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Harry A Quigley

Publications and source records attributed to Harry A Quigley.

At least 19 recordsLinked to original sources
PubMed2007

Determinants of normal retinal nerve fiber layer thickness measured by Stratus OCT.

PURPOSE: To determine the effects of age, optic disc area, ethnicity, eye, gender, and axial length on the retinal nerve fiber layer (RNFL) in the normal human eye as measured by Stratus OCT (optical coherence tomography). DESIGN: Cross-sectional observational study. PARTICIPANTS: Three hundred twenty-eight normal subjects 18 to 85 years old. METHODS: Peripapillary Fast RNFL scans performed by Stratus OCT with a nominal diameter of 3.46 mm centered on the optic disc were performed on one randomly selected eye of each subject. MAIN OUTCOME MEASURES: Linear regression analysis of the effects of age, ethnicity, gender, eye, axial length, and optic disc area on peripapillary RNFL thickness. RESULTS: The mean RNFL thickness for the entire population was 100.1 microm (standard deviation, 11.6). Thinner RNFL measurements were associated with older age (P<0.001); being Caucasian, versus being either Hispanic or Asian (P = 0.006); greater axial length (P<0.001); or smaller optic disc area (P = 0.010). For every decade of increased age, mean RNFL thickness measured thinner by approximately 2.0 microm (95% confidence interval [CI], 1.2-2.8). For every 1-mm-greater axial length, mean RNFL thickness measured thinner by approximately 2.2 microm (95% CI, 1.1-3.4). For every increase in square millimeter of optic disc area, mean RNFL thickness increased by approximately 3.3 microm (95% CI, 0.6-5.6). Comparisons between ethnic groups revealed that Caucasians had mean RNFL values (98.1+/-10.9 microm) slightly thinner than those of Hispanics (103.7+/-11.6 microm; P = 0.022) or Asians (105.8+/-9.2 microm; P = 0.043). There was no relationship between RNFL thickness and eye or gender. CONCLUSIONS: Retinal nerve fiber layer thickness, as measured by Stratus OCT, varies significantly with age, ethnicity, axial length, and optic disc area. These variables may need to be taken into account when evaluating patients for diagnosis and follow-up of glaucoma, particularly at the lower boundary of the normal range. Due to the relatively small numbers of subjects of Asian and African descent in the normative database, conclusions regarding the effect of ethnicity should be interpreted with caution.

Adolescent↗
PubMed2007

Factors affecting the decision to pursue glaucoma fellowship training.

PURPOSE: To identify factors associated with the choice to pursue glaucoma fellowship training by graduating ophthalmology residents. METHODS: An anonymous survey was sent to each graduating ophthalmology resident in the United States in February 2003. Demographic data and information relating to residency training, career goals, and factors influencing career choices were collected from the surveys. RESULTS: Surveys were completed by 215 (49.2%) residents, including 135 (62.8%) who were pursuing fellowships. Among residents undertaking fellowship training, 17 (12.6%) selected glaucoma and 118 (87.4%) chose other subspecialties. Residents entering glaucoma fellowships performed more glaucoma filtering procedures (P=0.006), and they were less likely to publish a paper (P=0.05) and have time allocated for research (P=0.04) than residents seeking fellowships in other subspecialties. Factors that were rated as less important to those choosing glaucoma fellowships included interest in challenging diagnostic problems (P=0.009), types of patient problems (P=0.015), an academic career (P=0.03), and working with new technology (P=0.04). The decision to pursue fellowship training was made later by residents entering glaucoma compared with those choosing other subspecialties (P=0.001). CONCLUSIONS: A variety of factors affect the decision to pursue fellowship training. There are differences in how these factors are weighed among residents seeking fellowships in glaucoma and other subspecialties.

Adult↗
PubMed2006

Optic nerve dynein motor protein distribution changes with intraocular pressure elevation in a rat model of glaucoma.

