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Biomedical subjects

R Ritch

Publications and source records attributed to R Ritch.

At least 109 records · Page 6Linked to original sources
PubMed1998

Factors affecting image acquisition during scanning laser polarimetry.

BACKGROUND AND OBJECTIVE: To illustrate artifacts that may be encountered during measurement of the peripapillary retinal nerve fiber layer (RNFL) using scanning laser polarimetry (SLP). PATIENTS AND METHODS: A total of 426 patients with a variety of ocular diagnoses underwent RNFL measurements using SLP from June 1996 to April 1997. Scanning was performed by two operators whose reproducibility of measurements had been previously validated. Images were selected to illustrate clinical features that adversely affected measurement of the thickness of the RNFL. RESULTS: Image acquisition was difficult in eyes with corneal grafts or edema, keratic precipitates, anterior uveitis, posterior subcapsular cataract, vitreous opacity, peripapillary atrophy, posterior staphyloma, and high axial myopia. These scans resulted in poor clinical correlation with visual field tests and optic nerve examination, poor reproducibility of images, and unreadable images. CONCLUSION: Anterior and posterior segment pathologies, particularly those localized to the cornea and lens, may produce spurious RNFL measurements and should be carefully considered prior to clinical decision making.

Aged↗
PubMed1998

Ultrasound biomicroscopy in the diagnosis and management of anterior segment tumors.

BACKGROUND: High-frequency ultrasound biomicroscopy has allowed eye care specialists to evaluate posterior extension of anterior segment tumors. This article evaluates the role of ultrasound biomicroscopy for the diagnosis and management of anterior segment tumors. METHODS: Fourteen patients with anterior segment tumors were selected for evaluation. Each patient underwent a complete clinical examination followed by slit-lamp photography and ultrasound biomicroscopy. RESULTS: Unlike standard ultrasonography of anterior segment tumors, high-frequency ultrasound biomicroscopy allowed quantitative measurements of tumor size, extension within and posterior to the iris, as well as differentiation of solid and cystic lesions. These characteristics were used to differentially diagnose anterior segment tumors and document the response of iridociliary body melanomas to radiotherapy. CONCLUSIONS: This study demonstrates how ultrasound biomicroscopy has become an effective and necessary procedure, used for both the diagnosis and management of anterior segment tumors.

Adult↗
PubMed1997

Identification of a gene that causes primary open angle glaucoma.

Glaucoma is a major cause of blindness and is characterized by progressive degeneration of the optic nerve and is usually associated with elevated intraocular pressure. Analyses of sequence tagged site (STS) content and haplotype sharing between families affected with chromosome 1q-linked open angle glaucoma (GLC1A) were used to prioritize candidate genes for mutation screening. A gene encoding a trabecular meshwork protein (TIGR) mapped to the narrowest disease interval by STS content and radiation hybrid mapping. Thirteen glaucoma patients were found to have one of three mutations in this gene (3.9 percent of the population studied). One of these mutations was also found in a control individual (0.2 percent). Identification of these mutations will aid in early diagnosis, which is essential for optimal application of existing therapies.

Base Sequence↗
PubMed1997

Isolation and culture of iris pigment epithelium from iridectomy specimens of eyes with and without exfoliation syndrome.

OBJECTIVE: To culture iris pigment epithelium (IPE) from surgical iridectomy specimens of eyes with and without exfoliation syndrome. METHODS: The IPE was treated to obtain a single cell suspension. Cells were cultured in Ham F12 nutrient mixture, which was supplemented with 30% fetal bovine serum, 50-micrograms/mL [corrected] gentamicin, and 2-mmol/L glutamine. After confluence, the cells were detached using a 0.125% trypsin-0.01% edetic acid solution, resuspended, diluted, and subcultured. The IPE from primary cultures and subcultures was studied by transmission electron microscopy. Immunocytochemical staining was performed. RESULTS: In the primary cultures of IPE from patients with exfoliation syndrome, curved, cross-banded, fine fibrils (diameter, 10-15 nm; periodicity, 10-14 nm) were found on the cell surface. Thicker fibrils (diameter, 24-48 nm; periodicity, 24-36 nm) were found external to the fine fibrils. Subcultures contained mainly fine fibrils. The IPE cells stained positively with anticytokeratin, S100 protein, and vimentin antibodies. CONCLUSION: Iris pigment epithelium can be successfully cultured from eyes with exfoliation syndrome. Studying the production of exfoliation material in vitro should provide information about the pathogenesis of exfoliation syndrome and about the nature of the exfoliation material. The cultivation of normal IPE from surgical specimens provides a source for the study of the growth regulation and pharmacophysiology of IPE in vitro.

