Outcomes of iStent inject combined with cataract surgery in Asian eyes: Australian data from the Fight Glaucoma Blindness international registry

PURPOSE

To analyse real-world outcomes in Asian eyes of iStent inject, a second-generation trabecular micro-bypass stent, combined with phacoemulsification.

METHODS

This is a multi-centre, observational study of glaucomatous Asian eyes that have undergone iStent inject implantation combined with cataract surgery. Patient data were extracted from the Fight Glaucoma Blindness! Registry. Outcome measures included those of IOP reduction, glaucoma medication reduction, and adverse events including the need for secondary surgery.

RESULTS

123 eyes of 86 patients with a mean age of 68.4 ± 9.3 years underwent iStent inject implantation with phacoemulsification. At baseline, the mean ± SD preoperative intraocular pressure (IOP) was 16.0 ± 4.4 mmHg, and the mean preoperative number of topical glaucoma medications was 1.9 ± 1.4. At 12 months 30.8% of eyes demonstrated a reduction in IOP greater than 20%, the mean IOP reduction was 12.5% with an additional reduction of 0.7 glaucoma medications. 40% of eyes were using no medications at 12 months compared to 16.3% preoperatively. 8.2% of eyes required a subsequent procedure within the 12-month follow-up window.

CONCLUSION

iStent inject implantation combined with phacoemulsification in Asian eyes showed a reduction of IOP and glaucoma medication use in a real-world clinical setting. The safety profile of the device is good with minimal adverse outcomes, however, a subset of patients required secondary procedures within the 12 month follow up.

Ethnicity-Specific Database Improves the Diagnostic Ability of Peripapillary Retinal Nerve Fiber Layer Thickness to Detect Glaucoma

PURPOSE

To determine the changes in optical coherence tomography (OCT) color probability codes and diagnostic ability for peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell complex (GCC) analysis after applying Chinese and white subjects normative databases.

DESIGN

Cross-sectional study.

METHODS

This study enrolled 219 healthy eyes (108 white and 111 Chinese patients) to construct an ethnicity-specific normative database for pRNFL and macular GCC thickness, which was tested then in 180 eyes with or without glaucoma (102 white and 78 Chinese patients). The percent of change of color probability codes were evaluated after applying the original built-in and the ethnicity-specific normative databases, respectively. Sensitivity and specificity were calculated to evaluate the change in diagnostic ability to detect glaucoma.

RESULTS

Healthy white subjects had a thinner pRNFL than Chinese subjects in the overall average thickness as well as the superior, inferior, and temporal quadrants (P < .001). Macular GCC did not differ between ethnicities. After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color code labels decreased significantly for the overall average thickness in the white subjects. This resulted in a significant increase in the specificity to detect glaucoma in the white population (P < .001). No significant changes were seen when applying an ethnicity-specific normative database for macular GCC thickness.

CONCLUSIONS

After applying an ethnicity-specific normative database, the percent of pRNFL abnormal color codes decreased significantly, improving the specificity to detect glaucoma in the white population. These findings suggest there may be utility in having ethnicity-specific normative databases for pRNFL thickness.

A multiethnic genome-wide analysis of 44,039 individuals identifies 41 new loci associated with central corneal thickness

Central corneal thickness (CCT) is one of the most heritable human traits, with broad-sense heritability estimates ranging between 0.68 to 0.95. Despite the high heritability and numerous previous association studies, only 8.5% of CCT variance is currently explained. Here, we report the results of a multiethnic meta-analysis of available genome-wide association studies in which we find association between CCT and 98 genomic loci, of which 41 are novel. Among these loci, 20 were significantly associated with keratoconus, and one (RAPSN rs3740685) was significantly associated with glaucoma after Bonferroni correction. Two-sample Mendelian randomization analysis suggests that thinner CCT does not causally increase the risk of primary open-angle glaucoma. This large CCT study explains up to 14.2% of CCT variance and increases substantially our understanding of the etiology of CCT variation. This may open new avenues of investigation into human ocular traits and their relationship to the risk of vision disorders.

Associations of nutrient intakes with glaucoma among Japanese Americans

The aim of this study was to investigate possible associations of nutrient intake on glaucoma in subjects of Japanese descent living in Los Angeles, CA.In this cross-sectional study, 581 Japanese American participants in Los Angeles underwent an interview, fundus photography, comprehensive physical, and blood examinations, along with determining the body mass index status and any confounding factors. CDSketch was used to measure the cup-disc ratio and rim width of each fundus in the retinal photographs. A multivariate logistic regression test with adjustment for confounding factors was used to assess the association between glaucoma and nutrient intake.A total of 61 of 581 participants were diagnosed with glaucoma in this study. Multivariate logistic regression analysis showed that a high intake of iron (odds ratio [OR]: 1.303, P = .004), low intake of vitamin A (OR: 0.365, P = .019), and vegetable fat (OR: 0.957, P = .004) were associated with an increased risk of glaucoma.Current findings showed that high iron intake and low vitamin A and vegetable fat intake appeared to be associated with an increased risk of glaucoma in subjects of Japanese descent living in the Los Angeles populations.

Systemic Determinants of Peripapillary Vessel Density in Healthy African Americans: The African American Eye Disease Study

PURPOSE

To determine the relationship between systemic factors and radial peripapillary capillary (RPC) vessel density (VD) in healthy African American (AA) participants of the African American Eye Disease Study.

DESIGN

A population-based, cross-sectional study.

METHODS

A total of 4135 eyes from 2127 AA participants aged 40 years and older in Inglewood, California, were imaged for 6×6-mm optic disc scans on a spectral-domain optical coherence tomography angiography (OCTA) device. Of these, 1029 eyes from 1029 participants who met the inclusion and exclusion criteria were analyzed, including only 1 eye per participant. Custom software was used to quantify RPC VD. Multivariate linear regression was used to identify systemic factors associated with RPC VD with a significance level set at 0.05. The contribution of each variable to the final model was estimated with the magnitude of standardized regression coefficients (SRCs). The fit of the final model was measured by R².

RESULTS

The average RPC VD was 0.346±0.045. Controlling for signal strength, the systemic variables in the final multivariate model associated with reduced RPC VD were older age (β = -0.0123 per decade; SRC = -0.2733; P < .0001), male sex (β = -0.0067; SRC = -0.0716; P = .0060), and longer diabetes duration (β = -0.0022 per 5 years; SRC = -0.0527; P = .0427). The model R² was 0.3689.

CONCLUSIONS

Age, sex, and systemic influences, such as diabetes duration, need to be considered when assessing changes in RPC VD in glaucoma and other ocular diseases. Longitudinal studies are needed to investigate whether reduced RPC VD and the factors that affect it are associated with an increased risk of developing glaucomatous nerve damage.

