Expression of transforming growth factor-beta in wound healing of vitamin A-deficient rat corneas.

Transforming growth factor-beta (TGF-beta) is a multifunctional peptide that modulates cell proliferation and differentiation in many cell types and accelerates tissue repair response. In this study, expression of TGF-beta was investigated immunohistochemically in the healing of central 3 mm epithelial wounds of vitamin A-deficient (A-) rat and pair-fed controls. In control rat corneas, a positive reaction to TGF-beta was not evident during wound healing.

Macular edema in branch retinal vein occlusion: types and treatment.

In this study of branch retinal vein occlusion, we distinguished between cystoid macular edema caused by increased capillary pressure and noncystoid edema due to hard exudates in the macula caused by chronic leakage from vascular abnormalities in the posterior pole or midperiphery. We performed laser photocoagulation in 51 eyes with cystoid macular edema to achieve focal narrowing of the retinal arterioles perfusing the macular area affected by the cystoid edema; good anatomic and functional results were achieved in 40 of these eyes (78%). In 25 of the five eyes, the treated segment of the retinal arteriole was outside the area of macular edema; results were successful in 19 of these eyes (76%).

Diagnosis and management of massive vitreous hemorrhage caused by retinal tear.

Fourteen cases of massive vitreous hemorrhage caused by a retinal tear, the cause having been confirmed during closed vitrectomy, were studied retrospectively. In the 3 cases with no retinal detachment and in the 6 cases with partial but not extensive retinal detachment at the time of surgery, the electroretinogram (ERG), visual evoked response (VER) and electrically evoked response (EER) were recordable preoperatively. After surgery the retina was attached in all 9 cases, but later redetached in one case.

Prospective, randomized trial of oral piroxicam in the prophylaxis of postoperative cystoid macular edema.

One hundred and seventy-eight patients undergoing uncomplicated cataract extraction with posterior chamber intraocular lens insertion completed a prospective, randomized, controlled trial of oral piroxicam in the prophylaxis of postoperative cystoid macular edema (CME), with a 1-year follow up. The incidence of "visually significant" CME, the mean interval to onset following surgery, clinical severity, recurrence rate, and the time to achieve best corrected visual result were unaffected by a 17-day piroxicam course. Oral steroid CME treatment produced a rapid response, but could not be shown to change the ultimate visual results.

Characteristics of the cellular response of the rat conjunctiva to topically applied leukotriene B4.

Cellular events in the rat conjunctiva were studied at 1, 6 and 24 h following the topical application of leukotriene B4. A significant increase was noted in the number of eosinophils (p less than 0.01) and neutrophils (p less than 0.

Repair of the corneal epithelial adhesion structures following keratectomy wounds in diabetic rabbits.

In corneal tissue from a diabetic patient 15 months after delayed epithelial healing following vitrectomy surgery, electron microscopy revealed a discontinuous basement membrane; immunohistochemically, fibronectin was present in the basement membrane zone. To determine whether alterations in repair of the basement membrane, anchoring fibrils and hemidesmosomes occur in wounds in diabetics, we studied the pattern of histochemical localization of bullous pemphigoid antigen (the intracellular hemidesmosome plaque component), laminin and type VII collagen (the anchoring fibril collagen) in alloxan-induced diabetic rabbits following superficial keratectomy. Ultrastructural studies of basal laminae and hemidesmosomes also were performed.

Distribution of collagenase and cell types in sterile ulceration of human corneal grafts.

Extensive clinical and experimental evidence has suggested a role for corneal epithelium, keratocytes, and acute inflammatory cells in sterile corneal ulceration, although the precise role of these cell types in stromal matrix degradation has not been elucidated. We studied two corneal buttons and two whole corneas from 4 patients with corneal grafts and sterile stromal ulceration. Each cornea was divided into several sections and examined morphologically, while adjacent sections were placed in tissue culture and assayed for collagenase activity against type I collagen.

Ocular anaphylaxis induced in the rat by topical application of compound 48/80. Dose response and time course study.

