Abstract
Purpose: :
To obtain direct and real time IOP measurements within the vitreous cavity during various stages of phacoemulsification.
Methods: :
In a first step an external 25g pressure transducer probe was attached to a standard Geuder S3 (phaco+vitrectomy) device. Via Ethernet the S3 was connected to a video-overlay-box which in turn sent the IOP data and the incoming microscope video signal to an external monitor. This setup allowed an exact assignment of IOP measurements and surgical maneuvers. In a prospective study 5 consecutive eyes of 5 patients undergoing combined phacoemulsification and pars plana vitrectomy were included.
Results: :
The mean IOP during phacoemulsification with posterior chamber lens implantation was 28.5 +/- 13 mmHg. The min. IOP was 7mmHg and the max.IOP was 64mmHg. Highest IOP levels and fluctuations were noticed during phacoemulsification of the nucleus and OVD removal by irrigation / aspiration. During capsularrhexis (20.1+/-2.9mmHg), hydrodissection (13.7 +/-5.2mmHg) and IOL implantation (20.2+/-6.5mmHg) IOP measurements showed physiological levels.
Conclusions: :
Using an additional 25g sclerotomy probe, IOP levels can be constantly monitored during phacoemulsification when a subsequent ppV is planned. Surgical maneuvers and corresponding IOP levels can be documented and further analyzed after the surgery is completed. The system allows further refinements of technical equipment and surgical manipulation.
Keywords: intraocular pressure • small incision cataract surgery • training/teaching cataract surgery