Orbital lymphatics: do they exist?

INTRODUCTION: Although the lymphatic system was first described almost 400 years ago, it is only in very recent years that researchers have been able to identify lymphatic channels with reasonable accuracy. Through advances in molecular biology and the development of endothelial cell markers the long held view that the human orbit is devoid of lymphatics has now been challenged. DISCUSSION: This review discusses the current evidence on this topic, which confirms the presence of orbital lymphatics in lachrymal gland and optic nerve sheath.

Observation of lymphatic vessels in orbital fat of patients with inflammatory conditions: a form fruste of lymphangiogenesis?

In the absence of antibodies specific for lymphatic vessels, analysis of lymphatic vessels within different tissues has been widely performed with light microscopic and, most importantly, electron microscopic techniques. In regard to lymphatic vessels in the ocular globe and the periocular structures, controversy remains about the specific distribution of lymphatic channels. It is postulated that bulbar and retrobulbar tissues are devoid of lymphatic vessels, but lymphatic vessels have been demonstrated in lacrimal gland and epibulbar conjunctiva. In this study, we analyzed orbital fat for the presence of lymphatic tissue using D2-40, a monoclonal antibody, specific for lymphatic vessels. We found lymphatic vessels present within bulbar conjunctiva extending to the level of the ciliary apparatus. No lymphatics were identified in healthy anterior orbital adipose tissue. In two cases of orbital mucor-mycosis and one case of panendophthalmitis, significant lymphovascular proliferation was present within granulation tissue associated with the acute inflammation. We conclude that lymph vessel proliferation may be induced in inflammatory conditions in tissues which are normally devoid of lymph channels.

Proliferation of D2-40-expressing intestinal lymphatic vessels in the lamina propria in inflammatory bowel disease.

Lymphatic vessels in the colon are normally distributed beneath the muscularis mucosae with rare branches reaching through the muscularis mucosae to the most basal aspect of the colonic crypts. In chronic inflammatory bowel disease demonstrating acute inflammation and architectural disarray, lymph vessel proliferation is seen within the lamina propria and within the submucosa. We analyzed the number and distribution of lymphatic vessels within the lamina propria and submucosa in chronic active and treated ulcerative colitis with restoration of architecture by immunostaining with D2-40, a specific monoclonal antibody against lymphatic vessels. We found significantly increased numbers of lymph vessels in chronic active ulcerative colitis both within the lamina propria and the submucosa as compared to normal mucosa. Numbers of lymph vessels in lamina propria were highest in severe chronic active ulcerative colitis and less in moderate and minimal residual disease with minimal architectural disarray (p<0.05). Lymph vessels in the submucosa were increased significantly above normal values in both severe, moderate and minimal residual disease. We conclude that lymph vessel distribution in chronic active ulcerative colitis extends into the lamina propria. With restoration of architectural morphology, the integrity of the lamina propria in regards to the distribution of lymph vessels is restored.

Identification of lymphatic vessels in malignant, adenomatous and normal colonic mucosa using the novel immunostain D2-40.

Distribution of lymphatic vessels in normal and neoplastic colon has been previously analyzed with electron microscopic techniques, as reliable antibodies have not been available for selective lymph vessel staining. A novel monoclonal antibody, D2-40, is recently available to differentiate lymphatic vessels from blood vessels. In this study, we analyzed the distribution of lymphatic vessels in normal colon, adenomas with and without superficial stalk invasion and invasive carcinomas without identifiable polypoid precursor lesions. In contrast to previous studies, we found lymphatic vessels in superficially misplaced stalk stroma in adenomas, and closely associated with early invasive epithelial nests in invasive lesions. Lymphatic vessels were identified within the lamina propria of the in situ aspect of in invasive tumors. We conclude that lymphatic vessel structures are seen more superficially in adenomas and invasive carcinomas than previously described. Since intramucosal carcinomas in adenomas do not metastasize, these lymph vessels may be immature or not communicate with deeper lymphatics. Proliferation and distribution of lymphatic vessels may be related to prognosis and early metastasis.

Optic nerve and orbital tumors.

