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Biomedical subjects

K To

Publications and source records attributed to K To.

At least 19 recordsLinked to original sources
PubMed1999

Cataracts, bilateral macular holes, and rhegmatogenous retinal detachment induced by lightning.

PURPOSE: To report ocular injuries, including a unilateral rhegmatogenous retinal detachment, induced by lightning. METHOD: Case report. A 30-year-old man was injured by lightning. RESULTS: The patient developed a severe decrease in visual acuity in both eyes, an afferent pupillary defect in his left eye, bilateral cataracts, posterior vitreous detachments, macular holes, and an inferotemporal retinal detachment with an associated flap retinal tear in his left eye. CONCLUSIONS: This is a case of bilateral cataracts, posterior vitreous detachments, macular holes, and a unilateral retinal detachment associated with lightning. We postulate that the heating of the retinal surface, the concussive forces on the eye, and a sudden lateral contraction of the attached vitreous resulted in bilateral posterior vitreous detachments and a unilateral peripheral retinal break.

Adult↗
PubMed1999

Effect of collagen implants in the reduction of high astigmatism induced by penetrating keratoplasty.

PURPOSE: To evaluate the insertion of EagleVision collagen plugs as spacers between corneal relaxing incisions to correct significant residual astigmatism after penetrating keratoplasty (PKP). SETTING: Ambulatory Clinic of the Department of Ophthalmology, Rhode Island Hospital, and Rhode Island Eye Institute, Providence, Rhode Island, USA. METHODS: This study comprised 8 patients meeting the following criteria: had previous PKP, had at least 5.0 diopters of residual keratometric astigmatism with all the sutures removed, were free from eye infection, and were at least 21 years old. All 8 patients had unilateral high astigmatism after PKP. Four eyes were randomly assigned to the control group of astigmatic keratectomy (AK) incisions without the collagen implants and 4 eyes to the experimental group of AK incisions with collagen implants. RESULTS: Best corrected visual acuity 1 day, 3 weeks, and 1, 2, and 6 months after AK showed decreased astigmatism in all the patients who had the relaxing incisions. The amount of astigmatism was lower in patients who received AK incisions with collagen implants (P < .28). Minimal adverse effects were noted. CONCLUSION: Implanting a biocompatible material into AK incisions to correct post-PKP astigmatism appears to be safe and may enhance astigmatic correction.

Adult↗
PubMed1999

Penetrating eye injury from a metal wedge.

The authors describe a patient with a penetrating ocular injury from a metal wedge, a common hand tool used by road service technicians for the purpose of opening a locked car door. The patient had a penetrating eye injury from a metal wedge when its sharp end released from a car door lock and retracted upward, striking the right eye. No report exists of ocular injury using a metal wedge for its intended purpose of opening a car door lock. The use of polycarbonate lenses might afford some protection.

Accidents, Occupational↗
PubMed1998

Histopathologic and immunohistochemical study of dominant cone degeneration.

PURPOSE: To report the histopathologic and immunohistochemical findings in autosomal dominant cone degeneration. METHODS: The autopsy eyes of a 75-year-old man with autosomal dominant cone degeneration were studied with both light and electron microscopy. In addition, immunofluorescent studies using antibodies to cone opsins and cone alpha transducin were performed. RESULTS: Histopathologic examination of the fovea disclosed loss of photoreceptors and attenuated retinal pigment epithelium. Reduced numbers of cones could be seen in the parafovea, and only occasional cones were visible in the periphery; rods were preserved in the periphery. CONCLUSION: The histopathologic and immunohistochemical findings in this case of dominantly inherited cone degeneration correlate well with the loss of cone function and preservation of normal or nearly normal rod function upon clinical examination. This condition affects red, green, and blue cones.

Aged↗
PubMed1996

Misdiagnosis of an interstitial ectopic pregnancy after unilateral salpingectomy.

A 36-year-old primigravida presented to us with symptoms and signs of ectopic pregnancy repeatedly but was misdiagnosed to have an intrauterine pregnancy based on 1 early ultrasound examination showing an 'intrauterine sac'. She suffered the morbidity due to ectopic pregnancy which included hysterectomy which may have been prevented had the correct diagnosis been made.

Adult↗
PubMed1994

Solitary fibrous tumor of the orbit.

