Comment to: Iris-claw intraocular lens implantation: Anterior chamber versus retropupillary implantation.

Sir,

We read with great interest the publication by Helvaci et al.[1] titled, “Iris-claw intraocular lens implantation: Anterior chamber versus retropupillary implantation,” in which the authors showed both anterior chamber and retropupillary implantation of iris-claw intraocular lens (IOL) are equally effective in visual improvement. We believe that the authors achieved a great work because the results of their study suggest that both anterior chamber and retropupillary implantation of Artisan IOL could be an easy, safe, and time-saving method for the surgical treatment of aphakia.

Although the study was undoubtfully well designed and conducted, we would like to point out that the study did not evaluate central corneal thickness (CCT) as well as endothelial cell count (ECC) as the authors mentioned at the conclusion of the study. Measurement of ECC before and after the implantation of iris-claw IOL can be helpful for the evaluation and comparison of the amount of endothelial cell damage caused by anterior chamber and retropupillary implantation. Likewise, measurement of CCT would also be useful for the determination of corneal damage. Serial measurement of ECC and CCT during the follow-up period would provide information about corneal healing process or further corneal damage that might be caused by iris-claw IOL. Visualization of cornea, iris, angle, and IOL using anterior segment optical coherence tomography (OCT) or ultrabiomicroscopy (UBM) could also be used for the determination of changes of the structures after surgery. As central macular thickness (CMT) reflects disruption of the blood-aqueous and blood-retinal barriers due to postoperative inflammation,[2] serial measurement of CMT using OCT might be provided information on the course of postoperative inflammation. Data obtained using these tools can be helpful for the evaluation of safety and efficacy of the iris-claw IOL implantation and comparison of safety between anterior chamber and retropupillary implantation.

In addition, follow-up period of 6 months appears to be insufficient for the evaluation of the safety of the procedure. Although a recent study showed that iris-claw phakic IOL implantation did not cause significant loss of ECC up to 10 years postoperatively,[3] a case report of late-onset corneal decompensation caused by anterior shift of the iris-claw phakic IOL over 7 years also exists.[4] Thus, we believe that longer follow-up periods would be needed for the evaluation of the safety of iris-claw IOL.

As the authors mentioned in their study, we also believe further studies with long-term follow-up that include ECC, CCT, UBM, and OCT data would be needed for the evaluation of safety and efficacy of iris-claw implantation.

Financial support and sponsorship

This study is supported by the 2015 Research Grant from Kangwon National University (No. 20150348).

Conflicts of interest

There are no conflicts of interest.