The Effect of Bimatoprost Implant on Glaucoma Patients: An Observational Study

PRCIS

In this retrospective study of glaucoma patients receiving the bimatoprost implant at Duke Eye Center, the number of topical intraocular pressure-lowering medications was significantly reduced through 12 months after the implant.

PURPOSE

To study the effects of the bimatoprost implant on intraocular pressure (IOP) and the need for topical IOP-lowering medications in glaucoma patients in the clinical practice setting.

PATIENTS AND METHODS

Patients who received the bimatoprost implant at Duke Eye Center from November 2020 to October 2021 were identified. Exclusion criteria included addition of other IOP-lowering medications concurrent with the implant and less than 1 month of follow-up. The change in IOP and number of topical IOP-lowering medications from baseline to months 1, 3, 6, 9, and 12 after the implant was calculated. Subgroup analysis was performed for different glaucoma severities.

RESULTS

A total of 63 patients and 92 eyes were included (mean age 77.8 ± 10.1 years). Glaucoma severity ranged from mild (11%), moderate (30%), to severe (54%). There was a nonsignificant decrease in IOP at all timepoints. The mean number of topical IOP-lowering medications significantly decreased by 0.81, 0.75, 0.63, 0.70, and 0.67 at month 1, 3, 6, 9, and 12, respectively (all P < 0.001). There was no significant change in the total number of medications including the bimatoprost implant. When divided by glaucoma severity, the reduction in the number of topical medications was significant at 1, 3, and 6 months for mild/moderate disease, and at 1 month for severe disease. During the follow-up period, 19 eyes underwent additional laser or surgical procedures, 68% of which had a history of prior incisional glaucoma surgery.

CONCLUSIONS

The bimatoprost implant may reduce the need for topical IOP-lowering agents over a 1-year period, especially in mild-to-moderate stage glaucoma. The efficacy of the implant may be more limited in severe glaucoma, and further work is needed to characterize its long-term effects.

Hydrogel Sealant for Closure of Clear Corneal Incisions in Combined Glaucoma Procedures

Purpose

The purpose of this study is to determine whether ReSure hydrogel sealant is superior to standard suture for closure of clear corneal incisions in the setting of combined glaucoma procedures.

Setting

Glaucoma Department, Duke University Eye Center.

Design

This is a retrospective case series. Subjects studied were patients in a 6-year period undergoing combined phacoemulsification and glaucoma surgery. All cases were performed by the same surgeon. Wound closure methods correlated with discrete timeframes, as ReSure replaced suture midway through the study period, thereby establishing sutured closure as an analogous control group.

Methods

All cases included a phacoemulsification procedure requiring a 2.4 mm clear corneal incision. Upon completion of the phacoemulsification portion of the case, the wound was closed with either ReSure hydrogel or standard 10–0 suture closure. The researchers assessed the rate of Seidel-positive corneal wound leak on postoperative day one.

Results

In all cases employing ReSure, no wound leak was observed at postoperative day one. Within the suture group, 3 cases showed Seidel positivity of the corneal incision. This equates to a statistically significant difference in wound leak frequency of 2.04% (P = 0.012); confidence interval, 0.21 to 5.82.

Conclusion

ReSure was able to maintain closure 100% of the time over hundreds of combined cases. Suture, though the standard of practice, did not perform to this level, presenting with 3 cases of spontaneous wound leak. We conclude that ReSure is highly effective and superior to suture in closure of clear corneal incisions in combined glaucoma procedures.

Risk Factors for Corneal Striae in Eyes After Glaucoma Surgery

PRCIS

Eyes with corneal striae had steeper cornea, induced astigmatism, and higher corneal hysteresis (CH), which implies a relationship between striae, corneal shape, and the cornea's resistance to deformation at low intraocular pressures (IOPs).

BACKGROUND

Anterior corneal striae (ACS) are associated with low IOP. However, the clinical significance of ACS is unclear. Here, we aim to evaluate differences in eyes with striae compared with eyes without striae.

METHODS

Adults with ACS (cases) and without ACS (controls) ≥8 weeks after glaucoma surgery with an IOP ≤10 mm Hg were enrolled. Optical coherence tomography and optical biometry were performed. CH, defined as the difference in pressure between corneal indentation and reformation in response to an air jet, was obtained by the ocular response analyzer. Hypotony maculopathy (HM) was defined as optic disc swelling, vascular tortuosity attributed to hypotony, or clinical presence of chorioretinal folds confirmed on OCT.

RESULTS

One hundred sixteen eyes (76 cases, 40 controls) were included. Cases had a lower IOP compared with controls (6.5±2.3 vs. 8.5±1, P<0.0001). A 1 mm Hg increase in CH increased ACS odds [odds ratio (OR)=1.51, P=0.01]. A 1 D increase in the flattest presurgical and postsurgical corneal power increased ACS odds by 1.83 (P=0.01) and 1.41 (P=0.02), respectively. Astigmatism increased in eyes with ACS by 1.11 D (P<0.001). ACS odds were increased with every 1 minute increase in mitomycin-C duration (OR=1.58, P=0.047) and decreased with the use of topical glaucoma medication (OR=0.62, P=0.03). Visual acuity decreased from logarithm of the minimal angle of resolution 0.22 (20/33 Snellen) presurgery to 0.28 (20/38) postsurgery (P=0.008), independent of ACS. HM occurred in 19% of cases (P=0.05). A higher postsurgical CH increased HM odds (OR=1.8, P=0.003). HM predicted a 0.41 mm decrease in axial length (P<0.0001), independent of IOP.

CONCLUSION

ACS were associated with a steeper cornea, induced astigmatism, and higher CH, suggesting a relationship between striae, corneal shape, and the cornea's ability to resist deformations at lower IOP. CH, HM, and axial length shortening were associated independently of IOP.

Association of Long-term Ambient Black Carbon Exposure and Oxidative Stress Allelic Variants With Intraocular Pressure in Older Men

Importance

Elevated intraocular pressure is a major risk factor for glaucoma, a leading cause of irreversible blindness worldwide. Environmental air pollution has been suggested as a potential contributor to elevated intraocular pressure; however, no studies have demonstrated such an association to date.

Objective

To investigate the association of long-term ambient black carbon exposure with intraocular pressure in community-dwelling older adults.

Design, Setting, and Participants

This population-based analysis, conducted from October 18, 2017, through March 22, 2018, used data from the all-male, New England-based Normative Aging Study of the US Department of Veterans Affairs. The analysis included 419 older men with a total of 911 follow-up study visits between January 1, 2000, and December 30, 2011. Intraocular pressure was measured by Goldmann applanation tonometry during the study visits. Validated spatiotemporal models were used to generate 1-year black carbon exposure levels at the addresses of the participants.

Main Outcomes and Measures

An independently developed genetic score approach was used to calculate allelic risk scores for 3 pathways associated with black carbon toxicity: endothelial function, oxidative stress, and metal processing. The associations among black carbon exposure, allelic risk scores, and intraocular pressure were explored using linear mixed-effects models.

