Concept: Lacrimal gland
A 25-year-old woman presented with a painless inferomedial subconjunctival mass in the right eye. The growth had been present since birth and had been increasing in size for over 1 year. Incisional biopsy with debulking proved the lesion to be a dermolipoma extending behind the globe that contained ectopic lacrimal gland tissue. The authors describe a very rare case of a complex dermolipoma arising in an atypical location and containing ectopic lacrimal gland.
Ragauskas et al.(1) demonstrated that when external pressure is applied, the orbit tends to equilibrate flow in the ipsilateral ophthalmic artery (OA) when its level approaches intracranial pressure (ICP). The authors detected this relationship by making the OA into a “natural pair of scales, in which the intracranial segment of the OA is compressed by extracranial pressure (Pe) applied to the orbit.”
To study electrical stimulation of the lacrimal gland and afferent nerves for enhanced tear secretion, as a potential treatment for dry eye disease. We investigate the response pathways and electrical parameters to safely maximize tear secretion.
The lacrimal gland has a multifaceted role in maintaining a homeostatic microenvironment for a healthy ocular surface via tear secretion. Dry-eye disease, which is caused by lacrimal gland dysfunction, is one of the most prevalent eye diseases that cause corneal epithelial damage and results in significant loss of vision and a reduction in the quality of life. Here we demonstrate orthotopic transplantation of bioengineered lacrimal gland germs into adult mice with an extra-orbital lacrimal gland defect, a mouse model that mimics the corneal epithelial damage caused by lacrimal gland dysfunction. The bioengineered lacrimal gland germs and harderian gland germs both develop in vivo and achieve sufficient physiological functionality, including tear production in response to nervous stimulation and ocular surface protection. This study demonstrates the potential for bioengineered organ replacement to functionally restore the lacrimal gland.
Dry eye is a multifactorial disease characterized by ocular discomfort and visual impairment. Lacrimal gland function has been shown to decrease with aging, a known potent risk factor for dry eye. We have previously found that orally administrated royal jelly (RJ) restored tear secretion in a rat model of dry eye.
- Clinical & experimental optometry : journal of the Australian Optometrical Association
- Published almost 3 years ago
Supernumerary punctum is an under-reported congenital anomaly, in which there is more than one lacrimal punctum. Although usually asymptomatic, supernumerary puncta have been reported to cause dry eye or epiphora (excessive tearing) and should be included in their differential diagnosis. Tearing is often associated with dry eyes and can lead to discontinuation of contact lens wear. A comprehensive evaluation of the causes of tearing may uncover other contributory factors of epiphora. This case report highlights unilateral inferior double puncta in an otherwise asymptomatic patient. Due to increased evacuation of tears in the affected eye, manual occlusion of the puncta was advocated to allow topical medication to be more efficacious.
The aesthetic outcome of a well-planned and executed vascularized composite tissue face allotransplant is unquestionable; however, complete functional restoration is necessary. The authors studied the possibility of restoring tear duct function in face transplant recipients. They also examined the technical specifics and feasibility of incorporating a lacrimal drainage apparatus into facial allografting. The authors performed a standardized face vascularized composite allograft on 4 hemi-faces (2 fresh cadavers). On one side of the face, a soft tissue myocutaneous alloflap was raised. They attempted to incorporate the nasolacrimal apparatus into the allograft to develop and describe an efficient harvest method. On the contralateral side, an osteocutaneous alloflap was raised with the midface and mandible. The authors describe 2 techniques to incorporate the lacrimal drainage system. The authors retrieved the graft in a consistent and replicable fashion within conventional alloflap retrieval times. The authors successfully incorporated the entire nasolacrimal drainage system into the conventional soft tissue-only myocutaneous alloflap by transforming it into a modified mini-osteomyocutaneous alloflap. They demonstrated that the contralateral conventional bi-maxillary osteocutaneous alloflap procedure, as an alternative comparative technique, provided another means to restore lacrimal drainage. In conclusion, surgically harvesting the nasolacrimal apparatus is technically feasible in vascularized composite tissue allotransplantation. Before translating this to a clinical setting, further dissections are necessary to explore the technical specifics of how to insert the harvested nasolacrimal apparatus into the recipient to restore a conduit for tear drainage. This study is the first step towards a fully functioning lacrimal drainage system in face transplant recipients.