Update: Incidence of Glaucoma Diagnoses, Active Component, U.S. Armed Forces, 2013-2017

Glaucoma is an eye disease that involves progressive optic nerve damage and vision loss, leading to blindness if undetected or untreated. This report describes an analysis using the Defense Medical Surveillance System to identify all active component service members with an incident diagnosis of glaucoma during the period between 2013 and 2017. The analysis identified 37,718 incident cases of glaucoma and an overall incidence rate of 5.9 cases per 1,000 person-years (p-yrs). The majority of cases (97.6%) were diagnosed at an early stage as borderline glaucoma; of these borderline cases, 2.2% progressed to open-angle glaucoma during the study period. No incident cases of absolute glaucoma, or total blindness, were identified. Rates of glaucoma were higher among non-Hispanic black (11.0 per 1,000 p-yrs), Asian/Pacific Islander (9.5), and Hispanic (6.9) service members, compared with non-Hispanic white (4.0) service members. Rates among female service members (6.6 per 1,000 p-yrs) were higher than those among male service members (5.8). Between 2013 and 2017, incidence rates of glaucoma diagnoses increased by 75.4% among all service members.

Trabectome success factors

Our objective is to investigate which factors and patient characteristics are associated with success in Trabectome surgery.A total of 658 phakic cases with at least of 12 months follow-up were included in the analysis. Baseline demographics and medical data were collected. The main outcome measure was intraocular pressure (IOP), glaucoma medication (Rx), and secondary glaucoma surgery if any. Success was defined as IOP reduction of 20% or more from preoperative IOP and IOP < 21 mm Hg with no secondary surgery throughout the follow-up period. Risk factors for failure were determined by using univariate and multivariate cox regression.At baseline, the average IOP was 23.6 ± 7.8 mm Hg and the average number of medications was 2.6 ± 1.3 for all cases. At 12 months, the average IOP was 16.0 ± 3.6 mm Hg (P < .01) and the average number of medications was 1.8 ± 1.3 (P < .01). Based on the result of multivariate cox regression model, we found that the Trabectome + Phaco (TP) and Trabectome alone (TA) group had a 94% and 79% survival rate at 12 months, respectively. TP cases had 78% lower risk of failure than TA (95% confidence interval [CI]: 54-89), diagnosis of pseudoexfoliation glaucoma had a 54% lower risk of failure than primary open angle glaucoma patients (95% CI: 1-78). Hispanics had an estimated hazard ratio that is 60% lower than Caucasians (95% CI: 18-80); 20% of TA cases and 3% of TP cases were required to undergo additional secondary surgery (P < .01).Trabectome surgery, whether in combination with phacoemulsification cataract removal or stand alone, is associated with a significant reduction of IOP and glaucoma medication. Patients having a higher baseline IOP are expected to have a higher IOP reduction after Trabectome. Pseudoexfoliation glaucoma, combination with phacoemulsification cataract surgery and Hispanic race are factors associated with enhanced Trabectome survival.

Maladaptive coping strategies and glaucoma progression

The identification of modifiable risk factors for glaucoma progression is needed. Our objective was to determine whether maladaptive coping styles are associated with recent glaucoma progression or worse visual field mean deviation.A hospital-based case-control study was conducted in the Glaucoma Service of Maisonneuve-Rosemont Hospital in Montreal, Canada. Patients with primary open angle glaucoma or normal tension glaucoma with ≥4 years of follow-up and ≥5 Humphrey visual fields were included. Cases had recent visual field progression as defined according to the Early Manifest Glaucoma Trial pattern change probability maps. Controls had stable visual fields. The Brief Cope questionnaire, a 28-item questionnaire about 14 different ways of coping with the stress of a chronic disease, was asked. Questions were also asked about demographic and medical factors, and the medical chart was examined. Outcomes included glaucoma progression (yes, no) and visual field mean deviation. Logistic and linear regressions were used.A total of 180 patients were included (82 progressors and 98 nonprogressors). Although none of the 14 coping scales were associated with glaucoma progression (P > 0.05), higher denial was correlated with worse visual field mean deviation (r = -0.173, P = 0.024). In a linear regression model including age, sex, education, depression, intraocular pressure, and family history of glaucoma, greater levels of denial (β = -1.37, 95% confidence interval [CI] -2.32, -0.41), Haitian ethnicity (β = -7.78, 95% CI -12.52, -3.04), and the number of glaucoma medications (β = -1.20, 95% CI -2.00, -0.38) were statistically significantly associated with visual field mean deviation.The maladaptive coping mechanism of denial was a risk factor for worse visual field mean deviation. Further prospective research will be required to verify the pathways by which denial may exert an effect on glaucomatous visual field loss.

Relationship between glaucoma and admixture in postmenopausal African American women

OBJECTIVE

To investigate the association between African admixture and glaucoma prevalence among African American women.

DESIGN, SETTING, PARTICIPANTS

Participants included 11616 African American women from the Women's Health Initiative Study (WHI) for whom admixture information was available and included 2548 who self-reported a diagnosis of glaucoma.

MAIN OUTCOME MEASURES

Glaucoma.

RESULTS

Significant association was observed between self-identified glaucoma status and admixture. However, this association was not significant in a model that included neighborhood socioeconomic status (NSES), hypertension, diabetes and body mass index (BMI). Self-identified glaucoma status was associated with diabetes that persisted after adjustment for admixture, NSES, hypertension, and BMI. Lower NSES was also associated with higher glaucoma risk but this association was marginal in the fully adjusted model and neither hypertension nor BMI showed association. When glaucoma status was limited to those reporting use or no use of appropriate ophthalmologic medication, no associations were observed in any of the models.

CONCLUSION

This study failed to find an independent association of glaucoma status and African admixture and these findings suggest that the higher frequency glaucoma in African Americans may be largely due to other factors.

Cytochrome P4501B1 mutations cause only part of primary congenital glaucoma in Ecuador

PURPOSE

To determine the role of cytochrome P450IBI (CYP1B1) mutations in causing primary congenital glaucoma (PCG) in a cohort of Native Americans from Quito, Ecuador.

MATERIALS AND METHODS

Seventeen patients with PCG from 15 Native American families were recruited from the Ophthalmology Clinic at Hospital Metropolitano, Quito, Ecuador. Experienced ophthalmologists examined all affected study subjects. Purified DNA was prepared from peripheral blood samples and CYP1B1 coding exons (exons 2 and 3) were amplified and sequenced. Southern blot was performed only on those affected patients who showed no mutations in the CYP1B1 coding exons.

RESULTS

The molecular basis of PCG in two families was determined: two novel mutations (a deletion and a point mutation) and one novel polymorphism in CYP1B1 were identified in addition to a previously described single amino acid substitution. Southern blot analyses on whole genomic DNA from affected individuals in whom no mutations were identified by the direct PCR/sequencing approach did not detect any large rearrangements or mutations outside the coding region.

CONCLUSION

These findings suggest that mutations in CYPIBI are not a major cause of PCG in this population and that at least one additional locus for this condition is responsible for most cases. Further, the PCG phenotype did not correlate readily with the molecular basis of the disorder, suggesting that careful clinical analysis of the phenotype cannot predict the molecular basis of the disease with accuracy.

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.

The British Infantile and Childhood Glaucoma (BIG) Eye Study

PURPOSE

Pediatric glaucoma is a rare, potentially blinding condition, yet, in the United Kingdom, there is a paucity of contemporary epidemiologic and clinical data regarding this condition. The British Infantile and Childhood Glaucoma (BIG) Eye Study is the first national population-based study conducted to examine the incidence, detection patterns, current management, and intraocular pressure (IOP) control at 1 year in children with newly diagnosed glaucoma in the United Kingdom.