Results

All 419 participants were men with a mean (SD) age of 75.3 (6.9) years. The mean (SD) 1-year black carbon exposure was 0.51 (0.18) μg/m3, and the mean (SD) intraocular pressure for the left eye was 14.1 (2.8) mm Hg and for the right eye was 14.1 (3.0) mm Hg. Of the 911 visits, 520 (57.1%) had a high endothelial function allelic risk score, 644 (70.7%) had a high metal-processing allelic risk score, and 623 (68.4%) had a high oxidative stress allelic risk score. In fully adjusted linear mixed-effects models, the association of black carbon with intraocular pressure was greater in individuals with a high oxidative stress allelic score (β = 0.36; 95% CI, 0.003-0.73) compared with individuals with a low score (β = -0.35; 95% CI, -0.86 to 0.15).

Conclusions and Relevance

Ambient black carbon exposure may be a risk factor for increased intraocular pressure in individuals susceptible to other biological oxidative stressors. If additional studies confirm these results, monitoring ambient black carbon exposure and physiological oxidative stress may prevent the development and progression of intraocular pressure-related disease.

Open-Angle Glaucoma: Burden of Illness, Current Therapies, and the Management of Nocturnal IOP Variation

Glaucoma is a chronic, debilitating disease and a leading cause of global blindness. Despite treatment efforts, 10% of patients demonstrate loss of vision. In the US, > 80% of glaucoma cases are classified as open-angle glaucoma (OAG), with primary open-angle (POAG) being the most common. Although there has been tremendous innovation in the surgical treatment of glaucoma as of late, two clinical variants of OAG, normal-tension glaucoma (NTG) and severe POAG, are especially challenging for providers because patients with access to care and excellent treatment options may progress despite achieving a “target” intraocular pressure value. Additionally, recent research has highlighted the importance of nocturnal IOP control in avoiding glaucomatous disease progression. There remains an unmet need for new treatment options that can effectively treat NTG and severe POAG patients, irrespective of baseline IOP, while overcoming adherence limitations of current pharmacotherapies, demonstrating a robust safety profile, and more effectively controlling nocturnal IOP.

Funding The Rapid Service Fees were funded by the corresponding author, Tanner J. Ferguson, MD.

Eight-Year Incidence of Open-Angle Glaucoma in the Tema Eye Survey

PURPOSE

To determine the incidence of open-angle glaucoma (OAG) and its risk factors in the Tema Eye Survey in Ghana, West Africa.

DESIGN

Longitudinal, observational population-based study.

PARTICIPANTS

One thousand two hundred five of 1500 participants 40 years of age or older selected randomly from 5603 participants originally drawn from the population and who had undergone a baseline examination.

METHODS

All participants underwent baseline and follow-up ophthalmologic examinations 8 years apart. Glaucoma diagnosis was determined based on the International Society for Geographical and Epidemiologic Ophthalmology criteria.

MAIN OUTCOME MEASURES

Incidence and odds ratio (OR).

RESULTS

The response rate was 80.3%. Of 1101 nonglaucomatous participants at baseline who had complete follow-up data, 4.6% (95% confidence interval [CI], 3.7%-5.2%) demonstrated OAG over the 8-year period, or 0.58% (95% CI, 0.4%-0.8%) per year. The 8-year incidence increased with age from 3.1% in those 40 to 49 years old to 7.0% in those 60 to 69 years old. Baseline risk factors for incident OAG were male gender (OR, 2.1; 95% CI, 1.1-4.0; P = 0.025), older age relative to those 40 to 49 years old (those 50-50 years old: OR, 2.6; 95% CI, 1.2-5.7; those 60-69 years old: OR, 4.3; 95% CI, 2.0-8.8; and for those 70 years of age and older: OR, 6.3; 95% CI, 2.6-15.4; all P < 0.001), higher intraocular pressure (IOP; OR, 1.4; 95% CI, 1.1-1.8; P < 0.001), larger vertical cup-to-disc ratio (OR, 5.8; 95% CI, 5.2-6.6; P < 0.001), and thinner central cornea (OR, 1.2; 95% CI, 1.03-1.5; P = 0.013). A separate analysis performed with central corneal thickness-based IOP correction did not change the outcome of the associative model of incident glaucoma.

CONCLUSIONS

The incidence of OAG is higher in this population than reported in nonblack populations outside Africa. This is important not only in Ghana and probably other West African countries but also wherever people of the West African diaspora reside. These data enhance our understanding of the epidemiologic factors of OAG in this setting and may serve as reference for public health policy and planning.

Primary Open-Angle Glaucoma Preferred Practice Pattern(®) Guidelines

PRIMARY OPEN-ANGLE GLAUCOMA PREFERRED PRACTICE PATTERN®

GUIDELINES

Evidence-based update of the Primary Open-Angle Glaucoma Preferred Practice Pattern® (PPP) guidelines, describing the diagnosis and management of patients with primary open-angle glaucoma with an algorithm for patient management and detailed recommendations for evaluation and treatment options.

Primary Angle Closure Preferred Practice Pattern(®) Guidelines

PRIMARY ANGLE CLOSURE PREFERRED PRACTICE PATTERN®

GUIDELINES

Evidence-based update of the Primary Angle Closure Preferred Practice Pattern® (PPP) guidelines, describing the diagnosis and management of patients with primary angle closure with detailed recommendations for evaluation and treatment options.

A common variant near TGFBR3 is associated with primary open angle glaucoma

Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10⁻³³), we observed one SNP showing significant association to POAG (CDC7–TGFBR3 rs1192415, OR_G-allele = 1.13, P_meta = 1.60 × 10⁻⁸). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis.

Osteogenesis imperfecta and primary open angle glaucoma: genotypic analysis of a new phenotypic association

PURPOSE

Osteogenesis imperfecta (OI) is a group of inherited disorders characterized by bone fragility. Ocular findings include blue sclera, low ocular rigidity, and thin corneal thickness. However, there are no documented cases linking OI and primary open angle glaucoma (POAG). In this report, we describe three individuals, one isolated case and two from a multiplex family, with OI type I and POAG.

METHODS

Available family members with OI and POAG had a complete eye examination, including visual acuity, intraocular pressure (IOP), pachymetry, slit-lamp exam, dilated fundus exam, and visual fields. DNA from blood samples was sequenced and screened for mutations in COL1A1/2 and myocilin (MYOC).

RESULTS

All subjects had OI type I. Findings of POAG included elevated IOP, normal gonioscopy, and glaucomatous optic disc cupping and visual field loss. POAG cosegregated with OI in the multiplex family. The multiplex family had a single nucleotide insertion (c.540_541insC) in COL1A1 resulting in a frameshift mutation and a premature termination codon. The sporadic case had a COL1A1 splice acceptor site mutation (c.2452-2A>T or IVS36-2A>T) predicted to result in a premature termination codon due to intron inclusion or a cryptic splice site. None of the glaucoma cases had mutations or sequence changes in MYOC.

CONCLUSIONS

We identified two novel mutations in COL1A1 in individuals with OI type I and POAG. Thus, some mutations in COL1A1 may be causative for OI and POAG. Alternatively, susceptibility genes may interact with mutations in COL1A1 to cause POAG.

Investigation of known genetic risk factors for primary open angle glaucoma in two populations of African ancestry

PURPOSE

Multiple genes have been associated with primary open angle glaucoma (POAG) in Caucasian populations. We now examine the association of these loci in populations of African ancestry, populations at particularly high risk for POAG.

