Racial Differences in Diagnostic Accuracy of Retinal Nerve Fiber Layer Thickness in Primary Open-Angle Glaucoma

Purpose

To evaluate the diagnostic accuracy of retinal nerve fiber layer thickness (RNFLT) by spectral-domain optical coherence tomography (OCT) in primary open-angle glaucoma (POAG) in eyes of African (AD) and European descent (ED).

Design

Comparative diagnostic accuracy analysis by race.

Participants

379 healthy eyes (125 AD and 254 ED) and 442 glaucomatous eyes (226 AD and 216 ED) from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study.

Methods

Spectralis (Heidelberg Engineering GmbH) and Cirrus (Carl Zeiss Meditec) OCT scans were taken within one year from each other.

Main Outcome Measures

Diagnostic accuracy of RNFLT measurements.

Results

Diagnostic accuracy for Spectralis-RNFLT was significantly lower in eyes of AD compared to those of ED (area under the receiver operating curve [AUROC]: 0.85 and 0.91, respectively, P=0.04). Results for Cirrus-RNFLT were similar but did not reach statistical significance (AUROC: 0.86 and 0.90 in AD and ED, respectively, P =0.33). Adjustments for age, central corneal thickness, axial length, disc area, visual field mean deviation, and intraocular pressure yielded similar results.

Conclusions

OCT-RNFLT has lower diagnostic accuracy in eyes of AD compared to those of ED. This finding was generally robust across two OCT instruments and remained after adjustment for many potential confounders. Further studies are needed to explore the potential sources of this difference.

Longitudinal stability of inter-eye differences in optical coherence tomography measures for identifying unilateral optic nerve lesions in multiple sclerosis

INTRODUCTION

Optical coherence tomography (OCT)-derived peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell+inner plexiform layer (GCIPL) thickness inter-eye differences (IEDs) are robust measurements for identifying clinical history acute ON in people with MS (PwMS). This study investigated the utility and durability of these measures as longitudinal markers to identify optic nerve lesions.

METHODS

Prospective, multi-center international study of PwMS (with/without clinical history of ON) and healthy controls. Data from two sites in the International MS Visual System Consortium (IMSVISUAL) were analyzed. Mixed-effects models were used to compare inter-eye differences based on MS and acute ON history.

RESULTS

Average age of those with MS (n = 210) was 39.1 ± 10.8 and 190 (91%) were relapsing-remitting. Fifty-nine (28.1%) had a history of acute unilateral ON, while 9/210 (4.3%) had >1 IB episode. Median follow-up between OCT scans was 9 months. By mixed-effects modeling, IEDs were stable between first and last visits within groups for GCIPL for controls (p = 0.18), all PwMS (p = 0.74), PwMs without ON (p = 0.22), and PwMS with ON (p = 0.48). For pRNFL, IEDs were within controls (p = 0.10), all PwMS (p = 0.53), PwMS without ON history (p = 0.98), and PwMS with history of ON (p = 0.81).

CONCLUSION

We demonstrated longitudinal stability of pRNFL and GCIPL IEDs as markers for optic nerve lesions in PwMS, thus reinforcing the role for OCT in demonstrating optic nerve lesions.

24-2 Visual Fields Miss Central Defects Shown on 10-2 Tests in Glaucoma Suspects, Ocular Hypertensives, and Early Glaucoma

PURPOSE

To investigate the prevalence of visual field defects in glaucomatous eyes, glaucoma suspects, and ocular hypertensives with 24-2 and 10-2 visual fields.

DESIGN

Prospective, cross-sectional study.

PARTICIPANTS

Patients with or suspected glaucoma tested with 24-2 and 10-2. Patients were classified into 3 groups on the basis of the presence of glaucomatous optic neuropathy (GON) and 24-2 visual field abnormalities: early glaucoma (GON and abnormal visual field, mean deviation >-6 decibels [dB]), glaucoma suspects (GON and normal visual field), and ocular hypertensives (normal disc, normal visual field, and intraocular pressure >22 mmHg). For the classification of visual field abnormalities, 24-2 and 10-2 tests performed on the same visit were analyzed.

MAIN OUTCOME MEASURES

Comparison of the prevalence of abnormal 24-2 versus 10-2 visual field results based on cluster criteria in each diagnostic group.

RESULTS

A total of 775 eyes (497 patients) were evaluated. A total of 364 eyes had early glaucoma, 303 eyes were glaucoma suspects, and 108 eyes were ocular hypertensives. In the glaucoma group, 16 of the 26 eyes (61.5%) classified as normal based on cluster criteria on 24-2 tests were classified as abnormal on 10-2 visual fields. In eyes with suspected glaucoma, 79 of the 200 eyes (39.5%) classified as normal on the 24-2 test were classified as abnormal on 10-2 visual fields. In ocular hypertensive eyes, 28 of the 79 eyes (35.4%) classified as normal on the 24-2 were classified as abnormal on the 10-2. Patients of African descent were more likely to have an abnormal 10-2 result (67.3 vs. 56.8%, P = 0.009).

CONCLUSIONS

Central visual field damage seen on the 10-2 test is often missed with the 24-2 strategy in all groups. This finding has implications for the diagnosis of glaucoma and classification of severity.

Population screening for association of mitochondrial haplogroups BM, J, K and M with multiple sclerosis: interrelation between haplogroup J and MS in Persian patients

Background: Multiple sclerosis (MS) is an immunological inflammatory disease of the central nervous system (CNS) which is chronically observed in young adults. On the basis of earlier studies, potential relatedness between MS and mitochondrial DNA (mtDNA) mutations was postulated. Materials and methods: 246 individuals were screened using the PCR-RFLP method, including 70 MS patients examined for mitochondrial haplogroups BM, J, K and M and 176, 149 and 70 normal controls examined for haplogroups BM and M, J and K, respectively. Results and discussion: Our analysis revealed a relatively high proportion of haplogroup BM in MS patients (∼26%) compared to normal controls (∼13%). In addition, a slightly significant increase of MS patients of haplogroup J (20% in MS patients versus 9.39% in normal controls at P-0.049), while haplogroups M and K did not show contribution to MS contingency (2.85 and 2.27%, respectively at P-1.000 in haplogroup M and 12.85 and 7.14% respectively at P-0.399 in haplogroup K).