In the present study we sought to develop a model of ocular anaphylaxis based on the topical application of compound 48/80 to the surface of the rat eye. Doses ranging from 50 to 1000 micrograms were found to produce graded edema of the conjunctiva and swelling of the lid. On histologic examination, 50 microns compound 48/80 produced no changes distinguishable from those in PBS-treated controls, 150 microns produced mild alterations, and 250, 500, and 1000 micrograms compound 48/80 produced a marked increase in degranulated mast cells and a mild influx of neutrophils.

Keratopathy of the rabbit cornea following complete eyelid closure.

The corneal response to a complete tarsorrhaphy was studied in 46 rabbits for time periods up to 21 days. During the first 7 days of complete eyelid closure corneal thickness increased up to 18.4%, glycogen decreased 32.

The epithelial basement membrane zone of the limbus.

The basement membrane zone of the limbal epithelium adjacent to the cornea was examined by ultrastructural and immunohistochemical techniques to determine whether differences exist between this region and central cornea. In human limbus, the percentage of basal cell membrane occupied by hemidesmosomes was significantly less (14.9 +/- 3.

BCNU in silicone oil in proliferative vitreoretinopathy: I. Solubility, stability (in vitro and in vivo), and antiproliferative (in vitro) studies.

Various pharmacologic agents have been tried to control proliferative vitreoretinopathy (PVR). However, most are water soluble and cannot be used with silicone oil (SO), a tamponade agent also used in PVR management. We evaluated a lipophilic, antiproliferative drug, BCNU, in regard to its solubility and stability in SO, its release from SO into an aqueous solution, and its effect on cell cultures.

Plasminogen activator activity in vitamin A-deficient rat corneas.

Plasminogen activator (PA) activity during epithelial wound healing in vitamin A-deficient rats was investigated to determine whether a relationship exists between corneal defect formation and PA activity. Uniform, central 3 mm diameter corneal epithelial wounds were made by scalpel debridement in vitamin A-deficient and in pair-fed control rats. Cryostat sections of such corneas, taken at various times post-scrape, were overlaid with fibrin films containing plasminogen to examine the distribution of PA activity; and antibodies to tissue plasminogen activator (tPA) or to urokinase-like activator (uPA) were incorporated into the films so that the immunochemical natures of detected PA activities could be determined.

A review of 324 cases of idiopathic premacular gliosis.

We reviewed the records of 324 patients (395 eyes) seen between 1973 and 1987 with a diagnosis of idiopathic premacular gliosis. Mean age of onset was 64.6 years, 189 (58.

Superoxide dismutase activity and growth of retinal pigment epithelial cells are suppressed by 20% oxygen in vitro.

Despite knowledge of the toxicity of oxygen to the retina, its effects on the retinal pigment epithelium have not been considered. We examined the effect of 20%, 10% and 5% oxygen on growth and superoxide dismutase (SOD) activity of porcine retinal pigment epithelial cells (RPE). Growth of RPE cells was very significantly lower in 20% oxygen than in either 10% or 5%; optimal growth occurred at 10% oxygen, the concentration most like their environment in vivo.

The role of the vitreous in diabetic macular edema.

The authors assessed retrospectively clinical records of 76 patients (125 eyes) 60 years of age or older with diabetic retinopathy who had undergone a vitreous examination. The groups consisted of 105 eyes (63 patients) with macular edema and 20 eyes (13 patients) without macular edema. Vitreous studies were done using the El Bayadi-Kajiura lens to determine whether or not the posterior vitreous was attached to the retina in the macula.

Treatment of small choroidal melanomas with photocoagulation.

Seventeen eyes with small choroidal melanomas presumed to be malignant were photocoagulated. The melanomas measured 7 to 15 mm at the tumor base and 2 t0 5 mm thick. First, photocoagulation using the green argon laser was aimed at closing the choroidal vascular supply of the tumor.

Aqueous humor flow measured with fluorophotometry in timolol-treated primates.