METHODS

We genotyped DNA samples from two populations: African American (1150 cases and 999 controls) and those from Ghana, West Africa (483 cases and 593 controls). Our analysis included 57 single nucleotide polymorphisms (SNPs) in five loci previously associated with POAG at the genome-wide level, including CDKN2B-AS1, TMCO1, CAV1/CAV2, chromosome 8q22 intergenic region, and SIX1/SIX6. We evaluated association in the full datasets, as well as subgroups with normal pressure glaucoma (NPG, maximum IOP ≤21 mm Hg) and high pressure glaucoma (HPG, IOP >21 mm Hg).

RESULTS

In African Americans, we identified an association of rs10120688 in the CDNK2B-AS1 region with POAG (P = 0.0020). Several other SNPs were nominally associated, but did not survive correction for multiple testing. In the subgroup analyses, significant associations were identified for rs10965245 (P = 0.0005) in the CDKN2B-AS1 region with HPG and rs11849906 in the SIX1/SIX6 region with NPG (P = 0.006). No significant association was identified with any loci in the Ghanaian samples.

CONCLUSIONS

POAG genetic susceptibility alleles associated in Caucasians appear to play a greatly reduced role in populations of African ancestry. Thus, the major genetic components of POAG of African origin remain to be identified. This finding underscores the critical need to pursue large-scale genome-wide association studies in this understudied, yet disproportionately affected population.

Low prevalence of myocilin mutations in an African American population with primary open-angle glaucoma

PURPOSE

Mutations in the myocilin gene (MYOC) are associated with primary open-angle glaucoma (POAG) in many different populations. This study represents the first large survey of MYOC mutations in an African American population.

METHODS

We recruited 529 African American subjects with POAG and 270 African American control subjects in this study. A complete eye examination and blood collection was performed in all study subjects. Genomic DNA was extracted. The entire coding sequence of MYOC was amplified and sequenced using the Sanger method. Identified MYOC variants were compared with previously reported MYOC mutations.

RESULTS

We identified a total of 29 MYOC variants including six potential MYOC mutations. Two mutations (Thr209Asn and Leu215Gln) are novel and are found only in cases and no controls. We also identified four previously reported MYOC mutations in cases and no controls (Tyr453MetfsX11, Gln368X, Thr377Met, and Ser393Arg). The overall frequency of glaucoma-causing MYOC mutations in our African American population with POAG was 1.4%.

CONCLUSIONS

We identified two novel probable glaucoma-causing MYOC mutations (Thr209Asn and Leu215Gln). This study indicates that, despite the high prevalence of POAG, MYOC mutations are rare in the African American population.

Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up

PURPOSE

To report 5-year treatment outcomes in the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTINGS

Seventeen clinical centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) ≥18 mm Hg and ≤40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

Tube shunt (350-mm(2) Baerveldt glaucoma implant) or trabeculectomy with mitomycin C ([MMC]; 0.4 mg/mL for 4 minutes).

MAIN OUTCOME MEASURES

IOP, visual acuity, use of supplemental medical therapy, and failure (IOP >21 mm Hg or not reduced by 20%, IOP ≤5 mm Hg, reoperation for glaucoma, or loss of light perception vision).

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At 5 years, IOP (mean ± SD) was 14.4 ± 6.9 mm Hg in the tube group and 12.6 ± 5.9 mm Hg in the trabeculectomy group (P = .12). The number of glaucoma medications (mean ± SD) was 1.4 ± 1.3 in the tube group and 1.2 ± 1.5 in the trabeculectomy group (P = .23). The cumulative probability of failure during 5 years of follow-up was 29.8% in the tube group and 46.9% in the trabeculectomy group (P = .002; hazard ratio = 2.15; 95% confidence interval = 1.30 to 3.56). The rate of reoperation for glaucoma was 9% in the tube group and 29% in the trabeculectomy group (P = .025).

CONCLUSIONS

Tube shunt surgery had a higher success rate compared to trabeculectomy with MMC during 5 years of follow-up in the TVT Study. Both procedures were associated with similar IOP reduction and use of supplemental medical therapy at 5 years. Additional glaucoma surgery was needed more frequently after trabeculectomy with MMC than tube shunt placement.

Postoperative complications in the Tube Versus Trabeculectomy (TVT) study during five years of follow-up

PURPOSE

To describe postoperative complications encountered in the Tube Versus Trabeculectomy (TVT) Study during 5 years of follow-up.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTINGS

Seventeen clinical centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) ≥18 mm Hg and ≤40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

Tube shunt (350-mm(2) Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC 0.4 mg/mL for 4 minutes).

MAIN OUTCOME MEASURES

Surgical complications, reoperations for complications, visual acuity, and cataract progression.

RESULTS

Early postoperative complications occurred in 22 patients (21%) in the tube group and 39 patients (37%) in the trabeculectomy group (P = .012). Late postoperative complications developed in 36 patients (34%) in the tube group and 38 patients (36%) in the trabeculectomy group during 5 years of follow-up (P = .81). The rate of reoperation for complications was 22% in the tube group and 18% in the trabeculectomy group (P = .29). Cataract extraction was performed in 13 phakic eyes (54%) in the tube group and 9 phakic eyes (43%) in the trabeculectomy group (P = .43).

CONCLUSIONS

A large number of surgical complications were observed in the TVT Study, but most were transient and self-limited. The incidence of early postoperative complications was higher following trabeculectomy with MMC than tube shunt surgery. The rates of late postoperative complications, reoperation for complications, and cataract extraction were similar with both surgical procedures after 5 years of follow-up.

A comparison of the Ex-PRESS™ mini glaucoma shunt with standard trabeculectomy in the surgical treatment of glaucoma

BACKGROUND AND OBJECTIVE

To compare the success and complication rates of patients with glaucoma who had an Ex-PRESS mini glaucoma shunt device implantation (Optonol, Ltd., Neve Ilan, Israel) to those who had conventional trabeculectomy.

PATIENTS AND METHODS

The records of 76 eyes of 69 consecutive subjects who had Ex-PRESS implants and 77 eyes of 65 consecutive controls who had trabeculectomy procedures were reviewed. All surgeries were performed by one of the authors (LWH). Success was defined as an intraocular pressure (IOP) between 5 and 21 mm Hg in patients who did not require further glaucoma surgery in the eye of note.

RESULTS

The difference in the percentage of cases of postoperative hypotony between the standard trabeculectomy group (16%) and the Ex-PRESS group (4%) was statistically significant (P = .023).

CONCLUSION

The Ex-PRESS device is at least as effective as the standard trabeculectomy in lowering the IOP of patients with glaucoma, with a significantly lower risk of postoperative hypotony. The data further suggest that the Ex-PRESS device results in an overall greater percentage reduction in IOP than with trabeculectomy, although this did not reach statistical significance.

Glaucoma Progression Analysis software compared with expert consensus opinion in the detection of visual field progression in glaucoma

PURPOSE

To compare the results of Glaucoma Progression Analysis (GPA, Carl Zeiss Meditec, Dublin, CA) to subjective expert consensus in the detection of glaucomatous visual field progression.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

We included 100 eyes of 83 glaucoma patients.

METHODS

Five serial Humphrey visual fields from 100 eyes of 83 glaucoma patients were evaluated by 5 masked glaucoma subspecialists for determination of progression. Four months later, with a randomly reordered patient sequence, the same visual field series were reevaluated by the same graders, at which time they had access to the Glaucoma Progression Analysis (GPA) printout.

MAIN OUTCOME MEASURES

The level of agreement between majority expert consensus and GPA, both before and after access to GPA data, was assessed using kappa statistics.

