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Biomedical subjects

H D Perry

Publications and source records attributed to H D Perry.

At least 73 records · Page 4Linked to original sources
PubMed1990

Posterior scleritis as an intraocular tumour.

Posterior scleritis rarely presents as a large 'intraocular tumour' and continues to be a challenge in diagnosis and management. We present the case of a 66-year-old male with no known rheumatic disease, pain, proptosis, or diplopia, but with progressively decreasing visual acuity and a large, discrete 'subretinal tumour', 15 X 17 mm basal diameter and 8.3 mm apical height. Histologically the tumour was shown to be grossly thickened and necrotic sclera.

Aged↗
PubMed1990

Symblepharon formation in epidemic keratoconjunctivitis.

Two case reports are presented in which patients with epidemic keratoconjunctivitis (EKC) develop symblepharon during the course of their infection. This report is the initial documentation of symblepharon formation in EKC and the first reported episode of conjunctival membrane formation in association with adenovirus type 2.

Adenovirus Infections, Human↗
PubMed1990

Transscleral microwave cyclodestruction.

A 4.6-gigahertz (GHz) microwave applicator was used to ablate the ciliary body in rabbit eyes. High-frequency electromagnetic radiation provides a favorable dose distribution to induce local heating of the ciliary body. For treatment, a 3-mm diameter disc-shaped applicator was placed on the conjunctiva and over the ciliary body. Conjunctival temperatures were monitored during treatment with a built-in thermocouple thermometer located at the center of the disc-shaped antenna. This allowed direct measurement (dosimetry) of the conjunctival temperature during treatment. Using this microwave-based heat-delivery system, doses in a range of 60 degrees for 30 or 60 seconds appeared to cause ciliary body damage with relative sparing of the conjunctiva and sclera.

Animals↗
PubMed1990

Intraocular radiation blocking.

Iodine-based liquid radiographic contrast agents were placed in normal and tumor-bearing (Greene strain) rabbit eyes to evaluate their ability to block iodine-125 radiation. This experiment required the procedures of tumor implantation, vitrectomy, air-fluid exchange, and 125I plaque and thermoluminescent dosimetry (TLD) chip implantation. The authors quantified the amount of radiation attenuation provided by intraocularly placed contrast agents with in vivo dosimetry. After intraocular insertion of a blocking agent or sham blocker (saline) insertion, episcleral 125I plaques were placed across the eye from episcleral TLD dosimeters. This showed that radiation attenuation occurred after blocker insertion compared with the saline controls. Then computed tomographic imaging techniques were used to describe the relatively rapid transit time of the aqueous-based iohexol compared with the slow transit time of the oil-like iophendylate. Lastly, seven nontumor-bearing eyes were primarily examined for blocking agent-related ocular toxicity. Although it was noted that iophendylate induced intraocular inflammation and retinal degeneration, all iohexol-treated eyes were similar to the control eyes at 7 and 31 days of follow-up. Although our study suggests that intraocular radiopaque materials can be used to shield normal ocular structures during 125I plaque irradiation, a mechanism to keep these materials from exiting the eye must be devised before clinical application.

Animals↗
PubMed1989

Massive suprachoroidal hemorrhage in penetrating keratoplasty.

We studied the frequency of massive suprachoroidal hemorrhage during and after penetrating keratoplasty. Nine cases of intraoperative or immediately postoperative massive suprachoroidal hemorrhage were identified in 830 consecutive patients (1.08%) undergoing penetrating keratoplasties at the Manhattan Eye, Ear, and Throat Hospital over a 2 1/2-year period. Six of the nine patients had atherosclerotic disease or hypertension, six of nine patients had glaucoma, and eight of nine patients had undergone previous intraocular surgery. Surgery was performed under general anesthesia in 714 patients, and four of these patients (0.56%) suffered hemorrhages. Five of 116 (4.3%) local anesthesia patients experienced expulsive choroidal hemorrhage. The increased resistance to venous outflow associated with retrobulbar anesthetic injection may significantly contribute to the risk of massive suprachoroidal hemorrhage.