Acute intraocular pressure (IOP) elevation causes accumulation of retrogradely-transported brain derived neurotrophic factor and its receptor at the optic nerve head (ONH) in rats and monkeys. Obstruction of axonal transport may therefore be involved in glaucoma pathogenesis, but it is unknown if obstruction is specific to certain transported factors or represents a generalized failure of retrograde axonal transport. The dynein motor complex mediates retrograde axonal transport in retinal ganglion cells (RGC). Our hypothesis was that elevated IOP interferes with dynein-mediated axonal transport. We studied the distribution of dynein subunits in the retina and optic nerve after acute and chronic experimental IOP elevation in the rat. IOP was elevated unilaterally in 54 rats. Dynein subunit distribution was compared in treated and control eyes by immunohistochemistry and Western blotting at 1 day (n=12), 3 days (n=4), 1 week (n=15), 2 weeks (n=12) and 4 weeks (n=11). For immunohistochemistry, sections through the ONH were probed with an anti-dynein heavy chain (HC) antibody and graded semi-quantitatively by masked observers. Other freshly enucleated eyes were microdissected for separate Western blot quantification of dynein intermediate complex (IC) in myelinated and unmyelinated optic nerve, ONH and retina. Immunohistochemistry showed accumulation of dynein HC at the ONH in IOP elevation eyes compared to controls (P<0.001, Wilcoxon paired sign-rank test, n=29). ONH dynein IC was elevated by 46.5% in chronic IOP elevation eyes compared to controls by Western blotting (P<0.001, 95% CI=25.9% to 67.8%, n=17). The maximum increase in ONH dynein IC was 78.7% after 1 week (P<0.05, n=5), but significant increases were also detected after 4 h and 4 weeks of IOP elevation (P<0.05, n=4 rats per group). Total retinal dynein IC was increased by 8.7% in chronic IOP elevation eyes compared to controls (P<0.03, 95% CI 1.4% to 16.1%, n=24). In the retina, IOP elevation particularly affected the 72 kD subunit of dynein IC, which was 100.7% higher in chronic IOP elevation eyes compared to controls (P<0.00001, 95% CI 71.0% to 130.4%, n=21). Dynein IC changes in myelinated and unmyelinated optic nerve were not significant (P>0.05). We conclude that dynein accumulates at the ONH with experimental IOP elevation in the rat, supporting the hypothesis that disrupted axonal transport in RGC may be involved in the pathogenesis of glaucoma. The effect of IOP elevation on other motor proteins deserves further investigation in the future.

Animals↗
PubMed2006

Central corneal thickness and corneal hysteresis associated with glaucoma damage.

PURPOSE: We sought to measure the impact of central corneal thickness (CCT), a possible risk factor for glaucoma damage, and corneal hysteresis, a proposed measure of corneal resistance to deformation, on various indicators of glaucoma damage. DESIGN: Observational study. METHODS: Adult patients of the Wilmer Glaucoma Service underwent measurement of hysteresis on the Reichert Ocular Response Analyzer and measurement of CCT by ultrasonic pachymetry. Two glaucoma specialists (H.A.Q., N.G.C.) reviewed the chart to determine highest known intraocular pressure (IOP), target IOP, diagnosis, years with glaucoma, cup-to-disk ratio (CDR), mean defect (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), and presence or absence of visual field progression. RESULTS: Among 230 subjects, the mean age was 65 +/- 14 years, 127 (55%) were female, 161 (70%) were white, and 194 (85%) had a diagnosis of primary open-angle glaucoma (POAG) or suspected POAG. In multivariate generalized estimating equation models, lower corneal hysteresis value (P = .03), but not CCT, was associated with visual field progression. When axial length was included in the model, hysteresis was not a significant risk factor (P = .09). A thinner CCT (P = .02), but not hysteresis, was associated with a higher CDR at the most recent examination. Neither CCT nor hysteresis was associated with MD, PSD, or GHT "outside normal limits." CONCLUSIONS: Thinner CCT was associated with the state of glaucoma damage as indicated by CDR. Axial length and corneal hysteresis were associated with progressive field worsening.

Adult↗
PubMed2006

Visual field defects and retinal ganglion cell losses in patients with glaucoma.

