Official ESCRS | European Society of Cataract & Refractive Surgeons
Copenhagen 2016 Registration Programme Exhibitor Information Virtual Exhibition Satellite Meetings Glaucoma Day 2016 Hotel Star Alliance

10 - 14 Sept. 2016, Bella Center, Copenhagen, Denmark

This Meeting has been awarded 27 CME credits


escrs app advert yo advert

Mechanical model of human eye compliance for volumetric occlusion break surge measurements

Search Title by author or title

Session Details

Session Title: Cataract Surgery Equipment/Instrumentation/Surgical Devices I

Session Date/Time: Monday 12/09/2016 | 14:00-15:30

Paper Time: 14:24

Venue: Hall C5

First Author: : K.Miller USA

Co Author(s): :    D. Dyk                    

Abstract Details


To develop a mechanical model of human eye compliance for volumetric studies of the occlusion break surge response.


Alcon Laboratories Lake Forest, CA


Compliance curves were obtained from 15 eyes. Each eye was subjected to a maximum 12 pressurization/depressurization cycles with 60 to 100 mmHg peak IOP. A piezoresistive transducer measured anterior chamber pressure. Volume change was measured from an ultrasonic flow sensor’s integrated output. Each eye’s average net volume change curves were calculated as a function of IOP after a boxcar filter and two-term exponential fit were applied to each pressurization cycle. Overall mean volumes were computed from each eye’s average at pressure points extrapolated over 5 to 90 mmHg. A two-term exponential function was fitted to these results.


Individual eye compliance curves varied greatly. The fitted function took the form, V=C1∙exp(C2∙P)+C3∙exp(C4∙P)-V0, where V is the volume (cc) and P is the IOP (mmHg).V0 was a chosen reference volume such that V=0 cc at 110 mmHg IOP. C1 through C4 were -0.07141, -0.23055, -0.14972, and -0.02006 respectively. The fitted results were modeled using a piston system employing three parallel springs with staged engagement. A test fixture was constructed that incorporates the mechanical model and enables timed occlusion of the end of a phaco needle. A laser confocal displacement meter measures piston displacement after an occlusion break. Surge volume is calculated from displacement of the piston.


A novel apparatus for reliably measuring the volumetric surge response following an occlusion break has been developed using compliance data from human cadaver eyes. The fixture will establish a new standard for evaluating an important safety issue of phacoemulsification/aspiration systems.

Financial Disclosure:

... is employed by a for-profit company with an interest in the subject of the presentation, ... research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented

Back to previous