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Biomedical subjects

Christopher A Girkin

Publications and source records attributed to Christopher A Girkin.

At least 19 recordsLinked to original sources
PubMed2006

Correlations between retinal nerve fiber layer and visual field in eyes with nonarteritic anterior ischemic optic neuropathy.

PURPOSE: To evaluate correlations between retinal nerve fiber layer (RNFL) thickness with visual field (VF) sensitivities in eyes with nonartertic anterior ischemic optic neuropathy (NAION). DESIGN: Case-control study in an academic, institutional setting. METHODS: One eye from 21 patients with NAION and 32 healthy participants were included in this prospective study. Humphrey visual field (HVF) sensitivities were obtained from standard achromatic HVF test (24-2 SITA). RNFL was measured with scanning laser polarimetry (SLP, GDx-VCC) and optical coherence tomography (OCT, StratusOCT). Correlations were evaluated between RNFL and sensitivities from global, hemifields, and regional locations of the VF pertinent to the RNFL distribution. A total of 15 NAION eyes had inferior altitudinal HVF defects, and their global and regional RNFL was compared with that of control eyes. The main outcome measure was correlation between HVF sensitivities and RNFL. RESULTS: Correlations of global, hemifield, and sectorial HVF sensitivities with RNFL were greater when RNFL was measured with OCT than with SLP, except for nasal and inferonasal sectors. RNFL thickness was far lower in the hemiretinas corresponding to the relative unaffected hemifield in eyes with altitudinal VF defect compared with controls. CONCLUSIONS: In patients with NAION, RNFL measured by OCT provided better correlation to HVF changes than SLP did. Both instruments showed decreased RNFL in NAION eyes with altitudinal VF defects compared with control eyes, demonstrating loss of RNFL even in sectors of the optic disk that corresponded to relatively unaffected hemifield, suggesting greater damage beyond the extent estimated by VF methods.

Arteritis↗
PubMed2006

Comparison of the Moorfields classification using confocal scanning laser ophthalmoscopy and subjective optic disc classification in detecting glaucoma in blacks and whites.

OBJECTIVE: To compare the diagnostic accuracy of the Moorfields regression classification (MRC) and subjective optic disc evaluation in discriminating early to moderate glaucomatous from nonglaucomatous eyes. DESIGN: Cross-sectional observational study. PARTICIPANTS: Two hundred thirty-three patients with glaucoma and 216 normal subjects were included in the analysis. Racial groups were defined by self-description. METHODS: All subjects underwent confocal scanning laser ophthalmoscopy, stereophotography, and standard perimetry. Glaucoma was defined by visual field defect alone and confirmed with a second visual field test. Stereo photographs were graded as either normal or glaucomatous appearing in a masked fashion by 2 independent graders and adjudicated by a third grader in cases of disagreement. Mean disc area was compared between patients correctly and incorrectly diagnosed with either technique. MAIN OUTCOME MEASURES: Sensitivity and specificity of MRC and subjective evaluation of stereophotographs in the detection of glaucomatous visual field loss. RESULTS: With the MRC, the sensitivity and specificity were higher using the 95% cutoff than using the 99.9% cutoff. Classification based on subjective photo assessment had a greater agreement with the diagnosis of glaucoma than the MRC for blacks (MRC, sensitivity = 62.5%, specificity = 93.2%; Photo, sensitivity = 76.5%, specificity = 91.5%) and whites (MRC, sensitivity = 67.0%, specificity = 92.2%; photo, sensitivity = 78.4%, specificity = 91.9%). Disc area was significantly larger in patients incorrectly diagnosed with the MRC (P = 0.0289). CONCLUSIONS: Subjective optic disc grading by glaucoma specialists outperformed the MRC with the HRT II in both black and white subjects. Both subjective and objective diagnostic methods were associated with similar sensitivity and specificity between racial groups. The MRC was more likely to provide an incorrect diagnosis in subjects with larger optic discs.

