Jeffrey R. SooHoo

Preclinical Investigation of Ab Interno Trabeculectomy Using a Novel Dual-Blade Device

PURPOSE To evaluate the effects of a novel ab interno trabeculectomy device on human trabecular meshwork (TM). DESIGN Laboratory evaluation. METHODS The TM from human cadaveric corneal rim tissue was incised using 3 instruments: (1) novel dual-blade device; (2) microvitreoretinal (MVR) blade; and (3) Trabectome. Tissue samples underwent histologic processing and comparative analyses. Subsequently, human eye perfusion studies were performed to evaluate intraocular pressure (IOP)-lowering effects of each device. Main outcome measures were degree of TM removal by histology and IOP in a perfusion model. RESULTS The MVR blade exhibited minimal removal of TM and obvious injury to the adjacent sclera. The Trabectome removed a large portion of the central TM, but leaflets of residual tissue remained and thermal injury was noted in all samples. The dual-blade device achieved a more complete removal of TM without injury to surrounding tissues. All devices resulted in statistically significant lowering of IOP during perfusion model studies. MVR blade treatment across 170.0 ± 14.1 degrees of TM resulted in a decrease of IOP from 18.5 ± 1.9 mm Hg to 12.8 ± 2.2 mm Hg (P < .01). Trabectome treatment across 117.5 ± 12.6 degrees resulted in a decrease of IOP from 18.8 ± 1.7 mm Hg to 11.3 ± 1.0 mm Hg (P < .01). Dual-blade device treatment across 157.5 ± 26.3 degrees resulted in a decrease of IOP from 18.3 ± 3.0 mm Hg to 11.0 ± 2.2 mm Hg (P < .01). CONCLUSIONS The novel dual-blade device demonstrated a more complete removal of TM without residual TM leaflets or damage to surrounding tissues and significantly reduced IOP in a human eye perfusion model.

Minimally invasive glaucoma surgery: current implants and future innovations

Traditionally, invasive surgical management of glaucoma is recommended when medication and/or laser trabeculoplasty fail to control intraocular pressure (IOP). Filtering procedures, such as trabeculectomy and glaucoma drainage devices, are effective in lowering IOP, but they have significant associated adverse events and rates of failure. For these reasons, a new group of surgical procedures has emerged that seeks to decrease IOP with lower associated rates of complications. The acronym MIGS, usually described as minimally invasive glaucoma surgery, has been coined to describe this group of procedures. As new devices become available, MIGS procedures will help to fill the gap between conservative medical and laser therapy and invasive surgical treatment of glaucoma to offer patients an earlier and safer transition to surgical management of their disease. In this review, we define the characteristics of an ideal MIGS procedure and discuss implants currently in use or under investigation.

Recent Advances in the Management of Neovascular Glaucoma

ABSTRACT The development of anti-vascular endothelial growth factor (VEGF) molecules has expanded the range of available treatment options for many ocular diseases, including neovascular glaucoma (NVG). A number of studies have explored the use of anti-VEGF agents as stand-alone or adjunctive treatment for NVG. Although no large, prospective, randomized trials have been performed to date, the growing body of knowledge suggests that anti-VEGF agents are effective at reversing iris and angle neovascularization and lowering intraocular pressure in patients with NVG. Response to a single injection is typically temporary; therefore, laser or incisional surgery is still necessary in most cases. Future research is needed to determine the optimal agent, dose, route of administration, and timing of treatment either as monotherapy or coupled with other medical and/or surgical interventions.

Ab interno trabeculectomy in the adult patient

Glaucoma is a potentially blinding disease that affects millions of people worldwide. The mainstay of treatment is lowering of intraocular pressure (IOP) through the use of medications, laser and/or incisional surgery. The trabecular meshwork (TM) is thought to be the site of significant resistance to aqueous outflow in open angle glaucoma. Theoretically, an incision through TM or TM removal should decrease this resistance and lead to a significant reduction in IOP. This approach, commonly referred to as goniotomy or trabeculotomy, has been validated in the pediatric population and has been associated with long-term IOP control. In adults, however, removal of TM tissue has been historically associated with more limited and short-lived success. More recent evidence, reveals that even adult patients may benefit significantly from removal of diseased TM tissue and can lead to a significant reduction in IOP that is long-lasting and safe. In this review, we discuss current evidence and techniques for ab interno trabeculectomy using various devices in the adult patient.

