ROTATIONAL STABILITY AND FACTORS AFFECTING ROTATION OF A PLATE-HAPTIC TORIC INTRAOCULAR LENS

To investigate the relationship between anterior segment parameters and rotational stability of a plate-haptic toric intraocular lens (IOL).

University of Health Sciences, Dışkapı Yıldırım Beyazıt Training and Research Hospital, Ankara, Turkey

The medical records of 21 eyes of 18 patients who had the same plate-haptic toric IOL (Acriva Toric BB T UDM 611, VSY, Istanbul, Turkey) implanted during the phacoemulsification surgery by a single surgeon (ASD) and had no complications during or after the operation were retrospectively reviewed. Patients with ocular comorbidities that could affect rotational stability (zonular weakness, uveitis, keratoconus, previous ocular surgery, and trauma) and patients with irregular astigmatism were excluded. The preoperative refractive parameters, and detailed parameters obtained from the corneal tomography (Sirius; Costruzione Strumenti Oftalmici (CSO), Florence, Italy) and optical biometry ( Lenstar 900, Haig-Streit International) were noted. A correlation analysis was performed between the parameters of the anterior segment and iol rotation. The patients were divided into two groups according to iol rotation (Group 1: IOL rotation < 5 °, Group 2: IOL rotation ≥ 5° ). Mann Whitney U test was applied to understand the differences in parameters between the two groups. Multiple logistic regression analysis was generated to determine the parameters that could predict the separation between the two groups.

The mean preoperative astigmatism was 2.57±1.15 D (range 1.50-5.50 D). The mean AL was 23.5±1.48 mm (range 20.8-26.00 mm). The mean IOL rotation was 5.05±4.08° and the residual astigmatism was 0.85±0.67 D. Spearman correlation analysis revealed an association between axial length (r:0.553 p:0.009), anterior chamber volume ( r:0.457 p:0.037) and IOL rotation. There were 12 eyes in Group 1 and 9 eyes in Group 2. There were no statistically significant differences in any of the parameters, including axial length and anterior chamber volume between Group 1 and 2. Multiple logistic regression analysis showed that only lens thickness (β: 2.083 p:0.043) was an independent factor to determine iol rotation degree as more or lower than 5°. 

Plate-haptic toric IOL rotated more in eyes with longer axial lengths and larger anterior chamber volume. Additionally, lens thickness could be a predictive parameter for IOL rotations greater than 5°.