METHODS

A prospective study was conducted wherein children in the United Kingdom and Republic of Ireland aged <or=16 years with newly diagnosed primary or secondary glaucoma, were identified by consultant ophthalmologists through active surveillance from December 2001 until November 2002. Eligible cases were re-evaluated 12 months after notification.

RESULTS

Of the 99 eligible children with newly diagnosed glaucoma, 47 had primary and 52 secondary glaucoma. The annual incidence of diagnosis of primary congenital glaucoma (PCG) in Great Britain was 5.41 in 100,000 (1/18,500) live births and in the Republic of Ireland, 3.31 in 100,000 (1/30,200). The incidence of PCG in children of Pakistani origin was almost nine times that of Caucasians. IOP control of <or=21 mm Hg was achieved in 94% with medications (60% without medications) in cases of PCG and in 86% with medications (28% without medications) in cases of secondary glaucoma.

CONCLUSIONS

The British annual incidence of PCG diagnosis is comparable to that reported for other similar populations. Ethnic minorities from South Asia are at significantly increased risk of PCG. Successful IOP control in PCG after surgery in Britain is comparable to that in the published literature.

Diagnostic value of GDx polarimetry in a Taiwan Chinese population

PURPOSE

To study the diagnostic ability of scanning laser polarimetry with variable corneal compensation (GDx VCC) for early glaucomatous (EG) eyes and glaucoma-suspect (GS) eyes in a Taiwan Chinese population.

METHODS

This prospective cross-sectional study included 82 EG eyes (mean deviation, MD: -3.32 +/- 2.20 dB), 45 GS eyes (MD: -2.43 +/- 2.16 dB), and 62 normal eyes. Retinal nerve fiber layer thickness of each subject was measured using GDx VCC and Humphrey Field Analyzer visual field testing. Measured GDx VCC parameters were compared among groups. The area under the receiver operating characteristic (AROC) curve of each parameter was used to differentiate normal from EG eyes or GS eyes. The correlation between MD and each parameter was also evaluated.

RESULTS

For both normal versus EG and normal versus GS, the largest AROC values were for nerve fiber indicator, superior average thickness, and inferior average thickness. There was no significant correlation between MD and GDx-VCC-measured parameters either in EG or GS eyes.

CONCLUSIONS

GDx VCC shows only moderate ability to distinguish normal eyes from eyes with early glaucoma. However, its diagnostic role in eyes with suspicious discs and normal visual fields is uncertain at this moment in the Taiwan Chinese population. Further studies are needed to address this issue.

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.

A Clinical and Molecular Genetic Study of Egyptian and Saudi Arabian Patients With Primary Congenital Glaucoma (PCG)

PURPOSE

To undertake mutation screening of cytochrome P4501B1 (CYP1B1, OMIM 601771) and myocilin (MYOC, OMIM 601652) genes in Egyptian and Saudi Arabian patients with primary congenital glaucoma (PCG).

PATIENTS AND METHODS

A clinical and molecular genetic study was performed on 11 Egyptian and Saudi Arabian patients with PCG. Clinical diagnosis was confirmed by slit lamp biomicroscopy, gonioscopy, measurement of intraocular pressure, and corneal diameter. The coding regions of CYP1B1 and MYOC genes were amplified by polymerase chain reaction for all affected subjects. Direct sequence analysis was performed to search for sequence alterations. Haplotype analysis and genotype/phenotype correlation were carried out.

RESULTS

Three CYP1B1 mutations were identified in 5 PCG patients (45.4%) of which 2 were novel (homozygous E173K and heterozygous N498D) and the third (G61E) had previously been reported. In addition 10 single nucleotide polymorphisms were identified in CYP1B1 and MYOC genes of which 2 were novel. However, no pathologic changes in either of the genes were detected in the remaining 6 patients.

CONCLUSIONS

This is the first report of molecular genetic analysis of PCG in the Egyptian population in which 2 novel mutations have been identified. It is possible that these mutations are specific to this population and may lead to alterations in the protein structure encoded by the gene. Patients with no mutations in the screened genes may have mutations in genes yet to be identified.

Lower energy levels adequate for effective transcleral diode laser cyclophotocoagulation in Asian eyes with refractory glaucoma

PURPOSE

To study the treatment parameters for diode laser cyclophotocoagulation (DLCP) in Asian Indian eyes using laser energy titrated to clinical response.

METHODS

This prospective interventional longitudinal study included 66 eyes of 66 patients with varied aetiology refractory glaucoma, no previous cycloablation, and minimum 1 year follow-up. DLCP was performed using the Oculight Diode laser system IRIS( Medical Instruments Inc., CA, USA). Power used per spot was titrated according to the audible 'pops' indicating tissue microexplosion. The mean laser energy delivered, post-laser intraocular pressure (IOP) reduction, complications, and requirement of re-treatment in various subgroups were analyzed. Differences in energy delivered in each subgroup were assessed by analysis of variance with post hocBonferroni corrections. Linear regression analysis was used to identify possible predictive factors for failure of cyclodiode therapy.

RESULTS

The mean total energy delivered per eye was 87.80+/-31.8 J (range 105.4+/-36.8 J in neovascular glaucoma (NVG) to 61.5+/-8.8 J in uveitic glaucoma (P=0.134)). Mean pre treatment IOP was 36.4+/-10.7 mmHg, which reduced to 19.4+/-9.8 mmHg (P<0.001) at 1 week, and 15.6+/-6.6 mmHg at 1 year. At 1 year, 58 of 66 patients had IOP<22.0 mmHg (response rate 87.8%), and six patients had hypotony (success rate 78.8%). The uveitic glaucoma group had 100% success rate. NVG group required maximum re-treatments.

CONCLUSIONS

DLCP with a titrated energy protocol needs resulted in lower energy in Asian Indian eyes compared to that reported in literature, and different energy levels are needed for different diseases. 'Standard treatment parameters' for DLCP may be inappropriate for all diseases and all races.

Optic nerve head parameters of an indigenous population living within Central Australia

PURPOSE

Clinical examination of the optic disc is an essential element in the assessment of its health. Previous work has described normal optic disc appearance among different races. No such description of optic discs exists for indigenous Australians, who are at low risk of developing glaucoma. This study was designed to evaluate optic disc parameters of indigenous Australians.

METHODS

A sample of 208 indigenous Australians were recruited as they presented to remote clinics in Central Australia. Each subject underwent optic disc photography using a Topcon TRC-NW100 digital fundus camera. Optic discs were measured and analysed with Topcon ImageNet 2000 software.

RESULTS

Among other parameters, mean vertical disc diameter and disc area were 2.13 +/- 0.21 mm (mean +/- SD) and 3.13 +/- 0.57 mm2, respectively, for right eyes and 2.14 +/- 0.21 mm and 3.16 +/- 0.58 mm2 for left eyes. When compared with published studies, these parameters were significantly larger than Caucasians, but similar to African individuals.

CONCLUSION

Our results suggest that indigenous Australians have optic discs that are larger than those of Caucasians, but similar to those of Africans who are considered to at a greater risk of glaucoma. Factors other than optic disc area are likely to underlie the higher prevalence of primary open angle glaucoma among African individuals.

Visual field defects and vision-specific health-related quality of life in African Americans and whites with glaucoma

PURPOSE

To examine the relationship of visual field impairment to vision-specific health-related quality of life and symptoms in a large cohort (N=345) of African Americans and Whites of non-Hispanic origin diagnosed with glaucoma.

