Central Corneal Thickness in the Ocular Hypertension Treatment Study (OHTS).

OBJECTIVE: Central corneal thickness influences intraocular pressure (IOP) measurement. We examined the central corneal thickness of subjects in the Ocular Hypertension Treatment Study (OHTS) and determined if central corneal thickness is related to race. DESIGN: Cross-sectional study. PARTICIPANTS: One thousand three hundred one OHTS subjects with central corneal thickness measurements. INTERVENTION: Central corneal thickness was determined with ultrasonic pachymeters of the same make and model at all clinical sites of the OHTS. MAIN OUTCOME MEASURES: Correlation of mean central corneal thickness with race, baseline IOP, refraction, age, gender, systemic hypertension, and diabetes. RESULTS: Mean central corneal thickness was 573.0 ± 39.0 µm. Twenty-four percent of the OHTS subjects had central corneal thickness > 600 µm. Mean central corneal thickness for African American subjects (555.7 ± 40.0 µm; n = 318) was 23 µm thinner than for white subjects (579.0 ± 37.0 µm; P < 0.0001). Other factors associated with greater mean central corneal thickness were younger age, female gender, and diabetes. CONCLUSIONS: OHTS subjects have thicker corneas than the general population. African American subjects have thinner corneas than white subjects in the study. The effect of central corneal thickness may influence the accuracy of applanation tonometry in the diagnosis, screening, and management of patients with glaucoma and ocular hypertension.

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.

Central Corneal Thickness and its Associations With Ocular and Systemic Factors in an Urban West African Population.

PURPOSE: To assess the associations of central corneal thickness (CCT) with ocular and systemic factors in a West African population. DESIGN: Population-based cross-sectional study. METHODS: Participants aged ≥40 years in the Tema Eye Survey who had clinically normal corneas were included in this study. CCT was determined bilaterally using handheld ultrasound pachymetry. The association between CCT and ocular or systemic factors was analyzed with univariable linear regression. Multivariable linear regression analysis was performed for variables significantly associated with CCT in the univariable analysis. Main outcome measures were CCT (µm) and its associations with age, sex, IOP, cup-to-disc ratio (CDR), glaucoma, hypertension, and diabetes. RESULTS: A total of 6806 eligible subjects were identified, of whom 5603 (82.3%) participated in the Tema Eye Survey. A total of 4737 participants (84.5% of participants) of West African descent and clinically normal corneas were included. The mean age ± standard deviation (SD) of participants was 51.2 ± 9.7 years and 38.7% were male. The mean ± SD CCT in the population was 533.9 ± 34.0 µm. In the multivariable linear regression analysis, increased CCT was significantly associated with younger age, male sex, and higher IOP (all P < .001). There were no significant associations between CCT and CDR, glaucoma, hypertension, and diabetes. CONCLUSIONS: This population-based cross-sectional survey of West African adults found a significant association between increased CCT and younger age, male sex, and higher IOP but not glaucoma or CDR. Variations in corneal thickness may influence the accuracy of IOP measurements in African persons.

The Philadelphia Glaucoma Detection and Treatment Project: Detection Rates and Initial Management.