Adolescent↗
PubMed1997

Influence of glaucomatous visual field loss on health-related quality of life.

We examined the influence of glaucomatous visual field defects on vision-targeted and generic health-related quality of life. Vision-targeted and generic health status were assessed across 5 glaucoma treatment categories and a normal reference group from 5 tertiary care ophthalmology practices during regularly scheduled eye care visits. The sample consisted of 147 patients who were members of specific glaucoma treatment categories and 44 reference group patients. For patients with glaucoma, eligibility included a diagnosis of glaucoma at least 1 year prior to enrollment and no evidence of other eye disease. Participants completed 2 vision-targeted surveys, the National Eye Institute Visual Functioning Questionnaire and the VF-14, and a generic health-related quality of life measure, the Medical Outcomes Study 36-Item Short Form. Data from automated perimetry (Humphrey Field Analyzer 24-2, Humphrey Instruments, San Leandro, Calif) were used to generate Advanced Glaucoma Intervention Study scores for all participants. The Medical Outcomes Study 36-Item Short Form scores from glaucoma and reference group participants collected on a random half of the sample were similar. However, comparisons of the vision-targeted surveys demonstrated significant mean differences on 7 of 11 National Eye Institute Visual Functioning Questionnaire scales, and a trend toward significant differences for the VF-14 (P < .07 by linear regression). Greater visual field defects in the better eye were significantly associated with poorer National Eye Institute Visual Functioning Questionnaire scores (P < .05), as well as with worse VF-14 scores. These findings were most dramatic for patients with the most severe field loss in the better eye. Vision-targeted questionnaires were more sensitive than a generic health-related quality of life measure to differences between glaucoma and normal reference participants. Our findings indicate that self-reports of vision-targeted health-related quality of life are sensitive to visual field loss and may be useful in tandem with the clinical examination to fully understand outcomes of treatment for glaucoma.

Adult↗
PubMed1997

Exfoliation syndrome in a 17-year-old girl.

A 17-year-old girl with unilateral congenital glaucoma who had undergone trabeculectomy and peripheral iridectomy in infancy developed apparent exfoliation syndrome (XFS) in the eye that underwent the surgical procedures. A conjunctival biopsy was performed and the specimen was fixed in 2.5% glutaraldehyde, embedded in epoxy resin (Epon-Araldite, Electron Microscopy Sciences, Fort Washington, Pa), and processed for routine electron microscopy and immunostaining for elastin. Results of ultrastructural study showed scattered fibrillar aggregates compatible with those of XFS in an older adult, differing chiefly in sparsity of granular interfibrillar matrix. The XFS fibers were closely associated with elastic fibers and microfibrils. Elastosis of the actinic-aging type was somewhat greater than expected for age. To our knowledge, this is the youngest patient described with characteristic ocular findings of XFS to date, supporting others who have suggested an association between iris surgery in youth and early onset XFS. Electron microscopy was essential in ruling out the possibility of a clinically similar entity caused by ultrastructurally different material.

Adolescent↗
PubMed1997

Latanoprost for uncontrolled glaucoma in a compassionate case protocol.