Risk Factors for Incident Open-angle Glaucoma

PURPOSE

To evaluate risk factors for definite open-angle glaucoma (OAG), based on African-descent participants of the Barbados Eye Studies.

DESIGN

Cohort study with 81% to 85% participation over 9 years' follow-up.

PARTICIPANTS

We evaluated 3222 persons at risk, 40 to 84 years old, who did not have definite OAG at baseline.

METHODS

Participants had standardized study visits at baseline and after 4 and 9 years, with structured interviews, blood pressure (BP), and other measurements. The ophthalmic protocol included automated perimetry, applanation tonometry, fundus photography, and comprehensive ophthalmologic examinations for those referred. Central corneal thickness (CCT) was measured in a subset at the 9-year examination. Incidence was estimated by the product-limit approach; relative risk ratios (RRs) with 95% confidence intervals (CIs) were based on Cox regression models with discrete time.

MAIN OUTCOME MEASURE

Nine-year incidence of definite OAG.

RESULTS

Over 9 years, 125 persons developed definite OAG (incidence, 4.4%; 95% CI, 3.7-5.2). Baseline factors influencing risk were age (RR, 1.04; 95% CI, 1.02-1.05 per year); family history of glaucoma (RR, 2.4; 95% CI, 1.3-4.6); higher intraocular pressure (IOP) (RR, 1.12; 95% CI, 1.08-1.16 per mmHg); lower systolic BP (RR, 0.91; 95% CI, 0.84-1.00 per 10 mmHg); and lower ocular systolic, diastolic, and mean perfusion pressures (RR, 0.66; 95% CI, 0.54-0.80 per 10 mmHg higher mean perfusion pressure) (RR, 2.6; 95% CI, 1.4-4.6 for low mean perfusion pressure [<40 mmHg]). Thinner CCT was also associated with OAG incidence (odds ratio, 1.41; 95% CI, 1.01-1.96 per 40 mum lower).

CONCLUSIONS

This is the first report of risk factors for long-term OAG incidence; it is also based on a sizable number of new cases. Incidence was high in this African-descent population, where the established factors of older age, higher IOP, and family history contributed to risk. Additional predictors were vascular factors, including lower systolic BP, and particularly lower ocular perfusion pressures, which more than doubled risk. Thinner CCT was also a factor. These findings indicate a multifactorial etiology of OAG and suggest that similar risk factors apply across populations. Results are relevant for understanding OAG causation and identifying groups at high risk.

Gray optic disc crescent: influence of ethnicity in a glaucoma population

PURPOSE

To evaluate the prevalence of the gray optic disc crescent within a glaucoma population and the influence of ethnicity and other variables.

PATIENTS AND METHODS

Consecutive patients of white or African American ethnicity, seen in the Glaucoma Service of Yale Eye Center, were included in the study. The 2 ethnic groups were not matched for refractive error, age, or stage of glaucoma. Stereodisc photos, suitable for detailed evaluation of disc and parapapillary features, of 1 or both eyes were selected by 1 investigator. The photos were masked to the other 2 investigators, who independently interpreted the disc and parapapillary features. The prevalence of the gray crescent in the 2 ethnic groups was compared by chi analysis. Correlation with age, sex, refractive error, intraocular pressure, and the presence and degree of glaucomatous optic neuropathy were also analyzed.

RESULTS

Of 225 patients (447 eyes), the gray crescent was seen in one or both eyes of 32 patients (14.2%), which included 21 of the 77 [27.3%, 95% confidence intervals (CI) 9.95] African Americans and 11 of the 148 (7.4%, 95% CI 4.23) whites. The difference in prevalence of the gray crescent between the 2 ethnic groups was significant (P<0.0001). The prevalence of the gray crescent did not correlate with age, sex, refractive error, intraocular pressure or the presence or degree of glaucomatous optic neuropathy.

CONCLUSIONS

The gray optic disc crescent is a common finding within a glaucoma population, especially among persons of African heritage, but does not correlate with the presence or degree of glaucomatous optic neuropathy nor other patient variables.

Awareness of Incident Open-angle Glaucoma in a Population Study

PURPOSE

To evaluate factors related to awareness of incident open-angle glaucoma (OAG) in the Barbados Eye Studies.

DESIGN

Cohort study with 81% to 85% response rate over 9 years.

PARTICIPANTS

Four thousand three hundred fourteen participants of African descent, 40 to 84 years old at baseline.

METHODS

Standardized study visits included an interview on demographic, medical, health care, and other factors; various ophthalmic measurements; fundus photography; and comprehensive ophthalmologic examinations for those referred.

MAIN OUTCOME MEASURES

Definite OAG was defined by both visual field and optic disc criteria after ophthalmologic confirmation, regardless of intraocular pressure (IOP). Definite incident participants without prior OAG diagnosis/treatment were considered unaware. Logistic regression analyses evaluated factors associated with OAG unawareness. Results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Over 9 years, 125 participants newly developed definite OAG, of whom 53% were previously unaware. At baseline, the unaware group had significantly lower mean IOP (OR, 0.86; 95% CI, 0.79-0.94) and more hyperopia (OR, 2.69; 95% CI, 1.08-6.69) than those aware. Most unaware and aware participants had > or =2 medical care visits in the previous year (72.7% vs. 83.1%). However, those in the unaware group sought eye care less frequently than those aware (last visit in preceding year, 33.4% vs. 64.4%); these visits were mainly for eyeglasses (71.4% vs. 12.5%), with most having glaucoma tests only during study visits (72.7% vs. 37.3%). The unaware group reported more visits to opticians/optometrists than to private ophthalmologists (OR, 4.20; 95% CI, 1.00-17.66) and fewer visits to a public ophthalmologic clinic (OR, 0.18; 95% CI, 0.04-0.86).

CONCLUSIONS

Over half of participants with incident OAG were unaware of their diagnosis. Unawareness was related to lower IOP, hyperopia, and eye care utilization patterns. Although persons in the unaware group had regular visits for medical care, visits for eye care and OAG testing were limited. Unawareness was 4 times more likely when opticians/optometrists were the regular eye care source, compared with private ophthalmologists, and about 80% less likely with a public ophthalmologic source. These findings highlight the high frequency of undiagnosed OAG and importance of comprehensive examinations in disease detection.