PURPOSE: To evaluate the detection rates of glaucoma-related diagnoses and the initial treatments received in the Philadelphia Glaucoma Detection and Treatment Project, a community-based initiative aimed at improving the detection, treatment, and follow-up care of individuals at risk for glaucoma. DESIGN: Retrospective analysis. PARTICIPANTS: A total of 1649 individuals at risk for glaucoma who were examined and treated in 43 community centers located in underserved communities of Philadelphia. METHODS: Individuals were enrolled if they were African American aged ≥50 years, were any other adult aged ≥60 years, or had a family history of glaucoma. After attending an informational glaucoma workshop, participants underwent a targeted glaucoma examination including an ocular, medical, and family history; visual acuity testing, intraocular pressure (IOP) measurement, and corneal pachymetry; slit-lamp and optic nerve examination; automated visual field testing; and fundus color photography. If indicated, treatments included selective laser trabeculoplasty (SLT), laser peripheral iridotomy (LPI), or IOP-lowering medications. Follow-up examinations were scheduled at the community sites after 4 to 6 weeks or 4 to 6 months, depending on the clinical scenario. MAIN OUTCOME MEASURES: Detection rates of glaucoma-related diagnoses and types of treatments administered. RESULTS: Of the 1649 individuals enrolled, 645 (39.1%) received a glaucoma-related diagnosis; 20.0% (n = 330) were identified as open-angle glaucoma (OAG) suspects, 9.2% (n = 151) were identified as having narrow angles (or as a primary angle closure/suspect), and 10.0% (n = 164) were diagnosed with glaucoma, including 9.0% (n = 148) with OAG and 1.0% (n = 16) with angle-closure glaucoma. Overall, 39.0% (n = 64 of 164) of those diagnosed with glaucoma were unaware of their diagnosis. A total of 196 patients (11.9%) received glaucoma-related treatment, including 84 (5.1%) who underwent LPI, 13 (0.8%) who underwent SLT, and 103 (6.2%) who were prescribed IOP-lowering medication. CONCLUSIONS: Targeting individuals at risk for glaucoma in underserved communities in Philadelphia yielded a high detection rate (39.1%) of glaucoma-related diagnoses. Providing examinations and offering treatment, including first-line laser procedures, at community-based sites providing services to older adults are effective to improve access to eye care by underserved populations.

Glaucoma Structural and Functional Progression in American and Korean Cohorts.

PURPOSE: To compare the rate of glaucoma structural and functional progression in American and Korean cohorts. DESIGN: Retrospective longitudinal study. PARTICIPANTS: Three hundred thirteen eyes from 189 glaucoma and glaucoma suspects, followed up for an average of 38 months. METHODS: All subjects were examined semiannually with visual field (VF) testing and spectral-domain optical coherence tomography. All subjects had 5 or more reliable visits. MAIN OUTCOME MEASUREMENTS: The rates of change of retinal nerve fiber layer (RNFL) thickness, cup-to-disc (C/D) ratios, and VF mean deviation (MD) were compared between the cohorts. Variables affecting the rate of change for each parameter were determined, including ethnicity, refraction, baseline age and disease severity, disease subtype (high- vs. normal-tension glaucoma), clinical diagnosis (glaucoma vs. glaucoma suspect), and the interactions between variables. RESULTS: The Korean cohort predominantly demonstrated normal-tension glaucoma, whereas the American cohort predominantly demonstrated high-tension glaucoma. Cohorts had similar VF parameters at baseline, but the Korean eyes had significantly thicker mean RNFL and larger cups. Korean glaucoma eyes showed a faster thinning of mean RNFL (mean, -0.71 µm/year vs. -0.24 µm/year; P < 0.01). There were no detectable differences in the rate of change between the glaucoma cohorts for C/D ratios and VF MD and for all parameters in glaucoma suspect eyes. Different combinations of the tested variables significantly impacted the rate of change. CONCLUSIONS: Ethnicity, baseline disease severity, disease subtype, and clinical diagnosis should be considered when comparing glaucoma progression studies.

Diagnostic Accuracy of the Spectralis and Cirrus Reference Databases in Differentiating between Healthy and Early Glaucoma Eyes.

