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Précis:The relationship between structural and hemodynamic parameters in patients with primary open angle glaucoma is strongest in the temporal region of the optic nerve. Purpose:To investigate the relationship between radial peripapillary capillary (RPC) vessel density (VD) and retinal nerve fiber layer (RNFL) thickness in quadrants and sectors of the optic nerve head (ONH) in patients with and without primary open angle glaucoma (POAG). Methods:In a cross-sectional prospective analysis, 191 subjects (80 early-stage POAG; 111 non-glaucomatous controls) were assessed for RNFL thickness and RPC VD in each quadrant [superior (S), inferior (I), nasal (N) and temporal (T)] and sector [inferior-temporal (IT), temporo-inferior (TI), temporo-superior (TS), superior-temporal (ST), inferior-nasal (IN), naso-inferior (NI), naso-superior (NS), and superior-nasal (SN) sectors] of the ONH through optical coherence tomography angiography (OCTA). Pearson correlations were used to test for associations between measurements, withP<0.05 considered statistically significant. Results:Significantly stronger positive correlations were found between RPC VD and RNFL thickness in the S, I, and T quadrants in POAG patients compared with non-glaucomatous controls (allP<0.05). The temporal quadrant in POAG patients displayed the largest difference in correlation compared with controls. A stronger positive correlation was also found between RPC VD and RNFL thickness in the temporal sectors of the ONH in POAG patients compared with controls, with the largest difference in the TS sector (allP<0.05). Conclusion:Early-stage POAG patients have a stronger relationship between RPC VD and RNFL in the temporal regions of the ONH compared with non-glaucomatous controls, with the TS sector demonstrating the largest difference between groups. Temporal sector VD loss may represent an early-stage biomarker for vascular-linked POAG disease. 

Background: The purpose of this study was to examine the changes in IOP, total macular and RNFL, ganglion cell layer (GCL) thickness, and aqueous humour flare in open angle glaucoma (OAG) patients before and 6 months after cataract surgery. Methods: This was a prospective observational case–control age- and gender-matched study. Groups: 40 subjects in a controlled OAG (OAGc) group, 20 subjects in an uncontrolled OAG (OAGu) group, and 60 control group subjects. Examination: complete ophthalmic evaluation, IOP measurement, anterior and posterior segment Optical Coherence Tomography (OCT), and laser flare photometry before and 6 months postoperatively. Results: Six months postoperatively IOP decreased in all groups. An increase in macular thickness was found postoperatively in all groups. Preoperative aqueous humour flare was higher in the OAGc group than in the control group. After cataract surgery, aqueous humour flare was higher in the control group compared to the preoperative result. Conclusions: Changes in IOP following cataract surgery were strongly negatively correlated with preoperative IOP. An increase in macular thickness was observed 6 months postoperatively in all groups. Aqueous humour flare did not differ in OAGc and OAGu groups pre- and postoperatively but significantly increased in the control group postoperatively. 

Growing evidence suggests that intracranial pressure (ICP) plays an important role in the pathophysiology of glaucoma, especially in normal-tension glaucoma (NTG) patients. Controversial results exist about ICP’s relationship to visual field (VF) changes. With the aim to assess the relationship between ICP and VF zones in NTG patients, 80 NTG patients (age 59.5 (11.6) years) with early-stage glaucoma were included in this prospective study. Intraocular pressure (IOP) (Goldmann), visual perimetry (Humphrey) and non-invasive ICP (via a two-depth Transcranial Doppler, Vittamed UAB, Lithuania) were evaluated. Translaminar pressure difference (TPD) was calculated according to the formula TPD = IOP − ICP. The VFs of each patient were divided into five zones: nasal, temporal, peripheral, central, and paracentral. The average pattern deviation (PD) scores were calculated in each zone. The level of significance p < 0.05 was considered significant. NTG patients had a mean ICP of 8.5 (2.4) mmHg. Higher TPD was related with lower mean deviation (MD) (p = 0.01) and higher pattern standard deviation (PSD) (p = 0.01). ICP was significantly associated with the lowest averaged PD scores in the nasal VF zone (p < 0.001). There were no significant correlations between ICP and other VF zones with the most negative mean PD value. (p > 0.05). Further studies are needed to analyze the involvement of ICP in NTG management. 

Glaucoma is a multifactorial disease and a leading cause of irreversible blindness worldwide. Current data has demonstrated the approximate distribution of primary openangle glaucoma (POAG) in patients of European, African, Hispanic, and Eastern Asian descent. However, a significant gap in the literature exists regarding the prevalence of POAG in Middle Eastern (ME) populations. Current studies estimate ME POAG prevalence based on a European model. Herein we screened 65 total publications on ME prevalence of POAG and specific risk factors using keywords: “glaucoma”, “prevalence”, “incidence”, “risk factor”, “Middle East”, “Mideast”, “Persian”, “Far East”, as well as searching by individual ME countries through PubMed, Embase, Ovid, Scopus, and Trip searches with additional reference list searches from relevant articles published up to and including March 1, 2021. Fifty qualifying records were included after 15 studies identified with low statistical power, confounding co-morbid ophthalmic diseases, and funding bias were excluded. Studies of ME glaucoma risk factors that identify chromosomes, familial trend, age/gender, socioeconomic status, lifestyle, intraocular pressure, vascular influences, optic disc hemorrhage, cup-to-disc ratio, blood pressure, obstructive sleep apnea, and diabetes mellitus were included in this systematic review. We conclude that the prevalence of POAG in the ME is likely higher than the prevalence rate that European models suggest, with ME specific risk factors likely playing a role. However, these findings are severely limited by the paucity of population-level data in the ME. Well-designed, longitudinal population-based studies with rigorous inclusion and exclusion criteria are ultimately needed to accurately assess the epidemiology and specific mechanistic risk factors of glaucoma in ME populations. 

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.