Comparison of diagnostic accuracy of Heidelberg Retina Tomograph II and Heidelberg Retina Tomograph 3 to discriminate glaucomatous and nonglaucomatous eyes

PURPOSE

To compare the diagnostic accuracy of the Moorfields regression analysis (MRA), parameters, and glaucoma probability score (GPS) from Heidelberg Retinal Tomograph (HRT) 3 (Heidelberg Engineering, Heidelberg, Germany) with MRA and parameters from HRT II in discriminating glaucomatous and healthy eyes in subjects of African and European ancestry.

DESIGN

Case-control institutional setting.

METHODS

Seventy-eight glaucoma patients (44 of African ancestry, 34 of European ancestry) and 89 age-matched controls (46 of African ancestry, 33 European ancestry), defined by visual fields and self-reported race were included. Imaging was obtained with HRT II, and data were exported to a computer with the HRT 3 software using the same contour line. Area under the receiver operating characteristic (ROC) curves (AUCs), sensitivity, and specificity were evaluated for the entire group, the African ancestry group, and the European ancestry group separately. Mean disk area was compared between correctly and incorrectly diagnosed eyes by each technique.

RESULTS

Disk, cup, and rim areas from HRT 3 were lower than HRT II (P < .0001). AUC (sensitivity at 95% specificity) was 0.85 (54%) for vertical cup-to-disk ratio (VCDR) HRT 3, 0.84 (45%) for VCDR HRT II, and 0.81 (44%) for GPS at the temporal sector. MRA HRT 3 showed greater sensitivity but lower specificity than HRT II for the entire group, the African ancestry group, and the European ancestry group. GPS classification had the lowest specificity. Glaucomatous eyes incorrectly classified by GPS had smaller mean disk area (P = .0002); control eyes incorrectly classified had greater mean disk area (P = .015).

CONCLUSIONS

VCDR from HRT 3 showed higher sensitivity than HRT II and GPS for the entire group and for those of African ancestry and of European ancestry separately. Sensitivity of MRA improved in HRT 3 with some trade-off in specificity compared with MRA of HRT II. GPS yielded erroneous classification associated to optic disk size.

Type 2 diabetes mellitus and the risk of open-angle glaucoma the Los Angeles Latino Eye Study

PURPOSE

To examine the relationship between type 2 diabetes mellitus (T2DM) and the risk of having open-angle glaucoma (OAG) in an adult Latino population.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Latinos 40 years and older (n = 5894) from 6 census tracts in Los Angeles, California.

METHODS

Participants from the Los Angeles Latino Eye Study (LALES), a large population-based study of self-identified adult Latinos, answered an interviewer-administered questionnaire and underwent a clinical and complete ocular examination, including visual field (VF) testing and stereo fundus photography. A participant was defined as having diabetes mellitus (DM) if she or he had a history of being treated for DM, the participant's glycosylated hemoglobin was measured at 7.0% or higher, or the participant had random blood glucose of 200 mg% or higher. Type 2 DM was defined if the participant was 30 years or older when diagnosed with DM. Open-angle glaucoma was defined as the presence of an open angle and a glaucomatous VF abnormality and/or evidence of glaucomatous optic disc damage in at least one eye. Logistic regression analysis was used to identify the risk of having OAG in persons with T2DM.

MAIN OUTCOME MEASURE

Prevalence of OAG.

RESULTS

Of the 5894 participants with complete data, 1157 (19.6%) had T2DM and 288 (4.9%) had OAG. The prevalence of OAG was 40% higher in participants with T2DM than in those without T2DM (age/gender/intraocular pressure-adjusted odds ratio, 1.4; 95% confidence interval, 1.03-1.8; P = 0.03). Trend analysis revealed that a longer duration of T2DM (stratified into 5-year increments) was associated with a higher prevalence of OAG (P<0.0001).

CONCLUSION

The presence of T2DM and a longer duration of T2DM were independently associated with a higher risk of having OAG in the LALES cohort. The high prevalences of T2DM and OAG and their association in this fastest growing segment of the United States population have significant implications for designing screening programs targeting Latinos.

Incident open-angle glaucoma and intraocular pressure

PURPOSE

To evaluate the role of baseline intraocular pressure (b-IOP) as a risk factor for incident open-angle glaucoma (OAG) in participants of African origin from the Barbados Eye Studies.

DESIGN

Population-based 9-year cohort study.

PARTICIPANTS

Three thousand two hundred twenty-two persons examined during the study period who were free of glaucoma at baseline and at risk of developing OAG during the 9-year follow-up.

METHODS

Study protocols were standardized and included ophthalmic and other measurements, automated perimetry, applanation tonometry, fundus photography, and comprehensive ophthalmologic examination for those referred. The product-limit approach was used to estimate incidence. Relationships between b-IOP and incidence were evaluated by adjusted relative risk ratios (RRs) with 95% confidence intervals (CIs), based on Cox regression models.

MAIN OUTCOME MEASURE

The 9-year incidence of OAG was based on both visual field and optic disc abnormalities, with ophthalmologic evaluations to exclude other possible causes.

RESULTS

The overall 9-year incidence of OAG was 4.4% (95% CI, 3.7%-5.2%), and the mean (standard deviation) b-IOP among persons at risk was 18.0 mmHg (4.1). Among the 125 incident OAG cases, the mean b-IOP was 21.9 mmHg and 46% had b-IOP of >21 mmHg. In contrast, the nonincident group had a mean b-IOP of 17.8 mmHg and only 12% had b-IOP of >21 mmHg. Overall, OAG risk increased by 12% with each 1-mmHg increase in IOP (RR, 1.12; 95% CI, 1.08-1.16). Incidence steadily increased from 1.8% (95% CI, 1.2%-2.7%) for persons with b-IOP of < or =17 mmHg (referent group) to 22.3% (95% CI, 15.8%-31.1%) for those with b-IOP > 25 mmHg, resulting in an adjusted RR of 13.1 (95% CI, 7.1-24.1) among the latter group. The attributable risk for IOP of >25 mmHg was 19%. Using 21 mmHg as a cutoff, the RR was 7.9 (95% CI, 3.8-16.2) and the attributable risk was 37%.

CONCLUSIONS

After 9 years' follow-up, the risk of OAG was positively related to IOP levels at baseline. Although persons with b-IOP of >25 mmHg had a 13-fold RR of developing OAG, most cases arose with lower b-IOP. This study thus confirms the role of IOP as an influential risk factor, yet at the same time underscores its limitations in predicting OAG.