PURPOSE: To evaluate and compare the diagnostic accuracy of global and sector analyses for detection of early visual field (VF) damage using the retinal nerve fiber layer (RNFL) reference databases of the Spectralis (Heidelberg Engineering, Heidelberg, Germany) and Cirrus (Carl Zeiss Meditec, Dublin, CA) spectral-domain optical coherence tomography (SD OCT) devices. METHODS: Healthy subjects and glaucoma suspects from the Diagnostic Innovations in Glaucoma Study (DIGS) and African Descent and Glaucoma Evaluation Study (ADAGES) with at least 2 years of follow-up were included. Global and sectoral RNFL measures were classified as within normal limits, borderline (BL), and outside normal limits (ONL) on the basis of the device reference databases. The sensitivity of ONL classification was estimated in glaucoma suspect eyes that developed repeatable VF damage. RESULTS: A total of 353 glaucoma suspect eyes and 279 healthy eyes were included. A total of 34 (9.6%) of the glaucoma suspect eyes developed VF damage. In glaucoma suspect eyes, Spectralis and Cirrus ONL classification was present in 47 eyes (13.3%) and 24 eyes (6.8%), respectively. The sensitivity of the global RNFL ONL classification among eyes that developed VF damage was 23.5% for Cirrus and 32.4% for Spectralis. The specificity of within-normal-limits global classification in healthy eyes was 100% for Cirrus and 99.6% for Spectralis. There was moderate to substantial agreement between Cirrus and Spectralis classification as ONL. CONCLUSIONS: The Spectralis and Cirrus reference databases have a high specificity for identifying healthy eyes and good agreement for detection of eyes with early glaucoma damage.

African Ancestry Is Associated with Higher Intraocular Pressure in Latinos.

PURPOSE: Intraocular pressure (IOP) is a major risk factor, as well as the only modifiable risk factor, for glaucoma. Racial differences have been observed in IOP measurements with individuals of African descent experiencing the highest IOP when compared with other ethnic groups. The purpose of this study was to examine the relationship between genetic ancestry and IOP in Latinos. DESIGN: Population-based genetic association study. PARTICIPANTS: A total of 3541 participants recruited from the Los Angeles Latino Eye Study. METHODS: Study participants were genotyped using the Illumina OmniExpress BeadChip (∼730K markers). We used STRUCTURE to estimate individual genetic ancestry. Simple and multiple linear regression, as well as quantile regression, analyses were performed to investigate the relationship between genetic ancestry and IOP. MAIN OUTCOME MEASURES: The relationship between genetic ancestry and IOP in Latinos. RESULTS: African ancestry was significantly associated with higher IOP in Latinos in our simple linear regression analysis (P = 0.002). After adjusting for age, gender, body mass index, systolic blood pressure, central corneal thickness, and type 2 diabetes, this association remained significant (P = 0.0005). The main association was modified by a significant interaction between African ancestry and hypertension (P = 0.037), with hypertensive individuals experiencing a greater increase in IOP with increasing African ancestry. CONCLUSIONS: To our knowledge, we demonstrate for the first time that African ancestry and its interaction with hypertension are associated with higher IOP in Latinos.

Low serum testosterone and increased diastolic ocular perfusion pressure: a risk for retinal microvasculature.

BACKGROUND: Low levels of testosterone in men and changes in retinal microvascular calibre are both associated with hypertension and cardiovascular disease risk. Sex hormones are also associated with blood flow in microvascular beds which might be a key intermediate mechanism in the development of hypertension. Whether a direct association between endogenous testosterone and retinal microvascular calibre exists is currently unknown. We aimed to determine whether testosterone is independently associated with ocular perfusion via a possible association with retinal vascular calibre or whether it plays only a secondary role via its effect on blood pressure in a bi-ethnic male cohort. PROBANDS AND METHODS: A total of 72 black and 81 white men (28-68 years of age) from the follow-up phase of the Sympathetic activity and Ambulatory Blood Pressure in Africans (SABPA) study were included in this sub-study. Ambulatory pulse pressure and intraocular perfusion pressures were obtained, while metabolic variables and testosterone were measured from fasting venous blood samples. Retinal vascular calibre was quantified from digital photographs using standardised protocols. RESULTS: The black men revealed a poorer cardiometabolic profile and higher pulsatile pressure (>50 mm Hg), intraocular pressure and diastolic ocular perfusion pressure than the white men (p≤0.05). Only in the white men was free testosterone positively associated with retinal calibre, i.e. arterio-venular ratio and central retinal arterial calibre and inversely with central retinal venular calibre. These associations were not found in the black men, independent of whether pulse pressure and ocular perfusion pressure were part of the model. CONCLUSIONS: These results suggest an independent, protective effect of testosterone on the retinal vasculature where an apparent vasodilatory response in the retinal resistance microvessels was observed in white men.