OBJECTIVE: To determine whether the structure-function relationships for glaucoma in humans and experimental glaucoma in monkeys are similar. METHODS: The study was based on retinal ganglion cell density and visual thresholds in patients with documented glaucoma. Data were analyzed with a model that predicted ganglion cell density from standard clinical perimetry, which was then compared with histologic cell counts. RESULTS: The model, without free parameters, produced accurate and relatively precise quantification of ganglion cell density associated with visual field defects. For 437 sets of data, the unity correlation for predicted vs measured cell density had a coefficient of determination of 0.39. The mean absolute deviation of the predicted vs measured values was 2.59 decibels (dB), and the mean +/- SD of the distribution of residual errors of prediction was -0.26 +/- 3.22 dB. CONCLUSIONS: Visual field defects based on standard clinical perimetry are proportional to neural losses caused by glaucoma. CLINICAL RELEVANCE: The evidence for quantitative structure-function relationships provides a scientific basis for interpreting glaucomatous neuropathy from visual thresholds and supports the application of standard perimetry to establish the stage of the disease.

Aged↗
PubMed2006

Chase the family.

Explore the source record for details and available documents.

Glaucoma, Open-Angle↗
PubMed2006

Long-term outcomes in fellow eyes after acute primary angle closure in the contralateral eye.

PURPOSE: To determine the long-term outcome of the contralateral eye in Asian persons with a unilateral attack of acute primary angle closure (APAC). DESIGN: Cross-sectional observational case series. PARTICIPANTS: Seventy-nine individuals who were examined from 4 to 10 years after a unilateral episode of APAC at 2 Singapore hospitals. METHODS: All subjects underwent a complete eye examination. The optic discs were graded clinically and photographically for the presence of glaucomatous optic neuropathy, and automated visual field tests were assessed for damage. All visual fields and optic nerve photographs (when available) underwent a second evaluation by a masked glaucoma specialist, who assessed whether the changes were compatible with glaucoma. MAIN OUTCOME MEASURES: Glaucomatous optic neuropathy, intraocular pressure (IOP), and visual impairment (defined as best-corrected visual acuity of worse than 6/12). RESULTS: Ninety of 138 eligible patients (65.2%) with APAC were examined, 79 with unilateral attacks. Subjects were predominantly Chinese (n = 68; 86%). There were 54 females (68%), and mean age was 68.5+/-8.9 years (standard deviation) at the time of APAC, with a mean duration of 6.3+/-1.5 years from the time of the APAC episode to the study examination. The contralateral eyes of 7 patients (8.9%) had definite or probable glaucoma, 2 of whom were felt to have glaucoma in that eye at the time of the attack. Three eyes had markedly cupped optic discs (cup-to-disc ratio > or = 0.9). Thirteen eyes (16.9%) had best-corrected vision worse than 6/12, due to cataract in almost half the cases. Only 1 eye had vision < 6/60, the cause of which was corneal decompensation. One other patient had only a central island remaining with vision of 6/12. Mean IOP of the study participants was 15.7+/-4.7 mmHg, with 6 subjects (7.6%) having undergone trabeculectomy. CONCLUSIONS: Definite or probable glaucoma was present at the time of diagnosis in 2 (2.5%) fellow eyes and developed in an additional 5 (6.5%) with a mean follow-up of 6 years. More than 80% of this cohort retained good vision in the contralateral eye, in contrast to the eye that underwent APAC. Unoperated cataract accounted for most of the visual impairment in this group.

Acute Disease↗
PubMed2006

The association between glaucomatous visual fields and optic nerve head features in the Ocular Hypertension Treatment Study.

PURPOSE: To determine the association between change from baseline in the optic nerve head (ONH) and the visual field (VF) during follow-up of ocular hypertension participants in the Ocular Hypertension Treatment Study. DESIGN: Longitudinal randomized clinical trial. PARTICIPANTS: One hundred sixty-eight eyes of 152 ocular hypertensive participants ages 40 to 80 years. METHODS: Cox hazard models were applied to 3232 eyes, which included 81 eyes that reached a study end point by developing a glaucomatous VF (VF end point) and 128 eyes that reached a study end point by developing an optic disc change (optic disc end point). MAIN OUTCOME MEASURES: Primary open-angle glaucoma end point as determined by changes in the VF or optic disc. RESULTS: Forty-one eyes reached an end point by both VF and optic disc criteria; 40 eyes reached only a VF end point, and 87 reached only an optic disc end point. Times to reach isolated disc or field end points were similar. Visual field end points were more likely (P<0.0001) in eyes that showed the following ONH features: an ONH hemorrhage, thinning of the optic disc rim, or enlargement of the horizontal cup-to-disc (C/D) ratio. Optic disc end points were more likely (P<0.0001) in eyes that showed the following VF features: some evidence of a nasal step or a partial arcuate VF defect, or an increase in the pattern standard deviation (PSD). CONCLUSIONS: Both the VF and the optic disc must be monitored with equal diligence, because either may show the first evidence of glaucomatous damage. Changes in the ONH based on stereophotographic observation (rim thinning, hemorrhage, or a slight increase in C/D ratio) and VF changes (evidence of a nasal step/partial arcuate defect or an increase in PSD) suggest that these cases have an increased risk of developing glaucoma. Confirmation of such subtle findings should be sought through repeat testing and correlation with other clinical results.