Black or African American↗
PubMed2006

Agreement in assessing cup-to-disc ratio measurement among stereoscopic optic nerve head photographs, HRT II, and Stratus OCT.

PURPOSE: To compare the level of agreement between subjective and objective methods in estimating horizontal and vertical cup-to-disc ratios (HCDR and VCDR, respectively) to determine if objective techniques may be used as surrogates for subjective cup-to-disc (CDR) estimation. METHODS: Fifty-one glaucoma patients and 49 control subjects underwent full ophthalmic examination, stereoscopic optic nerve head photographs (ONHPs), confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomography II [HRT II]), and optical coherence tomography (Stratus OCT). The intraclass correlation coefficient (ICC) and Bland Altman plots were used to assess the agreement across the three methods. Repeated measures analysis of variance (ANOVA), Tukey adjustment, and pairwise P values were used to compare the HCDR and VCDR estimates between three clinicians who reviewed photos, Stratus OCT, and HRT II. RESULTS: For the clinicians, the agreement in subjectively assessed HCDR and VCDR was substantial (ICC=0.84 and 0.85, respectively), and for all three methods, overall agreement was good (ICC=0.75 and 0.77 for the HCDR and VCDR, respectively). Stratus OCT provided the largest overall mean+/-SD HCDR (0.68+/-0.14) and VCDR (0.62+/-0.13). The smallest overall mean+/-SD HCDR was provided by ONHP (0.32+/-0.16), and the smallest overall mean+/-SD VCDR was provided by HRT II (0.26+/-0.20). Repeated measures ANOVA test demonstrated significant differences across the three methods for glaucomatous (P=0.0017 and 0.0016, HCDR and VCDR, respectively) and normal (P=0.0001 for both HCDR and VCDR) eyes. Tukey adjustment demonstrated specific statistical differences between pairs of methods. CONCLUSIONS: Although the overall agreement between various methods was good, the mean estimates were statistically different. Additional studies are needed to evaluate the sources of variability, their level of significance, and longitudinal agreement between various methods of the CDR estimation.

Adult↗
PubMed2006

Discrimination between glaucomatous and nonglaucomatous eyes using quantitative imaging devices and subjective optic nerve head assessment.

PURPOSE: To compare the diagnostic ability of the confocal scanning laser ophthalmoscope (HRT-II; Heidelberg Engineering, Heidelberg, Germany), scanning laser polarimeter (GDx-VCC; Carl Zeiss Meditec, Inc., Dublin, CA), and optical coherence tomographer (StratusOCT, Carl Zeiss Meditec, Inc.) with subjective assessment of optic nerve head (ONH) stereophotographs in discriminating glaucomatous from nonglaucomatous eyes. METHODS: Data from 79 glaucomatous and 149 normal eyes of 228 subjects were included in the analysis. Three independent graders evaluated ONH stereophotographs. Receiver operating characteristic curves were constructed for each technique and sensitivity was estimated at 80% of specificity. Comparisons of areas under these curves (aROC) and agreement (kappa) were determined between stereophoto grading and best parameter from each technique. RESULTS: Stereophotograph grading had the largest aROC and sensitivity (0.903, 77.22%) in comparison with the best parameter from each technique: HRT-II global cup-to-disc area ratio (0.861, 75.95%); GDx-VCC Nerve Fiber Indicator (NFI; 0.836, 68.35%); and StratusOCT retinal nerve fiber layer (RNFL) thickness (0.844, 69.62%), ONH vertical integrated rim area (VIRA; 0.854, 73.42%), and macular thickness (0.815, 67.09%). The kappa between photograph grading and imaging parameters was 0.71 for StratusOCT-VIRA, 0.57 for HRT-II cup-to-disc area ratio, 0.51 for GDX-VCC NFI, 0.33 for StratusOCT RNFL, and 0.28 for StratusOCT macular thickness. CONCLUSIONS: Similar diagnostic ability was found for all imaging techniques, but none demonstrated superiority to subjective assessment of the ONH. Agreement between disease classification with subjective assessment of ONH and imaging techniques was greater for techniques that evaluate ONH topography than with techniques that evaluate RNFL parameters. A combination of subjective ONH evaluation with RNFL parameters provides additive information, may have clinical impact, and deserves to be considered in the design of future studies comparing objective techniques with subjective evaluation by general eye care providers.

