Challenging the "Topical Medications-First" Approach to Glaucoma: A Treatment Paradigm in Evolution

Adopting Interventional Glaucoma Via Sustained-Release Therapies: The Wide-Ranging Impact of Procedural Pharmaceuticals in Ophthalmology

Topical medical therapy is the most common approach to the treatment of many ocular conditions. While effective, topical therapy has numerous important limitations. Eye drops can have unpleasant or even dangerous side effects, are often difficult to self-administer, and the application of multiple drops per day, possibly from multiple different bottles, can be burdensome. Perhaps the most important limitation of topical medical therapy is non-adherence, a complex multifactorial behavior that increases the risk of poor outcomes associated with undertreatment. There is growing interest in a class of therapeutics termed "procedural pharmaceuticals" (PPs), which remove the responsibility of self-dosing from patients. An array of PPs are available for the treatment of a variety of ocular conditions, such as those for glaucoma, retina, and cataract surgery; and many more will emerge in coming years. A paradigm shift away from patient-administered therapy toward provider-administered therapy will have important implications for both providers and patients. This paper explores the impact that PPs have had, and will have, on the clinical practice of ophthalmology.

Hyaluronate Protects From Benzalkonium Chloride-Induced Ocular Surface Toxicity

Purpose

The purpose of this study was to investigate the effect of sodium hyaluronate (SH) on benzalkonium chloride (BAK)-induced toxicity in the ocular surface epithelium and corneal nerves.

Methods

Ocular surface epithelial cells from Balb/c mice were cultured with 0.1% to 0.4% SH and 0.001% to 0.01% BAK and their metabolic activity, viability, and wound repair capacity were assessed in vitro. Following a controlled corneal wound, re-epithelialization and recovery of epithelial barrier function and mechanosensitivity were measured in Balb/c mice treated with 0.4% SH 3 times/day and 0.01% BAK twice daily for 3 weeks. Nerve morphology was assessed by confocal microscopy of corneal whole mounts.

Results

Whereas BAK exposure reduced metabolic activity, viability, and wound repair ability of ocular epithelial cells in vitro, pretreatment with SH ameliorated BAK toxicity in a concentration-dependent manner. The highest SH concentration partially reversed the effects of 0.01% BAK in vitro and increased the corneal healing rate of BAK-exposed mice. Although all corneal wounds closed after 4 days, continuous SH treatment improved corneal barrier dysfunction 18 days after wounding and accelerated the recovery of corneal mechanical sensitivity to baseline levels in BAK-exposed mice. SH treatment also increased corneal nerve density in the wounded area after 3 weeks.

Conclusions

SH mitigates BAK-associated ocular epithelial and neurotoxicity in a concentration-dependent manner.

Translational Relevance

Commercially available, high-concentration SH formulations may have added benefits in treating BAK-associated ocular surface toxicity.

Ten-Year Effectiveness and Safety of Trabecular Micro-Bypass Stent Implantation with Cataract Surgery in Patients with Glaucoma or Ocular Hypertension

INTRODUCTION

This study evaluated 10-year results of implanting one iStent trabecular micro-bypass stent during cataract surgery in eyes with open-angle glaucoma (OAG) or ocular hypertension.

METHODS

This retrospective, non-randomized study examined 10-year outcomes of iStent trabecular micro-bypass stent implantation with cataract surgery by one surgeon in eyes with OAG [including primary OAG (POAG) and pseudoexfoliative glaucoma (PXG)] or ocular hypertension at a multi-specialty German ophthalmology center. Study visits were conducted preoperatively and at 2.5, 3, 5, and 10 years postoperatively; examinations included intraocular pressure (IOP), medications, corrected-distance visual acuity (CDVA), and adverse events.

