Leon W. Herndon

Treatment Outcomes in the Tube Versus Trabeculectomy Study After One Year 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.

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.

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.

Primary Open-Angle Glaucoma Preferred Practice Pattern® Guidelines

UNLABELLED 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.

High failure rate associated with 180 degrees 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° 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 ≥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° selective laser trabeculoplasty.

A clinical comparison of transscleral cyclophotocoagulation with neodymium: YAG and semiconductor diode lasers

PURPOSE To compare the efficacy of transscleral cyclophotocoagulation using a neodymium: YAG (Nd:YAG) or semiconductor diode laser in controlling intraocular pressure in patients with refractory glaucoma. METHODS In a prospective study, 95 eyes of 91 patients with refractory glaucoma randomly received Nd:YAG or diode cyclophotocoagulation. Patients were followed for a mean of 10.4 months (10.42 +/- 3.16, mean +/- SD). We compared available data preoperatively and at 1 week, 1 month, 6 months, and 12 months postoperatively. Data analyzed were corrected visual acuity, intraocular pressure, and the type of glaucoma. RESULTS There was a statistically significant decrease in intraocular pressure after both Nd:YAG and diode cyclophotocoagulation at each time period. However, there were no significant differences in postoperative intraocular pressure or visual acuity change between Nd:YAG and diode procedures. CONCLUSIONS Compared with the Nd:YAG laser for transscleral cyclophotocoagulation, the diode laser has technological advantages including portability, durability, and smaller size, while providing equivalent postoperative intraocular pressure and visual acuity change.

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.

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.

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.