PURPOSE: To evaluate the ocular hypotensive response of latanoprost 0.005% administered as adjunctive therapy in patients with glaucoma who were receiving maximal tolerated medical therapy. METHODS: Consecutive patients entering a latanoprost compassionate clinical trial were enrolled at two sites. Latanoprost 0.005% was administered as a single drop between 6 and 8 PM, and all other medications were continued. Intraocular pressure was measured between 2 and 4 PM. Responders were defined as having a reduction in intraocular pressure of at least 20% from baseline. RESULTS: In 160 eyes of 160 patients, mean baseline intraocular pressure +/- SD was 23.3 +/- 6.9 mm Hg. Intraocular pressure was significantly reduced compared with baseline measurements (P < .01) with mean intraocular pressure measurement reductions of 4.1 +/- 5.2, 4.0 +/- 6.3, and 3.7 +/- 4.2 mm Hg at the 1-, 3-, and 6-month intervals, respectively. A reduction in intraocular pressure of at least 20% was observed in 64 (44.4%) of 144 patients, 46 (43.0%) of 107 patients, and 10 (32.3%) of 31 patients at the 1-, 3-, and 6-month visits, respectively. A 40% reduction in intraocular pressure was observed in 18 (12.5%) of 144 and nine (8.4%) of 107 patients at 1 and 3 months, respectively. Mean reduction in intraocular pressure was similar in the miotic and nonmiotic groups (P > .4 at all intervals). Eight patients (5.0%) developed ocular allergy or irritation necessitating cessation of latanoprost therapy. CONCLUSION: Latanoprost 0.005% may provide significant further intraocular pressure reduction in patients already receiving maximal tolerated medical therapy.

Adolescent↗
PubMed1997

Bleb-related ocular infection in children after trabeculectomy with mitomycin C.

OBJECTIVE: The purpose of the study is to report the clinical course of bleb-related ocular infection in children after trabeculectomy with adjunctive mitomycin C. DESIGN: The study design was a retrospective review of all patients with a diagnosis of bleb-related ocular infection after trabeculectomy with adjunctive mitomycin C. PARTICIPANTS: Three children were identified in whom late postoperative bleb-related ocular infection developed. INTERVENTION: Treatment consisted of vitreous biopsy with intravitreous antibiotic and corticosteroid injection and/or bleb culture with topical and intravenous antibiotic administration. MAIN OUTCOME MEASURES: Visual acuity and intraocular pressure were measured. RESULTS: Bleb-related ocular infection developed an average of 16.7 +/- 10.9 months after trabeculectomy (range, 4-23 months). The mean age at presentation was 7.0 +/- 2.6 years (range, 4-10 years). Vitreous cultures were positive for staphylococci in two cases. A bleb culture from the third case also grew staphylococcus. All of the children recovered their initial vision after treatment of infection. However, one lost six lines of vision after a subsequent retinal detachment. Additional glaucoma surgery was required in one patient. CONCLUSIONS: Late bleb-related ocular infection may occur in children after trabeculectomy with mitomycin C and is characterized by abrupt onset, bleb infiltration, and rapid progression. Despite early preservation of vision after treatment of infection, significant late visual loss can occur.

Anti-Bacterial Agents↗
PubMed1997

Glaucoma in phakomatosis pigmentovascularis.

BACKGROUND: Sturge-Weber syndrome, Klippel-Trenaunay-Weber syndrome, and oculodermal melanocytosis are neural crest disorders in which glaucoma is known to occur. Phakomatosis pigmentovascularis is a neural crest disorder that is found almost exclusively in Asians and has not been described previously in the ophthalmic literature. METHODS: The authors describe nine patients with combined oculodermal vascular malformations (five pigmentovascularis, two Klippel-Trenaunay-Weber, two Sturge-Weber) and oculodermal melanocytosis. RESULTS: Ocular melanocytosis was present bilaterally in seven patients and unilaterally in two. Of the 16 hyperpigmented eyes, 13 also had episcleral vascular malformations (EVM). Congenital glaucoma developed in all 10 eyes that had total melanocytosis and EVM. Ocular hypertension developed in one eye with diffuse melanocytosis but partial EVM in childhood. Glaucoma did not develop in one eye with extensive EVM but partial melanocytosis or in the four eyes with ocular melanocytosis but not EVM. CONCLUSION: When oculodermal melanocytosis and nevus flammeus (phakomatosis pigmentovascularis) occur together, with each extensively involving the globe, there is a strong predisposition for congenital glaucoma. When one or both are present with only partial involvement, elevated intraocular pressure may develop later in life, and patients should be followed-up at regular intervals for the development of glaucoma. The vascular malformations appear to play a more important role in the predisposition to glaucoma than does the oculodermal melanocytosis.

