The patient was under permanent immunosuppression with oral prednisone and tacrolimus due to a kidney transplantation 5 years ago. The infected skin of the exenterated orbit was cleared using forceps. MRI ruled out any bone infiltration. After systemic treatment with oral voriconazole and topical therapy with bifonazole ointment for 6 weeks, the patient recovered completely.

Optic Nerve Sheath Diameter for Assessing Prognosis after Out-of-Hospital Cardiac Arrest.

PURPOSE: Evaluate optic nerve sheath and pial diameters (ONSD, ONPD) via sonography and computed tomography (CT) after out-of-hospital cardiac arrest (CA) and to compare their prognostic significance with other imaging and laboratory biomarkers. MATERIALS AND METHODS: A prospective observational study enrolling patients after successful resuscitation between December 2017 and August 2021. ONSD and ONPD were measured with sonography. Additionally, ONSD, and also grey-to-white ratio at basal ganglia (GWRBG) and cerebrum (GWRCBR), were assessed using CT. Lactate and neuron specific enolase (NSE) blood levels were measured. RESULTS: Sonographically measured ONSD and ONPD yielded no significant difference between survival and non-survival (p values ≥0.4). Meanwhile, CT assessed ONSD, GWRBG, GWRCBR, and NSE levels significantly differed regarding both, survival (p values ≤0.005) and neurological outcome groups (p values ≤0.04). For survival prognosis, GWRBG, GWRCBR, and NSE levels appeared as excellent predictors; in predicting a good neurological outcome, NSE had the highest accuracy. CONCLUSIONS: CT diagnostics, in particular GWRBG and GWRCBR, as well as NSE as laboratory biomarker, appear as excellent outcome predictors. Meanwhile, our data lead us to recommend caution in utilizing sonography assessed ONSD and ONPD for prognostic decision-making post-CA.

[Evisceration, enucleation and exenteration-Indications, techniques, and postoperative care]. / Eviszeration, Enukleation, Exenteration ­ Indikationen, Techniken und postoperative Nachsorge.

Various surgical techniques are available for the extirpation of an eye, depending on the underlying disease. Typical indications encompass tumors, inflammatory and infectious processes, glaucoma, trauma as well as congenital malformations. Surgical procedures include evisceration (resection of the intraocular space with preservation of the sclera), enucleation (extirpation of the entire eyeball including sclera and cornea) and exenteration (resection of the complete orbital soft tissue). The early detection of postoperatively manifesting complications, such as implant extrusion, conjunctivitis, postenucleation socket syndrome as well as the development of enophthalmus or ptosis, is of particular relevance in the context of postoperative care regarding functional, esthetic and social outcome. Special attention must be paid to ensuring a complication-free rehabilitation process, including the supply of a suitable, precisely fitting prosthesis or epithesis. This ensures the patient's psychosocial reintegration, in which an integrated interdisciplinary cooperation with ocularists and psychologists is essential. The latter play a particularly important role, as the psychological stress resulting from the procedure is often associated with a considerable reduction in the quality of life.