J Korean Ophthalmol Soc.  1988 Aug;29(4):573-577.

Intraocular Pressure Measurement in Air-filled Eye Following Vitrectomy

• Chung H

Abstract

Gas tamponade is sometimes necessary after vitrectomy. Accurate measurement of intraocular pressure(IOP) in gas-filled eye is important, but is hard to get in operating table, because of lack of a good measuring device. Schiotz tonometry is the only possible method, but it usually gives a lower value than real, because gas-filled eye has a greater compressibility. But if the Schiotz tonometry can give a consistant value in relation to the real value, one can assume a true IOP by simply converting the value, and it will help the vitrectomy surgeon. Vitrectomy with or without lensectomy were done in 7 pigmented rabbits, and fluidair exchange were done at the end of the surgery. Intraocular pressure was monitored by an air infusion system, and true IOP was measured by a transducer from the anterior chamber. Schiotz tonometry was done ar each 5mmHg IOP level, and the values were compared. Schiotz tonometry always gave a lower pressure, and the discrepancy seemed to be greater in aphakic eye, and when the heavier plunger weight were used. Conversion equation was suggested, and their reliability was discussed.

MeSH Terms

Anterior Chamber
Intraocular Pressure*
Manometry
Operating Tables
Rabbits
Transducers
Vitrectomy*