Posters

Morphologic and intraoperative paramenters influencing the pupillary diameter under cataract surgery

Poster Details

First Author: A.Galbo Jacobsen DENMARK

Co Author(s):    H. Vorum   J. Hargitai           

Abstract Details

Purpose:

Proper preoperative mydriasis is a prerequisite to successful cataract surgery. Our purpose was to investigate the morphologic and intraoperative parameters that may influence pupillary diameter under elective cataract surgery.

Setting:

Department of Ophthalmology, Thy-Mors Hospital, Thisted, Denmark

Methods:

50 patients not taking any systhemic medications were studied pre- and intraoperatively. Thickness of the iris sphincter muscle region (SMR) along with the dilatator muscle region (DMR) were measured preoperatively using an anterior segment optical coherence tomography. All patients were dilated with the standardized mydriatic-cocktail soaked cellulose sponge method. Our cocktail consisted of oxybuprocain 0.4%, cocaine 4%, tropicamide 1%, phenylephrine 10%, diclophenac 0.1% along with chloramphenicol 0.5% . Pupil diameter was measured with 0.5 mm increments in the horizontal plain before surgery, after nucleus delivery and before intraocular lens implantation (IOL) using Geuder Castroviejo caliper. Intraoperative miosis was assesed between the preoperative pupil diameter and the pupil diameter after nucleus delivery (miosis 1); between the pupil diameter after nucleus delivery and pupil diameter before IOL implantation (miosis 2); and between the preoperative pupil diameter and the pupil diameter before IOL implanatation (total intraoperative miosis). Total phacoemulsification time (UST) and phacoemulsification time using the ELLIPS FX handpiece (EFX) were recorded. Minor and major intraoperative complications were registered. Correlation between the morphologic parameters of the iris, EFX and the intraoperative pupillary diameter measurments were calculated using MedCalc software.

Results:

The mean SMR thickness was 407,68±64,17µm, whereas DMR thickness was 343,04±67,15µm. Mean pupil diameter (mm) was preopertively: 8.74±0.67; after nucleus delivery: 7,40±1.00; before IOL implantation: 6.93±1.16. Mean UST and EFX were 65.91±32.19 and 38.00±20.45 seconds respectively. We observed significant correlation between EFX and miosis 1 (p= 0.0122) and between SMR and total intraoperative miosis (p=0.0035). We did not experience intraoperative complications.

Conclusions:

Intraoperative miosis under cataract surgery may be influenced by the thickness of the iris sphincter muscle region and the hardness of the lens. Measuring the thickness of the sphincter muscle region preoperatively may serve as a valuable predictor for the intraoperative pupillary behaviour and may thus contribute to predictable cataract surgery. FINANCIAL INTEREST: NONE