Biomedical subjects

U Ticho

Publications and source records attributed to U Ticho.

33 records · Page 2Linked to original sources

PubMed1979

Piloplex, a new long-acting pilocarpine polymer salt. B: Comparative study of the visual effects of pilocarpine and Piloplex eye drops.

Induced accommodation and changes in vision (distance and near) were measured monocularly and binocularly in 9 young healthy volunteers in a double blind study after administering to them pilocarpine hydrochloride 4%, Piloplex 3.4, and saline eye drop instillations. Piloplex 3.4, a new long-acting pilocarpine polymer salt, and pilocarpine hydrochloride 4% (both contain equal amounts of pilocarpine-3.4%) induced changes in vision and accommodation. These changes were greater with pilocarpine hydrochloride than with Piloplex. The maximum changes occurred half an hour after instillation and the effect vanished after an additional period up to 3 hours. The changes were greater when measured monocularly than binocularly. Piloplex initiates a prolonged hypotensive effect which lasts for 12 hours. Patients with glaucoma are thus able to use Piloplex on a twice-daily schedule. Consequently, visual disturbances occur only once a day in contrast to pilocarpine hydrochloride given 4 times a day, which induces 3 visual disturbances during the day.

Accommodation, Ocular↗

PubMed1979

Ocular changes in rabbits with corticosteroid-induced ocular hypertension.

Rabbit eyes with steroid-induced ocular hypertension were investigated in order to evaluate the histochemical abnormalities in the chamber angle region. The right eye of 14 rabbits was treated by dexamethasone 1% 3 times daily for 3 to 5 weeks. The eyes were stained by haematoxylin-eosin, periodic acid Schiff, fibrin, colloidal iron, and alcian blue with and without hyaluronidase. All treated eyes developed elevated intraocular pressure up to 4 weeks after treatment. These globes showed alcian-blue-positive hyaluronidase-sensitive staining in the amorphous material adjacent to Schlemm's canal and in the cytoplasmic granules of trabecular endothelial cells. There was no increase in incorporation of radioactive thymidine into nuclei of endothelial cells as seen by autoradiography. These results provide further support for the idea that there is abnormal accumulation of acid mucopolysaccharides in the chamber angle in steroid-induced ocular hypertension.

Animals↗

PubMed1979

Absence of association between HLA antigens and primary open angle glaucoma in Israel.

HLA antigens of the A and B loci were determined in 57 Israeli patients with primary open angle glaucoma (POAG) presenting visual field loss and in 715 normal control subjects. The glaucoma patients and control subjects were non-related and randomly selected from the Jewish Israeli population. Frequencies of HLA antigens among the POAG patients showed no differences from those observed in the control subjects. Similar results were observed for all patients as well as within subgroups of the patient population as defined by origin. Thus, the association reported between B7 and/or B12 and POAG in white and black Americans could not be confirmed in an Israeli population.

Adult↗

PubMed1979

A clinical trial with Piloplex--a new long-acting pilocarpine compound: preliminary report.

A clinical comparison of the effect of Piloplex (an emulsion containing a new pilocarpine polymer compound) to that of pilocarpine hydrochloride 2% q.i.d.hloride on the intraocular pressure (IOP) was performed on 93 eyes of 51 open-angle glaucoma cases. Clinical studies showed that Piloplex produced a prolonged therapeutic effect, this being consistent with the slow release pattern it has displayed during in vitro experiments. Comparison of diurnal IOP measurements of 84 eyes have shown that when treated with Piloplex, 11 b.i.d., 58 eyes (69%) were under control (IOP values less than 20 mm Hg), whereas only 34 of these 84 eyes (40.5%) were under control when treated with pilocarpine hydrochloride 2% q.i.d. The overall mean diurnal IOP value of the 84 eyes during the treatment with Piloplex, 11 b.i.d., was lower by 2.89 mm Hg (P less than 0.005) than the overall mean diurnal IOP of the same eyes while treated with pilocarpine hydrochloride 2% q.i.d.