MATERIALS AND METHODS

Participants consisted of persons > or =55 years of age recruited from university-affiliated ophthalmology and optometry practices in Birmingham, AL who had been diagnosed with glaucoma. Medical records were abstracted to collect information on demographics, visual acuity, and visual fields. A telephone survey was conducted to obtain information on vision-specific health-related quality of life [National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25)], glaucoma symptoms [Glaucoma Symptom Scale (GSS)], and cognitive status (Short Portable Mental Status Questionnaire). Visual fields were used to compute a visual field defect score for each eye based on the Advanced Glaucoma Intervention Study (AGIS) scoring system.

RESULTS

Mean NEI VFQ-25 subscale scores ranged from the 50s to 80s. Scores for African Americans and Whites did not differ except for the general health and ocular pain subscales for which African Americans had slightly higher scores. For both African Americans and Whites, as the AGIS score became worse in the better and/or worse eye, there was a decrease in VFQ subscale score for most VFQ subscales including general vision, distance vision, near vision, social functioning, color vision, and peripheral vision (P<0.05). AGIS scores were unrelated to the GSS subscales in African Americans; for Whites, the visual but not the nonvisual subscale was related to AGIS score.

CONCLUSIONS

Scores on most subscales of the NEI VFQ-25 and the 2 subscales of the GSS are highly similar in African Americans and Whites of non-Hispanic origin who have been diagnosed with glaucoma. In addition, for both African Americans and Whites, the VFQ subscales for the most part demonstrated good construct validity with respect to the extent of visual field impairment. Results imply that the NEI VFQ-25 and the GSS are appropriate instruments for studying the personal burden of glaucoma in studies whose samples involve both African American and White adults.

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.

The relationship among race, iris color, central corneal thickness, and intraocular pressure

PURPOSE

Central corneal thickness (CCT) influences applanation intraocular pressure (IOP) measurement. The present study sought to determine whether iris color might represent a qualitative surrogate for CCT or race, and therefore differential risk for elevated IOP and, consequently, developing glaucoma.

METHODS

Eligible patients included those with best-corrected visual acuity (BCVA) better than 20/40 and who had not worn contact lenses within 24 hours. Exclusion criteria were prior ophthalmic surgery, topical ocular or systemic medication that would influence IOP, previous ocular inflammatory conditions, or current treatment for ophthalmic treatment. Data collection included demographic (name, date of birth, race), BCVA, and iris color. Iris color was judged according to a purpose-developed chart (white: blue, green, brown or black: brown) and patients were assigned to one of four groups. Goldmann applanation tonometry and pachymetry measurements were performed consecutively. To attain a power of 90% to find a difference of 40 microm with alpha < 0.05, we examined at least 14 subjects (28 eyes) for each group.

RESULTS

Comparing pachymetry measurements among iris colors revealed no statistically significant difference among the three groups of whites: blue (552 microm), green (552 microm), and brown (562 microm). The same held true when comparing IOP and CCT-adjusted IOP with iris color: blue-15.2, 15.1, green-15.4, 15.2, and brown-14.7, 14.0. When comparing CCT between whites and blacks, CCT was significantly thinner in blacks (533 microm), whether evaluating all whites (555 microm, p = 0.03) or comparing only the brown-iris white group with the black group (562 microm vs. 533 microm, p = 0.03). Mean CCT-adjusted IOP was barely significantly different between whites (14.8) and blacks (16.7) (p = 0.04).

CONCLUSION

These results suggest that iris color is not associated with CCT and apparently iris color does not influence measured IOP. We were able to establish a relationship between race and IOP when adjusting IOP for CCT. Our data show a significantly higher CCT-adjusted IOP for blacks than whites demonstrating a racial difference in CCT-corrected IOP.

ReGAE 2: glaucoma awareness and the primary eye-care service: some perceptions among African Caribbeans in Birmingham UK

AIMS

Investigations into glaucoma awareness have drawn on informed, clinic-based populations. The paper reports a section of findings from a larger study that aimed to elicit the perceptions of those potentially less informed in community settings.

METHODS

A qualitative investigation used face-to-face interviews and focus group discussions with 48 African Caribbean participants outside the hospital eye-service. Interview data were transcribed and coded using manual and computer-aided methods. Inferences and interpretations were corroborated by discussion with expert advisors and community members not directly involved in the study.

RESULTS

Positive attitudes to health promotion existed, but 'eye health' did not appear to be integral to individuals' health schemas. The capacity for primary eye care to enhance glaucoma knowledge appeared under utilised and inconsistent across modes of service delivery and was undermined by perceived conflicts of interest.

CONCLUSIONS

Enhancing reciprocal understanding between service users and ophthalmic practitioners in primary care is central to developing flexible, responsive local eye-care services. The study suggested useful foci for cultural self-reflection and self-awareness on the part of health professionals themselves, in relation to glaucoma detection. Areas for further research are identified.

Detection of glaucoma using operator-dependent versus operator-independent classification in the Heidelberg retinal tomograph-III

OBJECTIVE

To compare the abilities of a new Glaucoma Probability Scoring (GPS) system and Moorfields regression analysis (MRA) to differentiate between glaucomatous and normal eyes using Heidelberg retinal tomograph (HRT)-III software and race-specific databases.

METHODS

In this prospective study, one eye (refractive error < or =5 D) each of consecutive normal patients and those with glaucoma was enrolled. All patients underwent a full eye examination, standard achromatic perimetry (Swedish Interactive Threshold Algorithm-standard automated perimetry (SITA-SAP), program 24-2) and confocal scanning laser ophthalmoscopy (HRT-II) within 1 month. Normal patients had two normal visual fields in both eyes (pattern standard deviation (PSD) >5% and Glaucoma Hemifield Test within 97% normal limits) and a normal clinical examination. Glaucoma was defined on the basis of SITA-SAP visual field loss (PSD<5% or Glaucoma Hemifield Test outside normal limits) on two consecutive visual fields. HRT-II examinations were exported to the HRT-III software (V.3.0), which uses an enlarged race-specific database, consisting of 733 eyes of white people and 215 eyes of black people. Race-adjusted MRA for the most abnormal sector (operator-dependent contour line placement) was compared with the global race-adjusted GPS (operator independent). MRA sectors outside the 99.9% confidence interval limits (outside normal limits) and GPS > or =0.64 were considered abnormal.

RESULTS

136 normal patients (72 black and 64 white patients) and 84 patients with glaucoma (52 black and 32 white patients) were enrolled (mean age 50.4 (SD 14.4) years). The average visual field mean deviation was (-)0.4 (SD 1.1) db for the normal group and (-)7.3 (SD 6.7) db for the glaucoma group (p<0.001). Mean GPS values were 0.21 (SD 0.23) and 0.73 (SD 0.27) for normal and glaucomatous eyes, respectively (p<0.001). Sensitivity and specificity values were 77.1% and 90.3% for GPS, and 71.4% and 91.9% for MRA, respectively.

CONCLUSIONS

In this cohort, GPS software sensitivity and specificity values are similar to those of MRA, which requires placement of an operator-dependent contour line. The development of software to detect glaucoma without a contour line is critical to improving the potential use of HRT as a tool for glaucoma detection and screening.

