PubMed Health⌕ Search

Biomedical subjects

James C Tsai

Publications and source records attributed to James C Tsai.

14 recordsLinked to original sources
PubMed2006

Resident physician mentoring program in ophthalmology: the Tennessee experience.

OBJECTIVE: To establish a mentoring program to provide resident physicians in ophthalmology with career guidance in practice management and to identify new and creative ways to involve future eye physicians in the legislative and political process. METHODS: A multicenter prospective study was conducted of the mentorship experiences of 24 (88.9%) of 27 resident physicians in Tennessee during the 2000-2001 academic year. Participants were assigned into 1 of 3 groups: an active mentorship group, a passive mentorship group, and a no mentorship group. The active mentorship group participated in preceptorship activities with "mentor" community-based eye physicians and scheduled meetings with state legislators and regulators. The active mentorship and passive mentorship groups attended a 1-day practice management seminar, but the no mentorship group received no formal mentorship during the 4-month study period. A survey instrument was given to all participants before and after the 4-month study period. RESULTS: Following completion of the mentorship program, the active mentorship group had favorable changes in perceptions and attitudes toward medical organizations (P<.03) when compared with baseline prementorship responses. Compared with the no mentorship group, the active mentorship group also reported an increased willingness to make political campaign donations (P<.05) and expressed an increased desire for the Tennessee Academy of Ophthalmology to offer practice management programs (P<.02). CONCLUSION: A short 4-month mentorship program can elicit favorable changes in residents' perceptions and attitudes toward medical professional organizations. Additional opportunities may lie with a lengthier and more intensive mentoring program.

Career Choice↗
PubMed2006

Retinal nerve fiber layer thickness in normal children measured with optical coherence tomography.

PURPOSE: To measure the peripapillary retinal nerve fiber layer (RNFL) thickness in normal children. DESIGN: Observational cross-sectional study. PARTICIPANTS: Ninety-two eyes of 92 normal children ages 4 to 17 years presenting to the Ophthalmology Clinic at the Harkness Eye Institute, Department of Ophthalmology, Columbia University. METHODS: Retinal nerve fiber layer thickness was measured with optical coherence tomography (OCT). Patient cooperation and signal strength of the OCT scans were assessed. Optic disc photographs were evaluated by a glaucoma specialist in a masked fashion. Eyes with abnormal optic discs were excluded. One eye of each subject was randomly selected for statistical analysis. The effect of several factors on RNFL thickness was investigated statistically. MAIN OUTCOME MEASURES: Retinal nerve fiber layer thickness. RESULTS: Ninety-one percent of the study subjects were Hispanic; 8%, African American; and 1%, Caucasian. Optical coherence tomography measurements were obtained in 117 of 121 (96.7%) subjects, and disc photographs were available for 92 of them. Mean age (+/-standard deviation [SD]) was 9.7+/-2.7 years. Mean global RNFL thickness (+/-SD) was 107.0+/-11.1 microm (range, 78.1-134.6). The RNFL was thickest inferiorly (136.9+/-16.9 microm) and superiorly (135.4+/-19.3 microm), thinner nasally (83.0+/-18.0 microm), and thinnest temporally (72.5+/-13.4 microm). In univariate regression analysis, age (P = 0.013) and refraction (P<0.001) had a significant effect on RNFL thickness; age had a significant effect on refraction (P<0.001). When controlling for refraction, age no longer had a significant effect. CONCLUSIONS: Optical coherence tomography can be used to measure RNFL thickness in children. Refraction had an effect on RNFL thickness. In normal children, variation in RNFL thickness is large. The normative data provided by this study may assist in identifying changes in RNFL thickness in children.

Adolescent↗
PubMed2006

The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma II: longer-term outcomes from a single surgeon.