Aged↗
PubMed1989

Dacryoadenoma. A unique tumor of the conjunctival epithelium.

For 15 years, a 48-year-old woman had been aware of a pinkish translucent inferior epibulbar mass toward the fornix that was stationary in size. Light microscopic evaluation of the excised specimen showed that it was a gland-forming benign tumor. It originated from the surface epithelium by the downward invagination of tubular formations that underwent secondary and tertiary ramifications. The surface epithelium overlying the mass was not normal conjunctival squamous epithelium, but it was a modification in the form of a superficial layer of columnar to cuboidal cells surmounting several nuclei similar to the cells lining the subepithelial lumen-forming units. Electron microscopy showed that both the surface and tumor epithelium contained apical lacrimal-type zymogen granules and basilar whorls of rough-surfaced endoplasmic reticulum. Scattered myoepithelial cells were associated with the acinar-type epithelium of the tumor, and there were goblet cells intermixed. Neither light nor electron microscopy disclosed the presence of true ducts. The authors conclude that the lesion was a benign proliferation of lacrimal secretory-type cells and suggest the term "dacryoadenoma" for this previously undescribed entity.

Adenoma↗
PubMed1989

Nocardia asteroides keratitis presenting as a persistent epithelial defect.

An elderly male presented with epithelial defect which resisted all medical and therapeutic approaches until Gram stain and cultural report documented the presence of Nocardia asteroides of the offending organism. A 3-month course of chronic keratitis with persistent epithelial defect resolved in 48 h following the use of topical trimethoprim-sulfamethoxazole.

Aged↗
PubMed1989

Hyperthermic treatment of rabbit corneas.

Well defined heat doses (temperature X time) were applied to normal rabbit corneas in an effort to determine thermal tolerance, and to examine the effects of heat on this tissue. A purely conductive heater was chosen to minimize intraocular penetration, and avoid findings attributable to nonthermal effects of inductive sources. The etched element heater was sewn to 38 rabbit corneas. Thirty-six were treated to temperatures of 38, 45, 52 and/or 59 degrees centigrade for durations of 5, 15, or 45 min. Three eyes were treated at each time-temperature interval and sacrificed at either time 0, 1 day or 1 week follow-up. Histologic examinations were performed on all corneas. A corneal haze was first noted at 45 degrees C X 45 minutes X 1 day follow-up. This correlated with a mild stromal edema on light microscopy. Higher thermal doses produced a spectrum of damage, with complete destruction of all keratocytes and endothelial cells at 59 degrees C X 45 min. At levels greater than 45 degrees C x 45 min, heat damage was noted to be increased at 24 hr followup. Some recovery was noted by 1 week follow-up, with the exception of the 59 degrees C X 15 or 45 min groups. These two heat doses induced a drop-out of cellular elements with evidence of disintegration and fragmentation of collagen fibrils. Conductive heating of up to 45 degrees C X 15 min appeared well tolerated by normal rabbit corneas.

Animals↗
PubMed1988

Transscleral neodymium:YAG thermal cyclophotocoagulation in refractory glaucoma. A preliminary report.

Thirty patients treated with transscleral neodymium:YAG laser cyclophotocoagulation (TSYLC) are reported. All patients had advanced glaucoma and had previously undergone one or more surgical procedures that failed, or were unsuitable for surgery. The average preoperative intraocular pressure (IOP) for the group was 43 +/- 12 mmHg. The average follow-up time was 6 months. The average energy level used was 3.8 J (range, 3.5-4.5 J). The patients were divided into two groups. Group 1 consisted of 20 patients in whom laser lesions were applied 3 mm from the limbus. Group 2 consisted of ten patients in whom laser lesions were applied 2 mm from the limbus. Success was defined as an IOP between 22 and 5 mmHg, regardless of the number of treatments required. The overall success rate was 86%. However, group 2 required significantly more retreatment than did group 1. Complications were moderate and transient.