Adult↗
PubMed2006

A statistical approach to the evaluation of covariate effects on the receiver operating characteristic curves of diagnostic tests in glaucoma.

PURPOSE: To describe an approach for the evaluation of covariate effects on receiver operating characteristic (ROC) curves and to apply this methodology to the investigation of the effects of disease severity and age on the diagnostic performance of frequency doubling technology (FDT) and standard automated perimetry (SAP) visual function tests for glaucoma detection. METHODS: The study included 370 eyes of 211 participants, with 174 eyes of 110 patients having glaucomatous optic neuropathy and 196 eyes of 101 subjects being normal. All patients underwent visual function testing with FDT 24-2 Humphrey Matrix and SAP SITA (Carl Zeiss Meditec, Inc., Dublin, CA). Disease severity was evaluated by the amount of neuroretinal rim loss assessed by confocal scanning laser ophthalmoscopy. An ROC regression model was fitted to evaluate the influence of disease severity and age on the diagnostic performance of the pattern SD (PSD) index from FDT 24-2 and SAP SITA. RESULTS: After adjustment for age, the areas under the ROC curves (AUCs) for SAP SITA PSD for 10%, 30%, 50%, and 70% loss of neuroretinal rim area were 0.638, 0.756, 0.852, and 0.920, respectively. Corresponding values for FDT 24-2 PSD were 0.766, 0.857, 0.922, and 0.962. For 10% and 30% rim loss, FDT 24-2 PSD had a significantly larger AUC than did SAP SITA PSD. CONCLUSIONS: A regression methodology to evaluate covariate effects on ROC curves can be useful for assessment of diagnostic tests in glaucoma. Using the proposed methodology, a significantly better performance of FDT 24-2 compared to SAP SITA for diagnosis of early glaucoma was demonstrated.

Age Factors↗
PubMed2006

Perceived barriers to care and attitudes about vision and eye care: focus groups with older African Americans and eye care providers.

PURPOSE: To identify by using focus group methods the perceived barriers to eye care and attitudes about vision and eye care among older African Americans as well as among ophthalmologists and optometrists serving their communities. METHODS: Seventeen focus groups of older African Americans residing in the Birmingham or Montgomery, Alabama, areas were led by an experienced facilitator. Discussion was stimulated by a semistructured script focused on their perceived barriers to eye care and attitudes about vision and eye care. Six focus groups of ophthalmologists and optometrists who practiced in this geographic region addressed the same topics. Discussion was audiotaped and transcribed. Comments were coded using a multistep content analysis protocol. RESULTS: One hundred nineteen African Americans (age range, 59-97 years) and 35 eye care providers (51% ophthalmologists, 49% optometrists) participated. The barrier-to-care problem most frequently cited by both African Americans and eye care providers was transportation. The next most common problems mentioned by African Americans were trusting the doctor, communicating with the doctor, and the cost of eye care; and for eye care providers, the next most common problems were cost, trust, and insurance. With respect to older African Americans' comments on their attitudes about vision and eye care, these comments were predominantly positive (69%), highlighting the importance of eye care and behavior in their lives and attitudes that facilitated care. However, when eye care providers relayed their impressions of African Americans' attitudes about vision and eye care, their comments were largely negative (74%) centering on concerns and frustrations that older African Americans did not have attitudes or engage in behavior that facilitate eye care. CONCLUSIONS: These results provide some guidance for the design of interventions to increase the use of routine eye care in this population. At a societal level, there is a need for affordable and accessible transportation services for older African Americans seeking eye care. For ophthalmologists, optometrists, and their staffs, there is a need for continuing education that imparts culturally sensitive and age-appropriate communication and trust-building skills for interactions with this population. In addition to reinforcing the generally positive attitudes of older African Americans toward the importance of eye care, community-based educational programs should be focused on strategies for overcoming the common barriers to care.

