Glaucoma is a multifactorial optic neuropathy characterized by the continuous loss of retinal ganglion cells, leading to progressive and irreversible visual impairment. In this minireview, we report the results of the most recent experimental studies concerning cells, molecular mechanisms, genes, and microbiome involved in neuroinflammation processes correlated to glaucoma neurodegeneration. The identification of cellular mechanisms and molecular pathways related to retinal ganglion cell death is the first step toward the discovery of new therapeutic strategies. Recent experimental studies identified the following possible targets: adenosine A_2A receptor, sterile alpha and TIR motif containing 1 (neurofilament light chain), toll-like receptors (TLRs) 2 and 4, phosphodiesterase type 4 (PDE4), and FasL-Fas signaling (in particular ONL1204, a small peptide antagonist of Fas receptors), and therapies directed against them. The continuous progress in knowledge provides interesting data, although the total lack of human studies remains an important limitation. Further research is required to better define the role of neuroinflammation in the neurodegeneration processes that occur in glaucomatous disease and to discover neuroprotective treatments amenable to clinical trials. The hereinafter reviewed studies are reported and evaluated according to their translational relevance.

Peer reviewed article authored by (Rolle T, Briamonte C, Curto D, Grignolo FM). Read article or submit your manuscript for publishing.

Purpose: To evaluate papillary, peripapillary, and macular vasculature with optical coherence tomography angiography in preperimetric (PPG), primary open-angle glaucoma (POAG), and normal eyes, and to assess diagnostic ability and associations among the vasculature and structural damage. Methods: This was an observational, cross-sectional study. Retinal nerve fiber layer (RNFL), ganglion cell complex thickness, whole-image (wiVD), inside disc (idVD), peripapillary (ppVD), and macular vessel densities were obtained. Analysis of variance, post hoc test, and Pearson coefficient were used. The areas under the receiver operating characteristic curve (AUC) and cut-offs were calculated. Results: Thirteen healthy, 39 PPG, and 19 POAG eyes were included. Papillary and peripapillary VD were lower in POAG eyes in all parameters analyzed. wiVD in PPG eyes (52.37 ± 5.04%) was significantly decreased compared to healthy eyes (58.02 ± 2.02%, p < 0.05). AUC ranged from 0.62 to 0.90; the established cut-off values were 56% for wiVD, 55% for idVD, and 62% for ppVD. Pearson’s correlation coefficient showed a direct correlation between the papillary or peripapillary VD and RNFL thickness. Conclusions: Vessel densities in POAG eyes are significantly lower than in healthy eyes, and they show good discriminatory abilities. A diminished microvascular network is associated with RNFL thinning more strongly in POAG than in PPG eyes.

Purpose: To evaluate the efficacy, safety, and tolerability of Timogel® preservative-free once daily compared to timolol 0.5% ophthalmic solution bid in patients with ocular hypertension (OHT) and patients with primary open-angle glaucoma (POAG). Methods: A total of 75 patients with OHT and patients with POAG treated with timolol 0.5% bid with intraocular pressure (IOP) ≤21 mmHg were enrolled. They underwent complete ophthalmologic examination, IOP measurements (at trough and daytime curve), evaluation of side effects, Schirmer test, break-up time [BUT], blood pressure, heart rate, ocular diastolic perfusion pressure measurements, and acceptance (Comparison of Ophthalmic Medications for Tolerability). Patients switched to Timogel® and were re-evaluated 3 months later. The analysis of variance and the Pearson χ² tests were used to test differences between the treatments. Results: Intraocular pressure reduction at trough was 23.6% with timolol 0.5% and 22.3% with Timogel®. No statistical differences were observed in IOP values at trough and in the daytime curve between the 2 treatments. Local and systemic side effects were less frequent with Timogel® (hazard ratio: p<0.05). Patients demonstrated a significant improvement of Schirmer test and BUT (p<0.05) and a reduction of dryness and foreign body sensation (42.6% vs 15.4%; p<0.01) after switching to Timogel®. Mild and short-lasting blurred vision after Timogel® instillation occurred in about 18.5% of patients. A total of 82% of patients were satisfied or very satisfied with Timogel® vs 61% with previous treatment (p<0.01). Conclusions: Timogel® preservative-free dosed once every morning has a 24-hour hypotensive effect with a better safety profile than timolol 0.5% bid and it is well-accepted by patients. The once-daily dosing improved acceptance and compliance.