Adolescent↗
PubMed1997

Tissue culture of adult human retinal ganglion cells.

PURPOSE: We wished to isolate and cultivate adult human retinal ganglion cells (RGC) from donor eyes. METHODS: Small pieces of retina from donor eyes were plated in dishes and cultured with Ham's F12 medium with 10% serum for organ culture. For cell culture, cells were isolated by mechanical or enzymatic dissociation methods and cultured with F12 medium with 10% serum, with or without nerve growth factor (NGF) and/or basic fibroblast growth factor (bFGF). RESULTS: In organ cultures, no neurite outgrowth from the retinal explants was observed. In cell cultures for which mechanical dissociation methods were used, the few cells that could be isolated showed poor viability. Better results were obtained with enzymatic dissociation methods. When cultured with medium supplemented with bFGF, some cells attached, spread, and sent out numerous dendrites, morphologically similar to RGC. These cells stained positively for neurofilaments and Thy-1 and negatively for glial fibrillary acidic protein (GFAP), indicating they were RGC. CONCLUSIONS: Cell cultures of human RGC can be established. This is a potential model system for studying effects of damaging and protective factors on RGC in vitro.

Adult↗
PubMed1997

Ultrasound biomicroscopy in anterior ocular trauma.

BACKGROUND AND OBJECTIVE: The authors investigated the role of ultrasound biomicroscopy after ocular trauma. PATIENTS AND METHODS: Ultrasound biomicroscopy was performed in six eyes of six patients at the New York Eye and Ear Infirmary after a variety of traumatic ocular injuries. RESULTS: Eyes with angle recession, iridodialysis, cyclodialysis, hyphema, an intraocular foreign body, scleral laceration, and subluxed crystalline lens were imaged without complication. Ultrasound biomicroscopy aided in the diagnosis when visualization was limited by media opacities or distorted anterior segment anatomy. CONCLUSION: Ultrasound biomicroscopy is a safe and effective adjunctive tool for the clinical assessment and management of ocular trauma, especially when visualization is limited and multiple traumatic injuries are involved.

Adult↗
PubMed1997

Lack of association between hearing loss and glaucoma.

Some studies have suggested a relationship between glaucoma and sensorineural hearing loss. Others have found no evidence for an association. We performed a study to determine whether there is a significant difference in hearing between patients with glaucoma and a matched control population. Patients presenting themselves to a glaucoma clinic were grouped by type of glaucoma: uveitis, primary open-angle, pigmentary, pigmentary dispersion, congenital, or ocular hypertension. Patients older than 60 were excluded from the study, as were those who met certain carefully chosen exclusion criteria. Subjects included 40 men and 27 women, ranging in age from 15 to 60 years. Glaucoma was bilateral in all cases. Auditory thresholds at 0.5, 1.0, 2.0, and 3.0 kHz were measured bilaterally and statistically compared with American National Standards Institute (ANSI) normative values. Speech reception threshold and intelligibility were also assessed. When compared with speech ANSI values, there were no significant differences in mean thresholds at any frequency for any of the glaucoma types. Mean speech reception thresholds and intelligibility scores were all within normal limits and no subjects showed evidence of sensorineural hearing loss greater than expected for age. There were no differences between glaucoma groups, and we found no evidence of an association between glaucoma and hearing loss. There is disagreement about whether or not an association exists between glaucoma and hearing loss. Among those who do feel there is a relation, there is wide disagreement about what proportion of glaucomatous patients have a hearing loss. Rampoldi (1) first described an association between glaucoma and inner ear disease in 1889. Since that time, a number of reports have suggested such an association (2-4; 6-12). However, many of these studies are methodologically flawed. A few studies found no evidence of a relationship between glaucoma and sensorineural hearing loss (14, 15). There have been few reports since the 1970s, and the question remains unresolved. If there is, in fact, a relationship between glaucoma and inner ear disease, potentially much could be learned about certain forms of hearing loss from the study of glaucoma. In particular, surgical specimens (trabecular meshwork) could be obtained in those patients who undergo operations for their glaucoma. This tissue could be examined using current histopathological techniques. On the basis of the results, hypotheses might be made, by inference about which pathological processes are manifested in the inner ear. Therefore, we performed a study to evaluate whether there is a significant difference in hearing between patients with glaucoma and a matched control population.