Black or African American↗
PubMed2005

Differences in visual function and optic nerve structure between healthy eyes of blacks and whites.

OBJECTIVE: To investigate differences in visual function, optic disc topography, and retinal nerve fiber layer (RNFL) thickness between healthy eyes of blacks and whites. METHODS: Visual function was assessed in healthy eyes of 50 blacks and 50 whites using standard automated perimetry, short-wavelength automated perimetry, and frequency doubling technology perimetry. Optic disc topography and RNFL thickness were measured using the Heidelberg Retina Tomograph and the optical coherence tomograph. RESULTS: Mean standard automated perimetry mean deviations were within the normal range for both groups. Blacks had worse mean deviation values than whites using frequency doubling technology perimetry (mean +/- SD, -1.8 +/- 3.2 dB vs -0.1 +/- 2.4 dB), blacks had larger optic disc areas than whites using the Heidelberg Retina Tomograph (mean +/- SD, 2.1 +/- 0.4 mm2 vs 1.7 +/- 0.4 mm2), the RNFL of blacks was thicker than that of whites by 16.91 microm superiorly and 10.10 microm inferiorly using optical coherence tomography, and blacks had slightly higher intraocular pressures than whites (mean +/- SD, 16.5 +/- 2.5 mm Hg vs 15.2 +/- 3.2 mm Hg) and thinner central corneas (mean +/- SD, 540.5 +/- 43.2 microm vs 560.9 +/- 35.5 microm). No racial differences were found in mean RNFL thickness, pattern standard deviation on all tests, or any of the short-wavelength automated perimetry variables. CONCLUSIONS: Minimal racial differences in visual function were found, but race significantly affected optic disc topography and superior and inferior RNFL thickness measurements in healthy eyes. The racial differences observed for intraocular pressure could theoretically increase after correcting for central corneal thickness. Prospective studies are needed to further investigate these findings.

Anthropometry↗
PubMed2005

Glaucoma following penetrating ocular trauma: a cohort study of the United States Eye Injury Registry.

PURPOSE: To evaluate associations between baseline structural and functional ocular characteristics and the risk of developing posttraumatic glaucoma after penetrating ocular injury. DESIGN: Prospective cohort study. METHODS: Data from the United States Eye Injury Registry (USEIR) were obtained from a total of 3,627 patients who experienced penetrating ocular injury. The risk of posttraumatic glaucoma and associated structural and functional ocular risk factors was estimated. RESULTS: The risk of developing posttraumatic glaucoma was 2.67%. The development of glaucoma was independently associated with several baseline characteristics including advancing age (relative risk 1.02/yr 95% confidence interval [1.00, 1.03]), lens injury (1.56 [1.03, 2.35]), poor baseline visual acuity (2.59 [1.62, 4.14]), and inflammation (3.02 [1.52, 6.02]). CONCLUSIONS: This study provides an estimate for the risk of developing glaucoma after penetrating ocular injury in a large cohort of patients and determined several factors that are significantly associated with the development of post-traumatic glaucoma, including advancing age, lens injury, poor visual acuity, and intraocular inflammation.

Adult↗
PubMed2005

Differences in optic disc topography between black and white normal subjects.