The effects of preservatives of antiglaucoma medications on corneal surface and tear function have been widely shown in literature; it’s not the same as regards the active compounds themselves. The purpose of our study was to compare Ocular Surface Disease (OSD) signs and symptoms of Tafluprost 0.0015% versus preservative free (PF) Timolol 0.1% eyedrops in ocular hypertensive (OH) and in primary open-angle glaucoma (POAG) patients. A cross-sectional study included patients in monotherapy for at least 36 months with Tafluprost 0.0015% (27) or PF Timolol 0.1% (24) and 20 healthy age and sex-matched volunteers. All subjects underwent clinical tests (Schirmer I and break-up time), in vivo confocal microscopy (IVCM) and were surveyed using Ocular Surface Disease Index (OSDI) and Glaucoma Symptoms Scale (GSS) questionnaires. The groups were compared with ANOVA, Kruskal-Wallis test, t-test, Mann-Whitney test and Bonferroni’s adjustment of p-values. No significant differences were found in questionnaires scores, clinical tests, IVCM variables between therapy groups. Tafluprost 0.0015% group showed significantly higher OSDI score, basal epithelial cells density, stromal reflectivity, sub-basal nerves tortuosity (p = 0.0000, 0.037, 0.006, 0.0000) and less GSS score, number of sub-basal nerves (p = 0.0000, 0.037) than controls but similar clinical tests results (p > 0.05). PF Timolol group had significantly higher OSDI score, basal epithelial cells density, stromal reflectivity and sub-basal nerve tortuosity (p = 0.000, 0.014, 0.008, 0.002), less GSS score, BUT and number of sub-basal nerves (p = 0.0000, 0.026, 0.003) than controls. Compared to PF Timolol 0.1%, Tafluprost 0.0015% showed similar safety with regards to tear function and corneal status and a similar tolerability profile. Both therapy groups show some alterations in corneal microstructure but no side effects on tear function except for an increased tear instability in PF Timolol 0.1% group. Ophtalmologists should be aware that even PF formulations may lead to a mild ocular surface impairment.

Purpose To compare the effect of dorzolamide hydrochloride 2%, timolol maleate 0.5%, and their fixed combination on intraocular pressure (IOP) and retinal and optic nerve head haemodynamics in primary open-angle glaucoma patients. Methods Twenty-eight patients with early-moderate glaucomatous damage treated with β-blockers (>6 months) with IOP values ranging from 18 to 22 mmHg at trough participated in this trial. After a 4-week washout period, patients were randomized in two groups: group I started with dorzolamide 2% monotherapy and group II with timolol 0.50% monotherapy for 4 weeks. After this period, both groups switched to dorzolamide/timolol fixed combination for 4 weeks. IOP, ocular diastolic perfusion pressure (ODPP), heart rate, and Scanning Laser Doppler Flowmetry measurements at the peripapillary retina and neuroretinal rim were taken at T0 (enrolment), T1 (wash out), T2 (monotherapy), and T3 (dorzolamide/timolol). Data were compared between different study times. Statistical analysis was conducted using a paired t-test. Results Between T1 and T3, IOP decreased significantly in group I (−21.40%) (P<0.001) and in group II (−21.25%) (P<0.001). At the same time intervals, blood flow increased significantly at rim level for group I (+30.03%) (P<0.05) and also when all patients were considered (rim +17.99%) (P<0.05). Between T1 and T3, we also observed a significant increase of ODPP in group I (+7.24%) (P<0.01) and in group II (+6.08%) (P<0.05) and when all patients were considered (+8.43%) (P<0.01). Conclusions Dorzolamide/timolol fixed combination increased blood flow significantly at the neuroretinal rim showing a combination of hypotensive and haemodynamic effects.