Predictors for visual field progression and the effects of treatment with dorzolamide 2% or brinzolamide 1% each added to timolol 0.5% in primary open-angle glaucoma

How latanoprost changed glaucoma management

Glaucoma is currently considered one of the leading causes of severe visual impairment and blindness worldwide. Topical medical therapy represents the treatment of choice for many glaucoma patients. Introduction of latanoprost, 25 years ago, with an entirely new mechanism of action from that of the antiglaucoma drugs used up to that time was a very important milestone. Since then, due mainly to their efficacy, limited systemic side effects and once daily dosing, prostaglandin analogues (PGAs) have become as the first-choice treatment for primary open-angle glaucoma. PGAs are in general terms well tolerated, although they are associated with several mild to moderate ocular and periocular adverse events. Among them, conjunctival hyperemia, eyelash changes, eyelid pigmentation, iris pigmentation and hypertrichosis around the eyes are the most prevalent. The objective of this paper is to review the role of PGAs in the treatment of glaucoma over the 25 years since the launch of Latanoprost and their impact on clinical practice outcomes.

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Topical carbonic anhydrase inhibitors and glaucoma in 2021: where do we stand?

Carbonic anhydrase inhibitors (CAIs) have been used for many decades in the treatment of glaucoma. Systemic CAIs were an early treatment option to lower intraocular pressure by reducing aqueous humour production; however, frequent side effects including polyuria and paresthesia contributed to the eventual development of topical CAIs. As topical drug development evolved over time, prostaglandin analogues and beta-blockers have become the gold standard of glaucoma therapies. Although prescribed less often than other classes of topical glaucoma therapies, topical CAIs continue to be used in combination therapies with beta-blockers and alpha agonists. Topical CAIs have also been demonstrated to alter biomarkers of ocular haemodynamics, which have relevance in glaucoma. The purpose of this review is to review and summarise the current state of topical CAI prescribing trends, known efficacy and suggested mechanisms and potential influence on ocular haemodynamics for the future of glaucoma management.

Dorzolamide/Timolol Fixed Combination: Learning from the Past and Looking Toward the Future

The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC

[The role of retinal microcirculation disorders in the progression of glaucomatous optic neuropathy]

PURPOSE

To assess the progression of primary open-angle glaucoma (POAG) and to study the role of retinal microcirculation in its progression.

MATERIAL AND METHODS

In this 2-year prospective study, the rate of POAG progression was determined using perimetry (ROP1) and spectral domain optical coherence tomography (SD-OCT) by thinning of retinal nerve fiber layer (RNFL) (ROP2) and ganglion cell complex (GCC) (ROP3). The vessel density of parafoveal superficial plexus (VD parafovea) and peripapillary retina (VD ppr) was assessed using OCT angiography, peripheral resistance index (RI), and blood flow velocity in the posterior short ciliary arteries (PSCA) and central retinal artery (CRA) with the use of color Doppler mapping. The predictive properties of each parameter were calculated using the area under receiver operating curve (AUC).

RESULTS

Progression was detected in 9.8% cases by perimetry and in 19.7% cases by OCT. The combination of these two methods increased the detection up to 32.8%. Circulatory parameters - VD parafovea (AUC 0.70±0.07), VD ppr (0.715±0.07), PSCA RI (0.801±0.12), CRA RI (0.798±0.11) - had similar high predictive properties as IOP max (0.79±0.05), corneal hysteresis (0.755±0.07), thickness of inner parafoveal layers (0.728±0.07) and RNFL (0.692±0.06). The study revealed the following correlations: ROP1 with maximum IOP (p=0.01), ROP2 with blood flow velocity in PSCA (p=0.01), VD parafovea with corneal hysteresis (p=0.01), and GCC thickness with ocular perfusion pressure (p=0.01).

CONCLUSION

The obtained data demonstrates the importance of combining perimetry with OCT for detecting the progression of glaucoma and indicates its relationship with reduced ocular hemoperfusion.

Management of the open angle glaucoma in patients with central/hemicentral retinal vein occlusions

AIM

To prospectively assess the cumulative prevalence and management of open angle glaucoma (OAG), including primary open angle glaucoma (POAG) with high and normal-pressure, as well as pseudoexfoliative glaucoma (PEXG), in patients with central/hemicentral retinal vein occlusions (RVOs) over a 3-year follow-up period.

