Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry

IMPORTANCE

Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders.

OBJECTIVES

To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma.

DESIGN, SETTINGS, AND PARTICIPANTS

A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14 917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma.

EXPOSURES

Genetic variants associated with primary open-angle glaucoma.

MAIN OUTCOMES AND MEASURES

Presence of primary open-angle glaucoma. Genome-wide significance was defined as P < 5 × 10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data.

RESULTS

A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-β A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; P = 2 × 10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14 917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; P < .001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; P = 4 × 10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry.

CONCLUSIONS AND RELEVANCE

In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies.

Oral administration of the 11β-hydroxysteroid-dehydrogenase type 1 inhibitor RO5093151 to patients with glaucoma: an adaptive, randomised, placebo-controlled clinical study

Background/aims

Cortisol is involved in the regulation of intraocular pressure (IOP). This study aimed to assess the effect of 11β-hydroxysteroid-dehydrogenase type 1 (11βHSD1) inhibition by oral administration of RO5093151 on IOP.

Methods

The exposure of key ocular compartments following oral administration was assessed in rabbits. An adaptive, randomised, placebo-controlled study gated by a Bayesian decision criterion was performed in 35 patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). Following a 7-day placebo-controlled run-in period, 200 mg twice daily RO5093151 or placebo (4:1) were administered for 7 days. The extent of 11βHSD1 inhibition was assessed by the ratio of urinary tetrahydrocortisol (5α and 5β)/tetrahydrocortisone (THF/THE). Time-matched IOP assessments were performed.

Results

A high distribution of RO5093151 into the rabbit eye was observed. In humans, a high and sustained inhibition of 11βHSD1 was shown by the decrease of THF/THE from 0.9 at baseline to 0.18 on day 7. There was no statistically significant difference in change of IOP from baseline. In the ‘worse eye’, the adjusted least square mean change from baseline was −2.7 mm Hg (95% CI −4.2 to –1.2) and −2.9(95% CI −5.9 to 0.1) in the RO5093151 and placebo group, respectively.

Conclusions

Despite high inhibition of 11βHSD1 and expected moderate to high tissue distribution in ocular tissues, a 7-day treatment with a high oral dose of RO5093151 did not result in a clinically meaningful effect on IOP in patients with POAG or OHT.

A Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of 2 and 4 Weeks of Twice-Daily Ocular Trabodenoson in Adults with Ocular Hypertension or Primary Open-Angle Glaucoma

Purpose: To evaluate the safety and ocular hypotensive efficacy of 4 trabodenoson doses administered twice daily over 14 or 28 days in subjects with ocular hypertension or primary open-angle glaucoma (POAG).

Methods: In this multicenter, randomized, double-masked, placebo-controlled, dose-escalation Phase 2 study, patients received unilateral topical twice-daily trabodenoson (50, 100, or 200 mcg) or placebo for 14 days, or 500 mcg trabodenoson or placebo for 28 days. Ocular and systemic safety and tolerability were assessed by examinations, clinical and laboratory studies. Intraocular pressure (IOP) was assessed using Goldmann tonometry.

Results: Trabodenoson was well tolerated; no clinically meaningful ocular or systemic side effects were identified. Trabodenoson produced a dose-dependent IOP reduction. IOP reductions in the 500 mcg group were significantly greater than placebo at all time points at Day 28. Mean IOP reductions from diurnal baseline ranged from −3.5 to −5.0 mmHg with a mean change of −4.1 mmHg in the 500 mcg group compared −1.0 to −2.5 mmHg with a mean change of −1.6 mmHg for the placebo group, and the Day 28 drop was significantly greater than at Day 14 (P = 0.0163) indicating improvement in IOP lowering with longer treatment time. IOP remained significantly reduced 24 h after the final 500 mcg dose (P = 0.048).

Conclusion: Twice-daily ocular doses of trabodenoson, from 50 to 500 mcg, were well tolerated and showed a dose-related decrease in IOP that was statistically significant and clinically relevant at 500 mcg in patients with ocular hypertension or POAG.

Fixed-combination brinzolamide 1%/brimonidine 0.2% vs monotherapy with brinzolamide or brimonidine in patients with open-angle glaucoma or ocular hypertension: results of a pooled analysis of two phase 3 studies

Purpose

To describe pooled efficacy and safety data from two phase 3 studies comparing brinzolamide 1%/brimonidine 0.2% fixed combination (BBFC) with its component medications, brinzolamide and brimonidine, in patients with open-angle glaucoma or ocular hypertension.