Optic disk size in chronic glaucoma: the Beijing eye study

PURPOSE

To evaluate whether eyes with chronic glaucoma have a larger or smaller optic disk than normal eyes.

DESIGN

Population-based, cross-sectional cohort study.

METHODS

The study included 4439 subjects out of 5324 subjects invited to participate with an age of 40+ years. Color optic disk photographs (45 degrees ) were morphometrically examined.

RESULTS

After exclusion of aphakic eyes, pseudophakic eyes, and highly myopic eyes, data of 3989 subjects entered the statistical analysis. The mean optic disk area did not vary significantly (P > .05) between the nonglaucomatous group (2.61 +/- 0.50 mm(2)), eyes with glaucomatous appearance of the optic disk (2.69 +/- 0.63 mm(2)), eyes with glaucomatous optic disks and visual field defects (2.66 +/- 0.70 mm(2)), and eyes with elevated intraocular pressure (2.63 +/- 0.49 mm(2)).

CONCLUSIONS

In adult Chinese, optic disk size may not markedly differ between normal eyes and eyes with chronic glaucoma.

Factors associated with failure to follow up after glaucoma screening: a study in an African American population

PURPOSE

To evaluate variables associated with failure to access free eye care after participating in glaucoma screening.

DESIGN

Review of responses to a survey completed by participants during glaucoma screening.

PARTICIPANTS

Two hundred seventy-three surveys completed by participants of African descent during screening.

METHODS

African Americans 40 years or older participated in community glaucoma screening clinics, which included a survey with demographic and social variables. Each participant was given a preliminary diagnosis and encouraged to attend a free eye clinic for a complete examination. Survey results were correlated with attendance at the follow-up examination, using Student's t test, chi-square test, and logistic regression analysis.

MAIN OUTCOME MEASURE

Noncompliance with follow-up after glaucoma screening.

RESULTS

When adjusting for risk factors in logistic regression analysis, noncompliance was associated with living alone (P = 0.008), smoking (P = 0.0005), and lacking a car (P<0.01). Odds of noncompliance for participants living alone were 2.2 times higher than those for participants not living alone. Odds of noncompliance for participants who smoked were 3.0 times greater than those for participants who did not smoke. Odds of noncompliance for participants who did not have access to a car for their last eye examination were 2.1 times greater than those for participants who did.

CONCLUSION

Socioeconomic factors such as smoking, lack of access to a car for eye examinations, and living alone are associated with noncompliance to follow-up after glaucoma screening clinics. Identifying persons with these variables may facilitate improved compliance.

Ahmed Glaucoma Valve Implantation in African American and White Patients

OBJECTIVE

To evaluate the results of Ahmed Glaucoma Valve implantation in African American and white patients.

METHODS

In this retrospective, comparative case-control study, we reviewed 86 eyes of 86 patients, comparing the surgical outcomes in white patients (n = 43) with matched African American patients (n = 43). Success was defined as an intraocular pressure (IOP) between 6 mm Hg and 21 mm Hg with or without glaucoma medicines, without further glaucoma surgery, and without loss of light perception (definition 1) and an IOP between 6 mm Hg and 21 mm Hg and achievement of a 20% reduction in IOP from the preoperative level (definition 2).

RESULTS

The mean follow-up was 2.3 years for white patients and 2.5 years for African American patients (P = .50). At the last follow-up, the mean +/- SD IOP was 15.3 +/- 3.3 mm Hg and 15.3 +/- 3.5 mm Hg (P = .77) in white and African American patients, respectively. Life table analysis showed a significantly lower success rate for African American patients compared with white patients by both definition 1 (P = .03) and definition 2 (P = .006). Cox proportional hazards regression analysis detected African American race as a risk factor for surgical failure by both definitions. Visual outcomes and complications were comparable between the 2 groups.

CONCLUSION

African American patients have a greater risk of surgical failure after Ahmed Glaucoma Valve implantation compared with white patients.

Molecular and clinical evaluation of primary congenital glaucoma in Kuwait

PURPOSE

To report the spectrum of the CYP1B1 mutation in Kuwaiti patients with primary congenital glaucoma (PCG).

DESIGN

Clinical diagnosis of PCG and laboratory based experimental study.

METHODS

Polymerase chain reaction-restriction polymorphism length fragment (PCR-RPLF) and direct sequencing of exon 2 and the coding region of exon 3 of CYP1B1 gene were the methods used for screening 17 PCG patients, their families, and 105 health individuals from the same ethnicity.

RESULTS

Four different mutations were detected in CYP1B1 in 70.6% of the screened patients. The most common one (47%) was homozygote Gly61Glu mutation, previously described in Saudi Arabia, Turkey, and Morocco; all patients were products of consanguineous marriages. The second common mutation was a novel missense (Ala388Thr) mutation found in three patients (17.6%) as compound heterozygote with Arg368His in one patient, and with Gly61Glu in another one while the second mutation in third patient was not detected in the CYP1B1 gene. One patient (5.8%) was homozygote for Cyt280X mutation previously reported in only one Japanese family. In addition to these mutations, a novel Val422Gly polymorphic site was found in three of the PCG patients and in 18 of the 210 tested chromosomes of healthy volunteers.

CONCLUSIONS

The CYP1B1 mutation spectrum of Kuwaiti PCG patients is similar to that detected in the neighboring countries. No clear genotype-phenotype correlation detected in patients showed different types of CYP1B1 mutation.

Globally, CYP1B1 mutations in primary congenital glaucoma are strongly structured by geographic and haplotype backgrounds

PURPOSE

To obtain a global perspective on the distribution and evolution of CYP1B1 mutations in primary congenital glaucoma (PCG) worldwide.

METHODS

Five intragenic single-nucleotide polymorphisms in CYP1B1-R48G, A119S, V432L, D449D, and N453S-were used to generate haplotype data from 138 Indian patients with PCG and 132 ethnically matched normal controls, which were then analyzed in conjunction with data from other populations. Maximum-likelihood estimates of haplotype frequencies were estimated from the genotype data. Subsets of patients and normal control subjects were also genotyped with respect to eight short tandem repeat (STR) markers around the CYP1B1 locus (D2S305, D2S165, D2S367, D2S2259, D2S391, D2S3337, D2S23678, and D2S286), to gain evolutionary insights.

RESULTS

Common mutations in CYP1B1 that are causal of PCG occurred on a uniform haplotype background among Indian patients, which is completely distinct from the modal haplotype background found among unaffected control subjects. Comparison of these data with data from other global regions reveals strong clustering of CYP1B1 mutations by geographic and haplotype backgrounds. The two distinct modal haplotypes found among Indian patients with PCG and control subjects are both ancient with ages of similar magnitudes, as indicated by large variances in the number of repeats at eight STR loci. Together with data from chimpanzee and normal control subjects from India and other global regions, it was possible to make a parsimonious reconstruction of the evolution of these haplotypes.

CONCLUSIONS

The strong association of specific haplotypes with some predominant CYP1B1 mutations underlying PCG and the observed geographical clustering, probably due to founder effects, may be useful for predictive testing.

Racial differences in glaucoma care: the longitudinal pattern of care

OBJECTIVE

To examine if racial differences exist in longitudinal care patterns for Medicare beneficiaries with glaucoma.