OBJECTIVE: To analyze the longer-term surgical outcomes of Ahmed and Baerveldt shunt implants in the treatment of refractory glaucoma. DESIGN: Retrospective, nonrandomized, comparative trial. PARTICIPANTS: Consecutive patients who underwent glaucoma shunt implantation (70 Baerveldt, 48 Ahmed) by a single surgeon. METHODS: Follow-up retrospective analysis of 118 consecutive cases of refractory glaucoma that required placement of either Ahmed or Baerveldt shunt implants for intraocular pressure (IOP) control. The longer term clinical course (survival curve analysis up to 48 months) was reviewed. MAIN OUTCOME MEASURES: The primary outcome measure was surgical success (6 mmHg < or = IOP < or = 21 mmHg without additional glaucoma surgery or devastating complication). Secondary outcome measures included mean IOP and number of medications used at the following postoperative visits: day 1, 1 week, 1 month, 3 months, 6 months, and every 6 months thereafter (up to 48 months). In unsuccessful cases, the median time to failure was determined. RESULTS: No significant differences in success rates were noted at 1, 2, 3, or 4 years after surgery, with 4-year success rates of 62% for the Ahmed group and 64% for the Baerveldt group (P = 0.843). Mean IOPs were comparable from 1 to 48 months (P>0.05). However, patients in the Ahmed group required more glaucoma medications at 18, 24, 30, and 36 months (P<0.05). The median times to failure were 3.2 months in the Baerveldt group, compared with 15.0 months in the Ahmed group (P = 0.009). CONCLUSIONS: No differences were observed in longer term survival rates and IOP profiles between Ahmed and Baerveldt shunt implants up to 48 months following surgery. Patients in the Baerveldt group were more likely to develop early postoperative hypotony-related complications and failure, whereas patients undergoing Ahmed implants were more likely to be on additional glaucoma medications (starting at 18 months postsurgery) and develop later onset failure.

Aged↗
PubMed2006

Glaucoma medications: use and safety in the elderly population.

As with many diseases, glaucoma increases in frequency in older populations, and is very often encountered in patients taking multiple medications. While the exact mechanism of glaucomatous optic neuropathy (GON) is not known, intraocular pressure (IOP) is thought to be central to the process, and reducing IOP is the only known effective treatment. The newer definition of glaucoma is an IOP-sensitive optic neuropathy. While large, controlled studies have indicated that reducing IOP will slow the progression of disease, the contributions of other conditions and medications have not been adequately studied. As the adverse effect profiles of medical therapies for glaucoma have improved, use of these agents has increased greatly. This has resulted in a large number of older patients taking glaucoma medications. Since topical medications can easily be overlooked in a medical history, and are for the most part well tolerated, systemic complications from these agents can be missed. In addition to being a common disease requiring treatment, glaucoma is also a model system for other degenerative diseases, and many of the concepts originally developed in relation to neurodegenerative diseases such as Alzheimer's disease are under investigation for glaucoma. These include approaches targeted towards neuroprotection and excitotoxicity.

Adrenergic Agents↗
PubMed2005

Intravitreal administration of erythropoietin and preservation of retinal ganglion cells in an experimental rat model of glaucoma.

PURPOSE: The aim of this pilot study was to evaluate the potential neuroprotective effect of an intravitreal injection of erythropoietin (EPO) on retinal ganglion cell (RGC) preservation in an episcleral vessel cautery-induced rat model of glaucoma. METHODS: The animals were randomly assigned into an unoperated control group (n = 11) and three experimental groups: episcleral vessel cautery only (EVC: n = 4), episcleral vessel cautery with intravitreal normal saline injection (EVC-NS; n = 5), and episcleral vessel cautery with intravitreal EPO treatment (EVC-EPO; n = 9). The intravitreal injections were limited to 5 mul containing either normal saline alone or 200 ng of EPO in normal saline administered immediately after the cautery procedure. RGCs were labeled retrogradely by FluoroGold neuron tracer 5 to 7 days prior to the collection of eyes at day 21 and counted in whole flat-mounted retinas with fluorescence microscopy. RESULTS: Compared to the RGC counts in retinal specimens from unoperated control rats (12,619 +/- 310), the corresponding RGC counts were significantly decreased in both the EVC (9116 +/- 273; p < 0.005) and EVC-NS (9489 +/- 293; p < 0.005) groups but not significantly decreased in the EVC-EPO (11,212 +/- 414; p = 0.051) treated retinas. CONCLUSIONS: A single intravitreal 200 ng dose of EPO appears to have a protective effect on RGC viability in an in vivo rat model of glaucoma. Further experimental studies are needed to confirm these preliminary results and to optimize the appropriate dose and frequency of EPO delivery in animal models of glaucoma.