RESULTS

A total of 63 eyes of 45 patients with OAG (n = 60 eyes) or ocular hypertension (n = 3 eyes) and data through 10 years were analyzed. Mean preoperative IOP was 18.6 ± 4.4 mmHg on 1.83 ± 1.03 mean medications. At study visits through 10 years postoperative, mean IOP reduced by 12.9-19.0% (p < 0.005 at all points), and mean medication burden reduced by 37.8-51.4% (p ≤ 0.006 at all points). At 10 years postoperatively, 77.8% of eyes had IOP ≤ 18 mmHg and 47.6% had IOP ≤ 15 mmHg (vs. 50.8% and 25.4% preoperatively, respectively; p = 0.016). One-third (33.3%) of eyes were medication-free vs. 3.2% preoperatively (p < 0.001); 17.5% were on 2-5 medications (vs. 55.6% preoperatively, p = 0.005); and 93.7% of eyes were on the same or fewer medications vs. preoperative. Post-phacoemulsification CDVA improvement was maintained; no filtering surgeries were completed over 10-year follow-up.

CONCLUSIONS

Significant and safe IOP and medication reductions were observed through 10 years after iStent implantation with cataract surgery in patients with OAG or ocular hypertension.

7-Year Efficacy and Safety of iStent inject Trabecular Micro-Bypass in Combined and Standalone Usage

INTRODUCTION

This study evaluated 7-year effectiveness and safety of second-generation trabecular micro-bypass implantation (iStent inject) either in combination with cataract surgery or as a standalone procedure (Combined or Standalone subgroups, respectively) in eyes with open-angle glaucoma.

METHODS

This prospective, non-randomized, unmasked, longitudinal study included 125 consecutive iStent inject cases of a single surgeon at a large German academic hospital. Patients had considerable preoperative disease burden, with mean intraocular pressure (IOP) of 23.5 mmHg, 84.8% of eyes on ≥ 2 medications, and 38.4% of eyes with prior glaucoma surgery. IOP, medications, adverse events, and secondary surgeries were assessed through 7 years in the Overall cohort and in Combined (n = 81) and Standalone (n = 44) subgroups.

RESULTS

Over 7-year follow-up, mean IOP decreased by 36.2-40.0% in Overall eyes, 34.1-38.9% in Combined eyes, and 39.5-43.5% in Standalone eyes (p < 0.001 at all timepoints for all groups). Meanwhile, mean medications decreased by 59.3-71.3% in Overall eyes, 57.9-69.0% in Combined eyes, and 62.1-76.2% in Standalone eyes (p < 0.001 at all timepoints in all groups). At last follow-up (mean 77.4 months; 92.8% of patients with last visit at 6 or 7 years), 83.7% of Overall eyes, 82.3% of Combined eyes, and 86.4% of Standalone eyes had achieved ≥ 20% IOP reduction vs preoperative. At last follow-up vs preoperative, 100% of eyes in all groups had the same or lower IOP and 100% had the same or lower medication regimen. Safety outcomes were favorable, with no filtration surgeries and only 4.84% of eyes experiencing clinically significant visual field loss over 7 years of follow-up.

CONCLUSION

iStent inject implantation with or without phacoemulsification produced significant and durable 7-year reductions in IOP (~ 34-44% reduction) and medications (~ 58-76% reduction) while preventing filtering surgery in this cohort of patients with relatively high preoperative disease burden. Combined and Standalone cases had similarly favorable effectiveness and safety.

Early diagnostics and interventional glaucoma

The glaucoma treatment paradigm is starting to change from a more reactive approach that relies on topical medications to a more proactive approach that leverages procedural interventions. This evolution toward interventional glaucoma has been enabled by a growing array of lower-risk minimally invasive procedures such as laser trabeculoplasty, minimally invasive glaucoma surgery, and procedural pharmaceuticals. A common feature of these glaucoma interventions-as with all glaucoma interventions-is the need for early, prompt, and accurate diagnosis. The present review summarizes new and upcoming developments in glaucoma diagnostics. These include technologies and techniques for home-based intraocular pressure measurement, novel visual field platforms, photography- and optical coherence tomography-based visualization, and artificial intelligence applications. They also include emerging technologies such as mitochondrial flavoprotein fluorescence imaging, detection of apoptosing retinal cells, collector channel visualization, and genetic testing. These diagnostic modalities have the potential to circumvent the limitations of traditional diagnostic methods. By increasing the frequency and feasibility of obtaining valuable glaucoma data with more rapid detection of disease and progression, these diagnostics may enable an interventional approach to glaucoma treatment for the betterment of patient care.