METHODS

We analyzed national longitudinal Medicare claims data from January 1, 1991, through December 31, 1999 in 21 644 Medicare beneficiaries linked to the National Long-Term Care Survey. Logistic regression was used to predict whether a person underwent an eye examination or eye surgery during the year, and negative binomial regression was used to predict the number of eye examinations and surgical procedures for glaucoma per year. Annual use of eye examinations was nearly identical for black persons (1.85 per year) and white persons (1.89 per year), whereas surgery rates were higher among blacks (0.15) than whites (0.08, P<.001).

RESULTS

Blacks were more likely than whites to have glaucoma diagnosed, but rates among whites were higher than in prior population-based studies. When we controlled for other factors, blacks were not significantly less likely to undergo eye examination during the year; however, blacks were 78% more likely to undergo surgery (P < .001) and had 76% higher rates of surgical procedures (P < .001).

CONCLUSIONS

No systematic pattern was found of underuse among blacks relative to whites after glaucoma diagnosis. Higher rates of surgery among blacks may indicate delayed onset of care and/or greater disease severity.

Intermediate-term comparison of trabeculectomy with intraoperative mitomycin-C between Asian American and Caucasian glaucoma patients: a case-controlled comparison

PURPOSE

Compare the efficacy and survival of trabeculectomy with intraoperative mitomycin-C (MMC) between Asian American and Caucasian patients in the same clinical setting.

METHODS

In total, 29 Asian American patients (29 eyes) with trabeculectomies were matched case to case with 29 Caucasian patients (29 eyes) retrospectively. Matching criteria included age, glaucoma subtype, and preoperative intraocular pressure (IOP), gender, surgeon, ocular history, and glaucoma medications. Criteria of success included: (1) Final IOP>5 and <22 mmHg, (2) IOP reduction>or=20%, or final IOP<or=10 mmHg, and (3) without additional glaucoma surgery, loss of light perception, or complication.

RESULTS

Mean follow-up durations of Asian American and Caucasian group were 40.11+/-22.5 months and 38.8+/-17.7 months, respectively (P=0.81). At the final visits, IOP decreased from 18.7+/-6.1 to 10.9+/-4.0 mmHg (P<0.0001) in the Asian American group, and from 19.0+/-5.5 to 11.0+/-3.8 mmHg (P<0.0001) in the Caucasian group. There were no significant differences between the two groups in IOP levels at 6 months, 1 year, and final visits. The probabilities of trabeculectomy survival (continuing to meet definition of success criteria) at 12 and 48 months were 75.9 and 56.6% in the Asian American group and 82.8 and 66.6% in the Caucasian group, respectively. (P=0.46) There were no significant differences for rates of surgical success, failure, complication, vision decrease, hypotony, and cataract development. Patients who had episodes of hypotony had a higher rate of diagnosis of low-tension glaucoma subtype (P=0.02).

CONCLUSIONS

In a case-controlled comparison of an intermediate-term follow-up of trabeculectomy with intraoperative MMC, Asian American patients have a similar efficacy and survival probability as Caucasian patients.

Ethnic differences in glaucoma: prevalence, management, and outcome

PURPOSE OF REVIEW

Glaucoma has a disproportionate prevalence among specific ethnic groups. Therefore, the issue of 'race' and glaucoma has been the focus of much discussion. The purpose of this article is to provide a review of the literature regarding the prevalence, management, and outcome of glaucoma among different ethnic populations.

RECENT FINDINGS

This review highlights not only recent reports but also notes key studies from the past regarding glaucoma and ethnicity. Given the variation in presentation and the response to therapy, it is important to individualize one's therapeutic approach in any given patient.

SUMMARY

Our knowledge regarding glaucoma and ethnicity helps us to customize a patient's therapeutic regimen more effectively. Therefore, understanding an individual's heredity and culture is essential to properly identify, treat, and manage individuals at risk and existing patients with glaucoma.

Primary congenital glaucoma presenting within the first three months of life in a Bedouin population: prognostic factors

OBJECTIVES

To analyze the final outcome of surgery in Arab-Bedouin children with primary congenital glaucoma (PCG) presenting within the first three months of life, and to search for prognostic factors for success.

DESIGN

Retrospective study of all cases with follow-up of at least 24 months.

PATIENTS

Twenty-five Arab-Bedouin children (45 eyes) with PCG presenting within the first three months of life who underwent surgical procedures at the Soroka University Medical Center from January 1988 to December 1998.

METHODS

Patient's age, family history, main presenting features, data from examinations under anesthesia, including intraocular pressure (IOP), horizontal corneal diameter, and cup/disc (c/d) ratio, and the type of surgery performed were reviewed.

MAIN OUTCOME MEASURES

Success of the first operation, defined as final IOP < 21 mm Hg achieved after only one surgical procedure without anti-glaucoma medication, and final outcome, defined as good when IOP was < 21 mm Hg and > 5 mm Hg at the end of a 24-month follow-up period without anti-glaucoma medication, irrespective of the number of procedures performed.

RESULTS

At presentation mean IOP was 36.2 +/- 8.0 mm Hg, corneal diameter was 12.62 +/- 0.98 mm, and c/d ratio was 0.41 +/- 0.16. The mean age at first operation was 17 +/- 20 days, and median of 5 days. The mean follow-up period was 37.4 +/- 25.4 months. The success of the first operation performed was not related to the type of operation (P = 0.22), gender (P = 0.47), consanguinity (P = 1.0), family history (P = 0.12), clinical presentation (P = 0.81), or age at first operation (P = 0.38). Eyes with high initial IOP and greater c/d ratio were at a significantly higher risk for failure (P = 0.05, P = 0.04, respectively). A final outcome of IOP under 21 mm Hg and above 5 mm Hg was achieved in 39 eyes (86.5%). There was no statistical association between final outcome and the type of first surgical procedure performed, gender, consanguinity, clinical presentation, and age at first operation. Cases with no family history had a significantly better final outcome (P = 0.05). In multivariate analysis only initial IOP showed borderline significance as an independent risk factor for final outcome (P = 0.06).

CONCLUSIONS

Initial high IOP and higher c/d ratio were found to be predictive factors for failure of the first procedure. Final outcome was significantly better in cases with no family history, yet initial IOP was the only independent predictive factor for failure at the final outcome in a multivariate model. Findings of this type have not been previously reported, and they may constitute an important tool in predicting the treatment outcome of very young children with PCG.

A Cross-Sectional Study of Krukenberg Spindles and Pigmented Lens Striae in a Predominately Black Population

PURPOSE

To investigate the relationship of Krukenberg spindles (KS) and pigmented lens striae (PLS), clinical signs related to iris pigment dispersal and possibly glaucoma.

METHODS

During a 31-month period, 5 practitioners in an urban, primary eye care setting examined consecutive patients for KS and PLS. Multiple logistic regression was used to evaluate relationships among KS, PLS, and other variables.

