Pre-, Intra- and Postoperative High Resolution Extended Depth OCT imaging of Phakic Implantable Collamer Lens

Abstract

 

Purpose

 

To assess the use of high resolution extended depth OCT to evaluate preoperatively, intraoperatively and postoperatively the implantation of a phakic Implantable Collamer Lens (ICL, Staar Surgical Co., Monrovia, CA).

 

Methods

 

A consented patient who was scheduled to undergo phakic ICL surgery in both eyes was imaged with OCT. The imaging procedure followed an IRB-approved protocol. A custom made SD-OCT system combined with an accommodation stimulus (Ruggeri et al, Biomed Opt Exp 2012) was used preoperatively to evaluate the anterior chamber geometry. The same OCT system was used postoperatively to measure the distance between the ICL and the anterior crystalline lens (ACL) at the relaxed state and in response to an accommodative stimulus of 2D. For intraoperative imaging, the hand-held scanner of a portable commercial SD-OCT device (ENVISU R4400, Bioptigen, Inc, USA) was secured to a modified operating microscope stand (Aguilar et al, ARVO2011, E-abstract 4026) for imaging the patient in supine position during surgery, which enabled monitoring the ICL-ACL distance (vault) at several steps during surgery.

 

Results

 

Surgeries were uneventful. Uncorrected distance visual acuity at Postoperative day 10 was 20/25 in both eyes. Preoperative OCT measurements on the right eye showed an axial eye length of 25.80mm and an anterior chamber depth that varied from 3.01mm at 0D stimulus to 2.92mm at 2D stimulus. ICL-ACL distance measured intraoperatively with OCT was 403 µm after the lens was inserted in the anterior chamber and placed under the iris and 297 µm after drug-induced pupil miosis. Postoperative imaging showed an ICL-ACL distance of 97 µm at 0D stimulus at day 1 after surgery. The ICL-ACL distance decreased to 63 µm in the relaxed state and 20 µm in the accommodated state at day 4 and then increased to 112 µm in the relaxed state and 111 µm in the accommodated state at day 10 after surgery. Similar results were obtained for the left eye.

 

Conclusions

 

The study demonstrates the potential usefulness of OCT assisted preoperative ocular biometry to calculate the correct ICL power. Intraoperative OCT provides guidance to assure that adequate vault is maintained during surgery to avoid mechanical contact of ICL with the crystalline lens that could lead to cataract formation. Post-operative OCT enabled assessment of the ICL dynamics after surgery during accommodation.

 

 

Keywords: 685 refractive surgery: phakic IOL • 567 intraocular lens • 550 imaging/image analysis: clinical