Posters

Intraoperative method for estimating implantable collamer lens vault using the corneal inverted image on intraoperative optical coherence tomography

Poster Details

First Author: B.Armstrong UAE

Co Author(s):    W. Dupps                    

Abstract Details

Purpose:

The most unpredictable part of implantable collamer lens (ICL) placement is estimating proper ICL size. Excessive or inadequate ICL vault are the most common reasons for ICL exchange. At the slit lamp, vault is estimated relative to corneal thickness (CT) by tangential slit beam. Vault of 0.5 to 1.5x central CT is thought to be acceptable. Microscope-integrated intraoperative optical coherence tomography (OCT) can provide an analogous assessment in the operating room. By aligning the apex of the inverted optical image of the cornea to the center of the intraoperative ICL vault, we can directly compare CT to ICL vault.

Setting:

Cleveland Clinic Abu Dhabi – Abu Dhabi, UAE

Methods:

ICL surgery was performed on the eye of a patient in an operating room setting. After implantation of the toric ICL, alignment of the ICL along the proper axis, and removal of all ophthalmic viscosurgical material, the Rescan 700 intraoperative OCT was used to estimate ICL vault. There are no internal calipers on the software, so the surgeon adjusted the microscope focus with the foot pedal to superimpose the inverse corneal image onto the area of ICL vault to estimate the vault. Screenshots were saved and analyzed when alignment was ideal.

Results:

Based on image overlay of the inverted cornea over the ICL vault with intraoperative OCT, we estimated that the central CT occupied 90% of the axial distance between the anterior lens capsule and the posterior surface of the ICL, which represented an acceptable vault of 1.11 CT (based on preoperative CT of 484 microns). Intracameral Miochol and cefuroxime were instilled and the wounds were hydrated. Postoperatively, the ICL vault measured 1.12 CT at one day, 1.05 CT at one week and 0.94 CT at 2 months.

Conclusions:

Estimation of ICL vault by inverted overlay of the cornea is useful, and we believe this is the first case report where this principal was applied intraoperatively. This technique could have implications on intraoperative decision making by allowing real-time determination of whether ICL vault is too high or low. If needed, ICL vault could be adjusted intraoperatively with a non-toric ICL by rotating the haptics more vertically to decrease ICL vault or more horizontally to increase vault. In cases where vault is excessive or absent, the ICL should be removed.

Financial Disclosure:

None