Adolescent↗
PubMed1997

Peter's anomaly: diagnosis by ultrasound biomicroscopy.

Peter's anomaly is a congenital corneal disorder characterized by a central leukoma and adhesions at the periphery of the corneal opacity. A 35-year-old man presented for clinical evaluation of suspected sclerocornea. High-resolution ultrasound biomicroscopy revealed iridocorneal adhesions throughout the anterior segment, a shallow anterior chamber, and abnormal hyper-reflectivity along the posterior corneal surface. Through ultrasound biomicroscopy, characteristics of Peter's anomaly were recognized, and a diagnosis was established. This case illustrates how ultrasound biomicroscopy aids in the clinical differentiation between Peter's anomaly and other causes of congenital corneal opacification.

Adult↗
PubMed1997

Brimonidine: a new alpha2-adrenoreceptor agonist for glaucoma treatment.

PURPOSE: Brimonidine is a highly selective alpha2-adrenoceptor agonist. It has intraocular pressure (IOP)-lowering characteristics similar to other alpha2-agonists and acts by reducing aqueous humor production and increasing uveoscleral outflow. It is oxidatively stable, which may account for its lower reported rate of ocular allergy compared with other alpha2-agonists. The focus of this report is to review the receptor pharmacology and clinical experience with brimonidine tartrate, the newest of the alpha2-adrenergic agonists. METHODS: Clinical studies have been performed for acute indications using the 0.5% concentration and chronic indications using the 0.2% concentration. RESULTS: Brimonidine 0.5% given as one drop before, after, or both before and after 360 degrees argon laser trabeculoplasty significantly lowers the incidence of postlaser IOP spikes. Brimonidine 0.2% instilled twice daily offers long-term IOP control comparable with that achieved with timolol 0.5% and better than betatolol 0.25% suspension. CONCLUSIONS: In light of these data, brimonidine 0.5% may be considered for prophylaxis against laser-induced IOP spikes and brimonidine 0.2% for chronic use in patients with ocular hypertension and glaucoma.

Adrenergic alpha-Agonists↗
PubMed1996

Imaging congenital optic disc pits and associated maculopathy using optical coherence tomography.

OBJECTIVE: To elucidate the anatomy of congenital optic disc pits with and without maculopathy using optical coherence tomography. SETTING: All patient were examined, photographed, and scanned at the New York Eye and Ear Infirmary. PATIENTS: Ten eyes of eight consecutive patients with congenital optic disc pits were studied. Three eyes had associated serous macular detachment (group 1), four had evidence of resolved detachment (group 2), and three had no clinical macular pathologic lesion (group 3). METHODS: Optical coherence tomography, a new, noninvasive, noncontact, imaging technology capable of producing cross-sectional images of the retina in vivo with high resolution ( < 17 microns) was used to obtain multiple cross-sectional images of the pit, peripapillary retina, and macula. Ophthalmologic examination and standard fundus photography were performed on all eyes. Fluorescein angiography was performed in eyes that had associated macular detachment. RESULTS: Communication between a schisis cavity or subretinal space and the optic nerve pit was imaged in all eyes in group 1. No such communication could be identified in groups 2 and 3. Cystic degeneration and schisis were imaged in the peripapillary retina, macula, or both in all eyes of groups 1 and 2 and in one patient in group 3. A direct communication between the subretinal space and vitreous cavity could not be identified in any eye. CONCLUSIONS: Schisis formation plays an integral role in the development of serous retinal detachment in the presence of congenital optic disc pits. Our findings are consistent with the theory that the optic disc pit acts as a conduit for fluid flow between the schisis cavity or subretinal space and the subarachnoid space.

Adult↗