American Chinese Glaucoma Imaging Study: A Comparison of the Optic Disc and Retinal Nerve Fiber Layer in Detecting Glaucomatous Damage

PURPOSE

To compare the relationships between optic nerve structural measures and visual function, as well as the diagnostic sensitivity for glaucoma detection between the retinal nerve fiber layer (RNFL) and neuroretinal rim measurements.

METHODS

A total of 101 normal and 156 glaucomatous eyes of 257 enrolled subjects were examined. RNFL thickness was measured by optical coherence tomography, and the neuroretinal rim (rim area, rim/disc area, and rim volume) was measured with a confocal scanning laser ophthalmoscope. The relationship between the structural measures and visual field sensitivity was evaluated with linear and non-linear-regression (quadratic and logarithmic) models. The coefficient of determination (R2) was calculated, and the regression models were compared with Alkaike's information criteria and the F test. The diagnostic sensitivity for glaucoma detection in each structural measure was determined by the area under the receiver operating characteristic curve (AUC).

RESULTS

The relationship of the RNFL, rim area, rim/disc area, and rim volume with visual function was best described with nonlinear regression models (quadratic regression for the RNFL [R2 = 0.383]), rim area [R2 = 0.303]), and rim/disc area [R2 = 0.265]; and logarithmic regression for rim volume [R2 = 0.175]). The change of visual sensitivity at each level of structural damage was highest for the RNFL. The AUC for the RNFL also was higher than the neuroretinal rim measures. In this study population, at 90% specificity, the diagnostic sensitivities for detecting glaucomatous damage was 82.7%, 67.3%, 67.3%, and 52.6% for the RNFL, rim area, rim/disc area, and rim volume, respectively. (These values would apply only to a group with inclusion criteria and disease severity similar to those of the present cohort.)

CONCLUSIONS

The RNFL showed a stronger structure-function association and a higher diagnostic sensitivity for glaucoma detection than did the neuroretinal rim.

Is the ISNT rule violated in early primary open-angle glaucoma—a scanning laser tomography study

AIMS

To evaluate the relevance of the ISNT rule with reference to the optic nerve head, in differentiating normal and early glaucoma eyes and neuroretinal rim (NRR) area ratios as measures of glaucomatous optic neuropathy by confocal scanning laser ophthalmoscopy (Heidelberg retina tomography (HRT) II).

METHODS

The study included 136 control eyes and 63 eyes of early primary open-angle glaucoma. Each patient underwent a complete ophthalmic examination, HRT II (software 2.01) and achromatic automated perimetry using the Humphrey field analyzer Full threshold program 30-2 or 24-2. Topographic HRT parameters (disc area and rim area) were compared between the groups. To assess the statistical significance of differences between the study groups, the Student's t-test was used.

RESULTS

The ISNT rule was applicable in 71% of normal eyes and 68% of early glaucoma eyes. The superior to inferior area ratio was 0.96+/-0.01 in the normal group and 0.90+/-0.02 in the glaucoma group. There was a loss of approximately a quarter of the NRR in the inferotemporal and superotemporal quadrants. The inferonasal sector showed the least loss of NRR (4.34%).

CONCLUSION

The inferior NRR is marginally wider than the superior NRR in about 2/3 of normal eyes, but could not be clinically appreciated in many of these. The characteristic configuration of a normal optic disc with the rim width being greatest in the inferior disc region followed by the superior disc region was maintained even in most patients with early glaucoma.

Rule Extraction for Glaucoma Detection with Summary Data from StratusOCT

PURPOSE

To extract and induce rules of association for differentiating between normal and glaucomatous eyes based on the quantitative assessment of summary data reports from the StratusOCT (optical coherence tomography; Carl Zeiss Meditec, Inc., Dublin, CA) in a Taiwan Chinese population.

METHODS

One randomly selected eye of each of the 64 patients with glaucoma and each of the 71 normal subjects was included in the study. Measurements of glaucoma variables (retinal nerve fiber layer thickness and optic nerve head analysis results) were obtained with the StratusOCT. A self-organizing map and decision tree were applied to extract features and determine rules of association for glaucoma detection.

RESULTS

The average visual field mean deviation was -0.55 +/- 0.57 dB in the normal group and -4.30 +/- 3.32 dB in the glaucoma group. Vertical cup-to-disc (C/D) ratio and inferior quadrant thickness were extracted from the decision tree, and three association rules were determined for glaucoma detection.

CONCLUSIONS

The precise rules of association induced by a novel application of the decision tree may enhance glaucoma detection.

Assessment of a race-specific normative HRT-III database to differentiate glaucomatous from normal eyes

PURPOSE

To determine if a new, normative, race-specific database enhances the ability of confocal scanning laser ophthalmoscopy to differentiate normal from glaucomatous eyes.

METHODS

One eye of eligible normal and glaucoma patients was enrolled. All subjects underwent a complete ophthalmologic examination, standard achromatic perimetry (SITA-SAP, 24-2), and confocal scanning laser ophthalmoscopy [Heidelberg retinal tomograph (HRT-II)] within 1 month of enrollment. Racial groups were defined by self-report. Glaucoma was defined by the existence of reproducible SAP loss (pattern standard deviation <5% and/or Glaucoma Hemifield Test outside normal limits) on 2 consecutive fields. Normal subjects had 2 normal visual fields (pattern standard deviation >5% and Glaucoma Hemifield Test within 97% normal limits) and a normal clinical examination. HRT-II examinations were exported to the HRT-III software, which includes a large race-specific normative database consisting of 733 white and 215 black eyes. Moorfields regression analysis (MRA) for the most abnormal optic disc sector was compared between the HRT-II (MRA2) and the HRT-III software before (MRA3-B) and after (MRA3-A) adjustment for race. Sectors outside the 99.9% confidence interval limits ("outside normal limits") were determined to be abnormal.