Methods

Data were pooled from two nearly identical clinical trials comparing BBFC with its component medications, each given three times daily. The 3-month efficacy outcome was mean intraocular pressure (IOP) at 0800, 1000, 1500, and 1700 hours. Safety outcomes included adverse events (AEs), best-corrected visual acuity, examination of ocular structures, pachymetry, perimetry, and vital signs.

Results

A total of 1350 patients were enrolled and included in this analysis (BBFC, n=437; brinzolamide, n=458; brimonidine, n=455). Baseline mean IOP levels were similar among the three treatment groups. At 3 months, mean IOP of the BBFC group was significantly lower than that of either monotherapy group (P<0.0001) at all the four time points. A total of 272 patients (20.1%) experienced at least one treatment-related AE (BBFC, 24.6% brinzolamide, 18.7% brimonidine, 17.4%), the majority of which were ocular AEs. One serious AE, moderate intensity chest pain, was considered related to brinzolamide treatment and resulted in study discontinuation.

Conclusions

This analysis strengthens the conclusions drawn from the two individual phase 3 studies showing that, in patients with open-angle glaucoma or ocular hypertension, BBFC had significantly superior IOP-lowering activity compared with either brinzolamide or brimonidine alone and a safety profile consistent with that of its individual components.

Efficacy and safety of bimatoprost in patients with elevated intraocular pressure: a 30-day comparison with latanoprost

PURPOSE

To compare the safety and efficacy of bimatoprost and latanoprost in patients with primary open-angle glaucoma or ocular hypertension.

METHODS

This was a 30-day, multicenter, double-masked, randomized, clinical trial. Patients (n = 64) diagnosed with primary open-angle glaucoma or ocular hypertension were randomly assigned to receive bimatoprost 0.03%, latanoprost 0.005%, or vehicle topically in both eyes once daily, in the evening, for 29 days. The primary endpoint was the reduction in IOP from baseline on day 14 and day 29. Secondary outcome measures included eye examinations and safety parameters.

RESULTS

Bimatoprost and latanoprost significantly lowered IOP from baseline (p <.001). Bimatoprost lowered IOP more than latanoprost at every timepoint measured (bimatoprost: 25-34% reduction, 5.9-8.9 mm Hg; latanoprost: 20-31% reduction, 4.4-7.9 mm Hg), although the between-group differences did not reach statistical significance. Over the 12-hour course of IOP measurements on day 29, bimatoprost provided better diurnal IOP control than latanoprost (p =.0378, area under the curve of diurnal IOP reductions, 1-way ANOVA with pairwise t-test). Both treatment regimens were safe and well tolerated, with no significant between-group differences in reports of specific adverse events. The most common side effect was conjunctival hyperemia, which was similarly apparent in the bimatoprost and latanoprost treatment groups.

CONCLUSIONS

At the end of this 30-day trial, once-daily bimatoprost 0.03% provided better diurnal IOP control than latanoprost and was safe and well tolerated in patients with ocular hypertension and glaucoma.

The efficacy and safety of the dorzolamide-timolol combination versus the concomitant administration of its components

OBJECTIVE

To evaluate whether a fixed combination of 2% dorzolamide and 0.5% timolol given twice daily showed equivalent efficacy to the concomitant administration of 2% dorzolamide given three times daily and 0.5% timolol given twice daily in patients whose intraocular pressure (IOP) remained elevated during monotherapy with 0.5% timolol twice daily.

DESIGN

Multicenter, parallel, randomized, double-masked clinical trial with an open-label extension.

PARTICIPANTS AND INTERVENTION

In the masked phase, 242 patients received either the dorzolamide-timolol combination twice daily and placebo three times daily or dorzolamide three times daily and timolol twice daily for up to 3 months. In the open-label extension, 220 patients received the dorzolamide-timolol combination twice daily for up to 9 months.

MAIN OUTCOME MEASURES

The criterion for establishing treatment equivalency was a 95% or greater confidence that the absolute difference in the mean change in IOP from baseline was less than 1.5 mmHg between treatments.