Electrocoagulation↗
PubMed1988

Donor failure after corneal transplantation surgery.

Donor failure refers to graft edema present within the first 24 h after penetrating keratoplasty that persists in spite of maximal medical therapy. We reviewed the case histories of 1,351 penetrating keratoplasties. Of these, 17 (1.2%) were considered donor failures. Five cases were histopathologically consistent with Fuchs' dystrophy. Seven cases demonstrated mechanical stripping of the endothelium. Five cases, all from the same eye bank, revealed an absence of posterior stromal keratocytes. Storage medium at the eye bank of origin was found to have an alkaline pH. Careful preoperative evaluation of donor corneas is emphasized, but if an apparent "epidemic" of donor failure occurs, a thorough investigation of the eye bank methodology should be initiated.

Adolescent↗
PubMed1988

Corneal involvement in Reye syndrome.

Classic Reye syndrome and its sequelae have been described repeatedly in recent literature without any correlations to ocular pathology. To our knowledge, this is the first reported case of stromal infiltration and pannus formation associated with this disorder.

Child↗
PubMed1987

Systemic tetracycline treatment of alkali-induced corneal ulceration in rabbits.

Recent evidence has demonstrated a marked anticollagenolytic effect for the tetracycline antibiotics. We have examined the efficacy of systemic tetracycline hydrochloride in a rabbit model of corneal ulceration. A standard alkali burn (1N sodium hydroxide for 40 s) was delivered to 62 eyes (31 rabbits). Animals were then divided into three groups: group 1 (controls) (ten rabbits [20 eyes]) received no treatment; group 2 (ten rabbits [20 eyes]) received 10 mg/kg/d of tetracycline hydrochloride, given intramuscularly; and group 3 (11 rabbits [22 eyes]) received 50 mg/kg/d. Ulceration occurred in 85% (17/20) of control eyes. The higher dosage of tetracycline was more effective in preventing ulceration than the lower dosage (9.1% vs 55%). Eyes with higher levels of tetracycline in ocular tissues were less likely to ulcerate.

Alkalies↗
PubMed1987

Epibulbar choristomas containing lacrimal tissue. Clinical distinction from dermoids and histologic evidence of an origin from the palpebral lobe.

Three new cases of epibulbar choristomas, all containing lacrimal tissue, are presented and compared with those reported previously in the literature. The first and second cases were unilateral, complex choristomas, consisting of ectopic lacrimal tissue, smooth muscle, and cartilage; the first case was also remarkable for the presence of lesional tissue in the peripheral cornea and evidence of progressive growth during puberty. The third case was a bilateral, complex choristoma, manifesting epibulbar lacrimal tissue, cartilage, and smooth muscle; also associated were bilateral optic nervehead colobomas and a uniocular focus of posterior scleral cartilage demonstrated by computed tomography (CT) scanning. On clinical examination, all three lesions displayed highly vascularized thickenings of the conjunctiva with diagnostically useful gelatinous elevations, which corresponded microscopically to lobules of lacrimal tissue. In addition, all three cases had the interesting diagnostic feature of superficial corneal scarring or sclerosis, with a fine vascularity adjacent to the conjunctival lesional tissue. Electron microscopy of the third case demonstrated completely normal cytoarchitecture of the lacrimal tissue. Because of the frequent presence of Müller's smooth muscle in epibulbar lacrimal choristomas, the authors propose that these lesions represent embryologic ectopias or overly extensive field effects of the palpebral lobe of the lacrimal gland.

Adolescent↗
PubMed1987

Oversize donor buttons in corneal transplantation surgery for keratoconus.

The authors report preliminary findings in 34 patients treated with oversize donor buttons for keratoconus. Seventeen patients received oversize donor grafts and 17 received same-size material. A significant increase in myopia was observed in the oversize group when compared with the same-size group, which indicates a trend toward increased corneal curvature in oversized corneal grafts. Oversize material therefore is contraindicated in treating keratoconus.

Corneal Transplantation↗