RESULTS

We enrolled 124 black (52 glaucoma, 72 normal) and 96 white (32 glaucoma, 64 normal) subjects. Mean age was 51+/-13 years and 50+/-16 years for blacks and whites, respectively (P = 0.45). Visual field mean deviation was -7.3+/-6.7 db for glaucomatous eyes and -0.4+/-1.1 db for normal eyes (P < 0.001). Sensitivity and specificity for the HRT-II was 71.9% and 95.3%, respectively, for white subjects and 50.0% and 98.6%, respectively, for black subjects. Using the expanded HRT-III database, analysis yielded a sensitivity of 81.3% and specificity of 93.8% for whites and a sensitivity of 71.2% and specificity of 86.1% for blacks. After an adjustment for black ethnicity was made in the HRT-III program, the sensitivity and specificity for blacks was 65.4% and 90.3%, respectively.

CONCLUSIONS

A new, larger, race-specific HRT-III database increases sensitivity while maintaining specificity for whites and increases sensitivity but decreases specificity for blacks. New software and databases based on race require careful scrutiny before use in clinical practice.

Glaucoma Screening in a High-risk Population

PURPOSE

To evaluate a screening protocol for detection of individuals with a higher risk of chronic open angle glaucoma for which a complete glaucoma evaluation is indicated.

PATIENTS AND METHODS

African Americans over 40 years of age in New Haven, CT. In the screening phase, volunteers filled out a questionnaire and underwent measurements of visual acuity, intraocular pressure (IOP) with a Tono-Pen and visual field with Frequency Doubling Technology. Participants were categorized into "glaucoma likely" or "unlikely," but all were encouraged to follow up with a free complete glaucoma exam, which included applanation tonometry, pachymetry, visual fields with a Humphrey Visual Field Analyzer, gonioscopy, and fundoscopy. Based on the latter exam, patients were categorized into "glaucoma likely" (suspects and confirmed glaucoma) or "unlikely" groups.

RESULTS

One hundred eighty-four subjects completed both phases of the study and 76 of 93 patients (82%) who were classified as "glaucoma likely" in the final exam, were also classified as "glaucoma likely" in the screening. Adjusted analysis revealed family history of glaucoma in first degree relatives and screening IOP > 21 mm Hg to have statistically significant associations with the final impression of "glaucoma likely." A combination of these findings gave an overall sensitivity of 81.7% with a specificity of 55%.

CONCLUSIONS

In the study population, the combination of an IOP > 21 mm Hg and history of glaucoma in a first degree relative allowed the identification of a significant percentage of individuals with a higher risk of chronic open angle glaucoma, for which a complete glaucoma examination is indicated.

The ISNT Rule and Differentiation of Normal From Glaucomatous Eyes

OBJECTIVE

To determine whether the ISNT rule (that normal eyes show a characteristic configuration for disc rim thickness of inferior > or = superior > or = nasal > or = temporal), widely used for clinical evaluation of the optic nerve head, can differentiate normal from glaucomatous eyes.

METHODS

All subjects underwent complete eye examination, including achromatic automated perimetry, simultaneous stereoscopic disc photography, and confocal scanning laser ophthalmoscopy. Subjects with normal eyes had no evidence of glaucoma or ocular hypertension and had normal perimetry measurements. Subjects with glaucoma had a reproducible visual field defect. One eye from each subject was randomly enrolled. The ISNT rule was assessed by masked evaluation of disc photographs at the 3, 6, 9, and 12 o'clock positions.

RESULTS

Sixty-six subjects with normal eyes (33 black and 33 white individuals) and 43 with open-angle glaucoma (15 black and 28 white individuals) were enrolled. The ISNT rule was intact in 52 (79%) of 66 normal eyes and 12 (28%) of 43 glaucomatous eyes (P<.001). Multiple logistic regression indicated that the odds ratio for glaucoma associated with violation of the ISNT rule was 6.04 (95% confidence interval, 1.74-20.95) after adjustment for age; race was not a confounder of this association.

CONCLUSION

The ISNT rule is useful in differentiating normal from glaucomatous optic nerves and is unaffected by race.

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.

Iris colour, optic disc dimensions, degree and progression of glaucomatous optic nerve damage

PURPOSE

To evaluate whether iris colour influences size and shape of the optic nerve head and risk for glaucoma progression.

METHODS

The hospital-based observational study included 1973 eyes of 1012 Caucasian subjects with ocular hypertension or chronic open-angle glaucoma. For all patients, colour stereo optic disc photographs were evaluated, and corneal pachymetry and achromatic perimetry were performed. Main outcome measures were optic nerve head parameters, the development or progression of visual field defects and iris colour.

RESULTS

In most of the study groups, size of the optic disc, neuroretinal rim, alpha zone and beta zone of parapapillary atrophy, retinal vessel diameter and central corneal thickness did not differ significantly between eyes with blue, green, brown and mixed iris colour. In the normal-pressure glaucoma group, neuroretinal rim area was smallest in the population with mixed-coloured eyes and largest in the group of eyes with brown irides (P = 0.001 after correction for inter-eye dependency and multiple testing). For the ocular hypertensive subjects and glaucoma patients with follow-up examinations, the rate of development or progression of glaucomatous visual field loss was not significantly associated with iris colour (P = 0.060).

CONCLUSIONS

In Caucasian subjects, iris colour does not have a major association with the size of the optic nerve head structures, central corneal thickness and retinal arterial diameter. In Caucasian patients with ocular hypertension or chronic open-angle glaucoma, an influence of iris colour on the risk for development or progression of glaucomatous visual field defects could not be confirmed.

Discrimination between normal and glaucomatous eyes using Stratus optical coherence tomography in Taiwan Chinese subjects

BACKGROUND

We differentiated between normal and glaucomatous eyes in the Taiwan Chinese population based solely on the quantitative assessment of summary data reports from Stratus optical coherence tomography (OCT) by comparing their area under the receiver operating characteristic (ROC) curve.

METHODS

One randomly selected eye from each of the 62 patients with early glaucomatous damage (mean deviation -2.8 +/- 1.8 dB) and from each of the 62 age- and sex-matched normal individuals were included in the study. Measurements of glaucoma variables (retinal nerve fiber layer thickness and optic nerve head analysis results) were obtained by Stratus OCT. Twenty-one OCT parameters were included in a linear discriminant analysis (LDA) using forward selection and backward elimination to determine the best combination of parameters for discriminating between glaucomatous and healthy eyes based on ROC curve area.