The African Descent and Glaucoma Evaluation Study (ADAGES): predictors of visual field damage in glaucoma suspects.

PURPOSE: To evaluate racial differences in the development of visual field (VF) damage in glaucoma suspects. DESIGN: Prospective, observational cohort study. METHODS: Six hundred thirty-six eyes from 357 glaucoma suspects with normal VF at baseline were included from the multicenter African Descent and Glaucoma Evaluation Study (ADAGES). Racial differences in the development of VF damage were examined using multivariable Cox proportional hazard models. RESULTS: Thirty one of 122 African-descent participants (25.4%) and 47 of 235 European-descent participants (20.0%) developed VF damage (P = .078). In multivariable analysis, worse baseline VF mean deviation, higher mean arterial pressure during follow-up, and a race ∗ mean intraocular pressure (IOP) interaction term were significantly associated with the development of VF damage, suggesting that racial differences in the risk of VF damage varied by IOP. At higher mean IOP levels, race was predictive of the development of VF damage even after adjusting for potentially confounding factors. At mean IOPs during follow-up of 22, 24, and 26 mm Hg, multivariable hazard ratios (95% confidence intervals) for the development of VF damage in African-descent compared to European-descent subjects were 2.03 (1.15-3.57), 2.71 (1.39-5.29), and 3.61 (1.61-8.08), respectively. However, at lower mean IOP levels (below 22 mm Hg) during follow-up, African descent was not predictive of the development of VF damage. CONCLUSION: In this cohort of glaucoma suspects with similar access to treatment, multivariate analysis revealed that at higher mean IOP during follow-up, individuals of African descent were more likely to develop VF damage than individuals of European descent.

Meta-analysis of stratus OCT glaucoma diagnostic accuracy.

PURPOSE: To evaluate the diagnostic accuracy of glaucoma in different stages, different types of glaucoma, and different ethnic groups using Stratus optical coherence tomography (OCT). METHODS: We searched MEDLINE to identify available articles on diagnostic accuracy of glaucoma published between January 2004 and December 2011. A PubMed (National Center for Biotechnology Information) search using medical subject headings and keywords was executed using the following terms: "diagnostic accuracy" or "receiver operator characteristic" or "area under curve" or "AUC" and "Stratus OCT" and "glaucoma." The search was subsequently limited to publications in English. The area under a receiver operator characteristic (AUC) curve was used to measure the diagnostic performance. A random-effects model was used to estimate the pooled AUC value of the 17 parameters (average retinal nerve fiber layer thickness, temporal quadrant, superior quadrant, nasal quadrant, inferior quadrant, and 1 to 12 o'clock). Meta-regression analysis was used to check the significance of some important factors: (1) glaucoma severity (five stages), (2) glaucoma types (four types), and (3) ethnicity (four categories). RESULTS: The orders of accuracy among those parameters were as follows: average > inferior > superior > 7 o'clock > 6 o'clock > 11 o'clock > 12 o'clock > 1 o'clock > 5 o'clock > nasal > temporal > 2 o'clock > 10 o'clock > 8 o'clock > 9 o'clock > 4 o'clock > 3 o'clock. After adjusting for the effects of age, glaucoma severity, glaucoma types, and ethnicity, the average retinal nerve fiber layer thickness provided highest accuracy compared with the other parameters of OCT. The diagnostic accuracy in Asian populations was significantly lower than that in whites and the other two ethnic types. CONCLUSIONS: Stratus OCT demonstrated good diagnostic capability in differentiating glaucomatous from normal eyes. However, we should be more cautious in applying this instrument in Asian groups in glaucoma management.

Association between rates of binocular visual field loss and vision-related quality of life in patients with glaucoma.

