Absence of altered expression of optineurin in primary open angle glaucoma patients

PURPOSE

To investigate the expression level of the optineurin gene (OPTN) in the blood of primary open angle glaucoma (POAG) patients to determine if altered expression is playing a role in primary open angle glaucoma systemically.

METHODS

Patients (n=47) were eligible for inclusion if they met standard clinical criteria for POAG, including age greater than 40 years, intraocular pressure ≥21 mmHg in at least one eye before treatment, normal-appearing anterior chamber angles bilaterally on gonioscopy, and optic nerve injury characteristic of POAG. Control subjects (n=27) were recruited who were free from glaucoma by examination. DNA from patient was sequenced to look for possible mutations in the coding region of OPTN or its promoter. RNA was extracted from leukocytes of patients and controls and converted to cDNA by reverse transcriptase enzyme, and quantitative PCR was used to assess expression levels of OPTN and the β-globulin gene. The ratio of OPTN expression to β-globulin gene expression for POAG patients was compared to that of controls and to clinical characteristics of POAG patients.

RESULTS

No mutation(s) were detected in any of the patients after sequencing the full OPTN gene and its promoter region. Mean OPTN (p≤0.35), and β-globulin (p≤0.48) gene expression values were statistically similar in POAG patients and controls. OPTN/β-globulin (p≤0.83) ratios were also indistinguishable between POAG patients and controls. OPTN/β-globulin ratios were not significantly associated with age, sex, or ethnicity of patients within the POAG group. Similarly, OPTN/β-globulin ratios were not significantly affected by ethnicity or clinical parameters related to POAG severity including maximum intraocular pressure, vertical cup-to-disk ratio, static perimetry mean deviation, or static perimetry pattern standard deviation.

CONCLUSIONS

OPTN expression is not altered in the blood of POAG patients, suggesting that OPTN expression is not changed systemically and implying that other mechanisms are involved in POAG pathogenesis.

Fixed-combination brimonidine-timolol versus latanoprost in glaucoma and ocular hypertension: a 12-week, randomized, comparison study

OBJECTIVE

To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of fixed-combination brimonidine 0.2%-timolol 0.5% compared with latanoprost 0.005% in patients with glaucoma or ocular hypertension.

RESEARCH DESIGN AND METHODS

This was a prospective, randomized, multicenter, investigator-masked clinical trial. After washout of any previous IOP-lowering medications, patients with IOP of 24 mmHg or higher were randomized to twice-daily fixed-combination brimonidine 0.2%-timolol 0.5% (n = 73) or once-daily latanoprost 0.005% (n = 75, dosed in the evening, with vehicle control in the morning to maintain masking) for 12 weeks. IOP was measured at 8 a.m. (before dosing), 10 a.m., and 3 p.m. at baseline, week 6, and week 12.

CLINICAL TRIAL REGISTRATION

The trial is registered with the identifier 00811564 at http://www.clinicaltrials.gov .

MAIN OUTCOME MEASURES

The primary efficacy endpoint was diurnal IOP (averaged over 8 a.m., 10 a.m., and 3 p.m.) at week 12. Safety measures included biomicroscopy.

RESULTS

There was no statistically significant difference between the treatment groups in mean diurnal IOP at baseline (p = 0.118). At week 12, the mean (SD) diurnal IOP was 17.8 (2.9) mmHg with brimonidine-timolol and 17.9 (3.9) mmHg with latanoprost (p = 0.794). The percentage of patients achieving at least a 20% decrease from baseline diurnal IOP at week 12 was 87.7% in the brimonidine-timolol group and 77.3% in the latanoprost group (p = 0.131). Measured biomicroscopic changes from baseline to week 12 were infrequent in both groups.

CONCLUSIONS

Fixed-combination brimonidine-timolol was as effective as latanoprost in reducing IOP in patients with glaucoma or ocular hypertension. Both treatments demonstrated favorable ocular tolerability. The duration of the study was 12 weeks, and additional studies will be needed to compare the efficacy and safety of fixed-combination brimonidine-timolol and latanoprost during long-term treatment.