RESULTS

On initial review and on reevaluation with access to the GPA printout, the level of agreement between majority expert consensus and GPA was fair (kappa = 0.52, 95% confidence interval [CI], 0.35-0.69 and kappa = 0.62; 95% CI, 0.46-0.78, respectively). Expert consensus was more likely to classify a series of fields as showing progression than was GPA (P ≤ 0.002). There was good agreement between expert consensus on initial review and reevaluation 4 months later (kappa = 0.77; 95% CI, 0.65-0.90).

CONCLUSIONS

The level of agreement between majority expert consensus of subjective determination of visual field progression and GPA is fair. In cases of disagreement with GPA, the expert consensus classification was usually progression. Access to the results of GPA did not significantly change the level of agreement between expert consensus and the GPA result; however, expert consensus did change in 11 of 100 cases.

GALC deletions increase the risk of primary open-angle glaucoma: the role of Mendelian variants in complex disease

DNA copy number variants (CNVs) have been reported in many human diseases including autism and schizophrenia. Primary Open Angle Glaucoma (POAG) is a complex adult-onset disorder characterized by progressive optic neuropathy and vision loss. Previous studies have identified rare CNVs in POAG; however, their low frequencies prevented formal association testing. We present here the association between POAG risk and a heterozygous deletion in the galactosylceramidase gene (GALC). This CNV was initially identified in a dataset containing 71 Caucasian POAG cases and 478 ethnically matched controls obtained from dbGAP (study accession phs000126.v1.p1.) (p = 0.017, fisher's exact test). It was validated with array comparative genomic hybridization (arrayCGH) and realtime PCR, and replicated in an independent POAG dataset containing 959 cases and 1852 controls (p = 0.021, OR (odds ratio) = 3.5, 95% CI -1.1-12.0). Evidence for association was strengthened when the discovery and replication datasets were combined (p = 0.002; OR = 5.0, 95% CI 1.6-16.4). Several deletions with different endpoints were identified by array CGH of POAG patients. Homozygous deletions that eliminate GALC enzymatic activity cause Krabbe disease, a recessive Mendelian disorder of childhood displaying bilateral optic neuropathy and vision loss. Our findings suggest that heterozygous deletions that reduce GALC activity are a novel mechanism increasing risk of POAG. This is the first report of a statistically-significant association of a CNV with POAG risk, contributing to a growing body of evidence that CNVs play an important role in complex, inherited disorders. Our findings suggest an attractive biomarker and potential therapeutic target for patients with this form of POAG.

Genome-wide linkage scan for primary open angle glaucoma: influences of ancestry and age at diagnosis

Primary open-angle glaucoma (POAG) is the most common form of glaucoma and one of the leading causes of vision loss worldwide. The genetic etiology of POAG is complex and poorly understood. The purpose of this work is to identify genomic regions of interest linked to POAG. This study is the largest genetic linkage study of POAG performed to date: genomic DNA samples from 786 subjects (538 Caucasian ancestry, 248 African ancestry) were genotyped using either the Illumina GoldenGate Linkage 4 Panel or the Illumina Infinium Human Linkage-12 Panel. A total of 5233 SNPs was analyzed in 134 multiplex POAG families (89 Caucasian ancestry, 45 African ancestry). Parametric and non-parametric linkage analyses were performed on the overall dataset and within race-specific datasets (Caucasian ancestry and African ancestry). Ordered subset analysis was used to stratify the data on the basis of age of glaucoma diagnosis. Novel linkage regions were identified on chromosomes 1 and 20, and two previously described loci-GLC1D on chromosome 8 and GLC1I on chromosome 15--were replicated. These data will prove valuable in the context of interpreting results from genome-wide association studies for POAG.

Interobserver agreement and intraobserver reproducibility of the subjective determination of glaucomatous visual field progression

PURPOSE

To determine the extent of interobserver agreement and intraobserver reproducibility of the subjective determination of visual field progression with achromatic automated static perimetry in eyes with glaucoma, and to determine the impact of access to Glaucoma Progression Analysis (GPA) data on interobserver agreement.

DESIGN

Retrospective, observational case series.

PARTICIPANTS

Five glaucoma subspecialists from 5 different academic medical centers.

METHODS

Five visual field tests from each of 100 eyes of 83 patients being monitored for glaucoma were retrospectively identified and subjectively and independently evaluated by the 5 glaucoma subspecialists. Each set of visual fields was classified regarding progression as "none," "questionable," "probable," or "definite." More than 1 month later, the same expert observers reevaluated the same sets of visual field tests to allow determination of intraobserver reproducibility. A final subjective evaluation regarding progression was performed 3 months later, at which time the expert observers had access to the GPA printout.

MAIN OUTCOME MEASURES

The level of interobserver agreement and intraobserver reproducibility was estimated using kappa statistics on the raw classification data and also on dichotomized data in which "none" and "questionable" progression were reclassified together as nonprogressed and " probable" and "definite" were reclassified as progressed.

RESULTS

Intraobserver reproducibility was good to excellent (kappa = 0.62-0.78) for the raw data and moderate to good (kappa = 0.58-0.71) for the dichotomized data. Interobserver agreement was moderate (kappa = 0.45; 95% confidence interval [CI], 0.35-0.55) for the raw classification data and also for dichotomized data (kappa = 0.55; 95% CI, 0.46-0.64). Access to the GPA printout did not significantly change the level of interobserver agreement.

CONCLUSIONS

Five glaucoma experts had good to excellent reproducibility of the determination of visual field progression compared with earlier evaluation of the same field sets. Agreement among the experts with each other was only moderate, and did not improve when each had access to GPA results. .

Combined fluocinolone acetonide intravitreal insertion and glaucoma drainage device placement for chronic uveitis and glaucoma

PURPOSE

To determine whether a fluocinolone acetonide sustained-release intravitreal drug delivery system can be implanted safely at the same time that a glaucoma drainage device is placed for eyes with uveitis and elevated intraocular pressure (IOP) receiving maximum tolerated IOP-lowering therapy.

DESIGN

Retrospective, observational case series.

METHODS

Subjects had chronic noninfectious intermediate or posterior uveitis and elevated IOP while receiving maximum tolerated medical therapy. Fluocinolone acetonide implantation and glaucoma tube shunt placement were performed in a single surgical session. The main outcome measures were inflammatory recurrences, visual acuity (VA), use of adjunctive anti-inflammatory therapy, IOP, and adverse events.

RESULTS

Seven eyes of 5 patients were studied. The average number of recurrences 12 months before implantation was 3 episodes per eye; of the 3 eyes followed up for more than 30 months, none had an inflammatory recurrence within 30 months after implantation. The mean Snellen visual acuity 12 months after the combined surgery was 20/114, compared with 20/400 at baseline. Adjunctive steroid use decreased. Average IOP decreased from 27.3 mm Hg at baseline to 14.6 mm Hg 12 months after the combined surgery (P = .019).

CONCLUSIONS

The favorable results observed in all eyes suggest that fluocinolone acetonide implantation can be safely combined with glaucoma tube shunt placement in a single surgical session in eyes with uveitis and elevated IOP receiving maximum tolerated IOP-lowering therapy. Uveitis recurrences decreased, visual acuity improved, and IOP decreased. There were no adverse events during insertion of the fluocinolone acetonide implant and placement of the glaucoma tube shunt.