METHODS

The study encompassed 57 patients with unilateral acute central/hemicentral RVOs. A complete ophthalmic examination of both eyes was undertaken for all patients. Patients with OAGs associated with central/hemicentral RVOs were treated with the current ocular hypotensive medications used worldwide and/or surgery and aimed to reduce the intraocular pressure (IOP) by 30% from baseline values for the 3 OAG forms existing in our series. The cumulative prevalence of OAG and the efficacy of treatment were evaluated.

RESULTS

OAG was observed in 3 clinical forms, namely, POAG with increased IOP in 4 patients, POAG with normal IOP in 3 patients, and PEXG in 3 patients. The cumulative prevalence of OAG was 19.6% (95%CI: 8.7-30.5). Using available ocular hypotensive medications (8 patients) and trabeculectomy (2 patients), the IOP decreased significantly from 24.3±4.36 mm Hg to 16.55±2.85 mm Hg, a reduction of 31.89% compared with baseline values. Glaucoma progression was not detected in any of the cases.

CONCLUSION

The high value of the cumulative prevalence of OAG is a risk factor for the development of venous occlusion. The treatment of glaucoma prevented its progression over a follow-up period of 3y.

Direct and crossover effects of brinzolamide, betaxolol, and latanoprost on choroidal thickness

PURPOSE

To investigate the acute effects of brinzolamide, betaxolol, and latanoprost (drugs commonly used in the medical management of glaucoma) on choroidal thickness using enhanced depth imaging optical coherence tomography (EDI-OCT).

METHODS

Ninety healthy volunteers were evaluated in this prospective study. Participants were randomly divided into 3 groups. Brinzolamide, betaxolol, and latanoprost were administered into the left eyes of the first group (n = 30), second group (n = 30), and third group (n = 30), respectively, and artificial tear (Sodium hyaluronate) was instilled into the right eyes of all participants. Subfoveal choroidal thickness (SFCT) was measured using EDI-OCT before and 45 minutes after administration of the antiglaucomatous drops.

RESULTS

SFCT revealed a significant increase in the left eye (administered antiglaucomatous drop) in the brinzolamide (p = 0.001) and betaxolol groups (p = 0.049) and a significant increase also in the right eye (administered artificial drop) in the brinzolamide (p = 0.001) and betaxolol groups (p = 0.001). However, SFCT did not reveal a significant increase in the left eye (p = 0.213) or in the right eye (p = 0.062) in the latanoprost group.

CONCLUSION

Brinzolamide and betaxolol caused an increase in SFCT, while latanoprost had no significant effect on SFCT.

Effect of Latanoprost on Choroidal Thickness

PURPOSE

The purpose of this study was to evaluate the changes in choroidal thickness during the use of latanoprost eyedrops which shift fluid to the suprachoroidal space and change choroidal perfusion.

MATERIALS AND METHODS

This prospective study included 34 eyes of 17 bilateral glaucoma or ocular hypertensive patients who had no previous hypotensive therapy. Each patient had both eyes treated with latanoprost. Each patient also underwent a complete ophthalmological examination and optical coherence tomography measurement. Choroidal thickness measurements by optical coherence tomography were carried out on the first visit before latanoprost use and at time intervals of 7 and 30 days of therapy.

RESULTS

The patients' mean age was 62.3±11 years (range, 30 to 83 y). Of 17 patients, 7 were female individuals. There were no significant differences in central choroidal thicknesses at the fovea, or at each point within the horizontal nasal and temporal quadrants between visits (P<0.05 for all comparisons).

CONCLUSIONS

The current study showed that choroidal thickness does not change after latanoprost therapy. However, the choroidal changes of anterior part of the eye can be effected by the latanoprost therapy. Future studies investigating the anterior part of the eye and focusing on both choroidal perfusion and choroidal thickness may give additional information concerning the mechanism of action.

Relationship between blood pressure and retrobulbar blood flow in dipper and nondipper primary open-angle glaucoma patients

PURPOSE

To evaluate the relationship between retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery, and short posterior ciliary artery and 24-hour blood pressure (BP) measurements in dipper and nondipper patients with primary open-angle glaucoma (POAG).

METHODS

A prospective, cross-sectional, and observational study was conducted on consecutive patients, referred or recruited, attending the outpatient service of our ophthalmology department. Ambulatory BP monitoring, Doppler imaging, and ocular pulse amplitude measurements were performed on the same day. Patients with nocturnal BP decrease up to 10% of the diurnal BP were defined as dippers and those with BP decrease less than 10% were defined as nondippers.

