Pupil Dynamics Induced by Light Reflex After Posterior Chamber Phakic Intraocular Lens Implantation.

PURPOSE: To assess the light reflex of the pupil after Implantable Collamer Lens (ICL) (KS-aquaPORT; STAAR Surgical, Nidau, Switzerland) implantation to determine whether the ICL implantation might affect the pupil dynamics.

METHODS: This study examined 28 eyes of 28 consecutive patients who underwent implantation of the posterior phakic ICL for the correction of myopia and astigmatism. Patient age at the time of surgery was 31.1 ± 6.8 years (range: 25 to 42 years). Preoperative refraction was -7.38 ± 2.26 diopters (D) (range: -3.25 to -11.80 D). Light reflex was evaluated using the infrared pupillometer Iriscorder C7364 (Hamamatsu Photonics, Hamamatsu, Japan). Measured parameters included pupil diameter (D1), constriction ratio, maximum constriction velocity, maximum dilation velocity, and the time required to recover 63% of the pupil diameter (T5). At 6 months postoperatively, the authors also investigated the relationship with the amount of vault using the Pentacam (Oculus Optikgeräte, Wetzlar, Germany). Evaluations with the instrument were performed before and at 1, 3, and 6 months after surgery.

RESULTS: There was no significant association found between any of the parameters (analysis of variance, D1: P = .99, constriction ratio: P = .59, maximum constriction velocity: P = .87, maximum dilation velocity: P = .13, T5: P =.57). The vault of the ICL at 6 months postoperatively was 382.1 ± 176.5 μm. There were no significant associations between the maximum constriction velocity, maximum dilation velocity, and amount of vaulting (Spearman correlation coefficient maximum constriction velocity: r = 0.07, P = .71, maximum dilation velocity: r = 0.26, P = .28).

CONCLUSIONS: The light reflex of the pupillary dynamics continued to be maintained at 6 months after ICL implantation. Current findings also verified that ICL implantation had little influence on the postoperative function of the iris. [J Refract Surg. 2017;33(10):704-707.].