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Biomedical subjects

R Ritch

Publications and source records attributed to R Ritch.

At least 217 records · Page 12Linked to original sources
PubMed1987

Pseudoexfoliative fibrillopathy in the conjunctiva. A relation to elastic fibers and elastosis.

Pseudoexfoliative (PSX) material in the conjunctiva was found to have a close association with elements of the elastic system in 13 eyes of patients with PSX disease studied ultrastructurally. Pseudoexfoliation aggregates were rare within vascular walls but frequent in proximity to the plasmalemma of stromal fibroblasts. No amyloid was found. A striking feature was the association of PSX fibers with the elastosis seen in many of the specimens. Typical PSX fibers were present in clumps of oxytalan and around small elastic fibers. In five cases with more advanced elastosis, the aggregates of PSX fibers were larger and their usual loose fibrogranular matrix was extensively replaced by a dense elastotic one. Morphology of PSX here varied from typical to thicker, fragmented, and sometimes nondiagnostic fibers. This intermingling of PSX and elastotic materials suggested that PSX fibrillopathy is itself a type of elastosis, possibly resulting from abnormal aggregation of components related to elastic microfibrils.

Actin Cytoskeleton↗
PubMed1987

Intracameral gnathostomiasis: a cause of anterior uveitis and secondary glaucoma.

Recognition of parasitic diseases by Western physicians is becoming increasingly important because of increased international travel and the recent influx of refugees from South east Asia. We describe two patients who presented with acute anterior uveitis and secondary glaucoma caused by intracameral third stage larvae of Gnathostoma spinigerum. The parasites were successfully removed, with preservation of good visual acuity. The initial infection may occur through consumption of contaminated water and/or raw or undercooked foods, while the eyes may be involved even years later. Accurate diagnosis and surgical removal of the parasites may save life.

Adult↗
PubMed1987

Human trabecular meshwork cells in culture: morphology and extracellular matrix components.

This study demonstrates the presence of laminin and collagen type IV in the extracellular space of human trabecular meshwork (HTM) cells in culture and its absence in cultures of fibroblasts from sclera adjacent to the outflow pathway. These basement membrane components can be detected by standard immunohistochemical techniques. Positive staining for these macromolecules is found only after the HTM cells have reached confluence. The presence of laminin and human collagen type IV in the early passages can serve as additional criteria for identification of HTM cells in culture. These cells provide a useful experimental system for studying the effects of drugs and other factors on the synthesis of components of the extracellular matrix.

Adolescent↗
PubMed1986

Pseudophakic pupillary block with angle-closure glaucoma in diabetic patients.

Six diabetic patients (five women and one man, 63 to 79 years old) developed pseudophakic pupillary block with angle-closure glaucoma two days to one year after undergoing extracapsular cataract extraction. None of the six had had a peripheral iridectomy during the procedure. Symptoms included pain and visual loss. Corneal edema and intraocular pressures as high as 80 mm Hg were also present. Laser iridotomies decreased the intraocular pressure in three cases but failed in a fourth. In one case corneal edema prevented laser treatment but a surgical peripheral iridectomy was successful. One eye with central retinal vein occlusion was treated with panretinal photocoagulation and trabeculectomy.

Aged↗
PubMed1986

Coexistence of Prader-Willi syndrome, congenital ectropion uveae with glaucoma, and factor XI deficiency.

A patient with Prader-Willi syndrome and unilateral congenital ectropion uveae with glaucoma was found to have factor XI deficiency and reduced levels of serum luteinizing hormone, follicle-stimulating hormone, and testosterone. Administration of gonadorelin (LH-RH) increased serum levels of luteinizing hormone and follicle-stimulating hormone, while clomiphene citrate had no effect, suggesting a primary hypothalamic defect. Patients with congenital ectropion uveae should be followed up for the development of both glaucoma and neural crest disorders.

Adolescent↗
PubMed1986

Effect of adding betaxolol to dipivefrin therapy.

We evaluated the safety and effectiveness of adding topically administered betaxolol 0.5% twice daily in 39 patients with ocular hypertension or primary open-angle glaucoma already being treated with dipivefrin 0.1% twice daily. The addition of the betaxolol significantly decreased (P less than .01) the mean intraocular pressure after two weeks (2.82 mm Hg) and four weeks (3.63 mm Hg). There were no significant changes in pulse rate, mean arterial pressure, or pupil diameter. The administration of betaxolol to patients already receiving dipivefrin appears to be clinically useful.

Aged↗
PubMed1986

Aniridia, congenital glaucoma, and hydrocephalus in a male infant with ring chromosome 6.

A premature infant with unilateral aniridia and congenital ectropion uveae, contralateral Rieger anomaly, bilateral congenital glaucoma, and hydrocephalus was found to have ring chromosome 6. The findings are consistent with multiple manifestations of a neural crest-derived maldevelopment of the anterior segment and central nervous system. Comparison with the 14 previously reported cases of ring chromosome 6 illustrates the phenotypic variability of this syndrome.

Abnormalities, Multiple↗
PubMed1986

Clinical signs of the pseudoexfoliation syndrome.

Pseudoexfoliation syndrome (PXS) is a common cause of glaucoma throughout the world. It is most commonly diagnosed after the observation of pseudoexfoliation material (PXM) on the anterior lens surface. However, there are numerous clinical signs of PXS that should alert the examiner to search carefully for PXM on the anterior lens surface. These include pupillary ruff defects, iris sphincter transillumination, a characteristic whorl-like pattern of particulate pigment deposition on the iris sphincter, particulate pigment deposition on the peripheral iris and trabecular meshwork, and exfoliation material on the zonules and ciliary body. Accuracy of diagnosis is important for purposes of treatment, prognosis, and basic research in he mechanisms of glaucoma, particularly tissue culture.