Unaltered myocilin expression in the blood of primary open angle glaucoma patients

PURPOSE

To investigate the expression of the myocilin gene (MYOC) in the blood of primary open angle glaucoma (POAG) patients to determine if altered systemic expression is playing a role.

METHODS

Patients (n=47) were eligible for inclusion if they met standard clinical criteria for POAG. Control subjects (n=27) were recruited who were free from glaucoma by examination. RNA was extracted from leukocytes of patients and controls and converted to cDNA by reverse transcriptase enzyme, and quantitative PCR was used to assess expression levels of MYOC and the house keeping gene β-globulin (HBB). The ratio of MYOC expression to HBB expression for POAG patients was compared to that of controls and to clinical characteristics of POAG patients.

RESULTS

Mean gene expression values were statistically similar in POAG patients and controls for both MYOC (p≤0.55) and HBB (p≤0.48). MYOC/HBB ratios were also statistically indistinguishable between POAG patients and controls (p≤0.90). MYOC/HBB ratios were not significantly associated with age, sex, or ethnicity of patients within the POAG group. Similarly, MYOC/HBB ratios were not significantly associated with clinical parameters related to POAG severity, including maximum intraocular pressure, vertical cup-to-disk ratio, static perimetry mean deviation, or static perimetry pattern standard deviation.

CONCLUSIONS

MYOC expression is not altered in the blood of POAG patients, unlike MYOC expression in trabecular meshwork (TM) cultures. These results suggests that MYOC expression is not altered systemically but rather that MYOC expression may contribute to POAG pathogenesis in specific tissues such as TM.

A clinical method to assess the effect of visual loss on the ability to perform activities of daily living

BACKGROUND/AIMS

To develop a clinically applicable, performance-based measure of the ability to perform visually related activities.

METHODS

99 patients with glaucoma and 21 subjects with a normal ocular examination completed a nine-item performance-based test (the Assessment of Ability Related to Vision (AARV)), received a standard ophthalmic clinical examination and answered the questions on the National Eye Institute's Visual Functioning Questionnaire (NEI-VFQ-25). All combinations of two, three or four items of the full nine-item AARV test were analysed, and their scores were compared with the full AARV scores and with clinical measures.

RESULTS

The correlation of four items (detecting motion, reading signs, finding objects and navigating an obstacle course) reduced test time from 60±5 min to 14±4 min and yielded results highly related to the nine-item test, including maintaining the relationship with clinical measures and with the NEI-VFQ-25.

CONCLUSION

A compressed AARV correlates highly with the full test, with a method of evaluating quality of life, and with clinical measures, yet takes on average 14 min to perform. As such, it may provide a clinically useful method of evaluating the worsening effects of illness and the benefits of treatments that affect visual loss on the ability to perform visually related activities.

Comparison of human ocular distribution of bimatoprost and latanoprost

PURPOSE

This study investigated the ocular distribution of bimatoprost, latanoprost, and their acid hydrolysis products in the aqueous humor, cornea, sclera, iris, and ciliary body of patients treated with a single topical dose of 0.03% bimatoprost or 0.005% latanoprost for understanding concentration-activity relationships.

METHODS

Thirty-one patients undergoing enucleation for an intraocular tumor not affecting the anterior part of the globe were randomized to treatment with bimatoprost or latanoprost at 1, 3, 6 or 12 h prior to surgery. Concentrations of bimatoprost, bimatoprost acid, latanoprost, and latanoprost acid in the human aqueous and ocular tissues were measured using liquid chromatography tandem mass spectrometry.

RESULTS

Following topical administration, intact bimatoprost was distributed in human eyes with a rank order of cornea/sclera >iris/ciliary body >aqueous humor. Bimatoprost acid was also detected in these tissues, where its low levels in the cornea relative to that of latanoprost acid indicated that bimatoprost hydrolysis was limited. Latanoprost behaved as a prodrug that entered eyes predominantly via the corneal route. Levels of latanoprost acid were distributed as cornea >>aqueous humor>iris>sclera>ciliary body.