RESULTS

During 3 months of treatment, the dorzolamide-timolol combination reduced IOP relative to the 0.5% timolol baseline by approximately 14% at hour 0 (just before the morning dose), 20% at hour 2, and 15% at hour 8. The IOP-lowering effect of concomitant therapy with dorzolamide and timolol was approximately 16% at hour 0, 20% at hour 2, and 17% at hour 8. At hours 0, 2, and 8, there was greater than 97% confidence that the treatments were equivalent. During the open-label extension, the mean IOP reduction ranged from 14% to 15% at hour 0 and from 20% to 21% at hour 2. The treatment groups were generally comparable in terms of adverse events, symptoms, ocular signs, visual acuity, visual fields, physical examination, and laboratory measures.

CONCLUSIONS

The IOP-lowering effect of the dorzolamide-timolol combination is comparable to that of dorzolamide three times daily plus timolol twice daily and is maintained for up to 1 year. The dorzolamide-timolol combination provides clinically important reduction in IOP relative to baseline treatment with timolol alone and is generally well-tolerated for up to 1 year.

The efficacy and safety of the dorzolamide-timolol combination versus the concomitant administration of its components. Dorzolamide-Timolol Study Group

OBJECTIVE

To evaluate whether a fixed combination of 2% dorzolamide and 0.5% timolol given twice daily showed equivalent efficacy to the concomitant administration of 2% dorzolamide given three times daily and 0.5% timolol given twice daily in patients whose intraocular pressure (IOP) remained elevated during monotherapy with 0.5% timolol twice daily.

DESIGN

Multicenter, parallel, randomized, double-masked clinical trial with an open-label extension.

PARTICIPANTS AND INTERVENTION

In the masked phase, 242 patients received either the dorzolamide-timolol combination twice daily and placebo three times daily or dorzolamide three times daily and timolol twice daily for up to 3 months. In the open-label extension, 220 patients received the dorzolamide-timolol combination twice daily for up to 9 months.

MAIN OUTCOME MEASURES

The criterion for establishing treatment equivalency was a 95% or greater confidence that the absolute difference in the mean change in IOP from baseline was less than 1.5 mmHg between treatments.

RESULTS

During 3 months of treatment, the dorzolamide-timolol combination reduced IOP relative to the 0.5% timolol baseline by approximately 14% at hour 0 (just before the morning dose), 20% at hour 2, and 15% at hour 8. The IOP-lowering effect of concomitant therapy with dorzolamide and timolol was approximately 16% at hour 0.20% at hour 2, and 17% at hour 8. At hours 0, 2, and 8, there was greater than 97% confidence that the treatments were equivalent. During the open-label extension, the mean IOP reduction ranged from 14% to 15% at hour 0 and from 20% to 21% at hour 2. The treatment groups were generally comparable in terms of adverse events, symptoms, ocular signs, visual acuity, visual fields, physical examination, and laboratory measures.

CONCLUSIONS

The IOP-lowering effect of the dorzolamide-timolol combination is comparable to that of dorzolamide three times daily plus timolol twice daily and is maintained for up to 1 year. The dorzolamide-timolol combination provides clinically important reduction in IOP relative to baseline treatment with timolol alone and is generally well-tolerated for up to 1 year.

Effect of intracameral carbachol on intraocular pressure after cataract extraction

Thirty-two patients were randomly assigned to a treatment or a control group to determine the dose-response and duration of action of intracameral carbachol on immediate postoperative intraocular pressure after extracapsular cataract extraction using a viscoelastic substance. Patients in the treatment group received 0.5, 0.25, or 0.1 ml of 0.01% intracameral carbachol. Patients in the control group received 0.1 or 0.5 ml of balanced salt solution. Intraocular pressures of all patients were measured preoperatively and at three, six, 12, 24, and 48 hours postoperatively. The control group as a whole showed a 9.5-mm Hg intraocular pressure rise at three hours, a 10.0-mm Hg rise at six hours, a 9.0-mm Hg rise at 12 hours, and a 7.2-mm Hg rise at 24 hours postoperatively. The group treated with 0.5 ml of carbachol maintained stable intraocular pressures through the 48-hour measurement period. The groups treated with 0.25 and 0.1 ml of carbachol maintained stable intraocular pressures through 24 hours postoperatively. The differences in intraocular pressure were statistically significant for all treated groups through the 24-hour measurement.