Three-year follow-up of the tube versus trabeculectomy study

PURPOSE

To report 3-year results of the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTING

Seventeen clinical centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy, cataract extraction with intraocular lens implantation, or both and uncontrolled glaucoma with intraocular pressure (IOP) > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

A 350-mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC 0.4 mg/ml for 4 minutes).

MAIN OUTCOME MEASURES

IOP, visual acuity, use of supplemental medical therapy, surgical complications, and failure (IOP >21 mm Hg or not reduced by 20%, IOP < or =5 mm Hg, reoperation for glaucoma, or loss of light perception vision).

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At 3 years, IOP (mean +/- standard deviation [SD]) was 13.0 +/- 4.9 mm Hg in the tube group and 13.3 +/- 6.8 mm Hg in the trabeculectomy group (P = .78). The number of glaucoma medications (mean +/- SD) was 1.3 +/- 1.3 in the tube group and 1.0 +/- 1.5 in the trabeculectomy group (P = .30). The cumulative probability of failure during the first 3 years of follow-up was 15.1% in the tube group and 30.7% in the trabeculectomy group (P = .010; hazards ratio, 2.2; 95% confidence interval, 1.2 to 4.1). Postoperative complications developed in 42 patients (39%) in the tube group and 63 patients (60%) in the trabeculectomy group (P = .004). Surgical complications were associated with reoperation and/or loss of > or =2 Snellen lines in 24 patients (22%) in the tube group and 28 patients (27%) in the trabeculectomy group (P = .58).

CONCLUSIONS

Tube shunt surgery had a higher success rate compared to trabeculectomy with MMC during the first 3 years of follow-up in the TVT Study. Both procedures were associated with similar IOP reduction and use of supplemental medical therapy at 3 years. While the incidence of postoperative complications was higher following trabeculectomy with MMC relative to tube shunt surgery, most complications were transient and self-limited.

Optineurin coding variants in Ghanaian patients with primary open-angle glaucoma

PURPOSE

Coding variants in the optineurin gene (OPTN, GLC1E) have been reported to play a role in primary open-angle glaucoma (POAG) in various populations. This study investigated the role of OPTN sequence variants in patients with POAG in Ghana (West Africa).

METHODS

This is a case-control study of unrelated Ghanaian POAG cases and non-glaucomatous controls. Ascertainment criteria for POAG included the presence of glaucomatous optic nerve neuropathy, associated visual field loss, and elevated intraocular pressure (IOP) in both eyes, all in the absence of secondary causes of glaucoma. Controls had normal optic nerves, visual fields, and IOP. All the coding exons of OPTN were polymerase chain reaction (PCR) amplified and sequenced in all 140 cases and 130 controls using an ABI 3730 DNA analyzer.

RESULTS

All the coding exons of OPTN were sequenced in 140 POAG patients and 130 controls. Several coding variants were identified including M98K, A134A, V147L, P292P, A301G, S321S, and E322K. Three coding variants (V147L, P292P, and A301G) have not been reported previously. There were no significant differences on the frequencies of all the identified variants between POAG cases and controls in this population.

CONCLUSIONS

This is the first comprehensive study of OPTN in a single West African population. Our results suggest that coding variants in OPTN may not contribute to the risk for POAG in persons of West African descent.

Phthisis after endoscopic cyclophotocoagulation

A 47-year-old man was treated with one session of endoscopic cyclophotocoagulation for uncontrolled, elevated intraocular pressure. Before treatment, the eye was quiet and uninflamed. Pretreatment visual acuity was 4/200 and the intraocular pressure was 24 mm Hg. Treatment was applied to the ciliary processes for nearly 360 degrees. During the postoperative follow-up, the patient developed eye pain and persistent ocular inflammation. This ultimately led to phthisical changes evident 5 months postoperatively, when visual acuity was 1/200 and the intraocular pressure was 7 mm Hg. Eighteen months after endoscopic cyclophotocoagulation, visual acuity was light perception and intraocular pressure was less than 1 mm Hg. Phthisis is among the complications that may result after treatment with endoscopic cyclophotocoagulation.

Health literacy and vision-related quality of life

BACKGROUND

Non-visual factors influence a person's vision-related quality of life (VRQoL). The purpose of this study was to assess the relationship between health literacy and VRQoL in glaucoma patients.

METHODS

One hundred and ninety-five subjects with open-angle glaucoma participated in a cross-sectional patient survey and chart review. Subjects were administered a test of health literacy, an assessment of physical and mental well-being, and an assessment of VRQoL, the National Eye Institute 25-Item Visual Function Questionnaire (VFQ-25). Charts were reviewed for visual acuity and visual field results.

RESULTS

In univariate analyses, older age (p<0.001), non-White race (p<0.001), worse visual acuity (p<0.001), worse visual field scores (p<0.001), lower level of education (p<0.001), worse health literacy (p<0.001) and worse score on the mental health component of the SF-12 (p = 0.005) were associated with worse VFQ-25 scores. In multivariate analyses, only older age was associated with worse total VFQ-25 scores (p<0.001), although the association between health literacy and the VFQ subscale of dependency remained significant (p = 0.04).

CONCLUSIONS

Individuals with a lower health literacy do not appear to have a worse overall VRQoL compared with those with a higher literacy, but worse health literacy is associated with increased dependency.

Lack of association between LOXL1 variants and primary open-angle glaucoma in three different populations

PURPOSE

Significant association has recently been reported between pseudoexfoliation glaucoma (XFG) and two single-nucleotide polymorphisms (SNPs), rs3825942, and rs1048661, in the lysyl oxidase-like 1 gene (LOXL1). The purpose of this study was to investigate whether XFG-associated variants of LOXL1 play a significant role in primary open-angle glaucoma in the Caucasian, African-American, and Ghanaian (West-African) populations.

METHODS

POAG was defined as the presence of glaucomatous optic nerve damage, associated visual field loss, and elevated intraocular pressure (>22 mm Hg in both eyes). Thirteen tagging SNPs were genotyped by allelic discrimination assays in the Caucasian (279 cases and 227 controls), African-American (193 cases and 97 controls), and Ghanaian (170 cases and 138 controls) populations. Allele and genotype frequencies were compared between the cases and controls from each population.

RESULTS

None of the SNPs associated with XFG in LOXL1 were significantly associated with POAG in these populations. The risk allele frequencies for rs2165241 and rs3825942 were significantly lower in the African-American and Ghanaian populations, compared with Caucasian individuals.

CONCLUSIONS

There was no association between SNPs in the LOXL1 gene and POAG. This is the first analysis of the LOXL1 gene in African-American and West-African populations. LOXL1 gene variants do not appear to play a significant role in the pathogenesis of POAG in populations of either Caucasian or West-African ancestry.

Aqueous humor sCD44 concentration and visual field loss in primary open-angle glaucoma

PURPOSE

To correlate aqueous humor soluble CD44 (sCD44) concentration, visual field loss, and glaucoma risk factors in primary open-angle glaucoma (POAG) patients.

METHODS

Aqueous samples were obtained by paracentesis from normal and glaucoma patients who were undergoing elective surgery and analyzed for sCD44 concentration by enzyme-linked immunosorbent assay.

