Intraocular lens power calculation in a posterior chamber phakic intraocular lens implanted eye

To evaluate the effect of Eyecryl posterior chamber phakic intraocular lens (pIOL) on axial length measurement and intraocular lens power calculation.

Axial length (AL), keratometry (K), and IOL power calculations were compared at monthly preoperative and postoperative visits (preoperative vs 1-month). Preoperative IOL power (calculated using preoperative K and AL) was compared with a re-calculation where the pIOL was assumed to be in the posterior chamber (calculated using preoperative K value and postoperative AL).

Thirty-nine eyes of 39 patients were included. The mean preoperative AL and postoperative AL were 27.02 ± 1.50 and 27.17 ± 1.52 mm (p < 0.001), respectively. The mean preoperative and recalculated IOL powers to achieve emmetropia were 9.40 ± 3.35 and 8.98 ± 3.37 D (p < 0.001) with SRK-T formula, 8.82 ± 3.54 and 8.47 ± 3.60 (p = 0.02) with Holladay I formula, and 9.78 ± 3.43 and 9.44 ± 3.50 (p = 0.013) with Hoffer Q formula.

The presence of Eyecryl pIOL in the posterior chamber results in a small increase in the AL measurement, and this might result in a corresponding hypermetropic shift in the desired refraction.