RESULTS

A total of 114 patients (36 nondippers and 78 dippers) were included in the study. The end-diastolic velocity was significantly lower and the resistivity index (RI) was significantly higher in the dippers than in the nondippers (p&lt;0.0001 and p&lt;0.0001, respectively). The RI in the OA was significantly correlated with daytime and nighttime systolic BP and with the daytime mean arterial pressure in the dippers.

CONCLUSIONS

The RI in the OA significantly correlates with BP in patients with POAG with nocturnal BP dips. Additionally, retrobulbar blood flow parameters are reduced in dippers as compared with nondippers with POAG.

Value of Structural and Hemodynamic Parameters for the Early Detection of Primary Open-Angle Glaucoma

PURPOSE

To compare the diagnostic value of ocular blood flow parameters and choroidal thickness (CT) with standard structural parameters for early glaucoma detection.

METHODS

A total of 32 patients with pre-perimetric glaucoma were compared with 30 age-matched normal subjects. The thickness of the ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), and the choroid and foveal loss volume (FLV) were measured by means of optical coherence tomography (OCT). Retrobulbar blood velocities (Color Doppler Imaging), corneal compensated intraocular pressure (IOPcc), and corneal hysteresis (CH) were also evaluated. Mean ocular perfusion pressure (MOPP) was calculated by measuring IOP and mean arterial blood pressure as MOPP = ([2/3 diastolic BP + 1/3 systolic BP] × 2/3-IOP). The value of each diagnostic indicator (z-value) was calculated using the Wilcoxon-Mann-Whitney test and the area under the receiver operating characteristic curve (AUC).

RESULTS

The following indicators had the largest AUC and diagnostic value (z-value): mean blood flow velocity in the vortex veins (AUC 1.0; z-value 5.35) and central retinal vein (0.85; 3.74), diastolic blood flow velocity in the central retinal artery (0.73; 2.74) and lateral short posterior ciliary arteries (0.71; 2.53), IOPcc (0.74; -2.9), CH (0.69; 2.24), CT (0.69; -2.28), GCC (0.67; 2.05), and FLV (0.66; -1.86) to discriminate pre-perimetric glaucoma from healthy subjects.

CONCLUSIONS

Interestingly, ocular hemodynamic parameters performed better than structural parameters in detecting early glaucoma. This highlights the potential of techniques to measure ocular blood flow in glaucoma diagnostics independently of the question whether perfusion abnormalities are a cause or a consequence of the disease.

Pharmacotherapy of glaucoma

Glaucoma is a group of diseases involving the optic nerve and associated structures, which is characterized by progressive visual field loss and typical changes of the optic nerve head (ONH). The only known treatment of the disease is reduction of intraocular pressure (IOP), which has been shown to reduce glaucoma progression in a variety of large-scale clinical trials. Nowadays, a relatively wide array of topical antiglaucoma drugs is available, including prostaglandin analogues, carbonic anhydrase inhibitors, beta-receptor antagonists, adrenergic agonists, and parasympathomimetics. In clinical routine, this allows for individualized treatment taking risk factors, efficacy, and safety into account. A major challenge is related to adherence to therapy. Sustained release devices may help minimize this problem but are not yet available for clinical routine use. Another hope arises from non-IOP-related treatment concepts. In recent years, much knowledge has been gained regarding the molecular mechanisms that underlie the disease process in glaucoma. This also strengthens the hope that glaucoma therapy beyond IOP lowering will become available. Implementing this concept with clinical trials remains, however, a challenge.

[Hemodynamic component in glaucoma and its association with risk factors and cardiovascular disease]

BACKGROUND AND OBJECTIVE

We sought to study the association of glaucoma with vascular disease, with 2 independent pathways: the association of glaucoma with cardiovascular disease (CVD) and the study of ocular hemodynamic variables (OHV) in glaucoma.

MATERIAL AND METHOD

Cross-sectional study consisting of 73 patients: 25 without glaucoma, 28 primary open-angle glaucoma (POAG) and 20 normal-tension glaucoma (NTG). OHV, cardiovascular risk factors (CVRF) and CVD were determined.