RESULTS

In normal aqueous (n=124) the sCD44 concentration was 5.88+/-0.27 ng/mL, whereas in POAG aqueous (n=90) the sCD44 concentration was 12.76+/-0.66 ng/mL, a 2.2-fold increase (P<0.000001). In POAG patients with prior successful filtration surgery (n=13), the sCD44 concentration was decreased by 43% to 7.32+/-1.44 (P=0.001) in comparison with POAG patients without filtration surgery; however, the sCD44 concentration in the prior successful filtration subgroup with no medications and normal intraocular pressure was 12.62+/-3.81 (P=0.05) compared with normal. The sCD44 concentration of normal pressure glaucoma patients was 9.19+/-1.75 ng/mL, a 1.6-fold increase compared with normal (P=0.02). Race and intraocular pressure pulse amplitude were significant POAG risk factors in this cohort of patients. In both normal and POAG patients with mild and moderate visual field loss, sCD44 concentration was greater in African Americans than in whites (P=0.04).

CONCLUSIONS

sCD44 concentration in the aqueous of POAG patients correlated with the severity of visual field loss in all stages in white patients and in mild to moderate stages in African American patients. sCD44 concentration in aqueous is a possible protein biomarker of visual field loss in POAG.

Surgical complications in the Tube Versus Trabeculectomy Study during the first year of follow-up

PURPOSE

To describe the intraoperative and postoperative complications encountered during the first year of follow-up in the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTING

Seventeen clinical centers.

STUDY POPULATION

Two hundred twelve patients aged 18 to 85 years who had undergone previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

A 350-mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC).

MAIN OUTCOME MEASURES

Surgical complications, reoperation for complications, visual acuity, and cataract progression.

RESULTS

Intraoperative complications occurred in seven patients (7%) in the tube group and 10 patients (10%) in the trabeculectomy group (P = .59). Postoperative complications developed in 36 patients (34%) in the tube group and 60 patients (57%) in the trabeculectomy group during the first year of follow-up (P = .001). Surgical complications were associated with reoperation and/or loss of > or =2 lines of Snellen visual acuity in 18 patients (17%) in the tube group and 28 patients (27%) in the trabeculectomy group (P = .12).

CONCLUSIONS

There were a large number of surgical complications during the first year of follow-up in the study, but most were self-limited. The incidence of postoperative complications was higher after trabeculectomy with MMC than nonvalved tube shunt surgery. Serious complications resulting in reoperation and/or vision loss occurred with similar frequency with both surgical procedures.

Treatment outcomes in the tube versus trabeculectomy study after one year of follow-up

PURPOSE

To report one-year results of the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTING

17 Clinical Centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

350 mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC).

MAIN OUTCOME MEASURES

IOP, visual acuity, and reoperation for glaucoma.

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At one year, IOP (mean +/- SD) was 12.4 +/- 3.9 mm Hg in the tube group and 12.7 +/- 5.8 mm Hg in the trabeculectomy group (P = .73). The number of glaucoma medications (mean +/- SD) was 1.3 +/- 1.3 in the tube group and 0.5 +/- 0.9 in the trabeculectomy group (P < .001). The cumulative probability of failure during the first year of follow-up was 3.9% in the tube group and 13.5% in the trabeculectomy group (P = .017).

CONCLUSIONS

Nonvalved tube shunt surgery was more likely to maintain IOP control and avoid persistent hypotony or reoperation for glaucoma than trabeculectomy with MMC during the first year of follow-up in the TVT Study. Both surgical procedures produced similar IOP reduction at one year, but there was less need for supplemental medical therapy following trabeculectomy with MMC.

Health literacy and adherence to glaucoma therapy

PURPOSE

To describe the health literacy of subjects with open angle glaucoma and to investigate the hypothesis that low health literacy is associated with poor glaucoma medication adherence.

DESIGN

Cross-sectional patient survey and concomitant chart review.

METHODS

One hundred and ninety-seven subjects with open angle glaucoma participated in a survey which included basic demographic information such as age, gender, ethnicity, and level of education completed, and a test of heath literacy, the Rapid Assessment of Adult Literacy in Medicine. Information was collected regarding visual field tests and prescribed medication. The subjects' pharmacies were contacted to ascertain the number of refills requested over the previous six months.

RESULTS

Although 146 subjects (74%) reported completing high school, only 94 subjects (48.0%) read at or above a ninth grade level; 23 (11.7%) read at a level of third grade or below. The mean number of refills requested by a subject in the preceding six months was not predicted by race (P = .27,) gender (P = .31), age (P = .92), mean deviation of the visual field (P = .36), or level of education (P = .58). There was a positive relationship between health literacy and the number of refills obtained (P = .003).

CONCLUSIONS

Many patients with open angle glaucoma may have poor health literacy. The subjects in our study with low literacy were less adherent with their glaucoma medications than those with a higher level of literacy. Interventions specifically targeting patients with low literacy may improve medication adherence.

Measuring intraocular pressure-adjustments for corneal thickness and new technologies

PURPOSE OF REVIEW

Central corneal thickness has become an important biometric factor and is an essential part of the evaluation of glaucoma. Goldmann applanation tonometry is the most widely used method of measuring intraocular pressure, but it is well known that corneal parameters affect the accuracy of this instrument. Intraocular pressure reduction is currently the only treatment available for decreasing the risk of glaucoma progression, so it is important to have an accurate reading of the true intraocular pressure.

RECENT FINDINGS

New tonometers such as the dynamic contour tonometer and the Proview tonometer do not appear to be influenced by central corneal thickness. The ocular response analyzer provides a new measure of corneal biomechanics called corneal hysteresis. Rebound tonometry has been used in animal models of glaucoma, but has recently been compared to Goldmann applanation tonometry in humans. All of these technologies are presented in this review and the influence of corneal thickness on their accuracy is examined.

SUMMARY

Confronted with the expanding evidence that central corneal thickness is an important ocular parameter that should be measured in clinical practice, eye-care professionals understandably wonder how to best obtain the measurements and what to do with the information. There is wide disagreement among investigators as to if there is an adequately validated 'correction algorithm'; without a validated algorithm, the argument goes, clinicians cannot use the data. These newer technologies may allow clinicians to be able to accurately determine the true intraocular pressure without having to rely on a correction algorithm.

Longitudinal changes in central corneal thickness and their relation to glaucoma status: an 8 year follow up study

AIMS

To determine if central corneal thickness (CCT) changes over time and if this change relates to glaucoma progression.

METHODS

39 patients (64 eyes) with open angle glaucoma, ocular hypertension, glaucoma suspect status, or a normal eye examination were examined at two visits. CCT, age, race, sex, family history of glaucoma, presence of diabetes and systemic hypertension, diagnosis, visual acuity, spherical equivalent, intraocular pressure, vertical and horizontal cup to disc ratios, number of glaucoma medications prescribed, Advanced Glaucoma Intervention Study (AGIS) score and mean deviation of Humphrey visual fields, and interventions required were recorded. Statistical analysis used the Wilcoxon signed ranks test, linear regression, and analysis of variance.

RESULTS

Between the two visits (mean 8.2 years apart), mean CCT decreased by 17 mum in right eyes (p<0.002) and by 23 mum in left eyes (p<0.001). This decrease was greater in right eyes of patients with primary open angle glaucoma than in normals (p = 0.041). There was no significant association between change in CCT and other examination parameters. Change in CCT was not associated with topical carbonic anhydrase inhibitor use.

CONCLUSION

In this longitudinal study, CCT decreased over time, but this may not be related to glaucoma progression.