Anterior chamber aqueous humor flow rate was measured in unanesthetized owl monkeys using fluorophotometry and anterior chamber photogrammetry. The mean anterior chamber turnover constant (ko) was 0.01, the mean aqueous humor flow rate was 2.

Detection of HSV nucleic acid sequences in the cornea during acute and latent ocular disease.

This study evaluated the continued presence of herpes simplex virus (HSV) nucleic acid sequences after resolution of acute herpetic stromal keratitis in the rabbit ocular model. Forty-four rabbits were inoculated bilaterally with 10(5) plaque-forming units of RE strain HSV-1 by intrastromal injection. All eyes were cultured for the presence of HSV during acute disease and immediately before the animals were killed.

Intravitreal human chorionic gonadotropin decreases intraocular pressure in rabbits: mechanism of action.

Intravitreal injection of purified human chorionic gonadotropin (hCG) in rabbits decreased intraocular pressure (IOP). A dose-dependent decrease in IOP was observed with intravitreal hCG concentrations at 30 nM and 100 nM. The onset of this effect was later than 10 hr following the injection and it lasted for more than 24 hrs.

Attenuation of rat conjunctival response by repeated hapten applications.

Attenuation of the rat conjunctival response by repeated topical challenge with dinitrophenyl (DNP) hapten was demonstrated in our study. Adult rats were immunized by intraperitoneal injections of dinitrophenylated Ascaris suum extract (DNP-Asc) and alum. Serum levels of anti-DNP homocytotropic antibody were determined by passive cutaneous anaphylaxis in rats prepared with antibody 48 hours earlier.

Effect of stimulus field size and localization on the binocular pattern reversal visual evoked response.

The role of the central and peripheral stimulus fields on monocular and binocular amplitude and binocular summation of the pattern reversal visual evoked response were investigated. When the central stimulus field size was smaller than 2.4 degrees, there was no significant difference between the amplitude of the monocular and the binocular responses, but when it was equal to or larger than 3.

Extra-pituitary action of luteinizing hormone releasing hormone on intraocular pressure.

Luteinizing hormone releasing hormone (LHRH) given intraventricularly caused a delayed, significant decrease of intraocular pressure (IOP) in adult female rabbits for a prolonged period, but only elevated plasma gonadotropins for a few hrs. Intravenous injections of LHRH caused a similar elevation of plasma gonadotropins without any effect on IOP. It indicates that LHRH initiates a mechanism in the central nervous system to decrease IOP, which is unrelated to the conventional LHRH-gonadotropin axis.

Dark-staining bodies in the conjunctival epithelium of rats after multiple topical challenges with compound 48/80.

Over a 17-day period, 96 Sprague-Dawley rats received approximately daily topical applications of compound 48/80 to the ocular surface of one eye and phosphate-buffered saline (PBS) to the other eye. On histologic examination, dark-staining bodies appeared in the conjunctival epithelium in all 48/80-challenged eyes after day 3. These epithelial dark bodies (EDBs) rarely appeared in PBS-challenged or in single-dose 48/80-challenged tissues.

Comparison of proteins in lacrimal gland fluid secreted in response to different stimuli.

To determine if different stimuli cause secretion of different proteins in lacrimal gland fluid (LGF), rabbits were anesthetized and LGF collected under baseline conditions (with the local anesthetic proparacaine), with ocular reflexes present, and in response to arterial injection of the cholinergic agonist acetylcholine (ACh) or the peptide vasoactive intestinal peptide (VIP). Proteins in LGF were separated by nondenatured gradient polyacrylamide gel electrophoresis. Except for minor differences, the number, the approximate molecular weights, and the amounts were the same in LGF secreted in response to four different stimuli.

Preretinal oxygen changes in the rabbit under conditions of light and dark.

Preretinal oxygen measurements were made in pigmented rabbits under conditions of light and dark. The avascular rabbit retina was chosen to eliminate the effects of autoregulation by the retinal vasculature, thus more clearly defining the role of the photoreceptors on preretinal measurements of oxygen delivery from the choroid. Measurements were made 50-100 micron away from the retina using oxygen microelectrodes.