RESULTS

We found a greater number of CVRF and CVD in patients affected by POAG (P=.002 and P=.016) and NTG (P=.001 and P=.010) compared to the control group. With regard to OHV, in patients suffering from POAG, we found lower systolic and diastolic velocities and higher resistance index in the central retinal artery (P<.05). Moreover, in both types of glaucoma, we found higher resistance index in the posterior ciliary artery (P<.05).

CONCLUSIONS

There is a statistically significant association between the presence of CVD and/or CVRF and glaucomatous disease, a finding that is supplemented with data from the OHV. These values indicate a worst ocular perfusion in patients with glaucomatous disease.

Theoretical analysis of vascular regulatory mechanisms contributing to retinal blood flow autoregulation

PURPOSE

To study whether impaired retinal autoregulation is a risk factor for glaucoma, the relationship between vascular regulatory mechanisms and glaucoma progression needs to be investigated. In this study, a vascular wall mechanics model is used to predict the relative importance of regulatory mechanisms in achieving retinal autoregulation.

METHODS

Resistance vessels are assumed to respond to changes in pressure, shear stress, carbon dioxide (CO2), and the downstream metabolic state communicated via conducted responses. Model parameters governing wall tension are fit to pressure and diameter data from porcine retinal arterioles. The autoregulation pressure range for control and elevated levels of IOP is predicted.

RESULTS

The factor by which flow changes as the blood pressure exiting the central retinal artery is varied between 28 and 40 mm Hg is used to indicate the degree of autoregulation (1 indicates perfect autoregulation). In the presence of only the myogenic response mechanism, the factor is 2.06. In the presence of the myogenic and CO2 responses, the factor is 1.22. The combination of myogenic, shear, CO2, and metabolic responses yields the best autoregulation (factor of 1.10).

CONCLUSIONS

Model results are compared with flow and pressure data from multiple patient studies, and the combined effects of the metabolic and CO2 responses are predicted to be critical for achieving retinal autoregulation. When IOP is elevated, the model predicts a decrease in the autoregulation range toward low perfusion pressure, which is consistent with observations that glaucoma is associated with decreased perfusion pressure.

The effects of a fixed combination of 0.5% timolol and 1% dorzolamide on optic nerve head blood circulation

PURPOSE

The purpose of the present study is to evaluate the effects of a fixed combination of 0.5% timolol maleate (TM) and 1% dorzolamide hydrochloride (DZ) (FCTD(1%)) on optic nerve head (ONH) blood circulation.

SUBJECTS AND METHODS

A drop of 0.5% TM, 1% DZ, or FCTD(1%) was topically administered to the right eyes of 15 healthy Japanese subjects, and a drop of saline was likewise administrated to their left eyes. Systemic blood pressure, heart rates (HRs), intraocular pressures (IOPs), ocular perfusion pressures, and blood circulation by a laser speckle flowgraphy at the ONH were measured before administration, and again at 1.5 and 6 h afterward.

RESULTS

FCTD(1%) caused a significant increase in ONH blood circulation 6 h after the administration, while 0.5% TM and 1% DZ had no significant effect. The IOPs were significantly decreased in 0.5% TM (P<0.01) and FCTD(1%) (P<0.05) when compared with the saline-treated eyes at 1.5 and 6 h after administration, while 1% DZ did not show a statistically significant decrease. There were no significant changes in other systemic parameters except for a significant transient decrease in the HRs observed in 0.5% TM (P<0.01) when compared with the baseline at 1.5 h after the administration.

CONCLUSION

Our current results suggest that FCTD(1%) caused a significant increase in ocular blood circulation on the ONH in healthy Japanese subjects, presumably by a synergistic effect of 0.5% TM and 1% DZ, although neither 0.5% TM nor 1% DZ on their own had a significant effect.

[Comparative study of the pressure lowering efficacy and variations in the ocular pulse amplitude between fixed combinations of dorzolamide/timolol and brinzolamide/timolol]

OBJECTIVE

To determine possible differences in the intraocular pressure (IOP) and ocular pulse amplitude (OPA) lowering capacity of the fixed drug combinations dorzolamide/timolol and brinzolamide/timolol.

METHODS

In this cross-sectional study, one of the eyes of 25 healthy subjects was randomly assigned to treatment with dorzolamide/timolol and the other eye with brinzolamide/timolol. After instilling the drops, possible adverse effects (e.g., blurred vision, itching) were assessed in each eye. This assessment was repeated 30 minutes later. IOP and OPA were determined In each eye by dynamic contour tonometry at baseline and two hours following treatment.