The glaucoma research foundation patient survey: patient understanding of glaucoma and its treatment

PURPOSE

Determine patients' understanding of glaucoma and its treatment, their sources of information about glaucoma, their preferences for treatment, their experience with medication side effects, and their reasons for changing eye doctors.

DESIGN

Prospective, nonrandomized patient survey study.

METHODS

A questionnaire was developed and sent to the 22,000 subscribers of the Gleams newsletter who have glaucoma.

RESULTS

Questionnaires were returned by 4310 glaucoma patients. Most respondents received glaucoma information from their eye doctor. Only 28% of respondents reported having changed eye doctors for reasons related to their glaucoma. Of those who had, 60% cited poor communication as the reason. When queried about specific side effects associated with their medication, over 85% of responding patients were never or rarely bothered by headaches and eyelid darkening. Most respondents (67% and 55%, respectively) were rarely or never disturbed by red eye or burning and stinging. Most respondents understood the importance of intraocular pressure (IOP) lowering in glaucoma, and of those patients who expressed a preference, 92% reported that they would prefer the medication that lowers IOP the most, even if it caused red eye for a few weeks, over a medication that caused no red eye but did not get IOP as low.

CONCLUSIONS

Patients who subscribe to Gleams and responded to the survey rely most on their doctors for information about glaucoma and its treatment. Most understand the importance of maintaining low IOP to decrease the risk of vision loss, and most will tolerate temporary ocular side effects to achieve low IOP.

High Failure Rate Associated With 180?? Selective Laser Trabeculoplasty

PURPOSE

To determine the efficacy of selective laser trabeculoplasty (SLT) in a tertiary care referral center.

PATIENTS AND METHODS

In this retrospective study of selective laser trabeculoplasty performed by five physicians, 94 eyes from 94 patients were included. A majority (83/92, 90%) underwent 180 degrees selective laser trabeculoplasty. Selective laser trabeculoplasty failure was defined in two ways: (1) IOP decrease <3 mm Hg (definition one), or (2) IOP decrease <20% (definition two), on two successive visits > or =4 weeks after SLT.

RESULTS

Overall failure rates were 68% (64/94) and 75% (70/94) (by definitions one and two, respectively). By survival/life-table analysis, mean time to failure was 6 months and 5.5 months, by definitions one and two, respectively. By the end of the study (14.5 months), the failure rates were 86% and 92% by definitions one and two, respectively. By each definition, in both univariable and multivariable analysis, only lower baseline IOP was a significant predictor of failure.

CONCLUSIONS

Selective laser trabeculoplasty had an overall low success rate in our tertiary clinic population, with overall failure rates of 68% to 74% in those who underwent 180 degrees selective laser trabeculoplasty.

Early rapid rise in intraocular pressure after intravitreal triamcinolone acetonide injection

PURPOSE

To report the occurrences of early rapid increases in intraocular (IOP) after intravitreal glucocorticoid injection.

DESIGN

Observational case series.

METHODS

We retrospectively reviewed the records of three patients seen and treated at Duke Eye Center.

RESULTS

In all three cases, a significant rise in IOP occurred within 1 week of intravitreal triamcinolone injection for refractory macular edema. In one patient, a white material was found in the angle on gonioscopy. All three cases required surgical intervention to reduce the IOP.

CONCLUSIONS

Considering the early rapid rise in IOP in these three cases, we suggest that clinicians closely monitor patients after intravitreal triamcinolone injections for the development of acute glaucoma. Additionally, it may be advisable to perform gonioscopic examinations to look for any abnormal accumulation of material in the angle.

Clinical Comparison of the Proview Eye Pressure Monitor With the GoldmannApplanation Tonometer and the TonoPen

OBJECTIVE

To compare intraocular pressure (IOP) values obtained by patients using the new Proview eye pressure monitor (Bausch & Lomb, Rochester, NY) with those measured with the Goldmann tonometer and the TonoPen (Mentor, Norwell, Mass).

METHODS

Eighty-six patients (a total of 171 eyes) with a diagnosis of glaucoma or glaucoma suspect successfully completed the study. The IOP was measured by 3 methods in the following order: Goldmann tonometer, TonoPen, and Proview eye pressure monitor. The central corneal thickness was measured by an ultrasonic pachymeter. Separately for each eye, the differences in mean IOP values between measurement methods were assessed with paired t tests and also in multivariate models that tested the dependence of IOP difference on central corneal thickness.

RESULTS

There was a significant difference (P<.001) in the mean IOPs measured by the 3 different methods (Goldmann vs Proview, Goldmann vs TonoPen, and TonoPen vs Proview) for both eyes, and the difference was independent of the central corneal thickness. The differences between IOP measured by Goldmann and Proview were similar in all categories of patient-reported ease of using the Proview.

CONCLUSIONS

The IOPs obtained with the Proview eye pressure monitor are significantly lower than those measured with Goldmann tonometer and the TonoPen, and variations of the central corneal thickness do not contribute to the difference. Intraclass correlations of IOP values obtained with the Goldmann and the Proview or TonoPen and Proview are not strong. On the other hand, as expected, measurements with Goldmann and TonoPen agreed fairly well.

Central corneal thickness as a risk factor for advanced glaucoma damage

OBJECTIVE

To determine if central corneal thickness (CCT) is related to the level of glaucoma severity at the initial examination.

METHODS

The initial visit to a glaucoma specialist by consecutive patients with primary open-angle glaucoma from 1997 to 2002 was reviewed retrospectively. Each patient's age, sex, race, family history of glaucoma, number of glaucoma medications, visual acuity, spherical equivalent, intraocular pressure, CCT, visual field data, and vertical and horizontal cup-disc ratios were analyzed.

RESULTS

Three hundred fifty eyes of 190 patients met the inclusion and exclusion criteria. Central corneal thickness was significantly lower in blacks (mean, 537 microm) than in whites (mean, 556 microm). Lower CCT was significantly associated with worsened Advanced Glaucoma Intervention Study score, worsened mean deviation of visual field, increased vertical and horizontal cup-disc ratios, and increased number of glaucoma medications. In multivariate analysis, lower CCT was significantly associated with worsened Advanced Glaucoma Intervention Study score, worsened mean deviation of visual field, and increased vertical and horizontal cup-disc ratios.

CONCLUSIONS

Central corneal thickness is a powerful clinical factor in determining glaucoma severity at the initial examination by a specialist. Measuring CCT may aid the ophthalmologist in identification of glaucoma patients at high risk for progression.

Glaucoma in Ghana, West Africa: clinical features and the role of mutations in Myocilin

POAG is a severely debilitating disease in West Africa. Currently, many patients seem to be misclassified as having POAG who in fact have CACG. Improved examination techniques, including routine gonioscopy, would increase diagnostic accuracy and improve treatment strategies. The incidence of Myocilin mutations in this group of individuals is similar to that found in other populations around the world. Myocilin plays a limited role in the pathogenesis of POAG in this population.

Increased periocular pigmentation with ocular hypotensive lipid use in African Americans

PURPOSE

To report increased eyelid pigmentation as an adverse side effect associated with topical ocular hypotensive lipids in African Americans.

DESIGN

Interventional case series.

METHODS

Two African-American patients with open-angle glaucoma are described in whom increased eyelid pigmentation developed 1 month to 5 months after beginning treatment with either latanoprost or bimatoprost.