RESULTS

The average RNFL thickness was the best individual parameter for differentiating between normal eyes and glaucomatous eyes (ROC curve area 0.793). The maximum area under the ROC curve of six input parameters (average RNFL thickness; 10, 11, and 12 o'clock segment thicknesses; cup area; and vertical integrated rim area) generated by the forward selection method was 0.881. Whereas the maximum area under the ROC curve of 15 input parameters (average RNFL thickness; 1, 3, 4, 6, 8-10, 12 o'clock segment thicknesses; vertical integrated rim area; horizontal integrated rim area; disc area; cup to disc area ratio; cup to disc horizontal ratio; and cup to disc vertical ratio) generated by backward elimination method was 0.929.

CONCLUSIONS

The performance of individual parameters obtained from Stratus OCT is fairly reliable for differentiating the early glaucomatous eyes from normal eyes. However, the discriminant power increases when LDA with forward selection and backward elimination methods is applied.

Anterior Chamber Depth and the Risk of Primary Angle Closure in 2 East Asian Populations

OBJECTIVE

To evaluate the risk of peripheral anterior synechiae (PAS) and glaucomatous optic neuropathy attributable to primary angle closure at varying anterior chamber depths (ACDs) in two East Asian populations.

METHODS

Participants 40 years and older were from 2 population-based glaucoma surveys in Mongolia and Singapore. Central ACD was measured by optical pachymetry. Presence of PAS was determined by dynamic gonioscopy. Cases with secondary PAS were excluded. Glaucomatous optic neuropathy was diagnosed in subjects with structural and functional evidence of glaucoma.

RESULTS

A total of 2032 subjects, consisting of 942 Mongolians and 1090 Chinese Singaporeans, were included in this study. A logistic model of the relationship between ACD and PAS among Singaporeans showed a consistent, incremental increase in PAS across the entire range of ACD. In deeper anterior chambers the rate of PAS exceeded that seen in Mongolians. In Mongolians, there was a clear threshold for ACD (2.4 mm) at or above which PAS were very uncommon. With ACD less than 2.4 mm, the rate of PAS rose rapidly to overtake that seen in Singaporeans.

CONCLUSIONS

Shallow anterior chambers are a significant risk factor for angle closure in East Asians, although the nature of the association is specific to the individual population. There was a trend toward higher rates of glaucomatous optic neuropathy in people with the shallowest anterior chambers.

Clinical characteristics of African Americans vs Caucasian Americans with multiple sclerosis

BACKGROUND

African American (AA) individuals are thought to develop multiple sclerosis (MS) less frequently than Caucasian American (CA) individuals.

OBJECTIVE

To compare the clinical characteristics of AA and CA patients with MS.

METHODS

The clinical features of MS were compared in a large retrospective cohort of AA (n = 375) and CA (n = 427) subjects.

RESULTS

The proportion of women to men was similar in AA and CA subjects (81% [AA] vs 77% [CA]; p = 0.122). There were no differences in the proportions of subjects with relapsing-remitting, secondary progressive, primary progressive, and progressive relapsing MS. The median time to diagnosis was 1 year after symptom onset in AA subjects and 2 years after symptom onset in CA subjects (p = 0.0013). The age at onset was approximately 2.5 years later in AA than CA subjects (33.7 vs 31.1 years; p = 0.0001). AA subjects presented with multisite signs and symptoms at disease onset more often than CA subjects (p = 0.018). Clinical involvement restricted to the optic nerves and spinal cord (opticospinal MS) occurred in 16.8% of AA patients compared with 7.9% of CA patients (p < 0.001). Transverse myelitis also occurred more frequently in AA subjects (28 vs 18%; p = 0.001). Survival analysis revealed that AA subjects were at higher risk for development of ambulatory disability than CA subjects. After adjusting for baseline variations and differences in therapeutic interventions, AAs were at 1.67-fold greater risk for requiring a cane to ambulate than CA patients (p < 0.001). There was a trend suggesting that AAs were also at greater risk for development of wheelchair dependency (p = 0.099). Adjusted Cox proportional hazard models showed that this effect was in part attributable to the older age at onset in AAs (p < 0.001).

CONCLUSIONS

Compared with multiple sclerosis (MS) in Caucasian Americans, African American patients with MS have a greater likelihood of developing opticospinal MS and transverse myelitis and have a more aggressive disease course.

Ethnic variability of the vasculature of the optic disc in normal and in glaucomatous eyes

PURPOSE

Although disc pallor is associated with glaucoma, the structural macro-anatomy of the disc vasculature has received little attention, and possible ethnic differences have not been considered. Accordingly we studied the distribution of blood vessels crossing the rim of the optic disc.

METHODS

Thirty normal controls, and 50 glaucomatous cases with a unilaterally impaired visual field were studied. The sample populations included white Caucasian, and African and Afro/Caribbean volunteers. A b/w photographic method of imaging the blood vessels crossing the rim of the optic disc was used, the illuminant being green. The prints used in the analysis had been masked during their exposure to enhance contrast. The numbers of vessels, grouped into large (approximately 60nm), medium (approximately 30nm), and small (approximately 10nm) lumina, were counted, the disc images being divided radially into eight equal sectors.

RESULTS

While the large vessels crossed the rim mainly along the vertical, the small ones did so mainly in the horizontal. The distribution of the medium vessels was unpolarized but their crossings predominated on the nasal side. The vessel patterns differed significantly between the two ethnic groups as regards both number and distribution along the rim of the disc, the smaller vessels being more numerous in Caucasian eyes (p approximately 0.02). Rim crossings by vessels were smaller in glaucomatous eyes in both ethnic groups. In normal eyes there was a statistically significant age-related decline in the number of small vessels after the age of 20 years.

CONCLUSIONS

There exists a statistically significant inverse relation between the number of capillaries crossing the disc rim and the vertical cup/disc ratio. Caucasian rims show the larger number of capillaries crossing.

Visual field loss from primary angle-closure glaucoma: a comparative study of symptomatic and asymptomatic disease

PURPOSE

To assess the degree of visual field (VF) loss in subjects diagnosed with primary angle-closure glaucoma (PACG), and to compare the severity of such loss between those with symptomatic and asymptomatic disease.

DESIGN

Observational case series.

PARTICIPANTS

Seventy-six consecutive subjects with PACG who presented at a Singapore hospital.