IMPORTANCE: It is reasonable to hypothesize that for 2 patients with similar degrees of integrated binocular visual field (BVF) loss, the patient with a history of faster disease progression will report worse vision-related quality of life (VRQOL) than the patient with slowly progressing damage. However, to our knowledge, this hypothesis has not been investigated in the literature. OBJECTIVE: To evaluate the association between binocular rates of visual field change and VRQOL in patients with glaucoma. DESIGN Observational cohort study. SETTING: Patients were recruited from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. PARTICIPANTS: The study included 796 eyes of 398 patients with diagnosed or suspected glaucoma followed up from October 1, 1998, until January 31, 2012, for a mean (SD) of 7.3 (2.0) years. MAIN OUTCOME MEASURES: The VRQOL was evaluated using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at the last follow-up visit. The NEI VFQ-25 was completed for all patients during the period extending from December 1, 2009, through January 31, 2012. Integrated BVFs were calculated from the monocular fields of each patient. Linear regression of mean deviation values was used to evaluate rates of BVF change during the follow-up period. Logistic regression models were used to investigate the association between abnormal VRQOL and rates of BVF change, while adjusting for potentially confounding socioeconomic and demographic variables. RESULTS: Thirty-two patients (8.0%) had abnormal VRQOL as determined by the results of the NEI VFQ-25. Patients with abnormal VRQOL had significantly faster rates of BVF change than those with normal VRQOL (-0.18 vs -0.06 dB/y; P < .001). Rates of BVF change were significantly associated with abnormality in VRQOL (odds ratio = 1.31 per 0.1 dB/y faster; P = .04), after adjustment for confounding variables. CONCLUSIONS AND RELEVANCE: Patients with faster rates of BVF change were at higher risk of reporting abnormal VRQOL. Assessment of rates of BVF change may provide useful information in determining risk of functional impairment in glaucoma.

Retinal vascular geometry and glaucoma: the Singapore Malay Eye Study.

PURPOSE: To determine the associations of geometric measurements (tortuosity, branching angle, and fractal dimension) of retinal vessels with glaucoma. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Persons aged 40 to 80 years who participated in the Singapore Malay Eye Study (n=3280; 78.7% response rate). METHODS: Quantitative retinal vascular parameters (tortuosity, branching angle, and fractal dimension) were measured from digital retinal fundus photographs using a computer-assisted program following a standardized grading protocol. Glaucoma was diagnosed according to the International Society of Geographic and Epidemiological Ophthalmology classification system. MAIN OUTCOME MEASURES: The associations among retinal vascular parameters with glaucoma, the main glaucoma subtype primary open-angle glaucoma (POAG), and ocular hypertension (OHT). RESULTS: A total of 123 persons (4.4% of the 2789 participants) had glaucoma in the final analysis, 87 (70.7%) of whom were diagnosed with POAG. After adjusting for age, sex, body mass index, diabetes, hypertension, smoking, axial length, and intraocular pressure (IOP), decreased retinal arteriolar tortuosity (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.38-2.18, comparing lowest vs. highest quartiles), decreased retinal venular tortuosity (OR, 1.59; 95% CI, 1.29-1.97), and narrower retinal venular branching angle (OR, 1.22; 95% CI, 1.00-1.48) were associated with glaucoma. Similar associations were found between these retinal vascular parameters and POAG. Decreased retinal vascular fractal dimension was associated with OHT (OR 1.37; 95% CI, 1.04-1.82). CONCLUSIONS: Certain features of retinal vascular geometry are associated with glaucomatous optic neuropathy independently of vascular risk factors and IOP. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Comparison of glaucoma diagnoses using Stratus and Cirrus optical coherence tomography in different glaucoma types in a Chinese population.