RESULTS

Latanoprost was discontinued in an African-American patient, and pigmentation gradually diminished by 3 months after cessation of latanoprost. Increased eyelid pigmentation and increased eyelash length were noted in another African-American patient after just 4 weeks on bimatoprost.

CONCLUSIONS

An increase in eyelid pigmentation and eyelash growth is a possible complication of topical ocular hypotensive lipid therapy, even in African-American patients. The changes seems to present earlier after bimatoprost treatment then after latanoprost treatment. Cessation of these medications may lead to loss of induced pigmentation.

Using the arteriolar Pressure Attenuation Index to predict ocular hypertension progression to open-angle glaucoma

BACKGROUND

Vascular phenomena are considered important to optic nerve and visual field progression in open-angle glaucoma (OAG). A recently described formulation, the Pressure Attenuation Index (PAI), links arteriolar caliber variations to pressure loss along the retinal arteriolar system.

OBJECTIVE

To examine whether the PAI could predict ocular hypertension (OHT) progression to OAG.

METHODS

The PAI was calculated for 27 eyes of 14 patients with OHT using initial and final digitized optic disc photographs taken during a follow-up interval of 5 to 18 years. Serial stereo color disc photographs and visual fields were analyzed to determine progression.

RESULTS

At baseline, the arteriolar tree of 8 subjects with OHT that progressed to OAG (n = 8 eyes) demonstrated a 45.8% greater mean PAI value than that of 7 subjects who did not progress (n = 7 eyes) (mean +/- SEM, 5.31 +/- 0.93 vs 3.64 +/- 0.34; r = 0.83). Progression was independent of baseline cup-disc ratio. The PAI values of subjects with stable OHT remained stable after a median follow-up interval of 12.0 years. The PAI values of subjects with OHT that progressed demonstrated a further increase of 19.97% +/- 11.24% during a median follow-up period of 6.0 years.

CONCLUSIONS

The results support the hypothesis that low end-arteriolar pressure predicts the progression from OHT to OAG. The PAI provides a new, early, reproducible, and physiological method to study vascular phenomena in glaucoma.

Prevalence of myocilin mutations in adults with primary open-angle glaucoma in Ghana, West Africa

PURPOSE

Investigators have noted that primary open-angle glaucoma (POAG) in West Africa has an earlier age of onset and appears to be more clinically severe than in the United States and Europe. Primary open-angle glaucoma patients with mutations in myocilin have a similar phenotype. Therefore, we investigated the role of mutations in myocilin in patients with POAG in a West African population.

MATERIALS AND METHODS

Patients seen at the Emmanuel Eye Clinic in Accra, Ghana, were recruited for this study. Informed consent was obtained from all study patients. Glaucoma specialists from the sponsoring institution (PC, LWH, or RRA) ascertained all POAG and control patients. Age-matched unaffected controls were obtained in patients with an IOP < 22 mm Hg and normal-appearing optic nerves. PCR amplification of each of the three myocilin exons was performed. Denaturing high-performance liquid chromatography (Transgenomics Corp.) was used to detect allelic differences and samples demonstrating a mobility shift were sequenced in both directions.

RESULTS

Ninety unrelated affecteds with POAG and 76 control patients were recruited. Four individuals with severe POAG were found to have novel missense mutations in exon 3. Two exhibit an Asp380Asn mutation and two an Arg342Lys mutation. These changes were not detected in 152 ethnically matched control chromosomes. Fourteen affected individuals and eight controls exhibit a translationally silent polymorphism in codon 325 (Thr325Thr).

CONCLUSIONS

A total of 4.4% of patients with POAG have novel disease-associated mutations in myocilin. Mutations in myocilin appear to play a limited role in the pathogenesis of POAG in this region of West Africa.

Survey of glaucoma in an eye clinic in Ghana, West Africa

PURPOSE

To report the various types of glaucoma among West African patients presenting to an eye clinic in Ghana.

METHODS

A complete evaluation was performed in 198 consecutive Ghanaian glaucoma patients. Main outcome measures included intraocular pressure, visual acuity, gonioscopy findings, visual field, and total number of glaucoma medications.

RESULTS

The most common form of glaucoma was primary open-angle glaucoma (44.2%). Open-angle glaucoma suspects also comprised a large percentage of the group (30.5%). Chronic angle-closure glaucoma was diagnosed in 6.6% of the patients.

CONCLUSIONS

Primary open-angle glaucoma is the most common form of glaucoma being treated in this outpatient eye clinic in Ghana. Chronic angle-closure glaucoma was the second most common form of glaucoma in this series and was usually undiagnosed due to a lack of gonioscopic evaluation. Gonioscopy is an important diagnostic tool that should be promoted to guide more effective glaucoma treatment in this region. Pseudoexfoliation and pseudoexfoliation-associated glaucoma were not seen in this population.

Antithrombin III, a serpin family protease inhibitor, is a major heparin binding protein in porcine aqueous humor

Our hypothesis is that the proteins in aqueous humor may be involved in the regulation of outflow facility through the trabecular meshwork and uveoscleral meshwork. In this study, we analyzed the profile of heparin-binding proteins present in porcine aqueous humor to identify and characterize secretory proteins with a binding affinity for heparin. A single step involving heparin-sepharose affinity chromatography of porcine aqueous humor yielded a approximately 60 kDa protein as the major heparin-binding species. This protein was specifically eluted from the column by heparin. The N-terminal sequence and immunological cross reactivity of this protein confirmed its identity as antithrombin III. Aqueous humor from different species, as well as cells from human trabecular meshwork, Schlemm's canal, and lens epithelium, contained detectable amounts of antithrombin III. Based on its known anticoagulative function in endothelial cells and effects on the production of prostacyclin, it is reasonable to speculate that antithrombin III present in aqueous humor might influence the physiology of the trabecular and uveoscleral meshwork and thereby regulate intraocular pressure.

Excisional bleb revision to correct overfiltration or leakage

OBJECTIVES

To evaluate the effectiveness of excisional revision of filtering blebs for hypotony or leakage when more conservative measures have failed.

PATIENTS AND METHODS

Retrospective review of all patients who underwent excisional revision of a filtering bleb for hypotony (intraocular pressure [IOP] < 5 mm Hg) or leakage during a 3 year period. The revision consisted of excision of the avascular bleb, mobilization of the surrounding conjunctiva, and suturing of the conjunctiva at the limbus.

RESULTS

Sixteen patients were included in the study. The average age was 66.3 +/- 14.8 years (range, 39-83). Revision followed trabeculectomy in 11 cases, combined phacoemulsification-trabeculectomy in three cases, and inadvertent blebs in two cases. Five cases had bleb leaks without hypotony, four cases had hypotony alone, and seven cases had both hypotony and a bleb leak. Average follow-up after bleb revision was 25 +/- 11 months (range, 9-43). Average IOP increased from 3.8 +/- 5.6 mm Hg (range, 0-22) to 11.9 +/- 4.1 mm Hg (range, 3-18), with an average of 1.1 +/- 1.1 medication (range, 0-3). The IOP at the last visit was < 15 mm Hg in all but two patients, with 10 of the 16 patients requiring medications. At the last follow-up examination, visual acuity had improved > or = two lines in nine patients and was reduced two lines in one patient. Five patients had early postoperative limbal wound leaks; resuturing was required in one case.

CONCLUSIONS

Excisional bleb revision is an effective technique to correct hypotony or leakage after filtering surgery when other methods have failed. Intraocular pressure control is often maintained with the use of medications.