Calculation of A-constant for plate-torsion haptic intraocular lens

Session Details

Session Title: IOL Power Calculations

Session Date/Time: Sunday 11/09/2016 | 16:00-18:00

Paper Time: 17:06

Venue: Hall C2

First Author: : S.Kuznetsov RUSSIA

Co Author(s): :    D. Logunov                    

Abstract Details

Purpose:

To calculate A-constant for plate-torsion haptic intraocular lens (PTHIOL) model MIOL-28 (open-bag device)

Setting:

Department of Ophthalmology, Penza Federal State Institute for Postgraduate Medical Studies of the Ministry of Health of Russian Federation, Penza, Russia

Methods:

Theoretically calculated and optical results of 265 PHACO with PTHIOL MIOL-28 ('Reper-NN' Ltd.) implantation were analyzed. The patients average age was 64,2 ± 8,01 years, follow-up of 1.5 to 8 years. Standard in cataract surgery with intraocular correction preoperative examination was made. Calculations of PTHIOL optical power performed: 1. by A-constant theoretical definition according to average preoperative UBM-biometry data of anterior chamber depth (ACD) and the thickness of the lens (L) using formula SRK/T, Holladay-1, HofferQ; 2. by postoperative optical results processing for each formula.

Results:

The value of the A-constant equal to 122.2 was obtained by theoretical method for formula SRK/T. The value of the A-constant equal to 121.9 ± 0.34 was obtained on postoperative clinical data for formula SRK/T for PTHIOL MIOL-28. The values of constants for other formulas SF (Holladay) = 3.43, ACDconst (SRK/T) = 7.40 and pACD (HofferQ) = 7.24 were determined by converting the received standard A-constant.

Conclusions:

A-constant for PTHIOL equal to 121.9 was determined. The values of constants SF (Holladay), ACDconst (SRK/T) and pACD (HofferQ) denote PTHIOL maximum approximation to the posterior capsule of the lens, and prove PTHIOL concept effectiveness in complete recovery of anatomic and topographic eye parameters as a necessary destination for 'open-bag devices'.

Financial Disclosure:

NONE