We report three cases of an orbital soft tissue lesion that fulfills the histologic, immunohistochemical, and electron microscopic criteria for solitary fibrous tumor, an entity previously described as a pleural tumor, but recently reported to occur in other locations. All three patients presented with proptosis. Two of the patients were cured by simple excision, and one patient had two recurrences, the last recurrence incompletely excised. The findings indicate that solitary fibrous tumor can occur in the orbit and, like solitary fibrous tumors of other anatomic sites, may behave in a nonaggressive or occasionally, locally aggressive fashion, with as yet no metastatic potential demonstrated in orbital lesions.

Actins↗
PubMed1992

Acquired heterochromia with horner syndrome in two adults.

BACKGROUND: Heterochromia iridis, asymmetry of iris pigmentation, has been well described with congenital Horner syndrome. Acquired heterochromia associated with lesions in the ocular sympathetic pathways in adulthood, however, is rare. METHODS: Two cases are reported in which sympathectomy in adults resulted in ipsilateral Horner syndrome with heterochromia. In each case, pharmacologic testing with cocaine and hydroxyamphetamine was performed. RESULTS: In both cases, sympathectomy occurred at the level of the second order neuron, but hydroxyamphetamine testing suggested at least partial third order neuron involvement. CONCLUSION: Acquired heterochromia can occur in adults. The partial response to hydroxyamphetamine in the two cases presented may reflect trans-synaptic degeneration of the postganglionic neuron. A reduction in trophic influences on iris melanocytes may have contributed to the observed heterochromia.

Aged↗
PubMed1992

Hemangiopericytoma of the lacrimal sac.

Hemangiopericytoma is a rare soft-tissue neoplasm composed histologically of pericytes. Hemangiopericytoma of the lacrimal sac is exceedingly rare. This case provided the first known computed tomographic image of a hemangiopericytoma of the lacrimal sac prior to surgical intervention.

Female↗
PubMed1991

Mucoepidermoid carcinoma of the lacrimal gland. Report of a case with oncocytic features arising in a patient with chronic dacryops.

A 62-year-old woman had recrudescence of growth of a lacrimal gland fossa cystic mass present for more than 40 years. Results of histopathologic examination of the excised specimen showed infiltrating nests of epidermoid and mucin-producing cells, consistent with a mucoepidermoid carcinoma. Also present were numerous large oncocytic cells partially lining the lumens of the multiloculated cyst and penetrating the adjacent stroma. To the authors' knowledge, this is the first reported case of mucoepidermoid carcinoma with prominent oncocytic features arising in a previously documented chronic cystic lesion of the lacrimal gland. Because of the population of oncocytes (a metaplastic phenomenon encountered in ductular epithelial cells) among the cells lining the cyst, the authors conclude that the carcinoma arose from a long-standing dacryops. This conclusion was also supported by the electron microscopic demonstration of duct-type secretory granules within the mitochondria-rich oncocytes.

Carcinoma↗
PubMed1989

Posterior chamber intraocular lens dislocations and malpositions.

Decentration and malposition of posterior chamber intraocular lenses (PC IOL) accounts for one of the remaining and unresolved conditions associated with the implantation of these lenses. This condition assumes importance since in approximately 50% of cases where a PC IOL is removed there is an aspect of improper positioning. The common types of malpositions are: pupil capture; sunset syndrome; sunrise syndrome; horizontal decentration; and the windshield wiper syndrome. This paper will explore the causes and management of these conditions and discuss the virtues of capsular bag implantation.

Eye Diseases↗
PubMed1987

Semiconductor laser endophotocoagulation of the retina.

Laser endophotocoagulation is an important technique in vitreoretinal surgery. We performed successful retinal endophotocoagulation in the eyes of Dutch-belted rabbits, using high-power phased-array semiconductor lasers, emitting at 808 and 817 nm. The laser itself measured 25 X 30 X 21 mm, was air cooled, and was portable. At a treatment power of 100 mW, uniformly white photocoagulation lesions were seen at exposure durations of 0.2 to 1.0 s. Lesions were similar in appearance to argon laser photocoagulation lesions, as determined by ophthalmoscopy and fluorescein angiography. Thin-section histologic examination of acute lesions revealed injury localized to the outer retina; chorioretinal scar formation was noted ten days after photocoagulation. To our knowledge, this study is the first in which therapeutically useful lesions were produced using a diode laser and demonstrates the feasibility of using these highly efficient and compact laser sources for ophthalmic photocoagulation.

Animals↗