Pseudoexfoliative Deposits on an Implantable Collamer Lens: A Case Report

Dear Editor,

I would like to present a case of pseudoexfoliative material deposits on an implantable collamer lens (ICL). Written informed consent for publication of the research details and clinical images was obtained from the patient. A 56-year-old male patient presented with uncontrolled intraocular pressure (IOP). He had undergone ICL implantation (Model V4c, STAAR Surgical) in both eyes in 2017. In 2020, glaucoma was diagnosed in the right eye, and IOP-lowering eye drops were initiated. In 2024, the patient was referred to our clinic due to persistently elevated IOP. At the initial presentation, the IOP in the right eye was 45 mmHg despite the use of three IOP-lowering eye drops, including latanopsot (Xalost S, Taejoon Pharmaceutical), brimonidine tartrate (Alphagan P, AbbVie Inc), and brinzolamide/timolol (Elazop, Novartis AG). The refractive error was plano in both eyes and best-corrected visual acuity (BCVA) was 20/20 in both eyes. The axial lengths, measured using the by IOLMaster 700 (Carl Zeiss Meditec AG), were 27.05 mm in the right eye and 26.81 mm in the left eye.

Slit-lamp examination revealed pseudoexfoliative material deposits on the ICL surface of the right eye (Fig. 1). The lens vault evaluated using cross-sectional imaging obtained by anterior segment optical coherence tomography (CASIA, Tomey) was within the normal range (444 μm in the right eye and 431 μm in the left eye) and there was no contact with the pupillary margin. In the gonioscopic examination, the angle was wide, and the degree of pigmentation of the trabecular meshwork was minimal and evenly distributed (D40r+ according to the Spaeth gonioscopic grading system) in both eyes. Fundus examination revealed neuroretinal rim thinning with a cup-disc ratio of 0.9 and diffuse retinal nerve fiber layer defects in the right eye. Standard automated perimetry using the 24-2 protocol showed a mean deviation of −23.40 dB.

Fig. 1

Anterior segment photography. Slit-lamp examination revealed pseudoexfoliative materials on the implantable collamer lens surface of the right eye.

To control IOP, selective laser trabeculoplasty (SLT) was performed. Four days and one week after the SLT, the IOP decreased to 14 and 15 mmHg, respectively, with continued use of the previously prescribed eye drops. However, the patient did not return to the ophthalmology clinic for follow-up.

Three months after the SLT, the patient returned with an IOP of 50 mmHg and BCVA reduced to hand motion in the right eye. Glaucoma surgery was planned to manage the IOP. Due to geographic limitations affecting the patient’s ability to attend regular follow-ups, an Ahmed glaucoma valve (AGV; New World Medical Inc) was implanted. To minimize corneal endothelial cell loss, the tube tip in the anterior chamber was positioned as posteriorly as possible. Postoperatively, the IOP remained stable between 8 and 15 mmHg without IOP-lowering medications for 6 months, and BCVA improved to 20/100. The AGV tube was well-positioned, and the cornea remained clear without edema or opacity.

Pseudoexfoliative materials on intraocular lenses (IOLs) implanted after cataract surgery have been previously reported [1–3]. However, to date, little information is available regarding pseudoexfoliative deposits on ICLs. It has been hypothesized that the deposition of pseudoexfoliative material on the surface of the IOL may result from contact between pseudoexfoliative material in the aqueous humor and the IOL surface [1–3]. Similarly, as the ICL is also in contact with pseudoexfoliative material in aqueous humor, a comparable mechanism could explain the deposition of pseudoexfoliative material on the surface of ICL.

This case underscores the importance of carefully inspecting ICLs for pseudoexfoliative materials in eyes with preexisting ICLs, particularly to identify the possibility of pseudoexfoliative glaucoma (PXG). Both PXG and ICLs are associated with the risk of corneal endothelial cell loss [4,5]. Additionally, eyes with ICLs typically have a shallower anterior chamber than those without ICLs [4]. Therefore, when performing glaucoma drainage device surgery in eyes with PXG and ICLs, strategies to minimize corneal endothelial cell damage—such as positioning the tube away from the corneal endothelium, removing the ICL, or placing the tube in the ciliary sulcus or vitreous cavity—should be considered. If the tube is inserted into the anterior chamber with a preexisting ICL, ICL explantation would be considered if cataract surgery becomes necessary or if the presence of ICL is found to worsen corneal endothelial function by pushing the tube anteriorly.