The objective of this study was to describe the reference values of cranial measurements of capybaras, correlating the ocular orbit with the nasolacrimal duct. The documentation of its results can contribute to standardizing characteristics of anatomical normality and favouring the correct diagnosis and treatment of changes. The capybara carcasses, maintained by freezing, were distributed in two groups (G) designated GA (n = 12) adult animals (A) and GY (n = 13) for young animals (Y). All subjects underwent dacryocystography examination by computed tomography (CT) and cranial measurements. Descriptive analyses of cranial and nasolacrimal duct measurements and statistical analysis of the Pearson correlation with the variable weight were performed. In GA, there was no correlation between the nasolacrimal and cranial duct measurements. However, in the GY, a correlation was verified with facial length (r = .6233), facial width (r = .5771), cranial height (r = .6981), cranial length (r = .7116), total right length (r = .7517) and left length (r = .7999). Thus, in the young animals, cranial length measurements were strongly correlated with nasolacrimal duct lengths. However, this biological behaviour was not observed in adults, demonstrating stability in development. The capybara’s ocular orbit was found to be circular and incomplete, with developed zygomatic process of the maxilla. CT dacryocystography is indicated to evaluate the nasolacrimal canal pathway in capybaras, emphasizing the importance of normal anatomical study to aid in treating animals affected by diseases.
Isolated fractures of the orbital floor or medial wall are often referred to as blowout fractures (BOFs). Debilitating double vision and aesthetic deformity may affect the patients' quality of life and daily living skills, for instance, working or driving a car. The management of blowout fractures is, however, challenging, since not all fractures demand surgery. Some patients may have symptoms which subside, or may never develop symptoms. Due to a lack of evidence, there are still considerable differences in opinion on the criteria for surgery. The selection of patients for surgery is therefore crucial for optimal patient outcomes. The aims of this PhD project were to elucidate and investigate various clinical aspects of blowout fractures and to examine the anatomy of the orbital cavity, which included studying the symmetry of the two orbits, the location of orbital arteries, and the pathophysiology of blowout fractures. Several clinical specialties and basic research fields study the orbital cavity. The studies in this PhD project are based on collaboration between the Departments of Otorhinolaryngology, Ophthalmology and Radiology at the Copenhagen University Hospital Rigshospitalet and the Departments of Odontology and Anatomy (Cellular and Molecular Medicine) at the University of Copenhagen. We assessed the current treatment of blowout fractures at the Ear Nose and Throat (ENT) Department at our tertiary hospital in a retrospective study, and found that a third of the patients had persistent double vision 3 months post-trauma, irrespective of whether they had been managed surgically or conservatively (Paper I). We found that the left and right orbit are symmetrical with regards to various morphometrics of both the bony orbit and the intraorbital contents, e.g. volume, surface area and volume of fat and extraocular muscles, and distance to the ethmoidal arteries (Papers II, III and IV). This knowledge may be used in blowout fracture studies on surgical decision-making and orbital reconstruction and also in presurgical planning to avoid iatrogenic damage to the ethmoidal arteries in orbital surgery. In the first longitudinal MRI study of blowout fractures, dynamic post-traumatic changes in the intraorbital soft tissue were detected, i.e. to the best of our knowledge, for the first time indicative of an edema. We conclude that an edema subsides in the days following a blowout fracture and recommend a watchful waiting period before deciding on whether or not to operate (Paper III). The 24-12-6 mm rule of thumb determines orbital distances from the anterior lacrimal crest to the ethmoidal arteries and the optic canal. We questioned the applicability of this rule to all patients and investigated whether or not it is feasible to measure the distances on CT images. We found large inter-individual differences in the distances to the ethmoidal arteries and found that preoperative measurements on CT images are feasible and produce results with a low intra- and inter-observer variability.
Quantification of lacrimal total protein content (TPC) is an important tool for clinical scientists to understand disease pathogenesis, identify potential biomarkers and assess response to therapy, among other applications. However, TPC is not only affected by disease state but also by the method used for tear collection. Thus, the purpose of this study is to determine the impact on TPC of two methods of tear collection in dogs and cats: Schirmer strips and polyvinyl acetal (PVA) sponges.