Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Composite photograph showing the placement of the intraocular pressure pack. The disposable transducers (DTs) must be positioned as close to eye level as possible. If not, there will be a slight error (static pressure differential). CT refers to the coiled 2 m of tubing, and EC shows the disposable electrical connector. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Schematic diagram of the intraocular pressure pack layout. Disposable transducer A is connected to the line coming from the bottle (upstream). The second transducer is connected to the standard vitrectomy infusion cannula (downstream). B indicates the connector that fits with the vitrectomy cannula. The 2 m of tubing is shown by C. In actual use, the transducers were glued together back to back and the tubing was coiled into a bundle. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Disposable blood pressure transducer, which was used to sample infusion line pressures. The electrical connector is in the background. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: View of the 19-gauge catheter pressure transducer, which was implanted into the vitreous via an extra pars plana incision. The scleral flange was glued 4.6 mm from the tip of the catheter to allow for insertion into phakic eyes. PS indicates the strain gauge pressure sensor. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: True intraocular pressure (IOP) measured during 43.5 minutes of vitrectomy in case 1. Each division on the x-axis corresponds to 4.6 minutes (5000 time samples at 18 samples per second). A shows IOP at bottle height with no fluid flow. B indicates an IOP spike due to instrument pressure on the globe caused by placing sutures. C refers to an abrupt plunge in IOP when the globe was perforated. D shows rapid changes in IOP during aspiration, during which the aspiration vacuum ranged from 30 to 120 cm3/min. The sudden return to bottle height represents the surgeon removing the foot from the aspiration pedal. E refers to pressures higher than bottle height due to instrument activity in membrane peeling. F indicates brief study in which true IOP was compared with IOP on vitrectomy console during gas-forced infusion; true IOP was about 10 mm Hg higher than intended. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Calculated intraocular pressure (IOP) compared with measured IOP in case 1. The calculated IOP, determined using upstream and downstream infusion line pressures, approximates the measured IOP during fluid flow, and the underlying red color of the true IOP is visible in only a few places. The red color of the true IOP becomes apparent when there is no fluid flow and the pressure effects of instruments are noticeable. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: An expanded view of the intraocular pressure (IOP) comparisons in case 1, taken after 13.8 minutes of surgery, lasting 55 seconds. The predicted IOP approximates the true IOP very closely, with the largest variation about 1 mm Hg. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Intraocular pressure (IOP) time tracing of 21 minutes of vitrectomy for macular hole in case 2. The IOP ranges between 5 and 120 mm Hg. A indicates a stable IOP of 25 mm Hg during air-fluid exchange at the end of the case. This pressure corresponded exactly with the selected setting of 25 mm Hg on the vitrectomy console. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Comparison of calculated intraocular pressure (IOP) with measured IOP in case 2. The calculated IOP tracks the actual IOP during fluid flow only. Large spikes in IOP higher than bottle height (arrow) are due to pressure by forceps grasping the globe. During the air-fluid exchange at the end of the case, the calculated IOP remained at bottle height because there was no infusion fluid moving through the tubing. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.

Copyright © 2005 American Medical Association. All rights reserved. From: Dynamic Intraocular Pressure Measurements During Vitrectomy Arch Ophthalmol. 2005;123(11):1514-1523. doi:10.1001/archopht.123.11.1514 Figure Legend: Expanded view of comparison between calculated intraocular pressure (IOP) and measured IOP in case 2. There is a close correlation only during fluid flow; the IOP spikes higher than bottle height are the result of instrument manipulation of the globe. Date of download: 9/22/2017 Copyright © 2005 American Medical Association. All rights reserved.