Posters

New method of predicting postoperative anterior chamber depth

Poster Details

First Author: H.Juri JAPAN

Co Author(s):    S. Goto   K. Ohnuma   T. Noda        

Abstract Details

Purpose:

Many formulas have been proposed and used for calculating the powers of intraocular lenses (IOLs). However, these formulas cannot precisely estimation the postoperative anterior chamber depth (ACD) and the power calculation using only optical data. When predicting the ACD, the corneal curvature of the anterior surface, axial length, A constant, and the variables obtained by correcting these data are used. However, these variables may not be the best basis for predicting the ACD. Corneal optical coherence tomography (OCT) imaging provides many measures around the cornea and crystalline lens. Based on these, we are attempting to identify suitable variables for predicting the postoperative ACD.

Setting:

Tokyo Medical Center & Center for Frontier Medical Engineering, Chiba University

Methods:

Images obtained by corneal OCT (Tomey SS-1000 Casia, Tokyo, Japan) were used for this study. One examiner (TN) obtained OCT data from eyes implanted with Santen W-60 IOLs. The correlations between the postoperative ACD and five parameters, i.e., corneal thickness, preoperative ACD (ACDp), distance from angle to angle (ATA), distance from the crystalline lens surface to the ATA line, and distance from the posterior cornea to the line of the ATA (ATA depth) were evaluated. Each parameter was obtained using analysis software included in the Casia OCT machine. An ACD prediction formula was obtained and compared with the SRK/T prediction formula.

Results:

The ATA depth, ACDp, and ATA had good correlations with the postoperative ACD in that order. The following formula was obtained by multiple regression analysis: 〖ACD〗_Post=0.52536×ATA depth+0.15486×〖ACD〗_Pre+0.04041×ATA+1.54379 (R2=0.63). In contrast, the correlation constant of the SRK/T was R2=0.33.

Conclusions:

The formula obtained to predict the postoperative ACD is more accurate than the SRK/T formula. Further investigations to evaluate the validity of this formula using a variety of IOLs would be needed. FINANCIAL INTEREST: NONE