Ultrastructural Changes in Human Trabecular Meshwork Tissue after Laser Trabeculoplasty

Purpose. To compare morphologic changes in human trabecular meshwork (TM) after selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT). Design. Laboratory evaluation of ex vivo human eye TM after laser trabeculoplasty. Methods. Corneoscleral rims from human cadaver eyes were sectioned and treated with varying powers of either SLT or ALT. Specimens were examined using light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results. TEM of SLT at all powers resulted in disrupted TM cells with cracked and extracellular pigment granules. SEM of SLT samples treated at high power revealed tissue destruction with scrolling of trabecular beams. SEM of ALT-treated tissue showed increasing destruction with exposure to higher power. The presence or absence of “champagne” bubbles during SLT did not alter the histologic findings. Conclusions. SLT-treated human TM revealed disruption of TM cells with cracked, extracellular pigment granules, particularly at higher treatment powers. Tissue scrolling was noted at very high SLT energy levels. ALT-treated tissue showed significant damage to both the superficial and deeper TM tissues in a dose-dependent fashion. Further studies are needed to guide titration of treatment power to maximize the IOP-lowering effect while minimizing both energy delivered and damage to target tissues.

Systematic Review of Current Devices for 24-h Intraocular Pressure Monitoring

Glaucoma is a common optic neuropathy that can lead to irreversible vision loss, and intraocular pressure (IOP) is the only known modifiable risk factor. The primary method of treating glaucoma involves lowering IOP using medications, laser and/or invasive surgery. Currently, we rely on in-office measurements of IOP to assess diurnal variation and to define successful management of disease. These measurements only convey a fraction of a patient’s circadian IOP pattern and may frequently miss peak IOP levels. There is an unmet need for a reliable and accurate device for 24-h IOP monitoring. The 24-h IOP monitoring devices that are currently available and in development fall into three main categories: self-monitoring, temporary continuous monitoring, and permanent continuous monitoring. This article is a systematic review of current and future technologies for measuring IOP over a 24-h period.

Outcomes after combined phacoemulsification and trabecular microbypass stent implantation in controlled open-angle glaucoma

Purpose To study the effect of combined phacoemulsification cataract surgery and iStent (trabecular microbypass stent) implantation on intraocular pressure (IOP) and medication use in open‐angle glaucoma (OAG) patients with a low mean preoperative IOP. Setting University of Colorado Health Eye Center, Aurora, Colorado, USA. Design Retrospective case series. Methods Treatment outcomes analyzed included IOP, medication use, and corrected distance visual acuity (CDVA). Treatment success was defined as a 20% or more IOP reduction or discontinuation of at least 1 medication. Results Sixty‐four eyes of 45 patients were included in the analysis. At 1 year, the mean IOP was significantly reduced from 14.7 ± 3.2 mm Hg (SD) to 13.2 ± 2.8 mm Hg (P < .01) and the mean medication use decreased from 1.81 ± 1.13 to 1.41 ± 1.48 (P = .0001). The estimated IOP reduction at 1, 3, 6, and 12 months was 3.5% (P = .23), 7.9% (P = .04), 9.7% (P = .01), and 12.2% (P = .002), respectively. Treatment success at 1 year was achieved in 76.1% of patients, and 41% of patients were medication free at 1 year. The CDVA was significantly improved from 0.4 ± 0.38 logMAR at baseline to 0.17 ± 0.35 at 1 year (P < .0001). Conclusions Combined cataract surgery and trabecular microbypass stent implantation was statistically effective in reducing IOP and/or medication burden in OAG patients with a low preoperative IOP. During the informed surgical consent process, the physician and patient should consider the clinical benefit of modest IOP lowering and/or a decrease in medication use. Financial Disclosure Drs. Seibold, SooHoo, Pantcheva, and Kahook have received grant support from Glaukos Corp. No other author has a financial or proprietary interest in any material or method mentioned.

