Fluorescence-labeled lectins, glycoconjugates, and the development of the mouse AOP

The development of the aqueous outflow pathway (AOP) in early postnatal mouse eyes was examined for the presence of a variety of lectin receptors using fluorescein isothiocyanate (FITC) conjugated lectins, 1 micron araldite plastic sections, and computer-aided fluorescence photography. The trabecular meshwork anlage (days 1-4) was characterized by the presence of loosely arranged cells and an extracellular matrix that exhibited intense areas of Con A- and RCA-lectin staining, and absence of WGA- and LPA-lectin staining. By day 6, trabecular meshwork LPA- and WGA-positive materials were observed as focal areas of staining. By day 10, LPA- and WGA-positive materials were present as diffuse areas of staining, as the AOP differentiated into an organized and functional biological filter. The age-dependent pattern of LPA- and WGA-positive materials indicated that there were time-dependent points in the synthesis of glycoconjugates in the developing AOP. The results suggest: The composition and/or conformation of the glycoconjugates on cells and extracellular matrix changed as the AOP differentiated into a functional tissue. The use of FITC lectins as biological markers for studies of the AOP provided information on the potential role of glycoconjugates in the development of the normal AOP. Modification in the type, amount, and distribution of glycoconjugates may provide a basis for understanding the cellular mechanisms of abnormal development of the AOP, eg, congenital glaucoma.     

Gordon Holmes, the cortical retina, and the wounds of war

By the turn of the 20th century, localization of function in the cerebral cortex of the brain had advanced considerably, but a relatively vague idea only existed that human vision was represented in the vicinity of the calcarine cortex. World War I produced a large number of isolated missile wounds of the brain. Their study yielded a complete topographical mapping of the visual field in the primary cortical vision center, and is a basis of our modern interpretation of visual fields. This map has been recently modified by MRI studies to show that the magnification of the central retinal projection onto the cerebral cortex to be even greater than previously thought. Many names are associated with the story of how war led to this knowledge. This essay refers to Harvey Cushing, William Osler, Tatsui Inouye, and most particularly to the career and contributions of the British neurologist Gordon Holmes. Read in part, at the annual meeting of the Cogan Ophthalmic History Society, The National Library of Medicine, Bethesda, Maryland, March 15, 1996.     

Physiology, assessment, and disorders of the pupil

Proper examination of the pupil provides an objective measure of the integrity of the pregeniculate afferent visual pathway and allows assessment of sympathetic and parasympathetic innervation to the eye. Infrared videography and pupillography are increasingly used to study the dynamic behavior of the pupil in common disorders, such as Horner's syndrome and tonic pupil.     

The sclera, the prion, and the ophthalmologist

Prions have emerged in the past 5 years as serious transmissible infective agents. Ocular tissue transplantation has come under scrutiny after potential infected tissue was transplanted into healthy patients. In this review we examine the evidence for the risk of transmission of prions after scleral transplantation and explore alternative materials that may be used in ocular surgery.     

Abstracts of the 2010 Meeting of the International Neuro-Ophthalmology Society,Lyon, France

Abstract

Endovascular treatment, including transarterial embolisation and transvenous embolisation, is generally considered effective for treating carotid-cavernous fistula. Immediate cranial nerve palsy following the procedure is the most common complication, but it usually resolves spontaneously. The authors report two cases of late-onset abducens nerve palsy after successful obliteration of direct carotid-cavernous fistulas, both of which required strabismus surgery.     

Juvenile Xanthogranuloma of the Optic Nerve,Disc, Retina,and Choroid

A 20-month-old infant found to have a blind eye with neovascular glaucoma was thought to have a neoplasm of the optic nerve for which enucleation was performed with resection of a long segment of optic nerve. Microscopic examination revealed the enlarged optic nerve and optic papilla to be infiltrated densely by histiocytic cells, including Touton giant cells, all containing large amounts of neutral fat. The histologic picture was indistinguishable from that of juvenile xanthogranuloma. Occlusion of the central retinal vessels had led to hemorrhagic infarction of the retina and neovascular glaucoma. Thorough clinical and laboratory investigations repeated over a period of more than 2½ years failed to disclose any evidence of a systemic disease, and the child has remained in good health. This is believed to be a unique case of juvenile xanthogranuloma of the optic nerve and disc.     

Retinoblastoma, microphthalmia, coloboma, and neuroepithelioma of the pineal body.

A one-month-old infant boy was examined early in life because his mother had bilateral retinoblastoma and his father had bilateral microphthalmia. The ophthalmologist found his right eye was normal size with a coloboma of the iris, choroid, and retina. The left eye was microphthalmic with a coloboma of the uveal tract and retina. A vascularized fluffy white mass in the posterior pole was diagnosed clinically as a retinoblastoma. The tumor regressed with radiation. When the patient was four years of age, a large tumor was found in the region of the pineal recess, causing hydrocephalus and seizures. A biopsy showed an undifferentiated malignant neuroepithelial neoplasm. The patient died within three months of diffuse central nervous system tumor. The unusual findings of a retinoblastoma in a microphthalmic eye with bilateral colobomas and a neuroepithelial neoplasm of the pineal gland are discussed.