PURPOSE: To compare the glaucoma diagnostic power of Stratus and Cirrus optical coherence tomographies (OCTs) in a Taiwan Chinese population with different glaucoma types. PATIENTS AND METHODS: One eye each was chosen from 21 ocular hypertension (OH) patients, 27 glaucoma-suspect (GS) patients, 35 primary open-angle glaucoma (POAG) patients, 26 primary angle-closure glaucoma (PACG) patients, and 52 normal subjects. Early glaucoma (EG) was identified among glaucomatous eyes on the basis of the visual field severity (better than -9 dB). All participants were imaged using 2 OCT units at the same visit. The area under the receiver operator characteristic (AROC) curve was used to differentiate normal eyes from OH, GS, POAG, PACG, and EG eyes, and the sensitivity and specificity of each parameter from internal normative classifications were analyzed. RESULTS: For normal versus OH eyes, the best AROC value was the average thickness (Stratus, 0.693; Cirrus, 0.697). For normal versus GS eyes, the best AROC value was the average thickness (Stratus, 0.807; Cirrus, 0.776). For normal versus POAG eyes, the best AROC value was the average thickness (Stratus, 0.943; Cirrus, 0.930). For normal versus PACG eyes, the best AROC value was the 5-o'clock hour (Stratus, 0.830; Cirrus, 0.817). For normal versus EG eyes, the best AROC value was the average thickness with Stratus (0.868) and the 5-o'clock hour with Cirrus (0.876). All sensitivities in the 5 groups were fair on the basis of the internal normal classification database of both OCTs. CONCLUSIONS: Cirrus and Stratus OCTs showed equal diagnostic power in EG, OH, GS, POAG, and PACG eyes in a Taiwan Chinese population. The utility of the current internal databases of both OCT units for the Chinese population is an interesting issue that needs to be addressed in the future.

[Distribution of central corneal thickness in a melanoderm population]. / Distribution de l'épaisseur cornéenne centrale dans une population mélanoderme.

PURPOSE: To describe characteristics of central corneal thickness in a defined melanoderm population. PATIENTS AND METHODS: A retrospective study was performed on patients with and without glaucoma followed on the ophthalmology service of Tokoin teaching hospital in Lomé from January to September 2005. All subjects underwent central corneal thickness measurement by ultrasonic pachymetry between 8:00 and 11:00 am by the same operator. RESULTS: A total of 1205 subjects (609 men and 596 women) were included in the study, corresponding to 2410 eyes. The participants were 3 to 85years old. Mean central corneal thickness was 532.94±34.82µm for the entire population, 532.56±36.25µm for the right eye, 533.44±35.96µm for the left eye, 536.38±34.67µm in men and 529.41±34.64µm in women. Central corneal thickness was greater (542.94µm) in the 6- to 10-year-old group and gradually decreased after 35years. CONCLUSION: Melanoderm subjects have thinner central corneas, which may be related to the higher prevalence of ocular hypertension and glaucoma in our populations. Incorporation of corneal pachymetry with intraocular pressure measurements is essential in the early management of ocular hypertension and glaucoma, particularly in melanoderm subjects.

Variation in corneal hysteresis and central corneal thickness among black, hispanic and white subjects.

PURPOSE: To determine whether differences in corneal hysteresis (CH) and central corneal thickness (CCT) between black, Hispanic and white subjects exist independently of one another. METHODS: Retrospective, cross-sectional data were reviewed for 807 eyes of 410 patients consecutively evaluated for glaucoma. Included patients had open angles, at least one reliable 24-2 perimetric examination and no evidence of nonglaucomatous vision loss. Patients underwent CH measurement with the ocular response analyzer followed by CCT measurement and full ocular examination. Patients were asked to self-classify their race or ethnicity. Statistical analyses were performed to identify characteristics that varied between black, Hispanic and white subjects and to explain this variation. RESULTS: Of the 270 patients (511 eyes) included, 84 were black, 96 Hispanic and 90 white. There were no significant differences in diagnosis, sex, age, intraocular pressure or glaucoma severity between races/ethnicities (p ≥ 0.16). Blacks were found to have lower CCT (529.3 µm) and CH (8.7 mmHg) compared to Hispanics (544.7 µm, p = 0.008; 9.4 mmHg, p = 0.007) and whites (549.9 µm, p < 0.001; 9.8 mmHg, p < 0.001). On multivariable analysis, inter-racial/ethnic differences in CCT were not found to exist independent of CH (p ≥ 0.10), whereas the significant intergroup variation in CH remained after adjustment for CCT and other covariates (p ≤ 0.005). CONCLUSIONS: Variation in CCT between races/ethnicities does not exist independent of CH. However, significant intergroup variation in CH is present independent of CCT. This finding suggests that CH may be a preferable measurement to evaluate intergroup differences in corneal properties and their relationship to open-angle glaucoma.