Adult↗

PubMed1978

Argon laser trabeculotomies in primates: evaluation by histological and perfusion studies.

The continuous argon laser beam has been applied to the trabeculum at the anterior chamber angle of one eye of nine primates. The treatment was evaluated by light and scanning electron microscopy and constant rate infusion studies at different intervals following the laser treatment. This histological studies revealed coagulative necrosis, with trabeculotomies extending into Schlemm's canal in the immediate postoperative period. However, complete closure of the laser-induced trabeculotomies by healing was observed within 1 to 3 weeks following the treatment. Outflow facility data as measured by the perfusion studies revealed somewhat increased values of the treated eye during the early 2 weeks after laser treatment. On longer follow-up, no significant outflow differences were measured between the treated and untreated eyes.

Animals↗

PubMed1977

Automatic testing of the visual field using electro-oculographic potentials.

The central visual field is tested using static perimetry on a tangent screen located 1 m from the patient. During the test electro-oculographic (EOG) potentials, associated with eye movements, are recorded. For this purpose two pairs of electrodes are placed in such a way that one pair records the vertical and the other the horizontal component of the EOG potential. The EOG signals that are produced when the tested eye moves toward the light target on the screen are digitized and fed into a computer programmed to relate each pair of signals to the specific lamp on the tangent screen. The results of the test appear on a computer-printed chart that shows the distribution of the lamps on the testing board together with the information whether the lamp was seen by the subject. This method of visual field testing is both objective and automatic.

Automation↗

PubMed1977

Laser application to the angle structures in rabbits, cats, and in human glaucomatous eyes.

Argon laser lesions were induced to the structures of the anterior chamber angle in rabbits and cats and in a pre-enucleated infant's eye. Histopathological changes at different follow-up periods were analyzed. The argon laser beam was also applied to 28 uncontrolled glaucomatous eyes. Twenty-five eyes responded by an abrupt hypotensive effect, but in 21 of them, elevated pressure recurred after 20 to 40 days. Eight eyes maintained low intraocular pressure throughout the 12 to 20 month follow-up period. Of these, 3 were eyes of babies with congenital glaucoma, and 3 had simple glaucoma following an unsuccessful filtering operation. Seven eyes were medically controlled postoperatively and 13 eyes were failures which had to undergo further surgery.

Adult↗

PubMed1977

Reopening of occluded filtering blebs by argon laser photocoagulation.

We attempted to re-establish filtration in 11 glaucomatous eyes of patients who had undergone fistulizing surgery in the past, had poor or no filtration at various periods of time after surgery, and intraocular pressure above normal levels. Our technique consisted of applying an argon laser beam to the anterior chamber angle at the sclerotomy site of previous filtering and anterior to the iridectomy. Approximately 200 spots of 50 mu size were applied to this target with the help of a Goldmann prismatic goniolens. In five of 11 eyes the fistulizing blebs showed signs of activity shortly after the laser treatment with normalization of IOP during a follow-up period of over one year. Success was obtained in eyes with incomplete scarring of their fistulizing blebs with poor and nonfunctioning filtering cysts. Pigmentation of the target at the occluded sclerotomy site was significant.

Adult↗

PubMed1977

Steroid-induced glaucoma and cataract in renal transplant recipients.

Fifteen kidney transplant recipients were studied ophthalmologically for periods of one to five years following the transplantation. All subjects received maintenance immunosuppressive therapy which included azathioprine (IMURAN) and corticosteroids. Two patients developed posterior subcapsular cataracts. Seven patients (47%) developed increased intraocular pressure and one of these had glaucomatous field loss and disk cupping. The increased intraocular pressure responded favorably to topical treatment while the patients were under continuous treatment with systemic steroids and immunosuppressive drugs.