Adult↗
PubMed2006

Manometric calibration and comparison of TonoLab and TonoPen tonometers in rats with experimental glaucoma and in normal mice.

PURPOSE: To compare the TonoPen and TonoLab tonometers to each other and to manometrically set intraocular pressure (IOP) in the eyes of normal mice, normal rats, and rats with chronic IOP elevation. METHODS: The measurement of IOP by the TonoPen and TonoLab tonometers was made in 21 normal rat eyes, 10 normal mouse eyes, and 16 rats that had either 2 or 4-week experimental glaucoma. IOP was varied from 10 to 50 mm Hg in steps of 10 mm Hg under conditions in which the eye was either open or closed to the reservoir controlling IOP. RESULTS: In normal rat eyes, TonoPen overestimated manometric IOP at 10 mm Hg and underestimated it by up to 6 mm Hg at higher IOP, whereas the TonoLab matched set IOP within 1 mm Hg. In glaucoma rat eyes, the TonoLab accurately reflected manometric IOP under open stopcock conditions (linear regression: y = 0.99x -0.62, R = 0.98), whereas in the closed stopcock condition, IOP measured lower at the higher IOP levels (P = 0.0059, paired t test). In uncannulated rat glaucoma eyes, the tonometer used first gave higher IOP [paired t test, P = 0.015 (TonoLab first); P = 0.005 (TonoPen first)]. In normal mouse eyes under the open stopcock condition, the TonoLab nearly matched manometric IOP (linear regression: y = 0.98x + 1.57, R = 0.98). CONCLUSIONS: In mouse and rat eyes, including rats with chronic IOP elevation, the TonoLab accurately reflected manometrically set IOP in an efficient manner.

Animals↗
PubMed2006

Gaze behavior of the visually impaired during street crossing.

PURPOSE: This study explored the gaze patterns of fully sighted and visually impaired subjects during the high-risk activity of crossing the street. METHODS: Gaze behavior of 12 fully sighted subjects, nine with visual impairment resulting from age-related macular degeneration and 12 with impairment resulting from glaucoma, was monitored using a portable eye tracker as they crossed at two unfamiliar intersections. RESULTS: All subject groups fixated primarily on vehicles and crossing elements but changed their fixation behavior as they moved from "walking to the curb" to "standing at the curb" and to "crossing the street." A comparison of where subjects fixated in the 4-second time period before crossing showed that the fully sighted who waited for the light to change fixated on the light, whereas the fully sighted who crossed early fixated primarily on vehicles. Visually impaired subjects crossing early or waiting for the light fixate primarily on vehicles. CONCLUSIONS: Vision status affects fixation allocation while performing the high-risk activity of street crossing. Crossing decision-making strategy corresponds to fixation behavior only for the fully sighted subjects.

Adult↗
PubMed2005

The transcription factor c-jun is activated in retinal ganglion cells in experimental rat glaucoma.

