Posters

Intraocular lens axial displacements: diagnostics and prediction of postoperative refraction shift

Poster Details

First Author: E.Kokareva RUSSIA

Co Author(s):    A. Kulikov   A. Dzilikhov                 

Abstract Details

Purpose:

To diagnose the axial intraocular lens (IOL) displacements after phacoemulsification with optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) methods, and to reveal associated postoperative refraction shift

Setting:

Ophthalmology Department of S.M.Kirov Military Medical Academy of Ministry of defense, Saint-Petersburg

Methods:

There were 187 patients (220 eyes) undergone uncomplicated phacoemulsification with AcrySof® IOL implantation. Pre- and postoperative examination included “IOLMaster” and "Lenstar LS 900" biometry, "Pentacam HR" corneal topography and UBM "Accutome UBM Plus" measurement. IOL power was calculated with Hoffer Q, Holladay I and Haigis formulas according to “IOLMaster” biometry data. One month postoperatively OCT "Topcon 3D OCT-2000" and the UBM "Accutome UBM Plus" were used to determine IOL displacements. Values of subjective and objective refraction also were measured for all of the patients

Results:

OCT revealed cases of IOL tilt for 2 degrees or more in 4,11% of cases and IOL backward "deflection" in 17,27% of cases. Mean values of "deflection" was 8,41±8,28 µm (range from 0,00 to 30,00 µm). ROC-analysis identified biometry parameters reliably predicted IOL "deflection”. In selected cases there was significant hypermetropic shift of subjective refraction regarding values calculated with Hoffer Q, Holladay I and Haigis formulas. UBM revealed cases of axial forward and backward IOL displacements in reference to its haptic plane. They were also accompanied by statistically significant calculation errors with Hoffer Q, Holladay I and Haigis formulas

Conclusions:

OCT and UBM visualization methods are very important in detection such IOL dislocations as tilt, "deflection" and axial displacement from the haptic plane. They also permit to provide quantitative analysis. Axial length, IOL power, white to white distance and mean corneal power are reliable predictors of IOL "deflection". Revealed axial IOL displacements induces significant refraction shift. Refraction calculated with Hoffer Q, Holladay I and Haigis formulas significantly differ from subjective postoperative results despite correct biometry data. Thus, OCT and UBM visualization could explain calculation failures when the precise biometry measurement were made preoperatively

Financial Disclosure:

None