Split-Window OCT Offers High-Resolution ​​Visualization of Pseudophakic Eye Parameters

In pseudophakic eyes, split-window optical coherence tomography (SW-OCT) imaging can provide biometric measurements that are similar to swept-source optical coherence tomography (SS-OCT), but with significantly lower anterior chamber depth (ACD) and intraocular lens thickness (IOL LT) measurement failure rates, according to study findings published in Acta Ophthalmologica. 

Researchers say the split-window technology can offer high-resolution images of the axial length (AL), central corneal thickness (CCT), ACD, and IOL LT. The approach can help clinicians establish intraocular lens (IOL) position relative to the posterior capsule as well as the condition of the posterior capsule itself in a single assessment, the study explains.

The study included patients (N=69) with pseudophakic eyes who underwent cataract surgery with IOL implantation who were then evaluated with both a split-window OCT device and an SS-OCT device at 3.1±1.2 months after surgery. OCT measurements were compared between devices.

SW-OCT found axial lengths between 19.66 mm and 27.31 mm, IOL LTs of 0.55 mm and 1.51 mm, ACDs of 3.61 mm and 6.12 mm, and CCTs of 0.490 mm to 0.730 mm. These values were corrected manually in 9 eyes for ACD and 11 eyes for IOL LT.

The SW-OCT and SS-OCT found similar ALs (mean, 23.03 vs 23.04 mm; P =.2772), IOL LTs (mean, 0.92 vs 0.92 mm; P =.8660), ACDs (mean, 4.43 vs 4.42 mm; P =.0533), and CCTs (mean, 557 vs 559 μm; P =.0721).

The intraclass correlation coefficients (ICC) were 1.000 for axial lengths, 0.997 for lens thickness, 0.997 for anterior chamber depth, and 0.987 for central corneal thickness.

The major limitation of this study was the high failure rate of the SS-OCT device for measuring intraocular lens thickness and anterior chamber depth, which could only be measured in 22 and 30 eyes, respectively.

The investigators explain that SW-OCT biometry “can be potentially implemented into both SD and SS-based anterior/posterior segment OCT devices. It can be used not only in eyes with crystalline lenses, but also those after [IOL] implantation, including phakic [IOL] eyes and piggyback lenses. High-resolution imaging makes it ideal for assessing patient eligibility for cataract surgery whilst providing information about the central retinal structure, as well as for assessing eyes after cataract surgery. This also makes it a useful tool for future research.”

Disclosure: Multiple study authors have declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Sikorski BL, Hoffer KJ. Split-window OCT biometry in pseudophakic eyes. Acta Ophthalmol. Published online June 7, 2022. doi:10.1111/aos.15198