PURPOSE: To determine if differences in optic disc topography exist between blacks and whites independent of racial differences in the area of the scleral canal. DESIGN: Cross-sectional observational study. PARTICIPANTS: A cohort of 146 eyes from black subjects and 97 eyes from white subjects without detectable ocular disease. METHODS: Reliable bilateral images were obtained using a retinal topographer. Mean values for all topographic parameters were compared both unadjusted and adjusted for differences in optic disc area and/or reference plane height. Comparisons of group differences for parameters and linear discriminant functions were adjusted for interocular dependence and multiple comparisons. RESULTS: Blacks had a significantly greater optic disc area (mean disc area in right eye: black subjects, 2.14 mm(2); white subjects, 1.96 mm(2) [P = 0.02]; mean disc area in left eye: black subjects, 2.18 mm(2); white subjects, 2.02 mm(2) [P = 0.04]). Most racial differences in optic disc parameters were not significant after adjustment for differences in optic disc area and reference plane height. However, eyes of black subjects demonstrated a deeper maximum cup depth than those of whites (P = 0.004), independent of differences in disc area and reference plane height. The values of linear discriminant functions did not differ significantly between racial groups, and the Moorfield classification correctly identified a similar proportion of subjects as normal in each racial group. CONCLUSIONS: Most of the normal variation in optic disc topography between blacks and whites seen with a retinal topographer is due to either differences in disc area or differences in reference plane height. However, small residual differences remain in cup depth independent of these parameters. These racial differences in optic disc structure should be considered in the statistical judgment of disease status based on these parameters. The Moorfield classification, which takes disc area into account, performed with similar specificity in each racial group.

Adult↗
PubMed2005

Glaucoma after ocular contusion: a cohort study of the United States Eye Injury Registry.

PURPOSE: This cohort study was designed to evaluate risk factors for the development of posttraumatic glaucoma after ocular contusion. METHODS: Data from the United States Eye Injury Registry (USEIR) were obtained from a total of 6021 patients who experienced blunt ocular contusion. Logistic regression was used to evaluate the association between these baseline structural and functional ocular characteristics and posttraumatic glaucoma. Odds ratios with 95% confidence intervals were obtained. RESULTS: The 6-month incidence of developing posttraumatic glaucoma was 3.39%. The development of glaucoma was independently associated with: advancing age (OR = 1.02; 95% CI = 1.02, 1.03), visual acuity worse than 20/200 (OR = 1.92; 95% CI = 1.19, 3.10), iris injury (OR = 1.60; 95% CI = 1.05, 2.44), lens injury (OR = 1.86; 95% CI = 1.11, 3.11), hyphema (OR = 2.23; 95% CI = 1.40, 3.54), or angle recession (OR = 1.71; 95% CI = 1.00, 2.90). CONCLUSION: This study provides an estimate for the risk of developing glaucoma after ocular contusion in a large cohort of patients and has determined several independently predictive factors that were significantly associated with the development of posttraumatic glaucoma including poor initial visual acuity, advancing age, lens injury, angle recession, and hyphema.

Adult↗
PubMed2004

Risk assessment in the management of patients with ocular hypertension.

PURPOSE: To develop a model for estimating the global risk of disease progression in patients with ocular hypertension and to calculate the "number-needed-to-treat" (NNT) to prevent progression to blindness as an aid to practitioners in clinical decision making. DESIGN: Development of a mathematical model for estimating risk of glaucoma progression. METHODS: Population-based studies of patients with ocular hypertension and glaucoma were reviewed by a panel of glaucoma specialists. Measures of disease progression risks derived from three long-term studies and assumptions based on the available data were used to estimate the risk of progression from ocular hypertension to glaucoma and glaucoma to unilateral blindness for untreated and treated patients over a 15-year period. Using these estimates, the NNT (1/absolute risk reduction on treatment) to prevent unilateral blindness in one patient with ocular hypertension was calculated. RESULTS: In untreated patients, the estimated risk of progression from ocular hypertension to unilateral blindness was 1.5% to 10.5% and in treated patients, the estimated risk of progression was 0.3% to 2.4% over 15 years. From these estimates, between 12 and 83 patients with ocular hypertension will require treatment to prevent one patient from progressing to unilateral blindness over a 15-year period. CONCLUSION: Global risk assessment that incorporates all available data plays a vital role in managing patients with ocular hypertension. A more precise understanding of long-term vision loss should be factored into decisions pertaining to the initiation of glaucoma therapy. Undoubtedly, these estimates will evolve and change with the availability of new population-based epidemiologic information and improvements in multivariable model testing.

Blindness↗
PubMed2004

Glaucoma risk factor assessment and prevention: lessons from coronary heart disease.