RESULTS

Krukenberg spindles were present in 65 patients (52 females), comprised of 57 of 2647 (2.2%) blacks, 5 of 303 (1.7%) whites, 2 of 121 (1.7%) Hispanics, and 1 of 55 (1.8%) Asians. PLS were present in 64 subjects (56 females), comprised of 59 (2.2%) blacks, 3 (1.0%) whites, and 2 (3.6%) Asians. KS and PLS were coexistent in 27 subjects. Mean age +/- SD (range) of the KS and PLS subjects was 63.1 +/- 15.0 years (24-88 years) and 67.0 +/- 10.4 years (33-88 years), respectively. Mean refractive error +/- SD (range) of KS and PLS right eyes was +0.55 +/- 2.32D (-6.50 to +5.50D) and +1.34 +/- 2.18D (-6.50 to +7.25D), respectively. Controlling for other variables, PLS were highly predictive (OR = 30.2, P < 0.0001) of KS, and KS were highly predictive (OR = 29.5, P < 0.0001) of PLS. Ignoring presence or absence of PLS, increasing age (in decades) (OR = 1.60, P < 0.0001) was strongly associated with KS. Ignoring presence or absence of KS, age (OR = 1.74, P < 0.0001), female gender (OR = 2.96, P = 0.009), and increasing hyperopic refractive error (OR = 1.30, P < 0.0001) were strongly associated with PLS.

CONCLUSIONS

Krukenberg spindles and PLS were strongly associated in our patient population, and the likelihood of both increased with increasing age. Female gender and increasing hyperopic refractive error were highly significant predictors of PLS.

Central corneal thickness of Caucasians, Chinese, Hispanics, Filipinos, African Americans, and Japanese in a glaucoma clinic

OBJECTIVE

To characterize the central corneal thickness (CCT) of Asian (Chinese, Japanese, and Filipino), Caucasian, Hispanic, and African American patients in a multiethnic glaucoma practice.

DESIGN

Retrospective study (chart review).

PARTICIPANTS

Glaucomatous (n = 600) and nonglaucomatous (n = 201) eyes of 801 patients examined in a San Francisco glaucoma clinic from June 2002 to April 2004 who met inclusion criteria were included in the study. The 6 racial (ethnic) groups represented in the study were Caucasian (n = 186, 23.2%), Chinese (n = 157, 19.6%), Japanese (n = 121, 15.1%), Hispanic (n = 116, 14.5%), Filipino (n = 114, 14.2%), and African American (n = 107, 13.4%).

METHODS

Central corneal thickness was measured by means of ultrasound pachymetry in Asian (Chinese, Japanese, and Filipino), Caucasian, Hispanic, and African American participants with glaucomatous and normal eyes. The relationship between CCT and race was investigated using multivariate regression analyses, controlling for confounders. One eye of each of 801 participants was included for analysis.

MAIN OUTCOME MEASURES

Correlation of mean CCT with race, glaucoma diagnosis, age, spherical equivalent, gender, and history of ocular surgery.

RESULTS

The mean CCT of all participants was 542.9 mum. Central corneal thicknesses of Chinese (555.6 microm), Caucasian (550.4 microm), Filipino (550.6 microm), and Hispanic (548.1 microm) participants did not significantly differ. The CCT of Japanese participants (531.7 microm) was significantly less than that of Caucasians, Chinese, Filipinos, and Hispanics (all, P< or =0.001) and greater than that of African Americans (P = 0.03). African Americans had a CCT (521.0.0 microm) less than that of all races (P< or =0.05). Glaucoma suspects and patients with normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PEX), and chronic angle-closure glaucoma (CACG) had corneas significantly thinner than those of normal participants (P< or =0.004), whereas ocular hypertensives had significantly thicker corneas (P<0.0001). Among all participants, decreasing values of CCT were significantly related to older age (P<0.01). Less negative or more positive refractive errors, gender, and history of ocular surgery were not associated with changes in CCT (P = 0.38, P = 0.50, and P = 0.97, respectively).

CONCLUSIONS

Studies examining individual Asian subpopulations in isolation suggest that differences in CCT may exist among different Asian groups. The results of this study indicate that CCT does, in fact, vary among Asian subpopulations; Japanese have thinner corneas than Chinese and Filipinos. Caucasians, Chinese, Hispanics, and Filipinos have comparable CCT measurements, whereas the corneas of African Americans are significantly thinner. Additionally, older individuals; glaucoma suspects; and participants with NTG, POAG, PEX, and CACG have thinner corneas. Ocular hypertensives, however, have thicker corneas.

The influence of age, sex, race, refractive error and optic disc parameters on the sensitivity and specificity of scanning laser polarimetry

PURPOSE

To evaluate the influence of age, sex, race, refractive error and optic disc topography on the sensitivity and specificity of scanning laser polarimetry (SLP) in the diagnosis of glaucoma.

METHODS

A total of 88 normal individuals and 95 glaucoma patients were included in this study. Glaucoma was defined on the basis of both optic nerve damage and visual field defects. Scanning laser polarimetry, optic disc topography, automated perimetry and refractometry were performed in all subjects. The sensitivity and specificity of SLP were assessed applying a previously calculated cut-off to a previously described linear discriminant function (LDF).

RESULTS

The sensitivity and specificity of SLP in the study population were 82% and 83%, respectively. Sensitivity and specificity were not affected by age, sex, race, average disc diameter or disc area. The sensitivity of SLP tended to be higher in myopes (93%) than in emmetropes (80%) and hyperopes (71%) (p = 0.08). Sensitivities were higher in individuals with cup areas > 0.96 mm(2) (89%), rim areas < or = 1.36 mm(2) (92%), and cup area/disc area ratios > 0.45 (89%) (p < 0.05). Stepwise logistic regression analysis indicated that the presence of a cup area > 0.96 mm(2) and a rim area < 1.36 mm(2) significantly increased the sensitivity of the LDF, whereas a cup area/disc area ratio < or = 0.45 significantly increased the specificity of the LDF.

CONCLUSION

The sensitivity and specificity of SLP may be influenced by refractive error and optic disc parameters that are affected by glaucomatous damage (cup area, rim area and cup area/disc area ratio). These parameters must be considered in studies evaluating the sensitivity and specificity of optic nerve/retinal nerve fibre layer imaging technologies.

Mutation spectrum of the CYP1B1 gene in Indian primary congenital glaucoma patients

PURPOSE

The human Cytochrome P450 gene CYP1B1 has been implicated in primary congenital glaucoma worldwide. The aim of this study was to understand the role of CYP1B1 mutations in causing primary congenital glaucoma in Indian populations.

METHODS

The study included 64 new and unrelated cases of primary congenital glaucoma from different ethnic groups of India. Direct sequencing screened the coding and the promoter regions of CYP1B1.

RESULTS

Sixteen pathogenic mutations were observed in 24 cases, of which 7 were novel. These included two frameshift mutations leading to deletions of 23 bp (g.3905del23bp) and 2 bp (g.7900-7901delCG) in exons II and III, respectively. Four novel missense mutations viz. A115P, M132R, Q144P, S239R were noted in exon II, and one in exon III (G466D), whose residue is a part of the "signature sequence" (NH2-FXXGXXXCXG-COOH) and is present in all heme binding cytochromes. Overall, CYP1B1 was involved in 37.50% (24/64) cases and homozygosity of the mutant allele was seen in 29.68% (19/64) and compound heterozygosity in 3.12% (2/64) of the cases, respectively. The frequency of CYP1B1 mutations was comparatively lower than Saudi Arabian, Slovakian Gypsys, and Turkish populations, largely due to genetic heterogeneity and ethnic diversities in Indian populations. Genotype-phenotype correlation indicated variable prognosis that could be due to the type of mutation, leading to alteration of CYP1B1 protein.