Four-year incidence of open-angle glaucoma and ocular hypertension: the Los Angeles Latino Eye Study.

PURPOSE: To estimate the 4-year incidence of open-angle glaucoma (OAG) and ocular hypertension (OHT) among adult Latinos 40 years of age and older. DESIGN: Population-based longitudinal study. METHODS: Comprehensive ophthalmologic examinations including intraocular pressure, visual field testing, and stereoscopic fundus photography were performed at both baseline and the 4-year follow-up examination. Incident OAG at the 4-year follow-up examination was defined as the presence of an open angle and a glaucomatous visual field abnormality or evidence of glaucomatous optic disc damage, or both when not present at baseline. Incident OHT was defined as intraocular pressure of more than 21 mm Hg and the absence of optic disc damage or abnormal visual field results at the 4 year follow-up examination when not present at baseline. RESULTS: Among the 3939 participants (mean age, 54.7 ± 10.5 years) with complete data for a diagnosis of glaucoma at both baseline and follow-up examination, incident OAG at the 4-year follow-up was identified in 87 persons (4-year incidence rate, 2.3%; 95% confidence interval, 1.8% to 2.8%). Incident OHT at the 4-year follow-up was identified in 124 persons (4-year incidence rate, 3.5%; 95% confidence interval, 2.9% to 4.1%). In participants with OAG in 1 eye, the 4-year risk of OAG developing in the fellow eye was 5 times as high as the risk for those without OAG in either eye at baseline. In participants with OHT in 1 eye, the 4-year risk of OHT developing in the fellow eye was 10 times as high as the risk for those without OHT in either eye at baseline. The incidence rates of OAG and OHT were higher in older Latinos than in younger Latinos. CONCLUSIONS: Incidence of OAG in Latinos is higher than in non-Hispanic whites, but lower than in Afro-Caribbeans. The relatively high rate of incident OAG and OHT underscores the need for community screening programs in this fastest growing segment of the United States population.

The influence of central corneal thickness on response to topical prostaglandin analogue therapy.

OBJECTIVE: Central corneal thickness (CCT) affects intraocular pressure (IOP) readings; however, CCT influence on topical medication efficacy is unknown. We evaluated the IOP-lowering effect of topical prostaglandin analogues (PGAs) in relation to CCT. DESIGN: Post hoc analysis of a randomized prospective trial. METHOD: Subjects randomized to a PGA were followed for 24 weeks and were analyzed for relationship between CCT and IOP lowering. PARTICIPANTS: Patients with either newly diagnosed ocular hypertension or open-angle glaucoma. RESULTS: 75 subjects were enrolled. The mean age was 62.7 ± 10.5 years; 48 were Caucasian. The mean CCT was 562.4 ± 41.4 µ. At repeated measures, ANCOVA analysis showed a significant effect of both baseline IOP (p < 0.0001) and CCT (p = 0.003) on IOP. At week 12, a regression analysis of the effect of CCT on baseline IOP showed that for every 10 µ increase in CCT there was 0.3 mm Hg less IOP decrease from baseline. CONCLUSIONS: We found a statistically significantly association between a lower mean IOP and a thinner cornea when baseline IOP is controlled for. The magnitude of the relationship is small but may be clinically significant in patients with either very thin or very thick corneas.