Measurement of Intraocular Pressure during Automatic Needle Insertion using Corneal Applanation

Abstract

Applanation aided automatic needle insertion is a novel insertion method for deep anterior lamellar keratoplasty. The method uses corneal applanation to control insertion depth of needle, but it could increase intraocular pressure. Because high intraocular pressure (IOP) can cause glaucoma, measurement of IOP is required to ensure the safety of the proposed insertion method. This paper describes a design of applanation pad composed of two layered structure and IOP measuring system. For 7 porcine eyeballs, the maximum increase in IOP was 46 ± 10.8 mmHg in average and operation time was 97 seconds in average. Because the amount of IOP increase was lower than IOP increase of other eye surgery, applanation aided needle insertion can be utilized for the precise needle insertion in terms of IOP.2