Anterior Chamber↗
PubMed1986

The use of PhEA 34c in trabeculectomy.

PhEA 34c, a 1.9% solution of sodium hyaluronate (Healon = 1.0%) was injected intracamerally and between the scleral and conjunctival flaps after trabeculectomy in 15 eyes, while randomized controls received balanced salt solution (BSS). Anterior chamber depths in both groups in the early postoperative period were significantly different from baseline measurements, but were not different between the two groups at any interval. PhEA 34c did not prevent postoperative flat or shallow anterior chambers. There was no significant difference in the rate of success between the two groups for the duration of the study, but five patients in the PhEA 34c group developed loculated blebs.

Anterior Chamber↗
PubMed1985

A new lens for argon laser trabeculoplasty.

Most ophthalmologists perform laser trabeculoplasty with a Goldmann three-mirror lens with an anti-reflective coating. The view of the superior angle, which is frequently narrower than the inferior angle, often presents difficulties in treatment. A lens has been devised which gives improved views of the superior portion of the angle. Plano-convex buttons provide magnification and increase resolution for difficult situations.

Argon↗
PubMed1984

Laser trabeculoplasty. A prospective study of treatment variables.

Forty-five phakic eyes with open-angle glaucoma and uncontrolled intraocular pressure underwent laser trabeculoplasty. Each eye was assigned randomly to one of three treatment groups: group 1, 100 spots over 360 degrees; group 2, 50 spots over 180 degrees; or group 3, 50 spots over 360 degrees. A 50-micron spot was aimed at the anterior meshwork; power and time were varied to achieve a blanch. Forty-four eyes were followed up for at least four weeks without further intervention. The mean IOP before therapy and the initial IOP elevation were similar in all groups. After four weeks, the mean IOP reductions in 15 eyes in group 1, 15 eyes in group 2, and 14 eyes in group 3 were not significantly different. However, significantly more eyes in group 1 demonstrated a greater than 12 mm Hg reduction in IOP than eyes in the other groups. Group 2 tended to have the fewest eyes with reduced medications.

Aphakia↗
PubMed1984

Congenital ectropion uveae with glaucoma.

Congenital ectropion uveae (CEU) is a rare, nonprogressive anomaly characterized by the presence of iris pigment epithelium on the anterior surface of the iris stroma, often associated with neurofibromatosis and occasionally with other ocular anomalies. We present eight patients with unilateral CEU. Seven patients had glaucoma in the involved eye, while the eighth was a 10-week-old infant. In the two patients with bilateral glaucoma, the second eye was similar to the first, but without CEU. Three patients had neurofibromatosis, two had facial hemihypertrophy, one had Rieger's anomaly, one had Prader-Willi syndrome, and one had no systemic anomalies. Two had initially been misdiagnosed as having a large pupil in the involved eye and one as having a Horner's syndrome in the uninvolved eye. The finding of CEU in an infant warrants continued observation for the development of glaucoma and disorders of neural crest origin.

Abnormalities, Multiple↗
PubMed1984

Prognostic features in laser trabeculoplasty.

Of 59 phakic eyes with open-angle glaucoma initially treated with laser trabeculoplasty, 45 eyes were followed at least 6 months. Intraocular pressure (IOP) at 6 months was less than 22 mmHg in 37 (82%), of which 25 (81%) were on fewer medications; of 26 eyes followed at least 12 months, IOP was less than 22 mmHg in 24 (92%). Of 49 eyes of patients over 55 years, 43 (88%) had a final IOP less than 22 mmHg, significantly (P less than 0.01) greater than 5/10 eyes of patients under 55 years. Initial IOP correlated positively with reduction of IOP (r = 0.66). IOP was measured 1 h after treatment in 42 eyes, of which 11 (26%) rose greater than or equal to 8 mmHg. This pressure elevation did not significantly affect the success rate.

Argon↗
PubMed1984

Delayed hyphema after argon laser iridectomy.

A 77-year-old black woman without neovascularization developed spontaneous hyphema two days after laser iridectomy. Bleeding originated at the site of iridectomy. This complication has not been previously reported.

Aged↗
PubMed1983

Long-term results of valve implants in filtering surgery for eyes with neovascular glaucoma.

Filtration surgery was performed with a pressure-sensitive, unidirectional valve implant in 79 eyes with neovascular glaucoma. The device consisted of an open Supramid tube (outside diameter 0.58 mm) sealed to a Silastic tube with a slit valve. The Supramid tube was inserted at the corneoscleral limbus 1 to 4 mm into the anterior chamber. The Silastic portion was located under a scleral flap. Of the 79 eyes, 53 had postoperative intraocular pressures less than or equal to 24 mm Hg after a mean follow-up period of 23.7 +/- 10.9 months. Bleb revision for external scarring was required in ten of these 53 eyes and postoperative medical therapy was required in 26. The valve implant failed to control intraocular pressure in 26 of the 79 eyes. Failure was secondary to scarring of the external bleb in 18 eyes and to closure of the internal Supramid tube in five eyes. Mortality during the follow-up period was high: 12 of the 53 successfully treated patients and five of the unsuccessfully treated patients died.

Adolescent↗