Diagnosis of reverse Implantable Collamer Lens (ICL) orientation on Anterior Segment Optical Coherence Tomography (ASOCT).

A 21-year-old female patient, known case of high myopia, presented to our institute with unsatisfactory gain in vision of left eye after undergoing implantation of CentraFlow Toric ICL (STAAR Surgical company, Monrovia, CA). The preoperative Best Corrected Visual Acuity (BCVA) was noted to be 20/20 with −7.25/−3.0@180. White to white diameter was 11.6 mm, and anterior chamber depth was 3.05 mm. ICL of −11.0/+3.0/0.75 D, size 12.6 mm (TICL code number VTICM012.6) had been implanted. Residual refractive error post ICL insertion was +0.5/+1.75@48 and BCVA was 20/60.

On slit lamp examination, the anterior chamber was well formed, with a very low vault and central lens touch. Anterior Segment Optical Coherence Tomography (ASOCT) was performed using RTVue-100 (Optovue, Fremont, CA) with monochrome CCD camera and demonstrated extremely low central vault (66μ) with ICL almost resting upon the anterior lens surface (Fig. 1a). The scan for peripheral vault taken after dilatation demonstrated reverse anteroposterior orientation of ICL (Fig. 1b). The patient subsequently underwent ICL explantation along with re-implantation in correct anteroposterior surface orientation. Uncorrected Visual Acuity (UCVA) on 3rd postoperative day was 20/20. Central vault was 133μ with no lens touch (Fig. 2). Although the vault was less, ICL exchange for a different size was not reconsidered as there was no lens touch and the intraocular pressure was normal.

Figure 1

(a) ASOCT showing low central vault with ICL almost touching the anterior lens surface. (b) Scan for peripheral vault showing reverse anteroposterior orientation of ICL (note the concave surface of ICL facing up).

Figure 2

Correct orientation of ICL showing central vault and concavity facing downward.

The right eye had an uneventful course after ICL implantation.

Discussion

ASOCT is used to study angle anatomy, anterior chamber width, AC depth, and vault of ICL and to measure ciliary sulcus diameter for sizing of ICL. The ICL bears markings on the distal and proximal footplate to guide intraoperative loading and unfolding of the ICL in the right orientation. Once placed in the ciliary sulcus, it is difficult to judge whether the ICL is oriented correct/reversed because the marks are precluded by the peripheral iris. In the case presented to us, lens touch was due to reverse anteroposterior orientation. ASOCT proved to be a useful tool in identifying this rare complication. Thus we recommend that in patients with a low vault and lens touch, ASOCT may be performed to check orientation of ICL.

Conflict of Interest

The authors declared that there is no conflict of interest.