Analysis Of Long-Term Corneal Astigmatism Changes Following Phakic Intraocular Lens Removal Using Superior Scleral Tunnel Incision: Based On Types Of Astigmatism

To determine whether there is a long-term difference in postoperative corneal astigmatism changes between 2 types of astigmatism following phakic intraocular lens (pIOL) removal (Artisan, Artiflex) using superior scleral tunnel incision: With-the-Rule Astigmatism (WTR) and Against-the-Rule Astigmatism (ATR). 

 Institutional, retrospective

All patients were treated between April 2016 and March 2022 at a tertiary referral hospital. We retrospectively reviewed corneal astigmatism changes for 2 years after surgery in patients who received pIOL explantation using superior scleral tunnel incision - 6.5 mm incision (Artisan lens group) and 4.5 mm incision (Artiflex lens group). In each group, we analyzed astigmatism changes at 6, 12, 24 months postoperatively in both WTR and ATR astigmatism subgroups.

This study included 60 eyes from 37 patients with an average age of 41.5 ± 5.6 years (range: 27–57). After Artisan removal (n=40 eyes), in the WTR group (n=20 eyes), the mean corneal astigmatism showed significant decrease from -1.26±0.51D preoperatively to -1.17±0.52 D, -0.88±0.18 D, and -0.93±0.54 D at 6, 12, 24 months, respectively (P =0.008). On the other hand, in the ATR group (n=20 eyes), the values significantly increased from -1.55±1.04 D to -2.42±1.37 D, -2.19±1.49 D, and -2.01±1.21 D respectively (P = 0.001). There was no significant change after the Artiflex removal (n=20 eyes) in both WTR and ATR astigmatism subgroups (P = 0.426, 0.131). 

 Although the majority of young myopic patients have WTR corneal astigmatism, it is crucial to identify patients with ATR astigmatism when pIOL removal, (particularly with a 6.5mm incision for Artisan), to reduce postoperative astigmatism.