Posters

'Terminator', the wedge tool: a modified classical simple machine to crack and break the hard cataract

Poster Details

First Author: R.Prasad INDIA

Co Author(s):                        

Abstract Details

Purpose:

Is to describe an efficient and safe device terminator the wedge tool designed with the principle of classical simple machine and Griffith’s theory of brittle fracture to crack and break the mature hard cataract into full thickness free segments including the posterior plate with much ease and which is also free from high intensity shock and strain.

Setting:

400 cases of mature hard cataract were undertaken for the study at RP Eye Institute Delhi India. Single surgeon operated all the cases and used Terminator the wedge tool to crack and break the hard nucleus.

Methods:

We incorporated triangular wedge design into the tip of the Terminator in which pointed apex of wedge is kept at the inner edge of the tip while wide and flat base of wedge is placed at the posterior surface of the tip. Simply drawing the wedge inner edge of the terminator through the equator of the nucleus after hooking it around generate transversal fracture force with amplification, induces full thickness nuclear crack which automatically traverses through the entire nucleus breaking it into two complete free segments.

Results:

We used terminator the wedge tool in 1000 cases of hard cataract of LOCS grade II to grade VI nucleus in our study. We found that terminator the wedge tool was highly efficient, safe and simple to crack and break these hard nuclei into multiple free segments. Surgery was conducted successfully in all the 1000 eyes. Full thickness cracking was possible in 99.1% of cases. 0.9 % of cases nucleus was removed in total with ECCE technique. In one case PCR due to excessive stress force directed posteriorly. Cornea was clear in 98.2% of cases on first postoperative day.

Conclusions:

Wedges have been successfully used in rock excavation system since the ancient time to crack and break solid hard rocks. Similarly terminator the wedge tool efficiently breaks these solid hard nuclei at a stress that is much lower than the compressive stress and easily overcomes the tensile resistance and causes them to crack and split in tension.

Financial Disclosure:

None