Biomedical subjects
Publications and source records attributed to F G La Piana.
This overview of the practice of military ophthalmology by US army ophthalmologists during the Vietnam War focuses on administrative management of eye and adnexal injuries, care of the wounded military and of Vietnamese civilians, and research activities. It concludes with improvements that have been subsequently adopted.
We present a case of granular cell tumor of the eyelid. Although commonly reported elsewhere in the body, this entity rarely occurs in the ocular adnexa.
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Standard enucleation techniques provide excellent results. Modifications can render the operative field bloodless and permit the performance of all manipulations under direct visualization. Standard enucleation has been postulated to disseminate choroidal malignant melanoma cells as a result of fluctuations in intraocular pressure incident to surgical manipulations. It is possible that the stabilization of intraocular pressure preceding induction of tumor freezing may decrease such dissemination and thereby increase survival.
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Two patients with epibulbar juxtalimbal primary conjunctival melanomas experienced local intralymphatic metastases to the inferior cul-de-sac, and a hematogenous metastasis to the conjunctiva developed in five other patients with cutaneous melanomas. Whether reflective of a local or distant metastasis, all of the lesions histopathologically were located in the substantia propria, and were separated from the overlying epithelium by a thin mantle of collagen. There was no evidence of atypical intraepithelial melanocytic proliferation, as would be expected in association with a primary conjunctival melanoma. Two of the cutaneous metastases exhibited a binodular or multinodular appearance that correlated histopathologically with variably confluent micronodules suggestive of the origin of the clinical lesion from a shower of tumor cell emboli. Patients with local intralymphatic spread from a primary conjunctival melanoma may experience additional lesions in the conjunctival sac or eyelid skin and are at risk for regional or distant metastases. They should be examined closely several times a year. The patients with the distant metastases all had their previously diagnosed primary cutaneous tumors on the truncal skin (a similar tendency emerges from a review of previous ocular cases), typically had myriad other cutaneous lesions, and two of them had a neoplastic iridocyclitis and vitreitis. These patients tended to die of the disseminated tumors within 1 year after conjunctival metastases developed.
We present an unusual case of a melanocytoma of the optic disc that showed documented progressive growth over a period of six years. It reached the largest size of any reported optic nerve melanocytoma and the eye was enucleated because of the possibility of malignant degeneration. Optic nerve melanocytomas are locally invasive but are not known to undergo transformation into malignant melanoma. Follow-up should remain the primary approach in the management of patients with optic nerve melanocytomas, as previously advocated by Zimmerman.
Non-ophthalmologists must know how to detect, diagnose, and initially manage acute eye and ocular adnexal injuries in order to minimize their morbidity. Such instruction can be provided medical students in part from dog eyes and lids injured so as to produce models of common forms of ocular trauma. We describe the generation of such models and the format of instruction employed at the Uniformed Services University of the Health Sciences.
Two patients with postoperative cicatricial lower lid ectropion were managed by having the patient massage the lower lid in an upward direction over a methyl-methacrylate scleral ring. The ectropion was corrected. Such nonsurgical management may be attempted as an alternate initial therapy for the patient who refuses or should not immediately undergo additional surgery.
Intraoperative visual-evoked potential recording has been a potentially useful procedure for monitoring the functional status of the visual pathways during certain neurosurgical procedures. Technical problems have limited its adoption. We report a light-emitting diode array globe protector photostimulator which enhances the stimulation component of the visual-evoked potential recording technique.
In 1948, ophthalmologists started implanting plastic spheres partially covered with tantalum mesh (eg, the Valley Forge Implant) in anophthalmic sockets. Numerous patients have developed complications ten to 15 years after surgery: pain ("pinching" or "deep"), headache, heavy mucopurulent discharge and diffuse conjunctival inflammation, migration of the implant, thinning or erosion of tissues covering the implant (extrusion), and inability to wear an artificial eye. Management includes refabrication of the artificial eye and replacement of the implant with a dermis-fat graft or a silicone ball plus scleral graft. Tantalum-mesh--covered orbital implants should probably not be used.
Anophthalmic orbits that reject conventional implants may accept the dermis-fat graft. The subsequent fitting of such a socket differs in many important ways from the fitting of sockets containing conventional implants. Before surgery, the ocularist should construct a custom-made scleral ring to be inserted after the operation. This replaces the standard conformer that can erode the underlying dermis. The socket must be observed carefully for any evidence of damage to the conjunctiva-dermis suture line by the ring, and the latter modified or replaced as necessary. Granulation tissue forming around the sutures uniting conjunctiva and dermis may have to be resected and cauterized. Impression molding of an artificial eye is performed five weeks after surgery. The artificial eye always requires modifications over the first six months as the graft recedes due to partial atrophy of the fat of the graft, thus deepening the socket.
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The congenital eyelid tetrad (CET) comprises epicanthal folds, telecanthus, ptosis, and blepharophimosis. The natural history of CET is that with time the epicanthal folds disappear and the telecanthus becomes insignificant, but the ptosis and the blepharophimosis remain functional and cosmetic problems. Surgical correction of the ptosis and the blepharophimosis should be performed early in the patient's life, but surgical correction of the telecanthus and epicanthal folds should be deferred until growth is complete when such surgery may not be necessary.
The standard surgical technique for enucleation of an eye containing a malignant melanoma of the uvea elevates intraocular pressure markedly and may thereby disseminate tumor cells and cause death. It is possible to enucleate an eye bear a malignant melanoma of the choroid without elevating intraocular pressure to more than 27 mm/Hg by employing a manometric intraocular pressure regulating system and the adjustable cryo-ring. The value of this method of enucleation in diminishing tumor deaths remains unknown.
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Sector retinitis pigmentosa of Bietti has not been studied histopathologically and has not been reported as occurring in a patient with neurofibromatosis. This report describes a patients with neurofibromatosis and biopsy-proven optic nerve glioma who was noted before death to have bilateral sectoral retinal pigmentary disturbances that appeared histopathologically to be areas of retinitis pigmentosa.