METHODS

Primary angle-closure glaucoma was defined as the presence of glaucomatous optic neuropathy and compatible VF loss associated with closed angles. There were 2 groups of subjects studied: group A consisted of those who presented with acute symptomatic angle closure, and group B consisted of those who were asymptomatic. Subjects underwent static automated threshold perimetry, and the first reliable VF was analyzed using the Advanced Glaucoma Intervention Study (AGIS) scoring system. The field tests were graded according to severity as mild, moderate, severe, and end-stage VF defects, based on AGIS scores of 0 to 5, 6 to 11, 12 to 17, and 18 to 20 respectively.

MAIN OUTCOME MEASURES

Advanced Glaucoma Intervention Study scores of the first reliable threshold VF test.

RESULTS

The mean age of study subjects was 61.4+/-9.6 years (range: 33-84), and the majority of subjects were female (59%) and Chinese (91%). In group A (n = 40), most eyes had mild or moderate VF defects (23 eyes [57.5%]), whereas 7 eyes (17.5%) had end-stage defects. This was in contrast to group B (n = 36), in which the majority of eyes had end-stage VF loss (19 eyes [52.8%]), with only 5 eyes (13.7%) having mild VF defects. Mean AGIS scores were 9.1+/-7.6 for group A and 14.2+/-6.9 for group B (P = 0.004). Cup-to-disc ratio was a significant predictor for VF loss, but age, gender, and level of presenting intraocular pressure were not correlated with VF outcome.

CONCLUSIONS

Eyes with asymptomatic PACG often present with severe to end-stage VF loss at the time of first presentation to hospital. In contrast, most PACG eyes with previous symptomatic angle closure present with mild or moderate VF defects. The visual morbidity of PACG may be related to the finding that the asymptomatic form of the disease is visually destructive.

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.

Racial differences in optic disc topography: baseline results from the confocal scanning laser ophthalmoscopy ancillary study to the ocular hypertension treatment study

OBJECTIVE

To examine racial differences in optic disc topography among ocular hypertensive participants in the Ocular Hypertension Treatment Study.

METHODS

Four hundred thirty-nine participants from 7 Ocular Hypertension Treatment Study centers who had good-quality baseline images obtained using a quantitative 3-dimensional confocal scanning laser ophthalmoscope, the Heidelberg Retina Tomograph (Heidelberg Engineering, Dossenheim, Germany), were included in this study. The first 10 degrees- or 15 degrees-field of view mean topographic image acquired was included in all analyses. Differences in Heidelberg Retina Tomograph topographic optic disc parameter measurements by self-identified race were assessed using a mixed-effects linear model to control for confounders and for the use of both eyes in the model.

RESULTS

By self-attribution, 74 (17%) of the 439 participants were of African origin, 329 (75%) were white, 24 (5%) were Hispanic, and 12 (3%) were Native American, Native Alaskan, Asian, Pacific Islander, or unknown. The African American participants had statistically significantly (P<.001) larger mean (SD) optic disc areas than the other participants, 2.17 (0.41) mm(2) vs 1.87 (0.38) mm(2), respectively. African American participants had a larger cup area, cup volume, cup depth, neuroretinal rim area, rim volume, and smaller rim-optic disc area ratios than the other participants. No difference between African American and the other participants was found for cup shape and retinal nerve fiber layer thickness. After controlling for optic disc area, none of the differences between African American and the other participants found in the univariate analysis remained statistically significant (P>.10).

CONCLUSIONS

This study demonstrated in a large cohort of subjects with ocular hypertension, that African Americans have significantly larger optic discs, optic cups, neuroretinal rims, and cup-disc ratios than other racial groups. Furthermore, this study found that differences in topographic optic disc parameters between African Americans with ocular hypertension and other racial groups are largely explained by the larger optic disc area in the African Americans. These results highlight the need to consider race and optic disc size when evaluating the appearance of the optic disc in glaucoma.

Ability of Scanning Laser Polarimetry (GDx) to Discriminate among Early Glaucomatous, Ocular Hypertensive and Normal Eyes in the Korean Population

We investigated the ability of the GDx-Nerve Fiber Analyzer (NFA) to discriminate between normal and early glaucomatous eyes among Korean individuals by reviewing the medical records of 217 consecutive subjects: 61 early glaucoma patients, 68 ocular hypertensive patients, and 88 normal subjects. GDx parameters were compared using ANOVA. The Receiver Operating Characteristics (ROC) curve for each GDx-NFA variable was used to diagnose each parameter, and Pearson correlation coefficients were calculated to assess the association between GDx-NFA parameters and visual field indices in early glaucoma. The best GDx parameters to discriminate between early glaucomatous and normal subjects were the number, maximum modulation, ellipse modulation and inferior ratio (i.e. area under the ROC curve > 0.8). A value for the Number of equal to or greater than 27 was optimal for detecting early glaucoma, with a sensitivity of 80.3% and specificity of 80.7%. In addition, symmetry was positively correlated with the corrected pattern standard deviation (CPSD) among visual field indices in early glaucoma.

Determinants of intraocular pressure and its association with glaucomatous optic neuropathy in Chinese Singaporeans: the Tanjong Pagar Study

PURPOSE

To examine the relationship between intraocular pressure (IOP), anthropomorphic, demographic, socioeconomic, systemic, and ocular factors and glaucomatous optic neuropathy (GON) in Chinese people.

METHODS

Chinese people (n = 2000), aged 40 to 79 years, were selected from the Singapore electoral register. Of the 1717 considered eligible for examination, 1232 participated, representing a response rate of 71.8%. IOP was estimated with Goldmann applanation tonometry. The drainage angle was assessed with static and dynamic gonioscopy. The optic nerve was examined at high magnification through a dilated pupil with a fundus contact lens or a +78-D lens. Static automated visual field testing was performed on subjects with suspected glaucoma. GON was diagnosed on the basis of structural and functional abnormalities of the optic nerve.

RESULTS

The main independent determinants of higher IOP were higher systolic blood pressure (P < 0.001), quadrants of any peripheral anterior synechiae (PAS, P = 0.02) and width of the drainage angle (P = 0.049). A 100- micro m increase in corneal thickness was associated with an increase in mean IOP of 1.5 to 1.8 mm Hg (P < 0.001). Odds of GON increased 1.2 times per 1-mm Hg increase in screening IOP. A clear association between corneal thickness and GON was not identified.

CONCLUSIONS

Clinical IOP estimates are related to systolic blood pressure and corneal thickness. Variation in IOP with angle width may suggest that trabecular compaction significantly contributes to causes of the increase in IOP, independent of angle-closure. GON is an IOP-related phenomenon among Chinese Singaporeans.