This study investigates the role of the MAP kinase pathway including c-jun, ATF-2 and JNK in glaucomatous eyes of rats and in optic nerve transection. Glaucoma was induced in one eye of 51 adult Wistar rats by laser treatment to the trabecular meshwork. Eighteen further rats underwent unilateral optic nerve transection. We studied the transcription factor c-jun, its activated form, phospho-c-jun, the transcription factor p-ATF-2, and the enzyme JNK by immunohistochemistry. The activation of p-c-jun was also investigated using western blot analysis. Treated and control eyes were compared in a masked way at multiple time points after injury. We found a statistically significant increase in immunolabelling for c-jun and phospho-c-jun in retinal ganglion cells (RGCs) from 1 day to 4 weeks after intraocular pressure (IOP) elevation. At 1 and 2 days after the laser treatment, a mean of 2.9+/-3.3 RGCsmm(-1) were positive for c-jun (n=12, p=0.005, t-test), increasing to a mean of 13.4+/-7.5 cells mm(-1) at 1 week (n=18, p=0.00005), and decreasing to 2.3+/-2.0 cells mm(-1) at 2 weeks (n=5, p=0.04) and 0.1+/-0.1 cells mm(-1) at 2 months. Few of the 47 control eyes had any labelling for c-jun or phospho-c-jun, while between 80 and 100% of elevated IOP eyes showed positivity during the first 2 weeks of experimental glaucoma. After optic nerve transection, c-jun and phospho-c-jun were also significantly activated at 1, 2 and 9 days (p<0.03, t-test). Western blot analysis demonstrated significantly increased phospho-c-jun amounts in both transected and glaucomatous eyes compared to control fellow eyes 1 week following treatment. JNK was not significantly activated in glaucoma or optic nerve transection. P-ATF-2 was not significantly activated in glaucoma, but was significantly increased 2 days after optic nerve transection. We conclude that the process leading to RGC death in experimental glaucoma and after optic nerve transection involves the activation of c-jun at the RGC layer. C-jun is activated more gradually in glaucoma then after optic nerve transection.

Activating Transcription Factor 2↗
PubMed2005

Persistence and adherence with topical glaucoma therapy.

PURPOSE: The present study describes the patterns and predictors of treatment persistence and adherence among patients who are diagnosed with glaucoma or as glaucoma suspects (based on claims codes). DESIGN: A retrospective cohort study using health insurance claims data. METHODS: Newly treated individuals with diagnosed glaucoma (n = 3623) and suspect glaucoma (n = 1677) were obtained from healthcare claims data in the Ingenix Research Database. For each of these two diagnostic groups, we calculated the duration of continuous treatment with the initially prescribed medication (persistence) and the prevalence of use of the initial medication at various time points (adherence). Four drug classes were included: beta-blockers, alpha-agonists, carbonic anhydrase inhibitors, and prostaglandin analogs. RESULTS: Nearly one half of the individuals who had filled a glaucoma prescription discontinued all topical ocular hypotensive therapy within six months, and just 37% of these individuals recently had refilled their initial medication at three years after the first dispensing. Prostaglandins were associated with better persistence than any other drug class, which was indicated by hazard ratios for discontinuation of prostaglandins compared with beta-blockers of 0.40 (95% confidence interval, 0.35-0.44) for diagnosed patients and 0.44 (95% confidence interval, 0.37-0.52) for patients with suspect glaucoma. Prostaglandins showed a similar advantage in adherence. Furthermore, patients with diagnosed glaucoma were more likely to adhere to therapy than patients with suspect glaucoma (relative risk = 1.11; 95% confidence interval, 1.05-1.18). CONCLUSION: Persistence and adherence were substantially better with prostaglandins than with other drug classes, and patients with diagnosed open-angle glaucoma were more likely to adhere to treatment than suspected glaucoma.

Administration, Topical↗
PubMed2005

Factors influencing career choices among graduating ophthalmology residents.

OBJECTIVE: To identify factors influencing graduating ophthalmology residents to pursue subspecialty training or a career in comprehensive ophthalmology. DESIGN: Cross-sectional study. PARTICIPANTS: Residents graduating from U.S. ophthalmology residency programs who participated in the ophthalmology match program. METHODS: An anonymous survey was sent to each graduating ophthalmology resident in the United States between February 1, 2003, and February 28, 2003. Demographic data and information relating to medical school and residency training, career goals, and factors influencing career choices were collected from the surveys. MAIN OUTCOME MEASURE: The decision to pursue or not to pursue fellowship training. RESULTS: The individual response rate was 50.8% (222/437), and 74.1% (86/116) of residency training programs responded to the survey. After completion of residency training, 64% (142/222) were pursuing subspecialty training and 36% (80/222) planned to practice comprehensive ophthalmology. In a multivariate analysis, factors that predicted subspecialty training included a desire to acquire special skills (odds ratio [OR], 13.81) and a perceived more favorable job market (OR, 3.23) and prestige (OR, 3.20). Anticipated work hours (OR, 0.37) and preferred geographic location (OR, 0.47) were predictors of a career in comprehensive ophthalmology. Residents choosing comprehensive ophthalmology careers were more likely to plan to practice in a group private practice, and those seeking subspecialty training were more likely to intend to practice in a university setting or were undecided in their future practice type (OR, 2.04). CONCLUSIONS: Several factors influenced career choices among graduating ophthalmology residents. A desire to acquire special skills and perceived prestige and job market were major factors influencing ophthalmology residents to seek subspecialty training. Lifestyle considerations were more important to residents choosing a comprehensive ophthalmology career. There were significant differences in practice preferences among residents pursuing or not pursuing subspecialty training.