CONCLUSIONS

Our study provided experimental evidence that levels of bimatoprost in relevant ocular tissues, and not only aqueous humor, are needed to understand the mechanisms by which bimatoprost lowers intraocular pressure (IOP) in human subjects. The data suggest that bimatoprost reached the target tissues favoring the conjunctival/scleral absorption route. Findings of intact bimatoprost in the target ciliary body indicated its direct involvement in reducing IOP. However, bimatoprost acid may have only a limited contribution on the basis that bimatoprost has greater/similar IOP-lowering efficacy than latanoprost, yet bimatoprost acid levels were a fraction of latanoprost acid levels in the aqueous humor and cornea and only sporadically detectable in the ciliary body. In this report, human ocular tissues were examined concurrently with aqueous humor for the in vivo distribution of bimatoprost, bimatoprost acid, latanoprost, and latanoprost acid.

Effects of acutely lowering intraocular pressure on the results of multifocal visual evoked potential testing

PURPOSE

There have been many reports in the literature on the apparent reversal of optic nerve cupping in patients with glaucoma after lowering intraocular pressure (IOP) on clinical examination, as well as improvement in visual field testing, and increased nerve fibre layer thickness on optical coherence tomography. No studies to date have looked at improvement of multifocal visually evoked potentials (mfVEP) after lowering IOP.

METHODS

This was a prospective study of twenty consecutive patients with elevated IOP seen in the glaucoma department of Wills Eye Institute. Patients who met the inclusion criteria for this study had a complete eye examination including IOP measurement and underwent testing with mfVEP, Heidelberg Retinal Tomograph (HRT) and static achromatic automated perimetry with SITA-Standard 24-2 program Humphrey visual field (HVF) studies at baseline and 2 h post-IOP reduction. A minimum of 30% IOP reduction was required. IOP changes were then compared with various parameters of mfVEP, HRT and HVF using Spearman rank correlation coefficients.

RESULTS

The Spearman rank correlation values between change in IOP versus various parameters were calculated: Accumap severity index (ASI), 0.37 (p = 0.14); Accumap superior hemifield, 0.049 (p = 0.85); Accumap inferior hemifield, 0.030 (p = 0.91); HVF mean deviation, 0.081 (p = 0.76); HRT rim area, 0.17 (p = 0.51); HRT cup area, -0.006 (p = 0.98). Weak positive but insignificant correlations were seen for all parameters except cup area.

CONCLUSIONS

This pilot study failed to confirm statistically significant correlations between IOP reduction and changes in Accumap, HVF and HRT measures, although positive correlations were seen for most measures.

A comparison of active ingredients and preservatives between brand name and generic topical glaucoma medications using liquid chromatography-tandem mass spectrometry

BACKGROUND

This work compares the concentration of active ingredients and preservatives in commonly used brand name versus generic glaucoma medications.

MATERIALS AND METHODS

Active ingredient and benzalkonium chloride (BAK) concentrations in brand name latanoprost and dorzolamide-timolol were each compared to two generic counterparts using liquid chromatography-mass spectrometry at baseline and after exposure to 25°C and 50°C for 30 days. Micro flow imaging was used to quantify particulate material greater than one micron in diameter.

RESULTS

Brand name formulations contained active ingredients and BAK in concentrations that were generally in agreement with their package inserts at baseline. The two generic formulations of latanoprost contained baseline levels of active ingredients that were 10% greater than their labeled value. Generic latanoprost formulations had significant loss of active ingredient concentration after exposure to 25°C and 50°C for 30 days. Both generic and brand name dorzolamide-timolol appeared relatively resistant to degradation. BAK concentrations remained stable at 25°C but decreased in some bottles at 50°C. Bottles of both generic medications had higher levels of particulate matter compared to brand name versions.

CONCLUSIONS

Exposure to temperatures at the high end of the labeled value may lead to a significant decrease in concentration of active ingredients in generic formulations that could influence clinical efficacy. Re-evaluation of intraocular pressure lowering efficacy may be indicated in glaucoma patients switching from brand name to generic formulations.

The effects of Mozart's music on the performance of glaucoma patients on automated perimetry

PURPOSE

The purpose of this study was to examine the impact of the Mozart effect on the reliability of the Humphrey visual field (HVF; Carl Zeiss Meditec, Dublin, CA) test in subjects with glaucoma. A previous study showed improved reliability in normal subjects undergoing HVF testing.