Animals↗
PubMed2005

Current and emerging medical therapies for glaucoma.

Glaucoma is a multifactorial optic neuropathy in which there is a characteristic acquired loss of retinal ganglion cells, at levels beyond normal age-related baseline loss, and corresponding atrophy of the optic nerve. Although asymptomatic in its earlier stages, the disease is nevertheless one of the leading global causes of irreversible blindness. Although elevated intraocular pressure (IOP) is one of the most important risk factors and lowering of IOP is the only proven treatment so far, the definition of glaucoma has evolved from a disease caused by increased IOP to one characterised by an IOP-sensitive, progressive optic neuropathy. In recent years, safer and better tolerated topical medications have been developed to control IOP more effectively, thereby limiting the need for surgery. New research has also noted the importance of diurnal IOP variation as a critical risk factor for progression of glaucomatous optic neuropathy (GON) and subsequent visual field loss. Moreover, new discoveries have further elucidated the basic pathophysiological and genetic mechanisms underlying the elevated levels of IOP, as well as the cellular mechanisms of GON. As our understanding of these complex pathways continues to improve, development opportunities for new therapeutic modalities will be enhanced.

Administration, Topical↗
PubMed2004

Clinical significance of central corneal thickness in the management of glaucoma.

OBJECTIVE: To evaluate the effect of central corneal thickness determination on the clinical management of patients with glaucoma and glaucoma suspect. METHODS: A cross-sectional retrospective study was performed on 188 consecutive patients. Mean ultrasound pachymetry measurements of central corneal thickness and corresponding Goldmann applanation tonometry measurements were obtained. Intraocular pressures (IOPs) were corrected using linear and mathematical (Orssengo-Pye) algorithms. Measurement-significant outcomes were defined as an IOP adjustment of 1.5 mm Hg or greater and outcomes-significant results as an IOP adjustment of 3.0 mm Hg or greater. Changes in therapy such as the use of eyedrops and addition or cancellation of laser therapy or surgery were then noted for those individuals with measurement- or outcomes-significant changes. RESULTS: Using the linear correction scale, 105 (55.9%) of 188 patients had at least a measurement-significant adjustment in their IOP measurements: 67 (35.6%) had adjustments between 1.5 and 3.0 mm Hg, while 38 (20.2%) had an outcomes-significant IOP adjustment (> or =3.0 mm Hg). Among the 188 patients, 16 (8.5%) had a change in eyedrop therapy, 4 (2.1%) had a change regarding laser therapy, and 6 (3.2%) had a change in the decision regarding glaucoma surgery. Using the exponential correction (Orssengo-Pye) scale, similar percentages were obtained. CONCLUSION: Pachymetry-measured central corneal thickness has a significant effect on the clinical management of patients with glaucoma and glaucoma suspect.

Aged↗
PubMed2003

The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma: a single-surgeon comparison of outcome.

