Glow Characterization in Low-Pressure Radio-Frequency $\hbox{CH}_{2} \hbox{F}_{2}$ and $\hbox{C}_{2}\hbox{H}_{2}\hbox{F}_{4}$  Plasma Deposition Systems
The glow characteristics and deposited film structures of fluorocarbon monomers in radio-frequency glow discharges are investigated using CH<sub>2</sub>F<sub>2</sub> and C<sub>2</sub>H<sub>2</sub>F<sub>4</sub>, which were compared to hydrocarbon monomer such as CH<sub>4</sub>. The glow was characterized and investigated by optical photography, optical emission spectroscopy, and Fourier transform infrared spectrometry. The glow differences were attributed to the nature of the luminous gas phase in respect to polymer-forming species.
Deposition behavior in a low-temperature cascade arc torch (CAT) polymerization process
Two kinds of hydrocarbon type monomers and three kinds of organosilicons were polymerized by a low-temperature cascade arc argon plasma torch. Their deposition behaviors were studied as a function of experimental parameters and monomer elemental compositions. It was found that the normalized deposition rate (DR), expressed as deposition yield of DR/(FM) was determined by a composite operational parameter, W * (FM) c /(FM) where W is the power input, and (FM) c and (FM) m are the mass flow rates of carrier gases and monomers, respectively. Experimental results indicated that the deposition yield is highly dependent on the elementary compositions of monomers. Optical emission spectroscopy study on the argon plasma torch showed that the emission intensity of excited argon neutrals was proportional to the value of the parameter W * (FM) c . These results further certified that excited argon neutrals are the main energy carriers from the cascade arc column to activate monomers in the argon plasma torch.
Direct orbital manometry in patients with thyroid-associated orbitopathy.
PURPOSE
To determine orbital tissue tension and orbital compartment compliance in patients with and without thyroid-associated orbitopathy (TAO).


DESIGN
Prospective case series.


PARTICIPANTS
Orbits of patients with TAO (18 orbits) and control patients without TAO (35 orbits) were studied.


METHODS
An orbital manometer was designed to directly measure orbital tissue tension in patients undergoing ocular or orbital surgery.


MAIN OUTCOME MEASURES
Tissue tension was recorded before, during, and for 5 minutes after a 5-ml retrobulbar injection of anesthetic. Orbital compliance was calculated as change in volume divided by change in tissue tension.


RESULTS
Resting orbital tissue tension was 4.4 +/- 2.2 mmHg (mean +/- SD) in normal orbits and 9.7 +/- 4.8 mmHg in orbits of TAO patients (P = 0.0005) Following retrobulbar injection, orbital tissue tension rose to 12.0 +/- 3.6 mmHg (P = 0.0000000000000006 compared with baseline) in the control group and to 36.3 +/- 15.2 mmHg in the TAO group (P = 0.0000007 compared with baseline, and P = 0.000008 TAO group versus control group). Orbital compartment compliance was 0.80 +/- 0.50 ml/mmHg in the control group and 0.27 +/- 0.21 ml/mmHg in the TAO group (P = 0.00001). Resting orbital tissue tension in 8 TAO orbits with compressive optic neuropathy was 12.4 +/- 4.9 mmHg, and was 7.8 +/- 3.5 mmHg in 10 orbits of TAO patients without compressive optic neuropathy (P < 0.05). No adverse events occurred.


CONCLUSIONS
Retrobulbar injection causes consistent measurable changes in orbital tissue tension. Orbital manometry safely demonstrated higher orbital tissue tension and lower orbital compartment compliance in the orbits of TAO patients versus those of normal subjects. Resting orbital tissue tension was higher in the orbits of TAO patients with compressive optic neuropathy than in those orbits without. Compressive optic neuropathy may partially result from an orbital compartment syndrome in some patients with TAO. Directly assessing orbital dynamics in vivo may prove useful as an adjunct in the clinical evaluation of patients with TAO and other orbital disorders.