METHODS

One hundred sixty subjects with glaucoma were randomized to three groups: control, headphones, or music for 10 minutes before HVF testing. The headphone group was provided noise-cancellation headphones but no music. The music group listened to Mozart's Sonata for Two Pianos in D Major. After treatment, subjects took an HVF test in both eyes. The reliability of the test was then compared between the groups and also to prior HVF results with regard to fixation losses, false positives, and false negatives.

RESULTS

The rate of fixation losses did not differ significantly between the three groups (P = 0.30 right eye, P = 0.24 left eye). There were also no significant differences in the rate of false positives (P = 0.82 right eye, P = 0.18 left eye) or false negatives (P = 0.91 right eye, P = 0.97 left eye). The reliability of the subject's HVF result was also compared with past field results. No improvements were seen in fixation losses (P = 0.94 right eye, P = 0.17 left eye), false positives (P = 0.85 right eye, P = 0.38 left eye), and false negatives (P = 0.13 right eye, P = 0.50 left eye).

CONCLUSIONS

The rate of fixation losses, false positives, and false negatives did not improve in subjects with glaucoma after they listened to Mozart's music. The Mozart effect did not enhance the reliability of the visual field test to a statistically significant degree (ClinicalTrials.gov number, NCT01027039).

Managing refractory glaucoma with a fixed combination of bimatoprost (0.03%) and timolol (0.5%)

Glaucoma is a chronic progressive optic neuropathy characterized by progressive loss of retinal ganglion cells, which manifests clinically with loss of optic disc neuroretinal rim tissue, defects in the retinal nerve fiber layer, and deficits on functional visual field testing. The goal of glaucoma treatment is to reduce the intraocular pressure to a level that prevents or minimizes the progressive loss of vision. The current standard of management for the newly diagnosed primary open angle glaucoma (PAOG) patient is to start topical medication. Available topical medications include: beta-adrenergic antagonists, alpha-adrenergic agonists, carbonic anhydraze inhibitors, prostaglandin analogues and miotics. In some patients, IOP is not adequately controlled by monotherapy. In those refractory patients, where more efficacy is required, shifting to another medication or adding a second medication is indicated. The complimentary action between two drugs serves as the basis for combination medications. One avenue of delivering a second medication is through a fixed combination medication that has the advantage of providing two medicines within one drop. Bimatoprost/timolol represents a new fixed combination which is clinically and statistically more effective than either of its active constituents for patients with refractory glaucoma. As regard the safety of the combination, there were no signs or symptoms of intolerance and the incidence of conjunctival hyperemia was clinically and statistically significantly less than each of the two components separately. Bimatoprost/timolol fixed combination offers cost and time savings, which may enhance compliance; also reducing the amount of preservative applied to the eye, will improve tolerability and may also favorably improve eventual surgical outcomes in patients who might require filtering procedures.

Steroid-induced iatrogenic glaucoma

Steroids in susceptible individuals can cause a clinical condition similar to primary open-angle glaucoma. Five percent of the population are high steroid responders and develop an intraocular pressure (IOP) elevation of more than 15 mm Hg above baseline. IOP elevation may occur as early as 1 day to as late as 12 weeks after intravitreal triamcinolone in 20-65% of patients. On average, 75% of eyes with steroid implants require IOP-lowering therapy at some point within 3 years of follow-up. The exact mechanism of steroid-induced glaucoma is not totally understood, but decreased trabecular meshwork outflow is regarded as the main cause of IOP elevation. High-risk patients who receive steroids should be monitored closely and if they develop elevated IOP, steroids with lower potency or steroid-sparing agents should be used. The IOP usually returns to normal within 2-4 weeks after stopping the steroid. About 1-5% of patients do not respond to medical therapy and need surgery. Trabeculectomy, trabeculotomy, shunt surgery, and cyclodestructive procedures are among the methods employed. Removal of residual sub-Tenon or intravitreal steroids may help hasten the resolution of the steroid response. Early results with anecortave acetate, an analog of cortisol acetate with antiangiogenic activity, in controlling IOP have been promising.