PURPOSE: To compare the surgical outcome of Baerveldt and Ahmed shunt implants in the treatment of refractory glaucoma. DESIGN: Retrospective, nonrandomized, comparative trial. METHODS AND PARTICIPANTS: Medical records of 118 consecutive patients who underwent glaucoma shunt implantation (70 Baerveldt, 48 Ahmed) by a single surgeon were reviewed. MAIN OUTCOME MEASURES: The primary outcome measure was surgical success (6 mmHg <or= intraocular pressure [IOP] <or= 21 mmHg without additional glaucoma surgery or devastating complication) at 12 months after surgery. Secondary outcome measures included mean IOP and number of medications used at the following postoperative visits: day 1, 1 week, 1 month, 3 months, 6 months, and every 6 months thereafter. Additional outcome measures evaluated include visual acuities, prevalence and timing of postoperative choroidal detachment, and clinical bleb encapsulation. RESULTS: Survival curve analysis showed success rates of 82.9% of the Ahmed group and 72.9% of the Baerveldt group at 12 months after surgery (P = 0.257). Patients in the Ahmed group exhibited lower IOPs at 1 day (P < 0.001) and 1 week (P < 0.001) after surgery and were taking fewer glaucoma medications at 1 week (P < 0.001) and 1 month (P < 0.001) after surgery. A higher proportion of Ahmed patients experienced clinical bleb encapsulation than did the Baerveldt patients (60.4% vs. 27.1%; P < 0.001). Moreover, the first observation of postoperative bleb encapsulation was sooner after surgery for the Ahmed patients (50.0 +/- 43.8 days) than for the Baerveldt patients (69.8 +/- 22.6 days; P = 0.001). CONCLUSIONS: The Ahmed shunt implant exhibited better control of IOP in the early postoperative period (1 day and 1 week) with patients requiring fewer glaucoma medications at 1 week and 1 month after surgery. There was both a higher prevalence and earlier onset of bleb encapsulation observed with the Ahmed shunt implant.

Aged↗
PubMed2003

Compliance barriers in glaucoma: a systematic classification.

PURPOSE: To systematically identify and describe common obstacles to medication adherence (i.e., compliance) for patients with glaucoma. METHODS: A prospective case series of structured interviews were conducted with 48 patients with glaucoma. The subjects' responses were recorded verbatim on interview forms as well as recorded on audiotapes. Situational obstacles to medication adherence were elicited. Using hierarchical cluster analysis, the situational descriptions were stratified, grouped, and analyzed by frequency distribution. RESULTS: Seventy-one unique situational obstacles were reported. These were then grouped into 4 defined and separate categories: situational/environmental factors (35 of 71 situations; 49%), medication regimen (23 of 71; 32%), patient factors (11 of 71; 16%), and provider factors (2 of 71; 3%). CONCLUSION: Significant barriers to compliance exist for patients with glaucoma in addition to those cited by previous ophthalmic studies. A systematic classification (i.e., taxonomy) of these barriers was formulated to assist in optimizing patient education and problem-solving regarding prescribed therapeutic regimens.

Adult↗
PubMed2002

Supplemental transscleral diode laser cyclophotocoagulation after aqueous shunt placement in refractory glaucoma.

OBJECTIVE: To assess the outcome of supplemental transscleral diode laser cyclophotocoagulation after aqueous tube shunt placement to obtain effective intraocular pressure (IOP) control. DESIGN: Retrospective non-comparative case series. PARTICIPANTS: Twenty-one eyes in 21 subjects with uncontrolled IOP despite the presence of an aqueous tube shunt and maximally tolerated glaucoma medications. INTERVENTION: Supplemental transscleral diode laser cyclophotocoagulation was performed. MAIN OUTCOME MEASURES: Reduction of intraocular pressure and reduction of glaucoma medications. RESULTS: Twelve adults and nine children underwent supplemental transscleral diode cyclophotocoagulation and were followed postoperatively for a mean of 26.9 +/- 13.4 (standard deviation [SD]) months (range, 7-58 months). Average IOP was significantly reduced from a preoperative level of 35.7 +/- 14.7 (SD) mmHg to a postoperative level of 13.6 +/- 7.1 (SD) mmHg (P < 0.001) with the mean number of medications significantly reduced to 1.5 +/- 1.3 (SD) (P < 0.001). Seven subjects (33%) had additional laser treatment to achieve IOP control. Six subjects who were therapy failures included three who developed no light perception in the setting of proliferative diabetic retinopathy, one subject with chronic angle-closure glaucoma who gradually developed no light perception after refusing further treatment or medication, and two subjects who developed retinal detachments. One child who was a qualified success underwent enucleation and debulking of an enlarging neurofibroma that caused significant proptosis and disfigurement. CONCLUSIONS: In cases of glaucoma that are uncontrolled despite a glaucoma aqueous tube shunt and multiple medications, adjunctive transscleral diode cyclophotocoagulation treatment(s) is a viable option to lower IOP.

Adult↗