Chronic angle-closure with glaucomatous damage: long-term clinical course in a North American population and comparison with an Asian population

PURPOSE

To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients.

DESIGN

A retrospective, interventional case-control study series.

PARTICIPANTS

Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI).

METHODS

The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period.

MAIN OUTCOME MEASURES

The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy.

RESULTS

The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery.

CONCLUSIONS

Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.

Neuro-ophthalmological manifestations of systemic lupus erythematosus in Asian patients

PURPOSE

To report eight patients with diagnosed systemic lupus erythematosus (SLE) who presented with a variety of neuro-ophthalmological complications and outcomes.

METHODS

A review of the follow up, subsequent management and outcomes of the neuro-ophthalmological complications of eight patients with SLE.

RESULTS

The patients presented with a myriad of symptoms of varying severities. The most common manifestations were that of optic neuropathy and eye movement abnormalities. The outcome was variable ranging from complete recovery to optic atrophy with navigational visual acuity. Treatment was often empirical, although early treatment with corticosteroids has been tried with varying success,

CONCLUSIONS

The pathophysiology in the neuro-ophthalmological manifestations of SLE is thought be due to vaso-occlusive disease of the small vessels of the nerve and brain, secondary to an autoimmune process. Ophthalmologists may need to consider the diagnosis of SLE in young women who present with a recent onset of neuro-ophthalmological symptoms and signs.

Optic-spinal form of multiple sclerosis and immune-mediated myelopathy in Japan

Optic-spinal form of multiple sclerosis (OS-MS) and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) are two immune-mediated myelopathy relatively common in Japan. (1) Transverse myelitis, once seen in 60% of MS, mostly OS-MS, 30 years ago, drastically decreased (5%) recently in Japan. In contrast, frequency of conventional form of MS (C-MS) increased during this period of time. But unlike C-MS in white patients, cerebellar hemispheric lesions are uncommon in Japanese C-MS. These findings emphasize influence of changes in exogenous factors on manifestations of MS and distinct genetic factors related to MS in Japanese and white patients. (2) To clarify the reason of high HTLV-I proviral load in HAM/TSP, we studied cellular immune surveillance against HTLV-I and found that significant cytotoxic T lymphocyte activity, and suppressed natural killer activity and antibody-dependent cell-mediated cytotoxicity in the patients. These altered immune surveillance may be associated with the spread of HTLV-I infection and the pathogenesis of HAM/TSP.

Incidence of open-angle glaucoma: the Barbados Eye Studies. The Barbados Eye Studies Group

OBJECTIVE

To measure the 4-year risk of open-angle glaucoma (OAG) in a black population.

DESIGN

Population-based cohort study with 4 years of follow-up.

SETTING

Simple random sample of residents of Barbados, West Indies, aged 40 years or older.

PARTICIPANTS

A total of 3427 members of the cohort (85% of those eligible).

MAIN OUTCOME MEASURE

Development of glaucoma visual field defects and optic disc damage, confirmed by automated perimetry, independent fundus photographic gradings, and standardized ophthalmologic examinations.

RESULTS

The 4-year risk of OAG in black participants was 2.2% (95% confidence interval, 1.7%-2.8%), based on 67 newly developed cases of OAG. Incidence rates increased from 1.2% at ages 40 to 49 years to 4.2% at ages of 70 years or more, tending to be higher in men than women (2.7% vs 1.9%). About half of the incident cases were undiagnosed previously, and the rest were receiving OAG treatment. Of the 67 new cases of OAG, 32 had intraocular pressure of 21 mm Hg or less at baseline (1.2% incidence) and 35 had higher pressures (9% incidence). Risk was highest among persons classified as having suspect OAG at baseline (26.1%), followed by those with ocular hypertension (4.9%) and lowest in the remaining population (0.8%).

CONCLUSIONS

This longitudinal study provides new information on OAG risk, as well as the first incidence measurement in a black population. Although intraocular pressure increased risk, about half of the new cases had baseline pressures of 21 mm Hg or less. Results substantiate the high OAG risk in the population of African origin, especially in older adults; the relative role of intraocular pressure; and the considerable underdetection of new disease after 4 years of follow-up.

The Ocular Hypertension Treatment Study: design and baseline description of the participants

BACKGROUND

The Ocular Hypertension Treatment Study (OHTS) seeks to evaluate the safety and efficacy of topical ocular hypotensive medication in preventing or delaying the onset of visual field loss and/or optic nerve damage in subjects with ocular hypertension at moderate risk for developing primary open angle glaucoma.

OBJECTIVE

To describe the study protocol, the questions to be answered, and the baseline characteristics of the subjects.

DESIGN

Multicenter randomized clinical trial with 2 groups: topical ocular hypotensive medication and close observation.

SETTING

Subjects were enrolled and evaluated at 22 participating clinical centers. Visual fields and stereoscopic optic disc photographs were read in masked fashion.

METHODS

We determined eligibility from a comprehensive eye examination, medical and ocular history, visual field testing, and stereoscopic optic disc photography.

RESULTS

We describe the baseline characteristics of 1637 subjects randomized between February 28, 1994, and October 31, 1996. The mean age was 55 years; 56.9% of the subjects were women; and 25% were African American. The baseline intraocular pressure was 24.9 +/- 2.7 mm Hg (mean +/- SD). Systemic diseases and conditions reported by subjects included previous use of medication for ocular hypertension, 37%; systemic hypertension, 38%; cardiovascular disease, 6%; diabetes mellitus, 12%; and family history of glaucoma, 44%. The mean horizontal cup-disc ratio by contour estimated from stereophotography was 0.36 +/- 0.18. Qualifying Humphrey 30-2 visual fields had to be normal and reliable for entry into the study. Health-related quality of life (36-item short form health survey) scores in the OHTS sample were better than the age- and sex-matched population norms. African American subjects had larger baseline cup-disc ratios and higher reported rates of elevated blood pressure and diabetes than the rest of the subjects.

CONCLUSIONS

The intraocular pressure among enrolled subjects was sufficiently high to provide an adequate test of the potential benefit of ocular hypotensive medication in preventing or delaying glaucomatous damage. The large number of African American subjects enrolled should provide a good estimate of the African American response to topical medication.