Non-steroidal drug-induced glaucoma

Numerous systemically used drugs are involved in drug-induced glaucoma. Most reported cases of non-steroidal drug-induced glaucoma are closed-angle glaucoma (CAG). Indeed, many routinely used drugs that have sympathomimetic or parasympatholytic properties can cause pupillary block CAG in individuals with narrow iridocorneal angle. The resulting acute glaucoma occurs much more commonly unilaterally and only rarely bilaterally. CAG secondary to sulfa drugs is a bilateral non-pupillary block type and is due to forward movement of iris-lens diaphragm, which occurs in individuals with narrow or open iridocorneal angle. A few agents, including antineoplastics, may induce open-angle glaucoma. In conclusion, the majority of cases with glaucoma secondary to non-steroidal medications are of the pupillary block closed-angle type and preventable if the at-risk patients are recognized and treated prophylactically.

Down-regulation of OPA1 in patients with primary open angle glaucoma

PURPOSE

Heterozygous optic atrophy type1 (OPA1) mutations are responsible for dominant optic atrophy, and the down regulation of OPA1 expression in patients with Leber hereditary optic neuropathy may imply that Opa1 protein levels in mitochondria play a role in other spontaneous optic neuropathies as well. Mitochondrial and metabolic abnormalities may put the optic nerve at risk in primary open angle glaucoma (POAG), and this preliminary study was designed to investigate whether altered OPA1 expression might be present in the progressive optic neuropathy of POAG.

METHODS

Patients were eligible for inclusion if they met standard clinical criteria for POAG, including age greater than 40 years, intraocular pressure ≥ 21 mmHg in at least one eye before treatment, normal-appearing anterior chamber angles bilaterally on gonioscopy, and optic nerve injury characteristic of POAG. RNA was extracted from leukocytes and converted to cDNA by reverse transcriptase enzyme, and real time PCR was used to assess expression levels of OPA1 and the β-globulin (HBB) housekeeping gene. The ratio of OPA1 expression to HBB expression (OPA1/HBB) for POAG patients was compared to that of controls and to clinical characteristics of POAG patients.

RESULTS

Forty-three POAG patients and 27 controls were completely phenotyped with a full ophthalmologic examination and static perimetry. Mean age (POAG 67.9 years; controls 61.8 years) and sex (POAG 26 males/17 females; controls 11/16) were similar for the two groups. Mean OPA1/HBB of POAG patients (1.16, SD 0.26) was 18% lower than controls (1.41, SD 0.50), and this difference was statistically significant (p≤0.021). OPA1 expression differed between the groups (p≤0.037), but HBB expression did not differ (p≤0.24). OPA1/HBB was not correlated with any clinical feature of POAG patients.

CONCLUSIONS

Transcriptional analysis of peripheral blood leucocytes is a limited model system for studying the consequences of mitochondrial abnormalities in the optic nerve. Nevertheless, OPA1 is known to affect mitochondrial stability and has now been implicated in several spontaneous optic neuropathies. Decreased OPA1 expression in POAG patients is another indication that mitochondrial function, and possibly mitochondrially-induced apoptosis, may play a role in the development of POAG.

Canaloplasty for pigmentary glaucoma with coexisting conjunctival lymphoma

This case report presents canaloplasty as a bleb-free surgical option for lowering intraocular pressure in cases with postoperative conjunctival scarring.

Iatrogenic glaucoma secondary to medications

Glaucoma is a progressive optic neuropathy with primary and secondary forms. Iatrogenic glaucoma secondary to medications is potentially blinding but preventable. Most drug profiles listing glaucoma as a contraindication or an adverse effect are concerned with inducing acute angle-closure glaucoma. Anticholinergic or adrenergic agents are the most common for inducing "pupillary block" angle-closure glaucoma. Patients with a narrow irido-corneal angle are at high risk. Sulfa drugs induce "non-pupillary block" angle-closure glaucoma as an idiosyncratic reaction to the drug in patients with an open or narrow irido-corneal angle. Steroids and a few antineoplastic agents induce open-angle glaucoma. The risk is higher with topical rather than systemic steroids. The first step in the management is discontinuation of the drug, followed by medical, laser, and, if necessary, surgical intervention.

