Edward Yung

An overview of home tonometry and telemetry for intraocular pressure monitoring in humans

PurposeTo review the existing technology for self-tonometry and evaluate methods for continuous monitoring of IOP currently undergoing development and clinical trials in humans.BackgroundGlaucoma is one of the leading causes of blindness worldwide. Current glaucoma therapy is focused primarily on lowering intraocular pressures (IOP). Decisions to modify treatment regiments are primarily based on office IOP. Since IOP fluctuates throughout the day, values obtained in the office may be a poor representation of the patient’s disease. IOP measurements outside of the physician’s office environment would provide better knowledge of the disease state and allow for better-informed medical decision making.Methods and resultsWe performed a literature search using Medline and IEEE database for studies investigating technologies that have been developed for continuous 24-hour IOP monitoring.ConclusionThere is currently no technology that has been approved for use to allow for continuous monitoring of IOP fluctuations. New experimental technology being developed and currently undergoing clinical trials has demonstrated potential for changing the diagnosis and management of glaucoma.

Current concepts in the treatment of vitreous block, also known as aqueous misdirection

Vitreous block (VB), a rare secondary angle-closure caused by anterior rotation of the ciliary body, occurs in a variety of settings, but most frequently after glaucoma filtering surgery. The etiology remains unclear, but choroidal expansion and anterior vitreous abnormalities have been proposed. In the past, treatment of VB has yielded high rates of failure and recurrence. Advancements in surgical techniques, however, have led to improved visual outcomes. We review the history of this condition and present a stepwise approach to its diagnosis and treatment using modern imaging modalities and surgical techniques.

Monitoring intra ocular pressure in glaucoma: current recommendations and emerging cutting-edge technologies

Measurements of intraocular pressure (IOP) are crucial to the diagnosis and management of glaucoma, the leading cause of irreversible blindness worldwide. Goldmann applanation tonometry remains the gold standard in obtaining IOP measurements, but is limited by its inability to obtain measurements outside of the clinical setting or account for diurnal variations in pressures. This review focuses on existing technologies available for measuring diurnal shifts in IOP at home, including portable tonometers and other temporary and permanent devices for continuous IOP monitoring using telemetry. We discuss the deficiencies of home tonometry technologies and present recent advances in telemetry technology that could revolutionize the ability to monitor IOP response to glaucoma therapy.

Pilot Study Assessing the Use of High-Density Polyethylene (Su-Por®) for Tube Shunt Patch Grafts

Purpose: To assess the viability of a manufactured high-density polyethylene patch graft material (Su-Por) for prevention of tube shunt exposure. Materials and Methods: Retrospective review of the first 11 patients from the Wills Eye Hospital Glaucoma Service to receive the high-density polyethylene patch graft during tube shunt surgery. Results: Four patients (36.3%) experienced an extrusion of the Su-Por patch without a leak within 2.5 months of postoperative follow-up. All 4 patients developed either symptomatic or progressive extrusion. Operative repair was completed with Su-Por removal and replacement with a new human donor patch graft. No patient developed any sign of infection despite the extrusions. The remaining 7 patients had an uneventful postoperative course and continue to have no complications from the Su-Por patch with 9 months of follow-up. Conclusions: Given the high rate of extrusion of the Su-Por graft, this material seems to be an inadequate alternative for covering tube shunts. Harvested human tissue or other more flexible, manufactured grafts remain the standard of care for covering tube shunts.