The close proximity of the orbit to the brain and the high frequency of ocular symptoms in patients with neurosurgical disease make it mandatory for neurosurgeons to be familiar with manifestations of orbital disease. Tumors of the optic nerve and orbit are important causes of vision loss and eye movement abnormalities. Similarly, intracranial tumors frequently present with eye movement abnormalities, vision loss, and optic nerve swelling. This overlap in the clinical characteristics of patients with orbital tumors and patients with neurosurgical problems makes familiarity with the types of clinical presentation of various orbital tumors important to the neurosurgeon. The history and examination of patients with orbital tumors are discussed and the clinical presentation of various orbital tumors is presented.

Identification of human orbital lymphatics.

PURPOSE: To identify lymphatic vessels in the human orbit. METHODS: Lymphatic and blood capillaries were distinguished histochemically by light microscopy using a 5'-nucleotidase (5'-Nase) and alkaline phosphatase (ALPase) double staining method. Identification of lymphatic vessels was based on strict morphologic criteria combined with specific 5'-Nase staining. RESULTS: The presence of conjunctival lymphatics was confirmed and used as a control tissue. Lymphatic vessels were identified in the lacrimal gland and in the dura mater of the optic nerve. Structures demonstrating positive 5'-Nase staining at the orbital apex were highly suggestive of lymphatics but did not meet the morphologic criteria established. Lymphatic vessels were not identified in the extraocular muscles or orbital fat. CONCLUSION: To the authors' knowledge, this study presents the first evidence for lymphatic capillaries in the dura mater of the human optic nerve and lacrimal gland.

Technique for combined blepharoplasty and ptosis correction.

Ptosis is one of the most common involutional changes of the eyelid. It frequently occurs concomitantly with dermatochalasis. The surgeon must be aware of the likelihood of this association when evaluating a patient for blepharoplasty because failure to develop an appropriate surgical plan will lead to an imperfect outcome. Ptosis correction can be undertaken at the same time as upper lid blepharoplasty. The many types of ptosis have a complex underlying anatomy and pathology, however, and the variety of surgical alternatives for ptosis repair are associated with a certain degree of unpredictability. The focus of this discussion is the management of acquired ptosis of aponeurogenic origin, which is most commonly associated with dermatochalasis. A surgeon who is conversant with the underlying anatomy of the ptotic lid and the general guidelines for ptosis repair will be prepared to manage combined dermatochalasis and ptosis.

Complications of blepharoplasty.

Blepharoplasty is one of the most commonly performed surgeries for rejuvenation of the periorbital region, yet its complexity is often underappreciated. The surgeon must have a precise understanding of the underlying anatomy from skin to orbital rim and must recognize which components require surgery to achieve a desired aesthetic result in each individual. Understanding the limitations imposed by a particular patient's anatomy and conveying realistic aesthetic expectations are essential to avoid complications. The underpinning of successful blepharoplasty is an awareness of potential complications (Table 1) and understanding how best to avoid them and how to manage them.

Oculinum injection-resistant blepharospasm in young patients.

Botulinum toxin has recently been used as a nonsurgical treatment for blepharospasm and other facial dyskinesias. This report describes four patients between the ages of 32 and 37 years who failed to respond to botulinum injections for severe blepharospasm. Other than age, no other features could be identified in these patients that would differentiate this group. Particularly early age of onset for essential blepharospasm might be an indicator of failure to respond to the injections.

In vivo induction of Ia expression in murine cornea after intravitreal injection of interferon-gamma.

Intravitreal injection of interferon gamma (IFN-gamma) induces increased expression of Class II major histocompatibility complex (Ia) antigen expression on corneal endothelial cells and stromal fibroblasts. In contrast, IFN-gamma has no detectable effect on Ia antigen expression in epithelium. Induction of Ia antigen expression was rapid with increases detectable as early as 6-12 hours after a single injection of 1 x 10(5) units. Expression peaked at 24-48 hours and decreased to background levels by 120 hours. The Ia antigen expression increased in a dose-dependent manner, and IFN-gamma treatment also induced the synthesis of increased amounts of a 65-kilodalton (kD) protein in the cornea. Increased levels of this 65-kd protein are seen as early as 12 hours after treatment and can be induced with as little as 1 x 10(2) units of IFN-gamma. The function of the 65-kd protein is unknown. This model should be useful in studies on in vivo modulation of Ia antigen expression.