Single needle revision of failing filtration blebs: a retrospective comparative case series with 5-fluorouracil and mitomycin C

PURPOSE

To assess the success of needling in failed filtration blebs and the potential benefit of using either 5-fluorouracil (5-FU) or mitomycin C (MMC).

METHODS

In this retrospective, comparative observational case series, 107 eyes that underwent needle revision with either 5-FU or MMC between July 2003 and May 2008 at Wills Eye Institute were selected. Exclusion criteria included follow-up less than 1 month and a history of glaucoma drainage device. Intraocular pressure (IOP) and number of glaucoma medications were recorded preoperatively and postoperatively. Success was defined as >20% decrease in IOP if glaucoma medications were resumed or <10% decrease in IOP if medications were not resumed post needling or fewer medications than pre needling.

RESULTS

Sixty-five patients received 5-FU and 42 patients received MMC for needling. Mean IOP changed from 23.9 mmHg to 13.8 mmHg in the MMC group and from 23.3 mmHg to 13.02 mmHg in the 5-FU group (both p<0.001). Mean glaucoma medications changed from 1.7 to 0.7 in the MMC group and 2.0 to 0.8 in the 5-FU group (both p<0.001) at the end of follow-up. After a mean follow-up of 14.5 months, overall survival was 49.5%. Mean time to failure was 7.7 months. There was a moderately weak association between survival and the immediate postoperative IOP (r=0.262, p=0.01). In comparing MMC and 5-FU, there was no statistically significant difference in survival rate (p=0.267).

CONCLUSIONS

Bleb needling may be a safe and effective means of prolonging bleb survival. The only factor associated with success was the immediate postoperative IOP. There was no apparent difference between the use of 5-FU and MMC in this population. A prospective study may provide further confirmation of this finding.

Agreement of visual field interpretation among glaucoma specialists and comprehensive ophthalmologists: comparison of time and methods

AIMS

To evaluate interobserver agreement and interpretation time for three clinically available formats of visual field presentation: serial Humphrey visual field (HVF), STATPAC2 and PROGRESSOR.

METHODS

40 field series from the Advanced Glaucoma Intervention Study were presented to eight glaucoma specialists and eight comprehensive ophthalmologists to determine whether each field series was stable or progressive. Interobserver agreement and agreement with Hodapp-Parrish-Anderson criteria were evaluated using κ statistics, and the interpretation time was compared.

RESULTS

For glaucoma specialists, median κ values for interobserver agreement were 0.47, 0.60 and 0.43 for HVF, STATPAC2 and PROGRESSOR, respectively. Respective κ values for comprehensive ophthalmologists were 0.43, 0.43 and 0.35. For glaucoma specialists, median κ values for agreement with Hodapp-Parrish-Anderson criteria were 0.52, 0.67 and 0.52 for HVF, STATPAC2 and PROGRESSOR, respectively. Respective κ values for comprehensive ophthalmologists were 0.41, 0.47 and 0.33. For glaucoma specialists, the mean±SD interpretation time for the series of 40 fields was 63.4±35.9, 57.1±23.1 and 41.1±15.3 min using HVF, STATPAC2 and PROGRESSOR, respectively. Respective interpretation times for comprehensive ophthalmologists were 72.9±38.3, 68.6±30.6 and 51±24.1 min. Interpretation time was decreased when STATPAC2 or PROGRESSOR was used rather than HVF. Time reduction was significant for glaucoma specialists using PROGRESSOR (p=0.02).

CONCLUSIONS

For glaucoma specialists, interobserver agreement and agreement with HPA criteria were moderate to substantial. For comprehensive ophthalmologists, interobserver agreement and agreement with HPA criteria were fair to moderate. Field interpretation time may be reduced clinically when using STATPAC2 or PROGRESSOR rather than HVF.

