Comparison of Cytotoxic Effects on Rabbit Corneal Endothelium between Preservative-free and Preservative-containing Dorzolamide/timolol

The Multifarious Effects of Various Glaucoma Pharmacotherapy on Corneal Endothelium: A Narrative Review

Corneal endothelium is a single cell layer that is mainly responsible for maintaining corneal clarity. Endothelial damage secondary to toxicity, stress, or genetic predisposition are common and in conjunction with the low regenerative ability of the cells, making their preservation critical for maintaining visual acuity. Patients with glaucoma, who are estimated to be close to 80 million worldwide, have a plethora of reasons for developing endothelial damage, being exposed to a spectrum that extends from various medical and surgical interventions to the disease itself. The wide spectrum of glaucoma pharmacotherapy that has been recently extended by addition of newer classes of medications has been the focus of extensive research on its effects on corneal endothelium. Both basic and clinical research have attempted to shine a light on the complex mechanisms associated with the effects of glaucoma medication on corneal endothelium and to answer the important question as to whether these findings are clinically significant. The aim of this review is to summarize and present current literature of the various findings, both from in vivo and in vitro studies that have focused on the complex relationship between different classes of glaucoma medication and their effect on corneal endothelium.

Comparison of the Safety and Efficacy between Preserved and Preservative-Free Latanoprost and Preservative-Free Tafluprost

In this study, we investigated the effect of preservative-free (PF) 0.0015% tafluprost (TA), to the preservative containing (PC) and the PF 0.005% latanoprost (LA) in Korean subjects. This study was conducted as a multi-center, randomized, investigator-blind, active controlled, parallel-group, clinical trial in adult patients (≥19 years) with open-angle glaucoma (OAG) and ocular hypertension (OHT). After a washout period, patients with an IOP between 15 and 35 mmHg were enrolled and evaluated the efficacy, safety, and compliance at 4, 8 and 12 weeks after the first administration. A total of 137 OAG and OHT patients were randomized. Statistically significant reductions in IOP were observed in all groups. Twelve weeks after each eye drop instillation, the mean IOP reduction was −4.59 ± 2.70 mmHg (−24.57 ± 13.49%) in the PC-LA group, −4.52 ± 2.17 mmHg (−24.41 ± 11.38%) in the PF-LA, and −3.14 ± 2.83 mmHg (−17.22 ± 14.57%) in the PF-TA group. The PF-LA showed significantly better responsiveness than did PF-TA. PF-LA was better tolerated than was PC-LA. There were no adverse events that led to cessation of eye drop use in any of the groups. In conclusion, IOP decreased similarly across the groups. PF-LA may provide a good choice for OAG patients with ocular surface diseases.

Comparison of the Intraocular Pressure-Lowering Effect and Safety of Preservative-Free And Preservative-Containing Brimonidine/Timolol Fixed-Combination Ophthalmic Solutions in Patients with Open-Angle Glaucoma

Purpose: To compare the therapeutic efficacy and safety of newly developed preservative-free (PF) brimonidine/timolol fixed-combination (BTFC) ophthalmic solutions and a preservative-containing (PC) BTFC ophthalmic solution in patients with open-angle glaucoma.Methods: This study was conducted as a multicenter, randomized, open-label, parallel-group clinical trial to evaluate the efficacy and safety of PF BTFC as compared with PC BTFC in adult patients (aged ≥ 19 years) with open-angle glaucoma (OAG) and ocular hypertension (OHT). A total of the 106 patients were enrolled, with 53 patients each randomized to the two treatment groups and included in the analysis of the safety set (SS).After a washout period, patients with an IOP below 35 mmHg at 9 a.m. were enrolled. After a full ophthalmic and glaucoma examination, a total of 106 OAG and OHT patients were randomized to the PF group or PC group.All subjects were examined 4 and 12 weeks after first administration. At each follow-up visit, IOP was measured at 9 a.m. and 11 a.m. and the efficacy, safety, and compliance were evaluated. Throughout the study, all adverse events were recorded and monitored by the investigators.Results The mean IOP changes from baseline to 12 weeks at 11:00 a.m. were -3.45 ± 2.53 mmHg in the PF group and -3.65 ± 2.76 mmHg in the PC group (p < .0001 for both). The difference in mean IOP change between the two groups was 0.20 ± 2.65 mmHg, which was not significantly different. The proportion of patients with IOP reductions of ≥ 15% and ≥ 20% and IOP at all-time points in the PF group were not significantly different when compared with in the PC group. There were no specific differences between the two groups regarding the incidence of adverse events.Conclusions PF BTFC ophthalmic solution shows a similar efficacy and safety profile to that of PC BTFC.

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

Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.

A Review of Corneal Endotheliitis and Endotheliopathy: Differential Diagnosis, Evaluation, and Treatment

The corneal endothelium plays an integral role in regulating corneal hydration and clarity. Endotheliitis, defined as inflammation of the corneal endothelium, may disrupt endothelial function and cause subsequent visual changes. Corneal endotheliitis is characterized by corneal edema, the presence of keratic precipitates, anterior chamber inflammation, and occasionally limbal injection, neovascularization, and co-existing or superimposed uveitis. The disorder is classified into four subgroups: linear, sectoral, disciform, and diffuse. Its etiology is extensive and, although commonly viral, may be medication-related, procedural, fungal, zoological, environmental, or systemic. Not all cases of endothelial dysfunction leading to corneal edema are inflammatory in nature. Therefore, it is imperative that practitioners consider a broad differential for patients presenting with possible endotheliitis, as well as familiarize themselves with appropriate diagnostic and therapeutic modalities.