CONCLUSIONS

This study provides a mutation spectrum of CYP1B1 causing primary congenital glaucoma in Indian populations that has implications in devising molecular diagnostics for rapid screening.

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.

A review of trabeculectomy in East Asian people—the influence of race

Glaucoma is the leading cause of irreversible blindness worldwide. East Asians account for approximately half of all glaucoma sufferers. It is likely that trabeculectomy will be needed for many of these people as the intraocular pressure is to be maintained at a satisfactorily low level. The eyes of East Asian people differ in some aspects from those of other races. This review describes the natural history of the eye after trabeculectomy in East Asians.

Experience with the use of Baerveldt and Ahmed glaucoma drainage implants in an Asian population

PURPOSE

To evaluate the efficacy and safety of Baerveldt and Ahmed glaucoma drainage implants in Asian patients with refractory glaucoma.

DESIGN

Retrospective nonrandomized study.

PARTICIPANTS

Forty-one patients.

METHODS

The authors reviewed the insertion of 18 Ahmed glaucoma valved (AGV-S2) implants and 24 350 mm(2) Baerveldt glaucoma implants performed by a single surgeon at the Department of Ophthalmology, National University Hospital, Singapore, from January 1, 2000, to December 31, 2000. A total of 42 glaucoma drainage implants was inserted into the eyes of 41 patients. All patients had at least 6 months of follow-up.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP), visual acuity, and complications.

RESULTS

Both drainage implants achieved remarkable reductions in IOP; from pretreatment IOP of 40.1+/-13.8 mmHg and 43.7+/-9.3 mmHg to postoperative IOP of 17.4+/-6.2 and 14.9+/-5.5 mmHg in the Baerveldt and Ahmed groups, respectively. A decrease in IOP of 56.6% and 65.9% had been achieved. Success rates were 20 (83.3%) for Baerveldt and 12 (66.7%) for Ahmed implants, whereas qualified success occurred in 1 (4.2%) Baerveldt and 3 (16.7%) Ahmed implants. Conversely, failure to control IOP occurred in 3 (12.5%) Baerveldt implants and 3 (16.7%) Ahmed implants. More than 80% of the patients had maintained or improved visual function, whereas only 4 (16.0%) of the patients with Baerveldt implants and 2 (16.7%) patients with Ahmed implants had loss of more than 1 Snellen line.

CONCLUSIONS

Both Baerveldt and Ahmed glaucoma drainage implants performed well in terms of IOP control, preservation of visual function, and having low complication rates.

Long-term surgical and visual outcomes in Indian children with developmental glaucoma operated on within 6 months of birth

PURPOSE

To determine the long-term surgical and visual outcomes in Indian children with developmental glaucoma operated within 6 months of birth.

DESIGN

Retrospective consecutive, noncomparative case series.

PARTICIPANTS

All children with developmental glaucoma who underwent surgery within 6 months of birth over a 12-year period were included.

METHODS

Two hundred ninety-nine eyes of 157 consecutive patients who underwent primary combined trabeculotomy-trabeculectomy for developmental glaucoma from January 1990 through December 2001 by a single surgeon were studied. However, for the purpose of statistical analysis, only 1 randomly chosen eye of patients with a bilateral affliction (142, 90.4%) was considered.

MAIN OUTCOME MEASURES

The main outcome measures were preoperative and postoperative intraocular pressures (IOPs), corneal clarity and diameters, visual acuities, refractive errors, success rate, time of surgical failure, and complications.

RESULTS

The series consisted of 299 primary combined trabeculotomy-trabeculectomy surgeries during 157 anesthesias. The intraocular pressure was reduced from 26.6+/-6.2 mmHg to 14.4+/-4.9 mmHg, with a mean percentage reduction of 41.1+/-28.8 (P<0.0001). The probability of success (IOP<21 mmHg) was 94.4%, 92.1%, 86.7%, 79.4%, 72.9%, and 63.1% at first, second, third, fourth, fifth, and sixth year, respectively (Kaplan-Meier analysis). The mean follow-up period was 26.5+/-25.1 months. Preoperatively, 133 eyes (84.7%) had significant corneal edema. Postoperatively, normal corneal clarity was achieved in 83 of 133 eyes (62.4%) with corneal edema. There were no major intraoperative complications. Postoperatively, 17 eyes (10.8%) had a shallow anterior chamber develop; 3 of these eyes (17.6%) required surgical reformation. There was no incidence of endophthalmitis or any other sight-threatening complication. Data on visual acuity were available in 49 patients (31.2%). At the final follow-up visit, 20 patients (40.8%) had normal visual acuity (best-corrected visual acuity of >/=20/60 in the better eye).

CONCLUSIONS

Primary combined trabeculotomy-trabeculectomy is safe and effective for developmental glaucoma when performed within 6 months of birth. It leads to excellent IOP control and moderate visual outcome.

Surgical outcomes of combined phacoemulsification and glaucoma drainage implant surgery for Asian patients with refractory glaucoma with cataract

PURPOSE

To examine the safety and efficacy of combined phacoemulsification and glaucoma drainage implant surgery in providing reduction of intraocular pressure (IOP) and visual rehabilitation in eyes with refractory glaucoma and cataract.

DESIGN

Interventional case series.

METHODS

A retrospective chart review was performed on all subjects who underwent combined phacoemulsification with intraocular lens implantation and glaucoma drainage implant surgery by a single surgeon at the National University Hospital, Singapore. The implants used were the 185 mm2 Ahmed glaucoma valve and the 350 mm2 Baerveldt glaucoma implant. In terms of IOP, a complete success was defined as IOP of between 6 to 21 mm Hg without medication, qualified success as IOP between 6 to 21 mm Hg with one or more medication, and failure as a sustained IOP of >21 mm Hg or <6 mm Hg with or without one or more medication on two or more visits.

RESULTS

A total of 32 combined phacoemulsification and glaucoma implant surgeries in 32 patients was performed. All patients were of Asian origin, and the mean age was 58 +/- 16 years (range, 20-78 years). The Baerveldt glaucoma implant and Ahmed glaucoma valve implant were inserted in 16 eyes each. With a mean follow-up of 13 +/- 5 months (range 6 to 22 months), IOP was reduced from a mean of 28.0 +/- 11.5 mm Hg to 15.2 +/- 6.0 mm Hg postoperatively (P <.0001), whereas the number of antiglaucoma medications decreased from a mean of 2.4 +/- 1.4 to.3 +/-.7 (P <.0001) at last follow-up. Overall, there were 24 eyes (75%) that were classified as complete successes, 4 eyes (12.5%) that were qualified successes, and 4 eyes that failed (12.5%). Twenty-three eyes (72%) had improvement of visual acuity, while only one eye had a loss of more than 1 line of Snellen acuity. There was no case that encountered an intraoperative complication, and postoperative complications occurred in 12 eyes (38%), the most common of which was hypotony (in six eyes, 19%).

CONCLUSION

For subjects with refractory glaucoma and cataract, combined phacoemulsification and glaucoma drainage implant surgery provide good visual rehabilitation and control of IOP, with low incidence of complications.