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


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

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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


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


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


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.


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.


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'.

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