Selective laser trabeculoplasty in steroid-induced and uveitic glaucoma.

OBJECTIVE: To compare primary selective laser trabeculoplasty (SLT) response in uveitic, steroid-induced, primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEX). DESIGN: Single-centre retrospective case-control study. PARTICIPANTS: Patients with uveitic glaucoma, steroid-induced glaucoma, POAG, or PEX who had their first SLT. METHODS: Eyes with POAG or PEX were in control groups. Eyes with steroid-induced or uveitic glaucoma were in experimental groups. Change in intraocular pressure from baseline, treatment failure, complication rates, and medication use were compared using rank-sum and log-rank tests. RESULTS: Six-hundred and eight eyes of 433 patients were enrolled. Steroid-induced glaucoma eyes had higher mean baseline pressure and a decrease in pressure at 3-8 weeks (27.6-17.4 mm Hg) than those with PEX (21.7-16.5 mm Hg; p < 0.001) or POAG (18.6-14.9 mm Hg; p ≤ 0.025). Failure rates after 2 years were lower in steroid-induced glaucoma (54%) than in PEX (84%; p = 0.01) or POAG (84%; p = 0.005). This survival benefit persisted when excluding patients with changes to their steroid dosing (p ≤ 0.03) but showed mixed results when compared with patients with a baseline pressure of 25mm Hg or greater (p = 0.020 vs PEX; p = 0.67 vs POAG). At 18 months, the steroid-induced group decreased ocular hypotensive medication use (3.5-1.9; p = 0.005); the uveitic group increased medication use (2.7-3.5; p = 0.02). CONCLUSIONS: SLT is an effective treatment for steroid-induced glaucoma, with greater response and a lower failure rate than in PEX and primary POAG, although high baseline intraocular pressure may be a confounder. Judicious use of SLT can be considered in uveitic glaucoma.

In Vivo Noninvasive Measurement of Young's Modulus of Elasticity in Human Eyes: A Feasibility Study.

PURPOSE: Abnormal ocular biomechanical properties may be important for understanding the risk of glaucoma. However, there are no clinical methods for measuring standard material properties in patients. In this feasibility study we demonstrated proof-of-principle for a novel method, ultrasound surface wave elastography (USWE), to determine the in vivo Young's modulus of elasticity of corneas in normal human eyes. METHODS: In total, 20 eyes of 10 healthy subjects (mean age, 51.4±7.2; ±SD; range, 43 to 64 y) were studied. A spherical-tipped probe (3-mm diameter) was placed on closed eyelids and generated a gentle harmonic vibration at 100 Hz for 0.1 second. Wave speed propagation in the cornea was measured by USWE, and Young's modulus was calculated from the wave speed. Associations between Young's modulus and intraocular pressure (IOP), age, central corneal thickness, and axial length were explored by the Pearson correlation. Statistical significance was determined by using generalized estimating equation models to account for possible correlation between fellow eyes. RESULTS: Mean IOP was 12.8±2.7 mm Hg. Mean wave speed in the cornea was 1.82±0.10 m/s. Young's modulus of elasticity was 696±113 kPa and was correlated with IOP (r=0.57; P=0.004), but none of the other variables (P>0.1). CONCLUSIONS: USWE is a novel noninvasive technique for measuring ocular biomechanical properties. Corneal Young's modulus in normal eyes is associated with IOP, consistent with measurements in cadaver eyes. Further work is needed to determine elasticity in other ocular tissues, particularly the sclera, and if elasticity is altered in glaucoma patients.

Personalizing Intraocular Pressure: Target Intraocular Pressure in the Setting of 24-Hour Intraocular Pressure Monitoring.

Determining target intraocular pressure (IOP) in glaucoma patients is multifaceted, requiring attention to many different factors such as glaucoma type, severity of disease, age, race, family history, corneal thickness and hysteresis, and initial IOP. Even with all these variables accounted for, there are still patients who have progression of the disease despite achieving target IOP. Intraocular pressure variability has been identified as a potential independent risk factor for glaucoma progression but is currently difficult to quantify in individual patients. New technologies enabling measurement of both diurnal and nocturnal IOP may necessitate modifying our concept of target pressure.

Amnion doughnut: a novel method for sutureless fixation of amniotic membrane to the bulbar and palpebral conjunctiva in acute ocular-involving Stevens-Johnson syndrome.

PURPOSE: The aim of this study was to describe a novel surgical method for the sutureless placement of amniotic membrane on the bulbar and palpebral conjunctiva in the setting of ocular-involving acute Stevens-Johnson syndrome. METHODS: Within 6 days of an acute Stevens-Johnson episode, a 27-year-old male developed early symblepharon, despite aggressive lubrication and topical steroid therapy. He underwent symblepharon lysis and placement of an amniotic membrane wrapped around a symblepharon ring. RESULTS: The patient maintained 20/20 vision in each eye with no recurrent symblepharon formation except for the temporal canthus (which was not covered with amniotic membrane). CONCLUSIONS: Symblepharon rings covered in amniotic membrane provide a sutureless way to fixate amniotic membrane to the bulbar and palpebral conjunctiva. This gave very good anatomic and functional outcomes in a patient with acute Stevens-Johnson syndrome. Future research could be directed toward the development of a symblepharon ring that will be able to better protect the far temporal conjunctiva.