Urothelial Carcinoma With Orbital Metastasis

A case of urothelial carcinoma of the bladder with orbital metastasis in a 53-year-old woman is presented. This case is unique in that the orbit was the sole site of metastasis and extensive lymph node dissection was negative just weeks before the diagnosis of orbital disease. Although rare, patients with urothelial carcinoma and ophthalmic signs or symptoms warrant specialist consultation and appropriate imaging.

One-day postoperative intraocular pressure spikes after phacoemulsification cataract surgery in patients taking tamsulosin.

Purpose To evaluate the relationship between 1‐day postoperative intraocular pressure (IOP) after phacoemulsification cataract surgery and tamsulosin use. Setting University of Colorado Health Eye Center, Aurora, Colorado, USA. Design Retrospective cohort study. Methods Registry data from men who had cataract surgery were used. Patients taking tamsulosin at the time of surgery were included as cases, while patients with no history of tamsulosin use were used as controls. The primary outcome was a 1‐day postoperative IOP spike defined as an IOP increase greater than 10 mm Hg compared with baseline or a 1‐day postoperative IOP of 30 mm Hg or higher. General estimating equations were used for analysis. Results The study comprised 584 men (864 eyes). An IOP increase greater than 10 mm Hg or IOP 30 mm Hg or higher after cataract surgery occurred in 12.4% and 9.3%, respectively, of eyes in the tamsulosin group versus 4.4% and 2.1%, respectively, in the control group (all P = .001). After adjusting for significant covariates, patients on tamsulosin were 2.6 times (95% confidence interval [CI], 1.2‐5.7; P = .01] and 3.8 (95% CI, 1.3‐10.9; P = .01) more likely to have a 1‐day postoperative IOP increase greater than 10 mm Hg or a 1‐day postoperative IOP of 30 mm Hg or higher. Conclusion Patients on tamsulosin had an increased risk of a 1‐day postoperative IOP spike after cataract surgery, showing the importance of identifying patients on tamsulosin preoperatively to better manage and potentially mitigate IOP spikes. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

Comparison of stability between a modular intraocular lens system and a single-piece hydrophobic acrylic intraocular lens

Purpose To compare the movement of a modular intraocular lens (IOL) with that of a standard single‐piece hydrophobic acrylic IOL in a human cadaver eye perfusion model. Setting Department of Ophthalmology, University of Colorado, Aurora, Colorado, USA. Design Experimental study. Methods Eight phakic human donor eyes of 4 patients had standard phacoemulsification with lens removal. One of 2 IOLs was then implanted in the capsular bag: a modular IOL (Harmoni) or a standard single‐piece IOL (Acrysof SN60). Each globe was connected to a programmable perfusion pump with an in‐line pressure transducer. Ultrasound biomicroscopy (UBM) was used to evaluate the anterior chamber depth (ACD) in each eye, measuring from the posterior cornea to the anterior surface of the optic at an intraocular pressure (IOP) of 5 mm Hg, 10 mm Hg, 20 mm Hg, and 30 mm Hg. Five consecutive measurements were recorded for all eyes at each pressure, and the results were averaged. Results There was significantly less movement in eyes with the modular IOL than in eyes with the single‐piece IOL. The mean position of the modular IOL varied from a minimum of 0.03 mm to a maximum of 0.07 mm, and the mean position of the single‐piece IOL varied from a minimum of 0.26 mm to a maximum of 0.87 mm (P = .002). Conclusions The modular IOL showed less movement with changes in IOP than a standard single‐piece IOL. Improved IOL stability might allow more accuracy in determining the effective lens position and hence improve the predictability of the refractive target. Financial Disclosure Proprietary or commercial disclosures are listed after the references.