PURPOSE: To determine whether multivariable risk factor assessment can be as successful in developing disease prevention strategies in patients with ocular hypertension as it has been in patients at risk for coronary heart disease (CHD). DESIGN: From a literature review of the evolution of the global risk assessment model for CHD, parallels are drawn to the evolution of a global risk assessment methodology for glaucoma. METHODS: This article summarizes the literature on global risk assessment and prevention of CHD in clinical practice, discusses the development of glaucoma risk assessment based on available trial and population data, and reviews the potential for prevention strategies founded on the cardiovascular disease model. RESULTS: To improve risk assessment in glaucoma and develop disease management strategies for patients with ocular hypertension, it is first necessary to identify and quantify levels of risk associated with factors that predict disease progression. In addition, the incidence of glaucoma and the average person's life expectancy based on his or her age are needed. Finally, it is necessary to quantify how long it takes to develop a visual defect that affects quality of life once a person develops glaucoma. CONCLUSION: The systematic application of epidemiologic data to CHD risk factor models provides insights into how global risk assessment can be incorporated into treatment recommendations for managing individuals with glaucoma. It is hoped that ophthalmologists can use the results of future clinical trials and long-term studies to develop disease prevention strategies in patients with ocular hypertension based on multivariable risk assessment.

Coronary Disease↗
PubMed2004

Secondary acute angle-closure glaucoma associated with vitreous hemorrhage after ruptured retinal arterial macroaneurysm.

PURPOSE: To report acute angle-closure glaucoma in a patient with dense vitreous hemorrhage due to a ruptured retinal arterial macroaneurysm. DESIGN: Interventional case report. METHODS: A male patient presented with severe pain and decreased vision in his right eye, nausea, and vomiting. Visual acuity was hand motions, intraocular pressure was 64 mm Hg, and light reflex was not detected in the right eye. The patient underwent comprehensive ophthalmologic examination and appropriate medical and surgical management. RESULTS: Examination of the right eye revealed a shallow anterior chamber and closed angle; ultrasound confirmed the presence of vitreous hemorrhage. After intensive medical treatment and subsequent pars plana vitrectomy with laser treatment to the ruptured retinal macroaneurysm, pain in the right eye subsided, visual acuity improved to 20/25, and intraocular pressure decreased to 20 mm Hg. CONCLUSION: We are unaware of previous clinical reports of this finding and could find no reference to it in a computerized search utilizing MEDLINE. In our patient the pressure stabilized and the vision improved after medical and surgical management.

Acute Disease↗
PubMed2004

Hypothyroidism and the development of open-angle glaucoma in a male population.

PURPOSE: To determine if hypothyroidism is associated with an increased risk of glaucoma using a large cohort of patients. DESIGN: Nested case-control study. PARTICIPANTS: Patients seen at the Veterans Affairs Medical Center in Birmingham, Alabama with newly diagnosed glaucoma between 1997 and 2001 were selected (n = 590) and age-matched to nonglaucoma controls (n = 5897). METHODS: Patient information was extracted from the Birmingham Veterans Affairs Medical Center data files containing demographic, clinical, and medication information. An index date was assigned to the glaucoma subjects corresponding to the time of diagnosis. Patients who had a glaucoma diagnosis before the observation period of the study were excluded. Ten controls were randomly selected for each patient and matched on age (+/-1 year) and an encounter on or before the index date of the matched case. MAIN OUTCOME MEASURES: Odds ratios (ORs) for the association between the prior diagnosis of hypothyroidism and the risk of developing glaucoma with adjustment for the presence of diabetes, lipid metabolism disorders, hypertension, cardiovascular disease, cerebrovascular disease, arterial disease, and migraines. RESULTS: After adjustment for the other potential risk factors, patients were significantly more likely to have prior hypothyroidism than controls (OR, 1.40; 95% confidence interval, 1.01-1.97). CONCLUSIONS: Our study has demonstrated a significantly greater risk of subjects with a preexisting diagnosis of hypothyroidism developing glaucoma, compared with controls, in a large Veterans Affairs Medical Center population.

