Preoperative simulation of iris-fixated phakic intraocular lenses (IF-pIOLs) does not add a significant benefit in the prediction of endothelial cell (EC) loss in myopic eyes

Session Details

Session Title: Presented Poster Session: Intraocular Refractive Surgery

Venue: Poster Village: Pod 2

First Author: : S.Jonker THE NETHERLANDS

Co Author(s): :    A. Ronden   T. Berendschot   I. Saelens   N. Bauer   R. Nuijts           

Abstract Details

Purpose:

Although proof exists that a smaller distance from an IF-pIOL to the corneal endothelium results in increased EC-loss, no model incorporates preoperative IF-pIOL simulations to predict EC-loss before surgery. We performed a prospective, observational clinical study using preoperative EC density (ECD), anterior chamber depth (ACD), and the simulated central (sCD) and peripheral (sPD) distance from the IF-pIOL to the endothelium to compose a model that predicts EC-loss in myopic eyes implanted with IF-pIOLs.

Setting:

Academic Center for Refractive Surgery, University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands.

Methods:

178 eyes of 94 patients that underwent preoperative IF-pIOL simulation followed by implantation of myopic (toric) IF-pIOLs at the University Eye Clinic Maastricht, between 2006 and 2016, were included for analysis. Preoperative mean age was 38±12 years. Optical Coherence Tomography (OCT) was used to determine ACD, sCD and sPD, and specular microscopy to determine ECD. Specular microscopy measurements were repeated 3, 6 and 12 months postoperatively, followed by annual assessments. A mixed-model linear regression analysis was performed with eye identification number as a grouping variable and time, preop ECD, ACD, sCD, sPD and significant interactions with time as covariates.

Results:

Multiple modelswere composed to assess the necessity of preoperative IF-pIOL simulation, because mean preoperative ACD (3.23±0.36mm), sCD (2.40±0.32mm) and sPD (1.91±0.29mm) were highly correlated (p<0.001). All models used preoperative ECD, time, covariate (ie. ACD/sCD/sPD), and interaction between time and covariate to predict ECD. Interactions between time and ACD (p=0.002), sCD (p=0.001), and sPD (p=0.047) were significant. Using the mean preoperative ECD and the mean ACD/sCD/sPD, the models reached a critical ECD of 1500cells/mm2 after 21-25 years (range 15-47 with mean±1SD ACD/sCD/sPD).

Conclusions:

The ACD model both supplied the most conservative estimations, as well as the best fit for the data.The results of all three models emphasize smaller anterior chamber dimensions as risk factors and predictors of  higher EC-loss, and suggest IF-pIOL simulation does not add a significant benefit in predicting EC-loss in IF-pIOL implanted myopic eyes.

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented, ... research is funded, fully or partially, by a competing company, ... receives non-monetary benefits from a competing company, ... receives non-monetary benefits from a company producing, developing or supplying the product or procedure presented, ... receives consulting fees, retainer, or contract payments from a competing company