Imaging modalities for localization of an iStent(®)

The iStent (Glaukos Corporation, Laguna Hills, CA) is a 1-mm, titanium trabecular bypass stent implanted across the inner wall of Schlemm's canal under direct gonioscopy. This study was designed to determine the best modality to identify iStent placement when gonioscopic visualization is not possible. In this in vitro study on a human cadaver eye, ultrasound biomicroscopy (UBM), anterior segment optical coherence tomography (AS-OCT), and B-scan ultrasonography were done to visualize and precisely locate two intentionally misplaced iStents. UBM could localize both intentionally misplaced stents, whereas AS-OCT could not visualize the iStent that was lodged in the sulcus. B-scan ultrasonography was unable to detect either of the stents. UBM may be a useful imaging modality to identify iStent in the anterior or posterior chamber, whereas AS-OCT is limited to detection of stents in the anterior chamber alone. B-scan ultrasonography is unable to identify iStent in either the anterior or posterior chamber.

Monocyte modulation of aqueous outflow and recruitment to the trabecular meshwork following selective laser trabeculoplasty

OBJECTIVES

To determine whether selective laser trabeculoplasty (SLT) induces monocyte recruitment to the trabecular meshwork (TM) in human and monkey eyes and whether monocytes increase both aqueous outflow in vivo and the conductivity of human Schlemm canal endothelial cells (SCEs) in vitro.

METHODS

Monocyte recruitment was examined morphometrically in control human and monkey eyes and compared with that following SLT applied 1 to 3 days earlier. Outflow facility was measured for up to 4 days after the intracameral infusion of autologous macrophages in rabbits. Schlemm canal endothelial cell conductivity was measured using flow meters after exposing cultured SCEs to monocytes and monocyte-secreted factors for 24 hours.

RESULTS

Our estimates show that the TM in the human eye normally had an average of 15 003 monocytes, while in the monkey eye there were 3181 monocytes, and this number increased 4- to 5-fold following SLT. The intracameral infusion of autologous macrophages in rabbits increased outflow facility 2-fold in a rapid and sustained manner. Human monocytes and monocyte-secreted factors increased SCE conductivity 2-fold in vitro.

CONCLUSIONS

The number of monocytes/macrophages in the TM increases substantially after SLT and monocytes augment both outflow facility and SCE conductivity. Clinical Relevance These findings indicate that the innate immune system in general and monocytes in particular play an important role in aqueous outflow homeostasis. The recruitment of monocytes in increased numbers after SLT likely plays a role in lowering the intraocular pressure after this procedure. The intracameral introduction of autologous monocytes harvested from a vein could have therapeutic potential as a cell-based individualized treatment of glaucoma.

Fixed combinations of dorzolamide-timolol and brimonidine-timolol in the management of glaucoma

IMPORTANCE OF THE FIELD

The emergence of fixed-combination drugs for the treatment of glaucoma has, to some extent, changed the medical management of glaucoma. The potential benefits of these drugs include a reduction in the total number of drops and preservatives instilled per day and improved patient comfort factors, which may contribute to better compliance. Combination medications may also improve therapeutic efficacy and play an important role in controlling medication cost. However, the fixed dosing may be a disadvantage in some cases.

AREA COVERED IN THIS REVIEW

This review describes the composition, pharmacokinetics, mode of action, efficacy, side effects, and safety profile of fixed-combination dorzolamide-timolol and fixed-combination brimonidine-timolol.

WHAT THE READER WILL GAIN

Understanding of the pros, cons, and safety profile of two FDA approved fixed-combination antiglaucoma medication.

TAKE HOME MESSAGE

Fixed-combination medications may be a reasonable adjunct to prostaglandins if a large drop in the intraocular pressure (IOP) is desired and adding only one medication is unlikely to reach the target IOP range. Both mentioned drugs are effective in reducing the IOP and further clinical studies will help identify differences in efficacy between the two. The clinician must make an individualized assessment of the medication's risk-benefit profile for each patient.

Efficacy, safety and tolerability of combination therapy with timolol and dorzolamide in glaucoma and ocular hypertension

Combination pharmacotherapy has simplified and improved glaucoma medication regimens. This update focuses on the previous and recent studies on efficacy and tolerability profile of dorzolamide–timolol in adult ocular hypertension and open angle glaucoma patients. Dorzolamide–timolol has been shown to be efficacious and well tolerated in clinical trials and the adverse effects reflect those of the individual components.