Administration, Oral↗

PubMed1977

Laser application to the angle structures in animals and in human glaucomatous eyes.

Argon laser lesions were induced in the structures of the anterior chamber angle of rabbits, cats and monkeys and in a pre-enucleated infnat's eye. Histopathological changes produced by this mode of treatment at different follow-up periods were analysed. The argon laser beam has also been applied in 28 selected, uncontrolled glaucomatous eyes. 25 eyes responded by an abrupt hypotensive effect, but in 21 of them, the elevated pressure returned during the 20- to 40-day follow-up period. Eight eyes sustained low intraocular pressure throughout the 12- to 20-month follow-up period. Of these, 3 were babies with congenital glaucoma, and 3 had simple glaucoma following an unsuccessful filtering operation. Seven eyes were medically controlled post-operatively and 13 eyes were failures which had to undergo further surgery.

Adult↗

PubMed1976

Argon laser application to the angle structures in the glaucomas.

The argon laser beams' effect on angle structures was studied in 20 uncontrolled glaucomatous eyes. Nineteen eyes became hypotensive quickly, but in 15, the elevated tension returned during the 20 to 40 day follow-up period. Four eyes sustained low pressures throughout the ten-month follow-up period. Two were of babies with congenital glaucoma, one had simple glaucoma following an unsuccessful filtering operation, and one was aphakic following congenital cataract extraction. Ten eyes were medically controlled postoperatively, and six were failures that had to undergo further surgery. Outflow facility measurements revealed an increase in C values during the hypotensive period. The C values were reduced later, with the decrease corresponding to the increase in intraocular pressures. The hypotensive effect together with the increase in outflow facility was probably related to laser-induced openings in the angle structures. The varying results at the later stages depended on whether or not these openings remained opened, or became partially or completely closed during healing.

Adolescent↗

PubMed1976

Lymphocyte sensitivity to glucocorticoids.

We evaluated the possibility of identifying patients with open-angle glaucoma based on the in vitro behavior of their lymphocytes in the presence of glucocorticoids. Our results do not support the hypothesis that lymphocytes from patients with open-angle glaucoma, as compared to those from normal subjects, are more sensitive to the presence of corticosteroids in vitro. In addition, the degree of inhibition induced by glucocorticoids was closely related to the amount of activation of the lymphocyte membrane induced by different concentrations of phytohemagglutinin. Our results indicated that this may be a general phenomenon rather than one that is specific to a particular ophthalmological condition.

Dexamethasone↗

PubMed1976

Lymphocytic choriomeningitis virus-induced ocular immunopathology.

Lymphocytic choriomeningitis (LCM) virus of the mice provides perhaps the most extensively studied model of viral-induced immunopathology. Intraocular inoculation of this virus in the adult mouse produces a severe and progressive uveitis with involvement also of the cornea and retina. Intracerebral infection of the newborn rat with LCM virus produces a severe retinopathy, with only minimal involvement of the uveal tract. We review in this paper recent studies on these two animal models of LCM virus disease which demonstrate: (1) the histopathology of the ocular lesion; (2) that immunosuppression after infection prevents development of the disease; (3) that passive transfer of sensitized lymphoid cells to the immunosuppressed infected animal can then trigger ocular disease, and (4) that T lymphocytes, and not circulating antibody, play the major role in the pathogenesis of this disease process.

Animals↗

PubMedDate not supplied

Theoretical approach to laser trabeculotomy.

Theoretical aspects of laser characteristics as well as the physics parameters involved in laser trabeculotomy in open-angle glaucoma are put forward. Outflow hydrodynamics and perforation mechanism as well as the required optical matching system are evaluated in detail.

Animals↗

PubMedDate not supplied

Familial band-shaped keratopathy.

A brother and sister out of a consanguinous family of four siblings are presented as prototypes of primary band-shaped keratopathy. The disease manifested sever progressive changes of secondary nature over two years of follow-up. Histology and treatment are described.

Child↗