Aged↗
PubMed2004

Radionecrosis of the inferior occipital lobes with altitudinal visual field loss after gamma knife radiosurgery.

A patient had bilateral superior altitudinal visual field defects because of radionecrosis of the inferior occipital lobes after gamma knife radiosurgery for a recurrent atypical cerebellar meningioma. Although radionecrosis of the anterior visual pathway has been well-documented, this is the first report of visual field loss associated with occipital lobe radionecrosis. The treatment dose this patient received is within the range of predicted tolerable radiosurgical dosing, although this patient was at increased risk for radionecrosis secondary to previous external beam radiotherapy. By offering an effective, noninvasive treatment, radiosurgery has changed the management of intracranial lesions. Radiosurgery targets a discrete volume of tissue and relatively spares the surrounding normal tissue. Radiation injury, or radionecrosis, is the only significant complication of radiosurgery (). We present a case of bilateral occipital lobe radionecrosis after gamma knife surgery that resulted in bilateral superior altitudinal defects.

Brain Diseases↗
PubMed2004

Relationship between structure of optic nerve/nerve fiber layer and functional measurements in glaucoma.

PURPOSE OF REVIEW: Glaucoma is a progressive optic neuropathy characterized by structural changes of the optic nerve and retina that are associated with the development of visual functional defects. The temporal relation between structural signs of the disease with psychophysical measures such as visual field tests is important to clarify to determine the best methods to detect glaucoma and progressive glaucomatous damage in the clinical setting. This paper reviews recent advancement in the perception of this structure-function relation. RECENT FINDINGS: Quantitative measurement of optic disc and nerve fiber layer integrity have shown initial promise in early longitudinal studies in detecting progressive glaucoma before the development of progression using standard perimetry. Additionally, selective measures of visual function may be able to detect glaucoma before conventional methods as well; however, the relation between these newer specialized functional tests and optic disc analyzers in detecting progression awaits further study. SUMMARY: Defining the clinical relation between structure and function cannot be done outside of the context of the instrumentation used to assess these parameters. Unfortunately, longitudinal studies that compare newer clinical instruments that measure the structural and functional characteristics of the optic nerve to current conventional testing are lacking, but are required to validate these emerging technologies.

Glaucoma, Open-Angle↗
PubMed2004

Subjective and objective optic nerve assessment in African Americans and whites.

OBJECTIVE: To compare the ability of quantitative optic disc topography and subjective optic disc evaluation to discriminate early glaucomatous from normal eyes in African Americans and whites. METHODS: Monocular data from eyes of 88 African-American patients and 63 eyes of white patients with glaucoma were included in the analysis. Sixty-three eyes of African American normal subjects and 42 eyes of white normal subjects were used as a control group. Racial groups were defined by self-description. All subjects underwent topographic imaging, stereophotography, and standard perimetry. Glaucoma was defined by visual field defect alone. Stereophotos were graded in a masked fashion by three independent graders. The areas under the receiver operator curve (aROCs) were calculated for the overall stereophoto grade, each confocal scanning laser ophthalmoscope (CSLO) parameter, and previously described discriminant functions. After adjustment for disc area and age, the aROC associated with each parameter, discriminant function, and subjective stereophoto grade were compared between African Americans and whites. RESULTS: The aROC for masked stereophotographic disc evaluation and the best discriminatory CSLO parameter (cup-to-disc ratio, CDR) was similar in whites (0.869 stereophotographic, 0.858 CSLO CDR) and African Americans (0.865 stereophotographic, 0.850 CSLO CDR). No significant differences were found between the aROC with subjective stereophotographic assessment and the most discriminatory optic disc parameter in either racial group. CONCLUSIONS: Previously described racial differences in optic disc structure have little impact on the relative ability of subjective or objective methods to discriminate between glaucomatous and nonglaucomatous optic discs; however, differences in normative values necessitate race-specific cutoffs, to optimize disease detection strategies.

Adult↗