RESULTS

Both fixed drug combinations significantly reduced IOP and OPA with no differences detected between treatment groups. Among the adverse effects recorded, itching was significantly greater in the first assessment in the eyes treated with dorzolamide/timolol (P = .011). This difference was no longer apparent in the second assessment.

CONCLUSIONS

Both fixed combinations were similarly effective in reducing intraocular pressure and ocular pulse amplitude. Adverse effects related to both treatments were mild and well-tolerated, though itching occurred most frequently in the eyes treated with dorzolamide/timolol.

Brinzolamide 1%/timolol 0.5%: safety and efficacy of a new fixed-combination IOP-lowering product for glaucoma

OBJECTIVE

To provide a commentary on recent studies with the new IOP-lowering fixed-combination product brinzolamide 1%/timolol 0.5%.

METHODS

Medline was searched for brinzolamide/timolol fixed-combination clinical literature (up to May 18, 2010) and the current comprehensive brinzolamide/timolol literature was reviewed.

RESULTS

Compared with another carbonic anhydrase inhibitor-containing product, dorzolamide 2%/timolol 0.5%, brinzolamide/timolol has similar IOP-lowering efficacy. Brinzolamide/timolol also produces superior comfort ratings as assessed by patients who have tried both drugs - this may be explained by the more physiologic pH of brinzolamide/timolol. A recent study reported that brinzolamide/timolol was preferred over dorzolamide/timolol at a ratio of nearly 4:1 among those expressing a preference.

CONCLUSION

These results demonstrate that brinzolamide/timolol is equally effective and more comfortable than dorzolamide/timolol, a fact that may positively impact patient adherence, leading to an increased likelihood of reaching target IOP goals.

Topical carbonic anhydrase inhibitors and visual function in glaucoma and ocular hypertension

BACKGROUND

Dorzolamide and brinzolamide are topical carbonic anhydrase inhibitors (CAI) indicated for patients with glaucoma and ocular hypertension.

SCOPE

An evidence-based review of clinical trials of dorzolamide and brinzolamide was undertaken to determine an effect of these medications on visual function (primarily visual field) in open-angle glaucoma and ocular hypertension. Using the keywords 'dorzolamide' and 'brinzolamide', all articles describing trials of these medications reporting on visual acuity, contrast sensitivity and visual field from September 1966 to July 2009 were found in MEDLINE and EMBASE databases. No information from other sources was included in this review.

FINDINGS

A relatively modest number of trials was identified, where impact of therapy on one or more of the visual function modes was reported. In the studies of less than 1 year duration (3 days to 1 year, 23 studies) in all but three studies treatment with topical CAIs did not influence visual function, in two studies with dorzolamide some improvement in the contrast sensitivity was observed and in one open-label retrospective no-control-group study with dorzolamide visual field indices improved significantly. A different picture was seen in long-term studies, which were designed and powered to detect changes in visual field. One large study (European Glaucoma Prevention Study) with dorzolamide versus placebo failed to detect significant protective effect of the drug on glaucoma occurrence in ocular hypertensives. Several interesting aspects of this study are discussed in detail. The other two long-term studies reported on the superiority of adding dorzolamide over timolol therapy alone, and the superiority of the combination of dorzolamide and timolol over brinzolamide and timolol in terms of improving ocular blood flow (retrobulbar Color Doppler Imaging--CDI parameters) as well as in terms of visual field preservation in glaucoma patients over 4 to 5 years.

CONCLUSION

For the first time one study could demonstrate that an improvement in ocular blood flow in the long run results in preservation of visual field in glaucoma patients. Dorzolamide, combined with the beta-blocker timolol, seems to be superior in this regard to brinzolamide plus timolol.

Update and critical appraisal of combined timolol and carbonic anhydrase inhibitors and the effect on ocular blood flow in glaucoma patients

Topical hypotensive therapy with both timolol and carbonic anhydrase inhibitors has been shown to be efficacious at reducing intraocular pressure. Many prospective studies have also suggested that carbonic anhydrase inhibitors augment ocular blood flow and vascular regulation independent of their hypotensive effects. Although consistent in their findings, these studies must be cautiously interpreted due to the limitations of study design and specific blood flow imaging modalities. The purpose of this review is to appraise and critically evaluate the current body of literature investigating the effects of combined treatment with topical carbonic anhydrase inhibitors and timolol in patients with glaucoma with respect to ocular blood flow, visual function, and optic nerve head structure.