Adult↗
PubMed2005

Variations in treatment among adult-onset open-angle glaucoma patients.

OBJECTIVE: To determine the predictors of treatment for glaucoma and suspect glaucoma in a nationally representative sample of diagnosed persons. DESIGN: Retrospective cohort study of persons enrolled in a large managed care organization. PARTICIPANTS: Thirty-five thousand seven hundred fifty-four diagnosed suspects, 5265 diagnosed glaucoma persons, and 2633 individuals coded as having cupping of the optic disc. METHODS: Linked pharmacy and patient care information were used to examine the predictors of initiating glaucoma treatment in this cohort of persons insured by a single managed care organization. Predictors entered into logistic regression models included diagnostic group (suspect vs. diagnosed), age group, gender, region of the country, provider type at the initial visit (optometrist or ophthalmologist), diagnosis index date divided into 2 periods (1995-1998 and 1999-2001), and health plan enrollment duration after the initial diagnosis. MAIN OUTCOME MEASURES: Occurrence of and factors associated with treatment for glaucoma (argon laser trabeculoplasty [ALT], surgery, or topical ocular hypotensives). RESULTS: A logistic regression model adjusting for glaucoma status, age, region, clinician seen at initial visit, and index date found that women were less likely to undergo treatment (topical ocular hypotensives, ALT, or surgery) than men (odds ratio, 0.76; 95% confidence interval, 0.71-0.80). Factors other than gender that were associated with greater likelihood of treatment were glaucoma diagnosis, older age, region, and longer follow-up. CONCLUSIONS: We have documented wide variation in treatment among individuals diagnosed as having glaucoma or as glaucoma suspects. Women were 24% less likely to be treated than men, and younger individuals were far less likely to be treated than older ones. Furthermore, treatment varied by region of the country. Understanding the sources of these variations will help in determining how to arrive at better management strategies for individuals with glaucoma and suspect glaucoma.

Adult↗
PubMed2005

Glaucoma management among individuals enrolled in a single comprehensive insurance plan.

OBJECTIVE: To determine the management patterns for glaucoma and suspect glaucoma in a nationally representative sample of newly treated persons. DESIGN: Retrospective cohort study of persons enrolled in a large managed care organization. PARTICIPANTS: One thousand seven hundred twelve diagnosed suspects and 3623 diagnosed glaucoma patients. METHODS: Linked pharmacy and patient care data were used to examine the glaucoma management and treatment patterns in this cohort of persons insured by a single managed care organization. Rates of monitoring and treatment were calculated for the 3 study groups. MAIN OUTCOME MEASURES: Probability of monitoring (return visits, visual fields [VFs], and optic nerve head imaging or photography) and treatment (argon laser trabeculoplasty [ALT] and surgery) for newly treated persons with suspect and glaucoma diagnoses. RESULTS: After a median follow-up of 440 days, 83% of treated diagnosed suspects had had a billed follow-up office visit to either an optometrist or an ophthalmologist at any time during follow-up, 46% had had at least one billed VF, and 13% had had some form of optic nerve head imaging. Rates were slightly higher for those with diagnosed glaucoma (P>0.05). Surgery and ALT were performed rarely in this treated population (1%-6% at 2 years). CONCLUSIONS: This study suggests that a large proportion of individuals felt to require treatment for glaucoma or suspect glaucoma are falling out of care and are being monitored at rates lower than expected from recommendations of published guidelines. More research is needed to confirm these findings and to determine the reasons for loss to follow-up and low monitoring rates.

Adult↗